1. science
2. medicine
3. surgery

LOCOMOTOR ADAPTATIONS IN THE LIMB SKELETONS OF
NORTH AMERICAN MUSTELIDS
by
Thor Holmes
A Thesis
Presented to
The Faculty of Humboldt State University
In Partial Fulfillment
of the Requirements for the Degree
Master of Arts
June, 1980
LOCOMOTOR ADAPTATIONS IN THE LIMB SKELETONS OF
NORTH AMERICAN MUSTELIDS
Approved by the Master's Thesis Committee
Chairman
Approved by the Graduate Dean
TABLE OF CONTENTS
Page
Acknowledgments
iv
Abstract
vi
Introduction
1
Materials and Methods
11
Results and Discussion
30
Intraspecific Variation
30
Species Comparisons
46
Forelimb
46
Hindlimb
68
Conclusions
91
Literature Cited
97
Appendices
105
ACKNOWLEDGMENTS
This study was partially funded by a thesis grant from
the Biology Graduate Student Association at HSU. I thank
the following museums and their curators for the use of
materials in their collections: American Museum of Natural
History; California Academy of Science; Carnegie Museum
of Natural History; Field Museum of Natural History;
Humboldt State University, Museum of Vertebrate Zoology;
University of Kansas Natural History Museum; Los Angeles
County Museum of Natural History; Museum of Zoology,
University of California, Berkeley; Michigan State University,
The Museum; National Museum of Natural History; San Diego
Museum of Natural History; San Diego Natural History Museum;
University of California at Los Angeles; University of
Michigan Zoology Museum; University of Montana Department
of Zoology; University of Puget Sound, Museum of Natural
History; I would like to thank particularly Murray Johnson,
Helen Kafka, and Shiela Kortlucke for help during the times
I used their collections.
Suzanne Edwards, Judy Fessenden, Cynthia Hofmann,
Rebecca Leuck, Bob Sullivan, my brother, Thomas, and my
wife, Elaine helped me make measurements. Mike Gwilliam,
Tim Lawlor, Steve Smith, and Bob Sullivan helped me with
computer programs. Cynthia Hofmann, Elaine Holmes, and
Kathy McCutcheon helped type the manuscript. Kathy typed
the final draft.
V
I would like to thank the members of my committee,
Jake Houck, Frank Kilmer, Tim Lawlor, John Sawyer, and Jim
Waters for time they invested in my thesis and my education.
I would like to thank particularly my major professor, Tim
Lawlor, for help, friendship, encouragement, and sundry
other contributions to my life and my education far too
numerous to mention here.
Finally I wish to thank Elaine, my wife, for a decade
of support in every sense of the word. And I wish to
acknowledge that she, more than any other person, is the
reason that I can look back from this point in my life and
smile.
ABSTRACT
The morphology and proportions of the limb skeletons of
thirteen species of North American mustelids are examined.
A series of forty-nine ratios is generated for each species.
Ratios are analyzed using standard descriptive statistics;
mean, standard deviation, variance, standard error, coefficient
of variation, and range. Ratios are also analyzed with a
closest connection (Prim) network. Qualitative comparisons
of appendicular skeletons are made with drawings of each
limb element.
Progressive specialization from an hypothesized primitive
condition to fossorial, arboreal-cursorial, aquatic, and
ambulatory modes of locomotion is revealed in limb skeletons
of the Mustelidae. Relationships between morphology and
proportions of mustelid limb skeletons, and modes of
locomotion are discussed.
INTRODUCTION
The family Mustelidae, comprising twenty-five recent
and some seventy fossil genera (Anderson and Jones, 1967),
is one of the most diverse families of carnivores. Only
its ecological counterpart in the Old World tropics, the
family Viverridae, contains more extant genera. Mustelids
range in size from small (35 g) to medium (37 kg). They
are distributed throughout the world except for Australasia
and Antarctica.
The Mustelidae apparently arose from the most ancient
carnivorans, family Miacidae, about 35 mybp. The origin of
the Mustelidae within the miacids seems to be separate from
that of the other canoid carnivores. They quickly adopted
the typical mustelid specializations of a strongly carnivorous dentition, short powerful jaws, prominent pre- and postglenoid processes, and a long cylindrical body (Ewer, 1973;
Romer, 1966). Mustelids as a group also are characterized
by a weak zygoma. Ewer (1973) and Gambaryan (1974)
suggested that the weak zygoma and a long cylindrical body
are adaptations to hunting small mammals within their
burrows, a method of predation that still characterizes the
largest and one of the most primitive living genera,
Mustela (Table 1).
Despite specializations of cranial and axial osteology
the mustelids retain a very generalized limb structure.
They do, however, show fusion of two carpals, the scaphoid
2
Table
1. --
Earliest record for ten genera of the family
Mustelidae (after Romer, 1966).
Genus
Time of Probable Origin
Mustela
Upper Miocene
Martes
Middle Miocene
Eira
Pleistocene
Gulo
Pleistocene
Spilogale
Lower Pleistocene
Mephitis
Pleistocene
Conepatus
Upper Pliocene
Taxidea
Upper Pliocene
Lutra
Lower Pliocene
Enhydra
Pleistocene
PLEISTOCENE
Mephitis
Eira
Gulo
Enhydra
Spilogale
Conepatus
Taxidea
PLIOCENE
Lutra
Mustela
MIOCENE
Martes
3
and lunar. They also have lost a third carpal, the centrale.
These are interpreted as cursorial specializations and are
the common heritage of all carnivores (Ewer, 1973; Vaughn,
1978). Mustelids are plantigrade to digitigrade. The
extent to which they are digitigrade is never as pronounced
as in the Felidae or Canidae. The mustelids are pentadactyl
and all of the digits touch the substrate. Members of the
family retain relatively short, stocky limbs and do not have
retractile claws.
Gambaryan (1974) suggested that the basic cursorial
gait in the Mustelidae, the bound or half bound, is a
result of their long narrow body. Variations on the basic
gait include a slow ambulatory walk (Mephitis, Conepatus),
a speedy trot (Taxidea, Mustela), and a bear-like shuffle
(Gulo).
The Mustelidae, at least as regards appendicular
anatomy, more closely resemble basal fissipeds than any
extant group of carnivores. While a generalized limb
skeleton characterizes most mustelids, some species have
evolved ambulatory, arboreal, semi-aquatic, aquatic, and
fossorial habits. Mustelids, therefore, present the student
an opportunity to observe a spectrum of locomotor adaptations in a single family.
There are numerous studies on locomotor specialists.
Horses, gazelles, cheetahs, whales, and moles have all been
examined. Studies of this kind are valuable in that they
reveal the types of adaptations to specific modes of
4
locomotion that typify specialists. I have chosen, however,
to examine the array of locomotor adaptations that characterize the Mustelidae. No mustelid is highly specialized
for a particular mode of locomotion. For that reason I
think that an investigation of the Mustelidae is of
particular interest because it promises to elucidate
locomotor trends in types of animals often ignored in the
locomotor literature.
Some recent members of the Mustelidae have been the
object of considerable osteological or myological study
(Fisher, 1942; Howard, 1973, 1975; Leach, 1977a, 1977b;
Leach and Dagg, 1976; Ondrias, 1960, 1961; Tarasoff, 1972).
As yet no one has studied the entire spectrum of locomotor
adaptations in the Mustelidae either myologically or osteologically. Some studies on the limb skeletons of other
families of carnivores have been made: Hildebrand (1952,
1954), on canids; Goynea and Ashworth (1975) and Hopwood
(1947), on fends; and Taylor (1970, 1974, 1976), on
viverrids. Techniques used in those studies could productively be applied to the Mustelidae. The burgeoning
literature on primate locomotion (Ashton et al., 1971;
Ashton and Oxnard, 1964; Jenkins, 1976; Lewis, 1972;
Reisenfeld, 1974) contains techniques with possible applications to mustelids. A similar, if somewhat older, literature
on locomotion in mammals in general (Brown and Yalden, 1973,
and citations therein) provides a valuable backdrop against
which to compare mustelids. Finally there are studies of
5
the effect of modes of life on the skeleton, or on particular
skeletal elements (Chapman, 1919; Jones, 1953; Lehmann, 1963;
Taylor, 1914; Yalden, 1972). These papers are especially
useful in that they elucidated the type of morphological
indicators that suggest specializations to a particular
mode of life.
The taxonomic position of some mustelids is not well
understood (Simpson, 1945), but the family lends itself to
separation into four locomotor categories corresponding
roughly to the four main recognized subfamilies (Fig.1 ).
The Mustelinae are weasel-like forms which typically have
sub-cursorial, scampering habits. This is the oldest and
most primitive subfamily. Martens, fishers, and tayras,
the larger members of this group, have arboreal proclivities.
The mink, another member of the Mustelinae, is amphibious.
The Mephitinae, the skunks, are ambulatory. The Melinae
include most of the badgers; they are fossorial. Finally,
the Lutrinae comprises the most aquatic fissipeds, the
otters. The American badger, Taxidea, and the wolverine,
Gulo, are the subject of some taxonomic debate. Nevertheless,
they may be conveniently grouped with the badger and weasel
subfamilies, respectively, in regard to locomotion.
North American mustelids encompass all of the locomotor
types that characterize the family as a whole. Hence they
should constitute a representative subset of the range of
locomotor specializations that characterize mustelids as a
whole. It appears that the different locomotor patterns in
6
FIGURE 1
1) Hypothesized trends in the appendicular skeletons of
twelve North American species of the family Mustelidae.
Species are arranged according to proposed continua of
progressive specializations for arboreal, cursorial
(sub-cursorial), aquatic, fossorial, and ambulatory modes
of locomotion. Species (continua) radiate from a hypothetical primitive condition simulated among extant forms
by Mustela frenata.
7
8
mustelids evolved from a more or less generalized, cursorial
creature that was, nevertheless, somewhat specialized to
hunt small, hole-frequenting prey in their burrows. That
primitive mustelid is probably best represented among
living forms by the weasels.
If an artificial line is drawn from the hypothetical
primitive mustelid condition, simulated among extant forms
by Mustela frenata, through an amphibious form (Mustela
vison) and a semi-aquatic form (Lutra canadensis) to a
strongly aquatic form (Enhydra lutris), a sequence toward
an aquatic tendency can be observed. It follows that
inspection of the limb skeletons of the animals along this
line should reveal morphological and proportional changes
that are related to increasing specializations for life in
water. Similarly, the limb skeletons of Mustela frenata,
Martes pennanti, Martes americana, and Eira barbara should
show progressively greater specialization for life in the
trees, because each of those animals is progressively more
arboreal. The limb skeleton of the American badger should
be strongly modified for fossorial life. Mustela nigripes,
a subterranean, if not strictly fossorial, form obligately
tied to life in prairie dog (Cynomys) towns, may have
specializations of the limb skeleton intermediate between
weasels and badgers. Although not a cursor in the strictest
sense, the wolverine, with a home range up to 500,000
acres (Ewer, 1973), is the widest-ranging mustelid. The
limb skeleton of wolverines should show specializations for
9
the life of a cursor, albeit an ungainly one. Finally a
line connecting Mustela frenata, Spilogale putorius,
Mephitis mephitis, and Conepatus mesoleucus extends from
small, predaceous carnivores to medium-sized, ambulatory
omnivores. This line may describe an actual relaxation of
locomotor specialization since there probably is no
particular premium on speed or agility in striped or
hognose skunks. There is, therefore, the possibility that
the limb skeletons of Mephitis mephitis and Conepatus
mesoleucus may be more variable anatomically than those of
Mustela frenata or any other non-mephitine mustelid. In
other words, skunks (particularly Conepatus and Mephitis)
may have the most generalized, although not the most
primitive, skeletons in the Mustelidae. Selection in the
Mephitinae seems to have favored extreme development of
circumanal glands and aposematic coloration rather than
locomotor ability.
From the literature (Brown and Yalden, 1973; Gambaryan,
1974; Hildebrand, 1974; Howell, 1944; Smith and Savage,
1956) I would expect to see the following trends in the
Mustelidae. Species with cursorial tendencies should have
long legs. Distal limb elements should be disproportionately
long. Limb bones should be slender with long out-levers
and short in-levers. Arboreal species should share many
of the specializations of sub-cursorial species. This is
because arboreal mustelids simply run in trees. These
species should have recurved claws and mobile ankles.
10
Fossorial mustelids should have short legs, with a
disproportionate shortening or distal limb elements. Limb
bones of diggers should be robust and highly sculptured
with short out-levers and long in-levers. The epicondyles
of the humerus should be wide, and the claws should be long
and powerful. Aquatic mustelids should be typified by
short legs with a disproportionate shortening of proximal
limb elements. Distal limb elements may be modified to be
paddle-like. The pubic symphysis may be weak. The skulls
of aquatic species may be foreshortened. The potential
value of the comparison of the limb skeletons of all these
species is enhanced by the fact that they are all phylogenetically close.
The objectives of my study are to:
(1)describe the morphology and proportions of elements of
the limb skeletons of several species of Mustelidae, and
(2)explore the relationships between modes of locomotion
and the limb skeletons of those species.
MATERIALS AND METHODS
A total of 558 individuals from twenty-two species of
the family Mustelidae were examined. This sample encompassed
sixteen genera and all of the mustelid subfamilies (Appendix
1). Nomenclature in this study follows Hall and Kelson
(1959) for North American material. The taxonomy of Old
World material is from Simpson (1945). Both males and
females were included. Individuals of unknown sex were
also examined, but were treated statistically only when
males and females were lumped together. Large samples
(n = 30) were obtained for eight species. Eight other
species were only represented by one specimen each and were,
therefore, unsuited to any statistical characterization.
However, single specimens of some species were compared as
individuals against the patterns of variation developed by
the better represented species.
Subspecific names and locality data were noted for use
in the examination of geographic variation in the locomotor
skeleton of the species studied. Because specimens for this
study were obtained from fifteen separate museum collections
(Appendix 2), and because specimens from any particular
collection often were taken at different times and from
different places, none of my samples actually represent
natural populations. So, for reasons of pragmatism, subspecies are treated as being broadly equivalent to
geographical races.
12
There are three North American species of weasels, one
of which I chose to simulate the hypothetical primitive
mustelid. I chose Mustela frenata as the representative
weasel for this study because it is the largest of the
weasels. All three species of North American weasels lead
essentially similar lives (Ewer, 1973; Powell, 1979;
Rosenzweig, 1966) and are all three likely to have similar
locomotor adaptations. All three species are strict carnivores which hunt hole-frequenting prey in its burrows.
Except for size differences all three species are strikingly
similar. Using the largest species serves to minimize
potential allometric problems arising from comparisons of
animals that differ considerably in size such as weasels,
otters, and wolverines. Mustela frenata is also the widestranging North American weasel, and is better represented in
most collections than M. rixosa and M. erminea. Similarly,
the three species of Spilogale examined in this study (S.
gracilis, S. putorius, and S. angustifrons) probably have
similar modes of locomotion. In contrast to the situation
with weasels, however, the similarity of adaptation could
be tested in Spilogale. The testing procedures, delineated
elsewhere, justified in my mind lumping all of the species
of Spilogale for my examination of limb skeletons. The
decision was not taxonomic, but functional, and had the
added practical effect of improving the sample size for a
critical position in. my hypothetical arrangement of locomotor
trends.
13
To assess limb dimensions and proportions, I measured
thirty-seven structures. Dimensions for left and right
sides were measured in 296 specimens, and for only one side
in 262 specimens. Measurements were chosen from Hildebrand
(1952, 1954), Leach (1977a), Ondrias (1961) and Taylor (1974,
1976), and are illustrated in Figs. 2-5. Measurements were
made with a vernier caliper accurate to .05mm. Those measurements not illustrated are noted by an asterisk (*) and are
briefly explained in the list.
*a)
1
*a )
Total length of body
Taken from
Length of tail
standard museum
*b)
Length of hindfoot
specimen tags.
c)
Total length of skull
d)
Zygomatic breadth
e)
Length of scapula
f)
Height of scapula
*g)
Maximum height of scapular spine--measured
perpendicular to the blade of the
scapula
*h)
Length of acromion process--measured from
the deepest point in the notch between
the acromion process and the glenoid
fossa
i)
Length of humerus
j)
Posterior displacement of humeral head,
consisting of two separate measures:
14
ja--the distance between the lateral aspect
of the humeral head and the most medial
aspect of the lesser tuberosity.
jp --the distance between the medial aspect
of the humeral head and the most lateral
aspect of greater tuberosity.
k)
Transverse width of medial epicondyles
1)
Maximum diameter of humerus at midshaft
m)
Minimum diameter of humerus at midshaft
n)
Total length of ulna
o)
Length of olecranon process
*p)
Angle of olecranon process with shaft-measured with a protractor; the angle
formed by the olecranon process and
the shaft of the ulna in anterior view
q)
Length of radius
r)
Maximum distal width of radius
s)
Length of third metacarpal
t)
Total length of pelvis
u)
Length of pubic symphysis
v)
Preacetabular length of pelvis
w)
Dorsoventral breadth of ilium
x)
Total length of femur
y)
Mediolateral width of femoral condyles
z)
Anteroposterior width of femoral condyles
A)
Maximum diameter of femur at midshaft
B)
Minimum diameter of femur at midshaft
C)
Total length of tibia
15
D)
Total length of tibia minus length of
medial malleolus
E)
Anteroposterior width of tibial head
F)
Mediolateral width of tibial head
G)
Maximum diameter of tibia at midshaft
H)
Minimum diameter of tibia at midshaft
I)
Length of fibula
J)
Postastragalar length of calcaneus
K)
Length of third metatarsal
*a-a1)
n-o)
Body length--Total length minus tail length
Total length of ulna minus length of
olecranon process
*i+n-o+s)
Sum of length of humerus plus length of
ulna minus length of olecranon process
plus length of third metacarpal
*x+C+K)
Sum of length of femur plus length of tibia
plus length of third metatarsal
I initially intended to use total length of body as a
standard against which to compare limb measurements, but of
the species measured only about half (232) were accompanied
by external measurements from standard museum specimen tags.
For that reason I searched for a more readily available
measure that might still provide a body size standard. A
number of similar studies have used a measure of the combined
lengths of the thoracolumbar vertebrae (Hildebrand, 1952;
16
FIGURES 2-5
2) Bones, aspects of bones, and dimensions examined in this
study. Letters are identified in text. Figures are of
Martes americana.
3) Same
4) Same
5)Same
17
Fig. 2
18
ULNA
lateral aspect
anterior aspect
medial aspect
RADIUS
lateral aspect
anterior aspect
WRIST AND HAND
dorsal aspect
palmar aspect
Fig. 3
19
PELVIC GIRDLE
dorsal aspect
ventral aspect
lateral aspect
FEMUR
lateral aspect posterior aspect
Fig. 4
medial aspect
20
FIBULA
TIBIA
lateral aspect
anterior aspect
CALCANEUM
lateral aspect
CLAW
anterior aspect
fore
medial aspect
hind
ANKLE AND FOOT
plantar aspect
dorsal aspect
Fig. 5
21
Ondrias, 1961; Thorington, 1972) as an indicator of body
size. Because of the disarticulated state of the material
I was using, such a measure in this study would have been
prohibitively tedious. I sought to find some other useful
and convenient measure of body size. The correlation
coefficient was computed between length of the body and
length of the skull (n = 132). A highly significant
correlation was found between body length and length of
skull (r = .92; p<.001) for all mustelids. I recalculated
the correlation coefficient without otters (r = .97;
p<.001). Otters have relatively shorter skulls than other
mustelids and therefore including otters diminishes the
correlation. Because of the divergent nature of the length
of the skull relative to body length in otters care must be
taken in the interpretation of any ratio with length of
skull (c) in it.
While length of skull is a good indicator
of length of body in most mustelids it over-estimates the
length of the body in otters. Still the correlation between
length of skull and length of body is highly significant
in the Mustelidae. Therefore I felt justified in using
length of skull as an indicator of length of the body.
In mustelids, and particularly the Mustelinae, males are
substantially larger than females (Ewer, 1973; Haley, 1975;
King, 1975; Powell, 1979). For this reason and because
wide-ranging mustelids (e.g., weasels) are geographically
variable (King, 1975) .I felt that it was statistically
suspect to combine raw measurements from different sexes or
22
different subspecies. Yet these individuals should have
proportionately similar limb dimensions despite absolute
size differences. The influence of sex and subspecific
variation was therefore assessed in species containing
sufficiently large samples.
The use of ratios is a time-honored technique in morphometric studies (Desmond, 1976; Howell, 1944; Tarasoff, 1972).
It is important to note that ratios are derived numbers.
Some of the attendant problems in the use of ratios are
treated by Atchley et al. (1976) and Simpson et al. (1960).
Despite some drawbacks there are several advantages to the
use of ratios (Corruccini, 1977). Of particular interest
to me is the value of ratios as a means of comparing the
limb skeletons of animals that differ widely in size. Stahl
(1962) notes, "When measured by the length of his own forearm every man is the same size as every other". That is
precisely the quality of ratios that I wished to exploit.
A total of forty-nine ratios was generated for each
side of all 558 specimens.
1
1)(a-a )/a
2)b/(a-a1)
3)c/(a-a1)
The ratios are listed here.
Length of body/Total length
Length of hindfoot/Length of body
Length of skull/Length of body
4)e/c
Length of scapula/Length of skull
5)e/(i+n-o+s)
Length of scapula/Total length of
forelimb
6)f/e
Height of scapula/Length of scapula
23
7)f/c
Height of scapula/Length of skull
8)i/c
Length of humerus/Length of skull
9)i/e
Length of humerus/Length of scapula
10) i/(i+n-o+s)
Length of humerus/Total length
of forelimb
11) ja/jp
Posterior displacement of humeral
head
12) k/i
Transverse width of epicondyles/
Length of humerus
13)m/1
Minimum diameter of humerus at
midshaft/Maximum diameter
of humerus at midshaft
14) n/c
Length of ulna/Length of skull
15) n/i
Length of ulna/Length of humerus
16) n/(i+n-o+s)
Length of ulna/Total length of
forelimb
17) o/n
Length of olecranon process/Length
of ulna
18) (n-o)/c
Length of ulna minus length of
olecranon process/Length of
skull
19)(n-o)/i
Length of ulna minus length of
olecranon process/Length of
humerus
20)(n-o)/(i+n-o+s)
Length of ulna minus length of
olecranon process/Total
length of forelimb
24
21)q/c
Length of radius/Length of skull
22)q/i
Length of radius/Length of humerus
23)r/q
Distal width of radius/Length of
radius
24)s/c
Length of third metacarpal/Length
of skull
25)s/(i+n-o+s)
Length of third metacarpal/Total
length of forelimb
26) t/c
Length of pelvis/Length of skull
27)t/(x+C+K)
Length of pelvis/Total length of
hindlimb
28) u/t
Length of pubic symphysis/Length
of pelvis
29) v/t
Preacetabular length of pelvis/
Length of pelvis
30) x/b
Length of femur/Length of hindfoot
31) x/c
Length of femur/Length of skull
32) x/(x+C+K)
Length of femur/Total length of
hindlimb
33) z/y
Anteroposterior width of femoral
condyles/Mediolateral width
of femoral condyles
34) y/x
Mediolateral width of femoral
condyles/Length of femur
35) z/x
Anteroposterior width of femoral
condyles/Length of femur
25
36) B/A
Minimum diameter of femur/Maximum
diameter of femur
37) D/C
Length of tibia minus length of
medial malleolus/Length of
tibia
38)C/b
Length of tibia/Length of hindfoot
39) C/c
Length of tibia/Length of skull
40)C/x
Length of tibia/Length of femur
41) C/(x+C+K)
Length of tibia/Length of hindlimb
42)E/F
Mediolateral width of tibial head/
Anteroposterior width of
tibial head
43) H/G
Minimum diameter of tibia/Maximum
diameter of tibia
44) I/C
Length of fibula/Length of tibia
45) J/K
Postastragalar length of calcaneus/
Length of third metatarsal
46) J/b
Postastragalar length of calcaneus/
Length of hindfoot
47) J/(x+C+K)
Postastragalar length of calcaneus/
Total length of hindlimb
48) K/(x+C+K)
Length of third metatarsal/Total
length of hindlimb
49) b/(x+C+K)
Length of hindfoot/Total length
of hindlimb
26
The following standard statistics were computed for the
ratios in samples of each species: range, mean, standard
deviation, variance, standard error, coefficient of variation,
and sample size.
To avoid complications due to age variation I used only
adult animals. Adult status was determined by closure of
cranial sutures and fusion of epiphyseal caps to long bones
(Hildebrand, 1952; Leach, 1977a, 1977b; Taylor, 1970, 1974,
1976). Variation between left and right sides was examined
by comparing the mean + two standard errors of ratios for
left and right sides of males of the same subspecies. A
total of fifteen ratios (6, 8, 9, 10, 12, 13, 14, 16, 17,
19, 22, 23, 26, 39, 40) were examined for thirteen species.
Variation between males and females was examined by comparing
the mean ± two standard errors of ratios for the right side
of males and females of the same subspecies. A total of
twenty ratios (1, 3, 6, 8, 9, 10, 12, 13, 14, 15, 17, 18,
19, 22, 23, 26, 28, 31, 36, 39, 40, 43) was examined for
thirteen species. Geographic variation was examined by
comparing the mean + two standard errors of ratios for the
right side of males in different subspecies. The same
ratios and species were examined for geographic variation
as for sex variation. The ratios examined embraced fore
and hindlimbs and girdles, ratios of length and robusticity
within limb, and limb/body ratios.
27
Histograms of frequency distributions for over 300
ratios were visually inspected to determine whether ratios
were distributed normally about their means.
Because sample sizes were small in a number of cases,
and because there were some deviations from normalcy in the
frequency distributions of some of the samples a series of
Student's t-tests were performed to check the accurace of
the mean ± two standard errors as a predictor of significant
difference.
Patterns among species were examined by use of Dice
grams of the mean ± two standard errors (Fig. 6), shortest
connection (Prim) networks, and qualitative appearances
from drawings. Prim networks are generated by summing the
differences between the means of any given sample of ratios
for the species to be compared. The summed differences are
used to produce a closest connection network which arrays
species based on least difference (closeness). Salient to
the interpretation of a Prim network are the relative
distance between two species along the network, and the
identity of nearest neighbors in the network. The branching
pattern (e.g. angle of branching) is not important to the
interpretation of a Prim network. Prim networks were
generated using eleven species (Mustela frenata, Mustela
vison, Martes americana, Martes pennanti, Eira barbara,
Gulo luscus, Spilogale, Mephitis mephitis, Conepatus
mesoleucus, Lutra canadensis, Enhydra lutris). Nine
combinations of ratios were used to generate Prim networks
28
of the limb skeletons of mustelids (e.g. forelimb lengths,
hindlimb lengths, robusticity). Networks were generated
for each combination using males only, females only, and
males and females combined. Networks were then compared
for similarity of pattern. Similarity of networks for
males only and females only was taken as evidence that the
two sexes of different species are very similar in regard to
the ratios used in that particular combination. By virtue
of the similar patterns for males only and females only I
felt justified in conducting my species-level examinations
on males and females combined. Networks based upon larger
numbers of species (thirteen or fifteen) were subsequently
generated to examine the degree of closeness of species of
Spilogale, or to incorporate species that were only
represented by males (badgers, black-footed ferrets). Of
course, utilization of species consisting only of males and
species consisting of males and females in the same sample
reduces resolution. Yet valuable information was provided
by including badgers and black-footed ferrets in networks
with other species of mustelids.
Limb skeletons of the twelve best-represented species
were compared by standardizing the linear dimension of each
limb element according to techniques developed by Hildebrand
(1952, 1954), Hopwood (1947), Jenkins and Camazine (1977),
and Taylor (1974, 1976). Drawings permitted qualitative
comparisons of shape, proportion, and sculpturing of various
bones that might have been missed in the numerical treatment.
29
The following caveats must be given. Some of the
species in this study are represented by relatively small
sample sizes. Statistical characterizations of such small
samples must be viewed askance and interpreted carefully.
The natural history of some of the species in this study
(Eira barbara, Conepatus mesoleucus) is poorly known,
making statements about their locomotion provisional.
Finally there is a duality to the use of ratios. There
are two ways to achieve a high value for a ratio: the
numerator can be large, or the denominator can be small.
It is possible to get a high value for length of femur/length
of hindlimb by having a relatively long femur, or by having
a relatively short leg. More to the point, it is possible
to get high values for length of humerus/length of skull,
length of ulna/length of skull, length of femur/length of
skull, etc. in Enhydra lutris not because the individual
limb elements are relatively long, but because the skulls
of sea otters are relatively short. This does not abrogate
the value of ratios, but rather dictates caution.
Fortunately most of the limb elements I examined were
treated in a series of ratios (e.g., i/c, i/e, i/(i+n-o+s))
and are therefore less likely to be misunderstood.
RESULTS AND DISCUSSION
Intraspecific Variation
Histograms of frequency distributions (Appendix 4)
that were plotted for samples of ratios permit the following
statements regarding the normalcy of the distribution of
the ratios about their mean. The effect of lumping the
ratios for males and females of a species generally leads
to a better approximation of a normal distribution than
either sex alone. This is no doubt partly the result of
increased sample size. In small mustelines the effect of
lumping ratios of males and females is usually a somewhat
platykurtotic curve if the denominator of the ratio is
length of skull (c). This apparently results from disproportionate sexual dimorphism in the size of skulls of males
and females. In other words, females of small mustelines
have disproportionately larger skulls than males of the
same species. Nevertheless, when ratios for males and
females are lumped together, they are approximately normally
distributed about their mean.
The effect of lumping the ratios of different subspecies
of a species is much the same as lumping sexes. It is
interesting to note that lumping subspecies of Mustela
frenata and Martes americana resulted in somewhat more
platykurtotic curves than those for other species. I suspect
that my larger samples for Mustela frenata and Martes
americana produce this result. My sampling of subspecies
31
is better for Mustela frenata and Martes americana than the
other species and leads, therefore, to a better picture of
geographic variation.
At the species level the distribution of ratios about
their mean provides the best approximation of a normal
curve of any sample of ratios examined. There is some
kurtosis and some skewness, particularly in the poorly
represented species (Conepatus mesoleucus, Eira barbara,
Mustela nigripes). Yet lumping both sexes and all subspecies
of a species has the general effect of improving the normalcy.
In any case, it is at the species level that I wish to make
my comparisons.
Results of Student's t-tests supported by use of the
mean ± two standard errors as an indicator of differences
between samples. Of 122 Student's t-tests, 113 (93%)
corroborated my estimates based upon the mean ± two standard
errors. Of the eleven t-tests that were unsupportive, nine
nonetheless showed a significant difference at the 95% level
when the mean ± two standard errors suggested that the two
samples were not quite significantly different at the 95%
level. If there is a preferred direction in which to be
wrong, it is in predicting that two samples are not significantly different when they are. This means that if I err
in my interpretation of the degree of difference between
two samples I will tend to underestimate it based upon the
mean ± two standard errors.
32
To test for differences between the ratios for left and
right sides I used my best-represented subspecies. As Fig.
7 indicates there is no significant difference between left
and right sides for Martes americana. A series of fifteen
t-tests showed no significant difference between any ratio
for left or right sides of any species.
Dice grams of the mean + two standard errors and t-tests
for differences between males and females of a subspecies
produced some interesting results. No sexual dimorphism was
found in any ratio for any species except when (c), length
of skull, was the denominator of the ratio (Figs. 7-9). In
ratios which have length of skull as the denominator a
significant difference is observed for small mustelines and
Spilogale (Table 2). As already noted females of the small
mustelines (and perhaps Spilogale) evidently have skulls that
are disproportionately large relative to the size of their
bodies when contrasted to males of the same species. There
are some exciting resource-partitioning implications in this
observation. It certainly merits further study.
In species that are sexually dimorphic (e.g. Mustela
frenata, Martes americana), males of different subspecies
show the same pattern relative to one another that females
do (Figs. 7-9). This observation improves my confidence
about combining males and females in order to estimate
overall patterns of variation in ratios for a subspecies or
a species.
33
Dice grams and t-tests for significant difference
between subspecies of a species document the existence of
geographic variation. Fig. 8 illustrates perhaps the most
striking example. Martes americana abietinoides and Martes
americana actuosa are decidedly different animals from other
martens, at least as regards relative length of olecranon
process. It is compelling to postulate that since M. a.
abietinoides and M. a. actuosa are residents of stunted,
boreal forest, and therefore are obliged to be somewhat more
cursorial than other martens, they should show a well-known
cursorial adaptation (reduction of the olecranon process)
relative to their conspecifics from more heavily forested
situations. A number of other ratios show similar
disparities between these subspecies of martens.
Geographic variation also exists in some of the ratios
for Mustela frenata, Mustela vison, Martes americana, Martes
pennanti, Gulo luscus, Spilogale, Mephitis mephitis, Taxidea
taxus, Lutra canadensis and Enhydra lutris (Table 4). It
is particularly pronounced in Mustela frenata and Martes
americana, the two best-represented species in this study.
I suspect that analysis of large samples of other mustelids
would also reveal extensive geographic variation. So while
a high score in Table 4 is a good indicator of geographic
variation in the ratios for a species, a low score more
likely reflects insufficient data than the absence of
geographic variation.. Of course, it is also likely that
some of the variation in Mustela frenata and Martes
34
FIGURES 6-9
6)Dice grams of mean, ± two standard errors, and range for
ratio #17 (o/n--length of olecranon process/length of
ulna) for thirteen mustelids. Sample sizes are shown in
parentheses. Mf, Mustela frenata; Mn, Mustela nigripes;
Mv, Mustela vison; Ma, Martes americana; Mp, Martes
pennanti; Eb, Eira barbara; Gl, Gulo luscus, S, Spilogale;
Mm, Mephitis mephitis; Cm, Conepatus mesoleucus; Lc, Lutra
canadensis, El, Enhydra lutris.
7)Dice grams of mean, ± two standard errors, and range for
ratio #14 (n/c--length of ulna/length of skull) comparing
sides, sexes, and subspecies of martens. Sample sizes are
shown in parentheses.
8)Dice grams of mean, ± two standard errors, and range for
ratio #17 (o/n--length of olecranon process/length of
ulna) comparing sexes and subspecies of martens. Sample
sizes are shown in parentheses.
9)Dice grams of mean, ± two standard errors, and range for
ratio #12 (i/i--transverse width across epicondyles/length
of humerus) comparing sexes and subspecies of martens.
Sample sizes are shown in parentheses. abi, Martes
americana abietinoides; act, M. a. actuosa; cau, M. a.
caurina; sie, M. a. sierrae; -abi, all subspecies except
M. a. abietinoides and M. a. actuosa; All, all subspecies
of Martes americana.
35
Fig. 6
36
Fig. 7
37
Fig. 8
38
Fig. 9
39
americana is a reflection of the wide geographic range of
these two species.
Prim networks were used to examine possible differences
in the relationship between males and between females of
eleven species of mustelids. Networks for males only and
females only were compared for similarity of pattern using
all nine combinations of ratios (Appendix 5). Figure 10
illustrates the poorest correspondence between Prim networks
for males and females in this study. There are some
differences between the network for males and the network
for females. The relationships between species and between
subfamilies are not significantly different for males and
for females however. Figure 11 illustrates a better and
more typical correspondence between Prim networks for males
and females. This examination indicates that males and
females of different species show the same relationships to
each other when ratios that reflect proportions of the limb
skeleton are used to generate a Prim network. It follows
from this similarity then that males and females are similar
to one another in appendicular anatomy, and that species
comparisons by Prim network are reasonable using samples
of males and females combined.
There are significant differences between males and
females in some ratios (Tables 2 and 3). There are also
some differences between ratios for different subspecies of
a species (Table 4).
Although combining sexes and different
subspecies of a species tends to mask sexual and geographic
40
FIGURES 10 & 11
10)Prim networks for females (A) and males (B) using
eleven species of mustelids and eight forelimb length
ratios.
11)Prim networks for females (A) and males (B) using
eleven species of mustelids and twenty-six fore and
hindlimb ratios.
41
FIGURE 10A
FIGURE 10B
42
FIGURE 11A
FIGURE 11B
Table 2. -- (+) scores for significant differences (P<.05) between ratios for males
and females. Data taken from best-represented subspecies in five species
of Mustelidae; Mustela frenata, Martes americana, Spilogale putorius,
Mephitis mephitis, Lutra canadensis.
f/e
i/c
i/e
n/c
n/i
(n-o)/c
(n-o)/i
q/c
q/i
M. f. nevadensis
+
-
+
-
+
-
+
-
+
-
M. a. abietinoides
+
-
+
-
-
-
+
-
+
-
S. 2. interrupta
-
-
+
-
-
-
-
-
-
-
M. m. avia
-
-
-
-
-
-
-
-
-
-
L. c. canadensis
-
-
-
-
-
-
-
-
-
-
43
f/c
44
Table 3. -- Scores for occurrence of sexual dimorphism in
eleven species of Mustelidae. Each ratio was scored 1
point if there was a significant difference (P<.05)
between the sexes. Scores were added for each species.
For example four forelimb and four hindlimb ratios were
significantly different for males and females of
Mustela frenata.
Species
Forelimb
Hindlimb
Combined
Mustela frenata
4
4
8
Mustela vison
4
3
7
Martes americana
4
3
7
Martes pennanti
4
0
4
Eira barbara
1
0
1
Gulo luscus
0
0
0
Spilogale spp.
2
1
3
Mephitis mephitis
0
0
0
Conepatus mesoleucus
0
0
0
Lutra canadensis
0
0
0
Enhydra lutris
1
0
1
45
Table 4. -- Scores for occurrence of geographic variation in
twelve species of Mustelidae. Each ratio was scored 1
point if there was a significant difference (P<.05)
between any two subspecies of a species. Scores for
each species were added. For example eight forelimb
and four hindlimb ratios in Mustela frenata revealed at
least one occurrence of significant differences between
subspecies.
Species
Forelimb
Hindlimb
Combined
Mustela frenata
8
4
12
Mustela vison
1
3
4
Martes americana
8
4
12
Martes pennanti
1
0
1
Eira barbara
0
0
0
Gulo luscus
1
0
1
Spilogale spp.
4
2
6
Mephitis mephitis
1
2
3
Conepatus mesoleucus
0
0
0
Taxidea taxus
1
2
3
Lutra canadensis
3
4
7
Enhydra lutris
0
1
1
46
variation, I made species level comparisons using combined
samples of males and females and all available subspecies
of a species. I did this for the following reasons: (1)
normalcy of the distribution of ratios about their mean
results from combining males and females, or subspecies;
(2) subspecies of males and of females exhibit the same
pattern of relationship to each other in Dice grams of mean
± two standard errors; males and females combined follow the
same pattern (Figs. 7-9); (3) Prim networks for males,
females, and males and females were similar.
Appendix 6 summarizes the descriptive statistics for
all ratios of males plus females and all subspecies of
thirteen species of the family Mustelidae.
Species Comparisons
FORELIMB
Clavicle
The clavicle is vestigial in all of the mustelids.
Hall (1927) reported that it is absent in Taxidea taxus.
Fisher (1942) and Howard (1973) recorded the absence of the
clavicle in the Lutrinae. Savage (1957) did not record a
clavicle in Potamotherium, an early lutrine. Hall (1926)
did not mention the occurrence of a clavicle in Spilogale
or Mephitis. Klingener (1972) noted that the clavicle of
mink is "a tiny vestigial bone buried between the clavotrapezius and clavodeltoid muscle". Martes has the most
47
highly developed clavicle of all mustelids observed. This
perhaps is owing to the arboreal habits of martens and
fishers. Even in Martes, however, the clavicle is quite
small (<1cm.), and does not articulate with the scapula
(Leach and Dagg, 1976). Ondrias (1961) did not mention the
clavicle in his study of the forelimbs of European mustelids.
Scapula
The scapula in all twelve species figured (Fig. 12) is
fairly uniform anatomically. The spine is well developed
in all mustelids. The acromion process is located above the
glenoid fossa anteriorly in the mustelines (excepting
Mustela vison), Spilogale, and Taxidea taxus. The metacromion process is poorly developed in the mephitines. The
metacromion process is well developed in the other species
examined and is particularly prominent in Mustela frenata,
Mustela vison, the lutrinae, and Taxidea taxus.
The profile of the scapula is essentially triangular
in Mustela frenata but tends to become more rectangular in
the Mephitinae and Taxidea taxus. The scapula of Enhydra
lutris is rectangular, but it is triangular in Mustela vison,
and very triangular in Lutra canadensis. The scapulae of
Martes, Eira barbara, and Gulo luscus are essentially like
that in Mustela frenata but are rounder, particularly in
Martes pennanti and Eira barbara.
The triangular or sub-round profile of the scapula is
a characteristic of generalized mammals (Hildebrand, 1974;
48
Jenkins, 1974; Taylor, 1974). A narrower more rectangular
profile suggests some limitation of movement, and specialization to strengthen those limited movements. A narrow
scapula can indicate fossorial or cursorial habits (Gray,
1968; Hildebrand, 1974).
Taxidea taxus, Lutra canadensis, and the larger
mustelines have a prominent post-scapular fossa which
extends the site of origin of the teres major muscle. The
teres major contributes to posterior movement of the humerus
as in digging or swimming. The presence of the post-scapular
fossa in the larger mustelines is owing perhaps to their
greater weight in comparison to Mustela frenata. Ewer
(1973) equated the possession of a post-scapular fossa in the
ursids to the combined effects of arboreality and great
weight. The absence of a post-scapular fossa in Enhydra
lutris is not surprising in light of the fact that sea
otters do not use the forelimb much in swimming (Tarasoff
et al., 1972). Taylor (1914) noted that the forelimb in
Enhydra lutris is an organ of prehension, not propulsion.
The scapula is long relative to the body in Conepatus
mesoleucus, Mephitis mephitis, and Gulo luscus. It is
shortest in Mustela and Martes. The scapula is long relative
to the forelimb in Enhydra lutris, but sea otters have
relatively short legs (Kenyon, 1969; Taylor, 1914). The
scapula is relatively short compared to the long legs of
Martes, Eira, and Gulo. The height of the scapula relative
to its length is greatest in Taxidea taxus, Lutra canadensis,
49
Enhydra lutris, and Gulo luscus, which have scapulae most
unlike that of Mustela frenata of all the species examined.
The height of the scapula is least in the mephitines,
particularly Conepatus mesoleucus and Mephitis mephitis.
This character suggests some restriction of forelimb
mobility, and is an unusual finding in light of the
locomotor habits of skunks.
There are trends in the morphology of the scapula in
the Mustelidae which serve to support my notion of progressive
specialization to different modes of locomotion. The
scapula becomes progressively longer relative to the body
in the following species sequences: Mustela frenata--Mustela
nigripes--Taxidea taxus; Mustela frenata--Mustela vison-Lutra canadensis; Mustela frenata--Spilogale--Mephitis
mephitis--Conepatus mesoleucus; Mustela frenata--Martes
americana--Martes pennanti--Eira barbara--Gulo luscus. The
length of scapula relative to the forelimb follows essentially
the same trends, except that because of their relatively
long legs, the scapulae of Martes, Eira, and Gulo are
relatively shorter than that of Mustela frenata.
Both indices of scapular height (relative to body
length, and relative to length of scapula) show essentially
the same progressive increases in height as are described
above for length of scapula. The skunks show a progressive
narrowing rather than widening of the scapula relative to
length of scapula.
50
Humerus
The humerus of msutelids (Figs. 13, 14) is most gracile
in Martes americana, Mustela frenata, Martes pennanti, Eira
and Mustela vison, and is most robust in Conepatus, Taxidea,
Gulo, Lutra, and Enhydra. Trends of increasing robusticity
closely follow proposed trends of locomotor specialization:
Conepatus, Taxidea, Lutra, Enhydra, and Gulo have the most
robust and elaborately sculptured humeri. I am obliged to
note that there is a size increase in all of my proposed
sequences; of course, an increase in mass will lead to an
increase in the robusticity of a limb element (Hildebrand,
1974; Pedley, 1977). In this case, however, increases in
robusticity and sculpturing are probably the result of both
increased size and different modes of locomotion between
the species. For instance the humerus of Spilogale is more
robust than that of Mephitis. Since Mephitis is heavier than
Spilogale, the greater robusticity of the humerus in Spilogale
cannot be attributed to greater weight. On the other hand
increasing robusticity in Martes americana, Martes pennanti,
Eira and Gulo is probably related to increased weight along
that sequence, since locomotion in those species is very
similar.
The humerus is longest relative to the body in Gulo,
Eira, Martes pennanti, Conepatus, Mephitis, and shortest
relative to the body in Mustela frenata. Ondrias (1961)
suggested that a shortening of the humerus is typical of
fossorial mammals that must turn around in narrow burrows.
51
Both Mustela nigripes and Taxidea have longer humeri than
Mustela frenata, making me suspect the accuracy of Ondrias'
generalization. The humerus is long relative to the body
in the long-legged Martes americana, Martes pennanti, Eira,
and Gulo; short relative to the body in otters and skunks;
and short in the badger, which, of course, has powerful
forelimbs. No mustelid has a humerus that is longer relative
to the forelimb than Mustela frenata, although the relationship is about the same for Enhydra. Martes and Gulo have
humeri that are short relative to length of forelimb, but
this is a reflection of lengthening of distal limb elements
(see below). Long legs and disproportionate lengthening of
distal limb elements is a cursorial specialization (Brown
and Yalden, 1973; Gray, 1968; Hildebrand, 1974).
The shaft of the humerus is curved in Lutra, Enhydra
and Taxidea. Savage (1957) noted that it is curved in
Potamotherium. Ondrias (1961) reported that it is relatively
straight in Meles.
The transverse width across the epicondyles of the
humerus is greatest relative to length of the humerus in
Conepatus, Taxidea, Lutra, Enhydra and Mephitis (Fig. 13).
Ondrias (1961) noted that it is also great in Meles
(European badger). The transverse width across the
epicondyles is narrowest in Martes americana and Mustela
frenata. There is a widening trend in the epicondyles along
all of the sequences I propose. A prominent medial
epicondyle is indicative of powerful flexors of the manus.
52
A prominent lateral epicondyle is indicative of powerful
extensors and supinators of the manus. The relatively deeper
groove between trochlea and capitulum in Taxidea, Lutra,
Enhydra, Mustela frenata, and Martes americana suggests
rigidity of the elbow in these species. Ondrias (1961)
suggested that widening of the epicondyles was correlated
with the powerful flexion of the elbow and pronation and
extension of the carpus and manus, and that it is characteristic of fossorial and semi-aquatic specialists. The
trends illustrated here corroborate that suggestion. No
mustelid has a trochlea as narrow as do the cursorial
Canidae. Among mustelids, the trochlea is narrowest in
Martes americana.
The posterior placement of the humeral head is somewhat
more enigmatic. The head is most anterior on the humerus in
Taxidea, Conepatus, Mephitis, and, oddly enough, in Martes
americana. The head is most posterior in the lutrines.
Taylor (1974) noted that the humeral head was most
posteriorly placed in cursors and less so in more generalized
forms. Unfortunately there are no aquatic viverrids with
which to contrast otters. Ondrias (1961) said the head of
Enhydra is placed almost as far posteriorly as in the
Phocidae (seals).
The head of the humerus is divergent, suggesting
mobility of the humerus, in Martes, Eira, Gulo, Lutra, and
Enhydra. The head is more firmly buttressed and less
divergent in Taxidea taxus and the skunks, suggesting that
greater stresses are passed through the head and along the
53
shaft of the humerus. Taylor (1974) noted from cineroradiographs that the head of the humerus can rock in the
glenoid in viverrids, making sphericity of the head a poor
predictor of mobility at the shoulder. The shaft of the
humerus is roundest in Martes americana, Mustela nigripes,
Eira, Martes pennanti, Mustela frenata, and Gulo, and is
most elliptical in Enhydra, Lutra, Mustela vison, Taxidea,
and skunks. The pectoral and deltoid ridges in Enhydra,
Lutra, Taxidea, and the skunks, are very strong and dominate
the shaft of the humerus, in contrast to Martes, Eira; and
Gulo. Hildebrand (1974) noted that round shafts of the
long bones can be correlated with cursorial or arboreal
habits. The greater tuberosity of the humerus is prominent
in Lutra, Taxidea, and the skunks, which correlates well with
power in lateral rotation of the humerus. The lesser
tuberosity is prominent in Enhydra. The greater and lesser
tuberosities are subequal in other mustelids.
Trends in length of humerus relative to body length and
other forelimb elements generally correspond to the proposed
sequences, as do trends in ellipticity of the shaft.
Ulna
The ulna is gracile in Martes americana, Mustela
frenata, Martes pennanti, Eira, Spilogale and robust in
Lutra, Enhydra, Mustela vison, and Gulo (Fig. 15).
Trends of increasing robusticity of the ulna generally
follow proposed continua from Mustela frenata. The ulna
54
of Enhydra is slightly less robust than that of Lutra. The
ulna of Taxidea is not so robust as might be expected for
a fossorial mammal, but the radius of badgers is quite
robust.
The length of ulna relative to body length is greatest
in Gulo which suggests some cursorial specialization. The
ulna is also long in Conepatus, Taxidea, and Mephitis, but
that is due partly to the disproportionately long olecranon
process in these species. The ulna is relatively short in
Mustela frenata, Mustela nigripes, Mustela vison, Lutra, and
Enhydra. The length of ulna relative to the humerus is
greatest in Taxidea, Conepatus, Mephitis (all three of which
have long olecranon processes), Lutra, Enhydra, and Gulo.
It is important to recall the relatively short humerus of
the otters when considering this relationship, because it
exaggerates the length of the ulna. The humerus and ulna
are about the same length in Martes and Eira. The ulna is
relatively short in Mustela frenata and Mustela vison. The
length of ulna relative to the forelimb shows essentially
the same relationship between species as length of the ulna
relative to body length.
The olecranon process of Taxidea, Conepatus, and Lutra
is long, providing a considerably greater mechanical
advantage, in extension of the forearm compared to other
mustelids. The olecranon process is short in Martes, Gulo,
and Eira. A long olecranon process is often correlated
with fossorial life or swimming movements of the forearm.
The long olecranon process of Conepatus and Mephitis may
be
55
an adaptation to turning over logs and rocks in search of
grubs. A short olecranon process has generally been
attributed to cursorial or arboreal habits (Flower, 1885;
Gambaryan, 1974). Trends in the length of the olecranon
process in the Mustelidae also closely follow my proposed
continua, except that the relative length of the olecranon
process is about the same in Mustela frenata and Enhydra.
Ondrias (1961) stated that the length of the olecranon
process in Lutra could not be correlated with semi-aquatic
life. Noting the progression in length of the olecranon
process in Mustela frenata, Mustela vison, and Lutra
canadensis, I would respectfully disagree.
I generated ratios using as the numerator the length
of the ulna minus the length of the olecranon process
reasoning that such a measure was more likely an indicator
of the relative contribution of the ulna to the total length
of the forelimb than length of ulna. Relative to body length,
length of ulna minus length of olecranon process is longest
for Gulo, Eira, Martes pennanti, and Martes americana and
reflects cursorial specialization in those species. Relative
to body length this measure is also long for Taxidea and the
skunks, albeit not as long, relatively, as suggested by
measures including the length of the olecranon process. The
length of the ulna minus length of olecranon process is
short in Mustela frenata, Mustela vison, and Lutra. Relative
to length of humerus, length of ulna minus length of
olecranon process is longest in Gulo and shortest in Mustela
56
frenata. Length of ulna minus length of olecranon process
relative to both body length and length of humerus follows
the sequences I suggest. Relative to total length of the
forelimb length of ulna minus length of olecranon process
is longest in Enhydra, Taxidea, and the skunks. This
relationship must be considered in light of the short limbs
of the otters. Lutra and Mustela vison have the shortest
length of ulna minus length of olecranon process, relative
to total limb length. This ratio generally follows my
proposed sequences. There is a trend toward distal broadening of the ulna in Taxidea, Gulo, Mustela vison, and
Lutra.
The angle between the olecranon process and the shaft
of the ulna is greatest in Mephitis, Mustela nigripes,
Lutra, and Mustela frenata; the angle is smallest in Mustela
vison, Martes pennanti, Conepatus, and Taxidea. The smaller
angle causing the olecranon process to be more in line with
the shaft of the ulna in Taxidea, Conepatus, and Mustela
vison seems as though it might improve leverage relative
to a greater angle. The function of the greater angle in
Mephitis, Lutra, Mustela nigripes, and Mustela frenata is
a mystery to me. Taylor (1974) suggested that a smaller,
more acute, angle between the olecranon process and the
shaft of the ulna would lengthen the triceps, slowing its
action and permitting more controlled movements of the
forelimb. He also proposed that a greater angle between
the olecranon process and the shaft of the ulna would shorten
57
the triceps muscle, thus leading to faster movements of the
forelimb. My data neither strongly support or negate
Taylor's suggestion.
The styloid process of the ulna is most divergent in
Mustela frenata, Mustela vison, and Martes americana. The
styloid process of the ulna is least divergent in Gulo,
Taxidea and the skunks.
Radius
The radius is most gracile in Martes americana, Martes
pennanti, Gulo, Mustela frenata, Spilogale, and Conepatus.
A much more robust radius typifies Lutra, Enhydra, Taxidea,
and Mephitis (Fig. 16). Trends from gracile to robust
generally follow my proposed sequences, although the radius
in Conepatus is unusual among skunks. The shaft of the
radius is curved dorsoventrally in Mustela vison, Spilogale,
Conepatus, Taxidea, and Lutra. The curve is particularly
noticeable in Mustela vison, Lutra, and Taxidea. The radii
of other mustelids examined were more or less straight.
Hildebrand (1974) correlates bowing of the radius with power
in supination of the manus.
The length of the radius relative to the length of the
body is greatest in Gulo and closely parallels the relationships already noted for the ulna. Trends in this ratio
closely follow proposed continua with even the typically
unusual Enhydra conforming. The length of the radius
relative to the humerus is greatest for Gulo, which is
58
followed by Taxidea, Conepatus, Mephitis, and Spilogale;
the latter also have relatively short humeri. My proposed
sequences are only partially supported by trends in this
ratio.
The distal width of the radius is greatest in Lutra and
Taxidea, and narrowest in Mustela frenata and Martes. The
trends I postulate in my sequences are supported. The only
deviation is that the distal end of the radius is wider in
Mustela frenata than in Martes; probably this condition is
due to the fossorial habits of Mustela frenata and selective pressure to strengthen the carpus.
Carpus and Metacarpus
The wrist and hand (Fig. 17) are particularly gracile
in Mustela frenata, and Martes and are robust in Taxidea,
Lutra, Mustela vison, and the skunks. The hand is particularly broad in Taxidea, Lutra, and the skunks. Ondrias
(1961) noted that the hand of Meles was very broad compared
to that of other European mustelids. The length of the
third metacarpal relative to the body is greatest in Gulo,
Martes, and Eira. The third metacarpal is shortest in
Enhydra, Taxidea, Spilogale, Mephitis, and is somewhat longer
in Mustela frenata. Trends in this ratio are somewhat
equivocal. Curiously, both Mustela vison and Mustela
nigripes have longer hands than Mustela frenata, even
though the hands of Enhydra and Taxidea are much shorter.
Relative to the length of the forelimb the length of the
59
third metacarpal is greatest in Mustela vison, and Lutra,
and shortest in Taxidea and Enhydra. The short hand of
Taxidea is a logical correlate of the power necessary for
fossorial life. The long hands of Mustela vison and Lutra
are probably due to the paddle-like function of the hand.
The relatively short hand in Enhydra is probably related
to the use of the hand for functions other than swimming
(Kenyon, 1969; Tarasoff, et al., 1972). The third metacarpal is actually relatively long in Martes, Eira, and
Gulo, but seems relatively short in this ratio due to the
relatively long legs of these species. The long hands of
these species probably represent adaptations to running
either in trees or on the ground; and correlate nicely with
the tendency toward a digitigrade stance in the arboreal,
sub-cursorial mustelines.
Foreclaws
The foreclaws (Fig. 18) are longest in Taxidea and are
undoubtedly correlated with fossorial life. The skunks have
very long claws as well. I suspect their length is related
to the opportunistic feeding habits of skunks, which turn
things over in search of food. The claws in Martes, Eira,
and Gulo are all strongly curved and correlate well with
the known arboreal tendencies of these species (Banfield,
1974; Coues, 1877, Walker et al., 1975). The foreclaws
of Mustela frenata are morphologically intermediate. In
Mustela vison, the foreclaws are rather strongly curved and
60
FIGURES 12-18
12) Lateral aspect of scapulae of twelve species of Mustelidae,
arrangement like that in Figure 1.
13) Anterior aspect of humeri of twelve species of Mustelidae,
arrangement like that in Figure 1.
14) Lateral aspect of humeri of twelve species of Mustelidae,
arrangement like that in Figure 1.
15) Lateral aspect of ulnae of twelve species of Mustelidae,
arrangement like that in Figure 1.
16) Anterior aspect of radii of twelve species of Mustelidae,
arrangement like that in Figure 1.
17) Dorsal aspect of carpus and metacarpus of ten species of
Mustelidae, arrangement like that in Figure 1.
18) Foreclaws (right) and hindclaws (left) of twelve species
of Mustelidae, arrangement like that in Figure 1.
61
Fig. 12
62
Fig. 13
63
Fig. 14
64
Fig. 15
65
Fig. 16
66
Fig. 17
67
Fig. 18
68
may aid in scrambling on stream sides or in prey capture.
The foreclaws are small in otters, particularly in Enhydra.
Bony support embracing the base of the keratinized sheath
of the claws is most noticeable in Enhydra, Taxidea,
Conepatus, and Gulo.
HINDLIMB
Pelvis
The pelvis is particularly narrow and gracile in Martes
americana but is fairly narrow in Martes pennanti, Eira,
Mustela frenata, Mustela vison, Spilogale, and Lutra (Fig.
19). The pelvis is wider and more robust in Mephitis, Gulo,
Taxidea, and particularly in Enhydra. Taylor (1914)
correlated flaring ilia with swimming movements of the hindlimb, noting that the anterior ends of the ilia of seals are
almost perpendicular to the vertebral column. The angle
that the ilium forms with the pubic symphysis is closest
to perpendicular in Martes, Mustela, and Eira (Fig. 20).
The angle is much more acute in the skunks, Taxidea, and
Enhydra. The angle in Lutra and Gulo is intermediate in
being more acute than Martes and less acute than Taxidea.
A less acute angle between the ilium and the rest of the
inominate is a specialization for speed (Smith and Savage,
1956). A rodlike ilium more or less parallel to the
vertebral column is a fossorial specialization (Shimer,
1903). A prominent constriction in the ilium just anterior
69
to the acetabulum is found in Taxidea, Enhydra, Lutra, Gulo,
Martes pennanti, and Eira. The constriction is less distinct
in Mustela frenata and in skunks.
The length of pelvis relative to body length is greatest in otters, Conepatus, and Mephitis. Mustela, Martes,
and Spilogale have a much shorter pelvis. This trend
parallels my proposed sequences closely. The length of
pelvis relative to length of hindlimb exhibit the same
trends as length of pelvis relative to length of body.
The pubic symphysis is shortest in the skunks and
Taxidea. The pubic symphysis is longest in the mustelines.
Symphysis length in the otters is intermediate between
weasels and skunks. Hall (1926) noted that the adductor
mass in Spilogale and Mephitis mephitis was not so expansive
as in Martes. He did not mention the pubic symphysis at
all, however. Hildebrand (1974) considered a poorly fused
pubic symphysis to be associated with fossorial habits.
Taylor (1914) noted that the poorly fused pubic symphysis
of sea otters was structurally antecedent to the condition
of the pubic symphysis in seals. The relative length of the
pubic symphysis corresponds to trends I propose for aquatic
and fossorial specializations. My sequences for arboreal
and ambulatory specialization are not followed closely.
The preacetabular length of the pelvis is one of the
least variable ratios in my study. Preacetabular length is
slightly longer in Mephitis than other mustelids and
slightly shorter in Taxidea and in otters. Taylor (1976)
70
noted that preacetabular length in viverrids is relatively
constant.
Femur
The femur of mustelids is most gracile in Martes,
Mustela frenata, Gulo, and Eira. A robust femur is found
only in Enhydra and Lutra; Taxidea and skunks are intermediate
(Figs. 21, 22). Trends of increasing robusticity follow the
sequences I propose. A constricted neck between the head and
shaft of the femur characterizes members of the Mustelinae
and Enhydra. Skunks, Lutra, and Taxidea, have a thicker
neck; the head of the femur is therefore more firmly
buttressed.
The length of femur relative to hindfoot length is
greatest in the skunks and Taxidea. Otters and Mustela
vison have the shortest femora. The hindfeet of otters
(and to a lesser degree mink) are somewhat longer than
those of other mustelids. The trends in this ratio follow
my proposed sequences except for skunks, which do not
differ appreciably among themselves. The length of femur
relative to the body is greatest in Conepatus, Eira, Gulo,
Martes pennanti, and Mephitis. The femur is shortest in
Lutra, Mustela vison, and Mustela frenata. The long femur
in arboreal species and runners (Eira Barbara, Gulo luscus,
and Martes pennanti) follows well-established trends for
cursorial specialization (Hildebrand, 1974; Howell, 1944;
Smith and Savage, 1956). The long femur of Conepatus
and Mephitis is mystifying. Relative to body length all
71
other mustelids have longer femora than Mustela frenata.
The femur is longest relative to hindlimb length in Taxidea,
suggesting that the distal limb elements have become
shortened in this species. The femur is shortest relative
to total length of the limb in the otters. This ratio
follows my proposed sequences closely.
Ratios examining the relative width across and depth
of the femoral condyles (z/y, y/x, z/x) show that otters,
Taxidea, Mustela vison, and skunks have femoral condyles
widened mediolaterally, whereas the condyles are narrow in
Mustela frenata, Martes, and Eira. The femoral condyles
are deep anteroposteriorly in otters and Mustela vison and
shallow in Martes americana, Martes pennanti, Eira, and
Spilogale. These ratios follow my proposed continua fairly
closely. The shaft of the femur is roundest in Martes,
Eira, Gulo, and Mustela frenata. The shaft of the femur
is most elliptical in the otters, Mustela vison, Taxidea,
Mustela nigripes, and Spilogale. The shaft of the femur is
expanded mediolaterally in Lutra and particularly in Enhydra.
Round shafts on long bones are correlated with running and
arboreal habits, while more elliptical shafts are typical
of aquatic and fossorial specialization (Hildebrand, 1974).
This ratio follows my proposed continua for running,
arboreal, and aquatic specializations. Skunks, Taxidea,
and Mustela nigripes do not conform to my continua.
Mustela nigripes and Spilogale both have more elliptical
72
femora than Taxidea taxus; Conepatus and Mephitis do not
differ appreciably from Taxidea.
Tibia
The tibia is most gracile in Mustela frenata, Martes,
Eira, Spilogale, and Gulo. The tibia is much more robust
in Taxidea, Lutra, Enhydra, and Mustela vison (Fig. 23).
The tibia is fused proximally to the fibula in Gulo and
Enhydra. This fusion likely restricts motion at the ankle
to flexion and extension of the pes (Barnett and Napier,
1953ab; Walmsley, 1918). The length of the medial malleolus
is greatest in Enhydra, Lutra, Mustela vison, Taxidea, and
Mustela nigripes, and is probably also an indication of
reduced mobility at the ankle of those species. A shorter
medial malleolus is characteristic of Martes, Eira, and
Gulo, which are decidedly more agile beasts than badgers or
otters. Trapp (1972) mentioned the ability to rotate the
hindfoot in Martes and other arboreal carnivores as an
adaptation permitting head-first descent from trees. Taylor
(1976) recorded more potential movement in the ankle of
Nandinia, an arboreal viverrid, than in any other African
species of the family.
The length of tibia relative to hindfoot length is
greatest in skunks, and least in the badger and otters. The
extraordinary claws of badgers explain partially the
relative shortness of the badger tibia in this ratio,
because the length of hindfoot measure that I used included
73
claws. Shortening of distal limb elements is a fossorial
adaptation (Smith and Savage, 1956). The long, paddle-shaped
feet of otters may account in part for the condition of
this ratio in otters. The tibia is longest relative to the
body in skunks but is also long in Martes, Eira, and Gulo.
A shorter tibia occurs in Taxidea, Mustela nigripes, and
Mustela frenata. The length of tibia relative to length of
femur is one of the classical relationships of locomotor
studies (Desmond, 1976) and has been widely used to illustrate cursorial adaptation. Gregory (in Desmond, 1976)
suggested that the higher the ratio of length of tibia/length
of femur (T/F) the faster an animal is structurally capable
of running. Desmond (1976) reported a T/F ratio of 0.92 in
race horses and 1.25 in gazelles. All of the species I
examined have a T/F ratio greater than 0.92 except Taxidea,
and Enhydra has a T/F ratio of more than 1.25. Mustelids,
and certainly otters, are not specialized cursors. Taylor
(1976) gave T/F ratios of 1.02-1.26 for viverrids. These
high T/F ratios point up one of the pitfalls of making
hasty comparisons. The femora of all carnivores are shorter
relative to their body lengths than the femora of ungulates
and render the comparison of T/F ratios between carnivores
and ungulates suspect.
Trends in the ratios of tibia length follow proposed
sequences except in skunks, which have surprisingly long
distal limb elements. The length of the tibia relative to
the length of the hindlimb is greatest in Lutra, Mephitis
and Conepatus. The tibia is shortest in Taxidea.
74
The mediolateral width of the proximal end of the
tibia is greatest in otters, and correlates well with the
wide femur of these species. The anteroposterior depth of
the proximal end of the tibia is greatest in Gulo. Trends
in widening or deepening of the proximal end of the tibia
do not fit my proposed sequences well.
The tibia of mustelids is most round in Mustela vison
and Martes, and most elliptical in the otters, Taxidea, and
Mustela frenata. Ellipticity of the tibia in Mustela
frenata is greater than that in any mustelids except
Taxidea and otters. Trends in ellipticity of the tibia do
not follow my sequences.
The lengthening of distal elements in the limb of
skunks is not reported in the literature to the best of my
knowledge . It seems reasonable that specializations for
increasing the length of stride in cursorial species would
be selectively advantageous in ambulatory species as well.
An increase in the length of stride should reduce the
energy investment to move a unit of distance regardless
of speed.
Fibula
The fibula of mustelids is gracile in Martes, Mustela,
Eira, Gulo, and the skunks. The fibula is more robust in
Taxidea, Lutra, and Enhydra (Fig. 24). Trends in robusticity
of the fibula follow my proposed sequences in the mustelines,
and in Lutra and Enhydra. The fibula of the three
75
mephitises I examined are almost identical. The fibula is
longest relative to the tibia in Martes, Eira, Gulo and
Spilogale. Mustela nigripes, Mustela vison, Taxidea, Lutra,
and Enhydra have short fibulas.
Calcaneus
The calcaneus is gracile in Martes, Gulo, Mustela vison
and Conepatus. A more robust calcaneus typifies Mustela
frenata, Taxidea, and Enhydra (Fig. 25). Postastragalar
length of the calcaneus is greatest in Conepatus, Taxidea,
and Mephitis. The postastragular length is much less in
Mustela frenata, Martes americana, and Enhydra. My proposed
sequences conform very well with trends in the postastragular
length of the calcaneus except, as usual, Enhydra is very
unlike other aquatic mustelids. The postastragalar length
relative to length of the third metatarsal and relative to
length of hind foot are essentially similar ratios. The
postastragalar length relative to length of hindlimb is
greatest in Taxidea, Lutra, Gulo, and Conepatus. The
postastragalar length is least in Mustela frenata and
Martes americana. This ratio parallels my proposed sequences
except in the case of Enhydra in which the postastragalar
length relative to hindlimb length is essentially the same
as in Mustela vison. Stains (1976) noted that the calcanea
of mustelids were at least subfamilially distinct, but drew
no functional conclusions from his work. Probably an
increase in postastragalar length increases the power of
76
extension of the pes in otters, badgers, and relatively
heavy-bodied sub-cursorial forms such as Gulo.
Pes
The hindfoot is most gracile in Mustela, Martes, and
Spilogale. The hindfoot of Taxidea, Lutra, Conepatus, and
Enhydra is much more robust (Fig. 26). Trends in robustness of the hindfoot follow my proposed sequences closely.
The length of the third metatarsal relative to the total
length of the hindlimb is greater by far in Enhydra, which
has large paddle-like feet and short legs. The third metatarsal is much shorter in Eira, Spilogale, Mephitis,
Conepatus, and Taxidea. Trends in skunks, arboreal
mustelines, Gulo, and fossorial mustelids correspond to my
proposed sequences.
Hindfoot length relative to length of hindlimb is
greatest in Enhydra and least in Spilogale and Mephitis.
Sample sizes for this ratio were the smallest in this study.
The length of the hindfoot relative to length of body is
greatest in Enhydra and Gulo. The hindfoot is shortest
relative to length of body in Mustela vison and Spilogale.
The long hindfoot of Gulo could be an adaptation to
sub-cursorial locomotion in this wide-ranging mustelid.
However, the size of hindfoot may be a reflection of the
large size and massiveness of Gulo compared to other
smaller mustelids. The long hindfoot of Enhydra may be a
function of the size of sea otters as well. Sea otters,
77
however, are not particularly adept at overland travel
(Kenyon, 1969; Tarasoff et al., 1972) and the long hindfoot
is most likely an adaptation to aquatic locomotion. The
relatively small hindfoot of Lutra correlates well with the
fact that more of the propulsive forces in river otters are
provided by the forelimb and tail than in sea otters
(Tarasoff et al., 1972). Indeed, terrestrial locomotion
is much more common in river otters than in sea otters. The
ratio of hindfoot length to body length in Lutra is more
similar to terrestrial mustelids than to Enhydra. The
smallest hindfeet in the Mustelidae belong to Spilogale,
Mustela frenata, Mustela vison, and Mustela nigripes, which
implies along the same line suggested for Gulo luscus that
little animals have relatively small feet.
Hindclaws
The hindclaws in the Mustelidae follow essentially the
same patterns described for the foreclaws (Fig. 18). In
skunks and badgers the hindclaws are much shorter than the
foreclaws. The structure of foreclaws and hindclaws is
very similar.
Tail
Ratio number 1, body length/total length documents, a
short tail in Taxidea, Gulo, and Enhydra. Long tails
characterize Lutra, Conepatus, and Mephitis. Short tails
are typical of fossorial mammals (Hildebrand, 1974; Shimer,
1903; Vaughan, 1978). Tarasoff et al. (1972) noted that
78
FIGURES 19-26
19) Dorsal aspect of pelvic girdles of twelve species of
Mustelidae, arrangement like that in Figure 1.
20) Lateral aspect of pelvic girdles of twelve species of
Mustelidae, arrangement like that in Figure 1.
21) Medial aspect of femora of twelve species of Mustelidae,
arrangement like that in Figure 1.
22) Posterior aspect of femora of twelve species of
Mustelidae, arrangement like that in Figure 1.
23) Anterior aspect of tibiae of twelve species of
Mustelidae, arrangement like that in Figure 1.
24) Lateral aspect of fibulae of twelve species of
Mustelidae, arrangement like that in Figure 1.
25) Anterior (left) and medial (right) aspects of calcanea
of twelve species of Mustelidae, arrangement like that
in Figure 1.
26) Dorsal aspect of tarsus and pes of eleven species of
Mustelidae, arrangement like that in Figure 1.
79
Fig. 19
80
Fig. 20
81
Fig. 21
82
Fig. 22
83
Fig. 23
84
Fig. 24
85
Fig. 25
86
Fig. 26
87
the tail was important in aquatic locomotion to both Lutra
and Enhydra. That information makes the short tail of
Enhydra somewhat enigmatic. The long bushy tail of skunks
is well known and serves more as a warning device than a
locomotor aid. The long tail of Martes pennanti is not
surprising in an arboreal runner and leaper (Hildebrand,
1974; Taylor, 1970). What is peculiar is the decidedly
shorter tail of the equally, if not more, arboreal Martes
americana (Powell, pers. comm.).
Figure 27 summarizes the results of Prim networks for
various aspects of the limb skeletons of thirteen species
of Mustelidae.
Prim networks show a strong similarity of form in the
limb skeletons of otters, badgers, and skunks. These three
subfamilies of the Mustelidae are particularly close with
regard to the forelimb skeleton and robusticity ratios. The
hindlimbs of otters are more reminiscent of members of the
genus Mustela than of skunks. Otters are always relatively
distant from whatever species they join in the networks.
Considering both limbs and robusticity, it is clear that
otters are closest to skunks and badgers. This similarity
in form and function between swimmers and diggers is not a
new observation (Gray, 1944, 1968; Hildebrand, 1974; Smith
and Savage, 1956). One interesting observation about otters
from the Prim networks is that in regard to forelimbs,
hindlimbs, and robusticity, Lutra canadensis, is more
distantly connected to other mustelids than is Enhydra
88
lutris. The implication is that Enhydra lutris, at least
regarding appendicular osteology, is more generalized than
Lutra canadensis.
89
FIGURE 27
Prim networks for males and females combined using thirteen
species and (A) twenty-six fore and hindlimb ratios;
(B) fifteen forelimb ratios; (C) nineteen hindlimb ratios;
(D) eleven robusticity ratios.
90
CONCLUSIONS
Taken as a whole my proposed sequences are borne out
by the data. However, there are some interesting divergences
between my predictions and my observations. Enhydra lutris
is not on the same continuum of locomotor specialization as
Mustela vison and Lutra canadensis. Enhydra is more aquatic,
and presumably more specialized for aquatic life, than
Lutra. Enhydra emphasizes different bone-muscle systems in
aquatic locomotion than Lutra or Mustela vison.
There are two problems with my proposed continua for
arboreal specialization. First, the species are not in
the appropriate order. Martes americana is, if anything,
a bit more specialized for arboreal life than Martes
pennanti or Eira. Second, arboreal and cursorial specializations are very similar in the Mustelinae. This statement
is demonstrated by the tendency of Martes, Eira, and Gulo
to group closely together in the majority of my ratios.
Gulo does have more pronounced cursorial adaptations (e.g.
increase in length, disproportionate increase in length of
distal limb elements) than other mustelids. Martes americana,
however, is nearly as specialized for running as Gulo, even
though Martes americana is a more arboreal mustelid; Eira
and Martes pennanti are intermediate between Mustela frenata
and Martes americana.
My data for skunks present some surprises. Skunks
have combined cursorial specializations (e.g. lengthening
92
of distal limb elements) and fossorial specializations (e.g.
robust skeletons, long claws, powerful forelimbs). This
combination of specializations suggests a lack of channelization to any particular mode of locomotion in skunks. In
oter words, skunks are more generalized in locomotor
tendencies with specializations characteristic of several
modes of locomotion.
The data for fossorial and aquatic locomotion (ignoring
for a moment Enhydra) provide strong support for my
proposed sequences. Mustela vison is intermediate between
Mustela frenata and Lutra. Mustela nigripes is intermediate between Mustela frenata and Taxidea.
The apparent similarity of form and function between
the skunks and badgers, and between the larger mustelines,
is probably at least partly a reflection of phylogenetic
closeness between the Mephitinae and the Melinae, and
between Martes, Gulo, and Eira (Anderson, 1970; Simpson,
1945; Winge, 1941). Still, there is little doubt in my
mind that the Prim networks, the drawings, and the statistical estimates of similarity reflect actual similarities
in mode of locomotion. My confidence is strengthened by
the following comparisons between New and Old World species.
Meles meles, the European badger, has generally similar
ratios to Taxidea taxus. The single specimen of Meles has
a longer, narrower scapula, a shorter humerus with wider
epicondyles, and a shorter ulna than Taxidea taxus. Meles
meles also have a longer pelvis, pubic symphysis, and ilium
93
than Taxidea taxus. Meles also has a slightly longer femur,
tibia, and hindfoot. Meles appears to be somewhat more
fossorial than Taxidea taxus.
Ratios for Mellivora sagulata (the ratel or honey
badger) are more similar to Taxidea taxus than Meles moles.
Ratios for Helectis moschata, the ferret badger, are intermediate between those for Taxidea taxus and Mustela nigripes.
Finally, the ratios for Arctonyx collaris, the hog badger,
are very close to those for both Taxidea taxus and Mellivora
sagulata.
The ratios for Amblonyx cinerea (the Oriental small
clawed otter) are more like Lutra canadensis than any other
North American mustelid. Amblonyx differs from Lutra in
having a shorter, wider scapula, a shorter humerus with
wider epicohdyles, a shorter ulna with a longer olecranon
process, and a radius that is wider distally. The pelvis
of Amblonyx is shorter than that of Lutra as is the tibia,
whereas the femur is a bit longer. The ratios of Pteronura
brasiliensis, (the giant otter of South America) are more
like Amblonyx than Lutra.
The ratios for Mustela putorius, the European polecat,
are similar to those for Mustela frenata, Mustela vison, and
Mustela nigripes which makes both functional and taxonomic
sense.
The implication to me, from my North American data and
the relatively scanty data on other mustelids, is that a
94
larger sample of mustelids worldwide would strengthen the
generality of my proposed sequences.
There clearly are different locomotor patterns among
species of Mustelidae. These locomotor patterns are
followed in type and degree by patterns of specialization
in the limb skeletons of the Mustelidae. Patterns of
specialization in the family are revealed by sampling North
American forms. The more cursorial forms show an increase
in the length of the limb bones, particularly the distal
limb bones, relative to more generalized species. Species
with cursorial (and arboreal) tendencies have longer bones
with rounder shafts compared to fossorial or aquatic species.
In mink and otters, and in black-footed ferrets and badgers,
there are progressive decreases in the length of long bones.
Mink and otters on one line, and black-footed ferrets and
badgers on another, show progressive increases in the length
of in-levers (olecranon process, calcaneus) and progressive
decreases in the length of out-levers (forearm, hindfoot)
compared to weasels. Certainly the specializations for
running in mustelids are not so pronounced as in ungulates
or even canids. Neither are fossorial adaptations as
pronounced as in moles, nor aquatic specializations as
spectacular as in pinnipeds. Trends are evident, however,
and to a considerable extent they appear to progress from
the hypothetical generalized condition observed in weasels.
Skunks appear to be quite generalized. Hall (1926)
noted that the muscular anatomy of Mephitis mephitis was
95
primitive (generalized?) compared to that of Martes which
he felt showed specializations for speed and agility.
Hall's view contradicts subsequent positions taken by Leach
(1976, 1977a, 1977b) and Ondrias (1961), who felt that the
anatomy of Martes was very generalized. When contrasted
to ungulates or dogs, the appendicular anatomy of martens
and fishers is generalized. In comparison to Mephitis, and
I presume other skunks as well, the opposite seems to be
true. The more or less central position of skunks in the
Prim networks suggests a generality in their limb skeletons,
although martens and fishers are often centrally located
in the networks as well.
Coefficients of variation were examined for all species
having samples of n>9 for all ratios (Appendix 6). The
most variable species for each of the 49 ratios was noted.
The number of instances in which each species exhibited the
highest coefficient of variation is as follows: Mustela
frenata, 4; Mustela vison, 5; Mustela nigripes, 0; Martes
americana, 1; Martes pennanti, 0; Eira Barbara, 1; Gulo
luscus, 0; Spilogale, 6; Mephitis mephitis, 16; Conepatus
mesoleucus, 0; Taxidea taxus, 6; Lutra canadensis, 2;
Enhydra lutris, 8.
A relative indication of variability at
the subfamilial level can be computed by dividing the number
of occurrences of the highest coefficient of variation in a
subfamily by the number of species examined in that subfamily.
Values for that computation are: Mustelinae, 1.57: Mephitinae,
7.33; Melinae, 6.0; Lutrinae, 5.0. This index suggests that
96
the Mephitinae are the most variable subfamily of mustelids
while the Mustelinae are the least. The variability in the
Mephitinae is actually underestimated in this calculation
because the sample of Conepatus mesoleucus is small
(n = 6); hence Conepatus was not scored although it has the
highest coefficient of variation in nine of the ratios. The
high coefficient of variation characteristic of skunks
suggests that they are generalized. I would argue that the
generalized limb skeletons of skunks and their variability
suggest that there are few selective pressures to be swift or
agile in skunks (particularly M. mephitis and C. mesoleucus)
compared to other mustelids.
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Appendix 1. -- Listing of specimens used for this study.
Specimens are arranged taxonomically and separated by
sex. Specimens of unknown sex are listed in a separate
column (?).
MUSTELIDAE
Mustelinae
MALES
FEMALES
?
TOTAL
goldmani
2
-
-
2
longicauda
1
-
-
1
munda
9
1
-
10
nevadensis
23
17
-
40
nigriauris
9
2
-
11
19
-
-
19
olivacea
4
2
-
6
primulina
2
-
-
2
other ssp.
-
1
-
1
69
23
0
92
7
-
-
7
aestuarina
16
5
-
21
energumenos
14
9
-
23
evagor
1
-
-
1
ingens
2
-
-
2
letifera
1
-
-
1
34
14
-
48
Mustela frenata
noveboracensis
Total
Mustela nigripes
subspecies
Mustela vison
Total
106
MALES
FEMALES
?
TOTAL
abietinoides
18
18
-
36
actuosa
18
-
-
18
caurina
13
7
-
20
1
-
-
1
21
5
-
26
1
-
-
1
72
30
-
102
columbiana
6
9
2
17
pacifica
4
4
2
10
pennanti
12
-
-
12
2
2
_
4
24
15
4
43
biologie
1
-
1
2
peruana
1
-
-
1
poliocephala
1
2
-
3
rara
1
-
-
1
senex
-
-
1
1
other ssp.
3
1
-
4
Total
7
3
2
12
Martes americana
humboldtensis
sierrae
vancouverensis
Total
Martes pennanti
other ssp.
Total
Eira barbara
107
MALES
FEMALES
?
TOTAL
luscus
15
8
1
24
luteus
1
2
-
3
16
10
1
27
amphialus
2
-
-
2
latifrons
21
2
-
23
microrhina
3
-
-
3
phenax
5
4
-
9
saxatilis
1
1
-
2
32
7
0
39
16
9
-
25
3
1
-
4
19
10
-
29
elata
-
1
-
1
TOTAL
51
18
0
69
Gulo luscus
Total
Mephitinae
Spilogale gracilis
Total
Spilogale putorius
interrupts
putorius
Total
Spilogale anguistifrons
108
MALES
FEMALES
?
16
11
-
27
elongata
2
-
-
2
estor
-
2
-
2
major
4
-
-
4
nigra
5
1
1
7
occidentalis
6
5
2
13
spissigrada
1
-
-
1
34
19
mearnsi
1
-
-
1
nicaraguae
1
1
-
2
sonorensis
1
1
-
2
other ssp.
1
-
____
1
_____
Total
4
2
0
6
7
-
-
7
taxus
17
-
-
17
Total
24
0
0
24
TOTAL
Mephitis mephitis
avia
Total
3 •
56
Conepatus mesoleucus
Melinae
Taxidea taxus
berlanderi
109
MALES
FEMALES
?
TOTAL
3
3
-
6
14
15
-
29
exeva
-
1
-
1
pacifica
2
-
-
2
periclyzomae
2
1
-
3
other ssp.
3
-
-
3
24
20
0
44
lutris
5
1
-
6
nereis
9
5
1
15
Total
14
6
1
21
-
1
-
1
-
1
-
1
Meles meles
-
1
-
1
Helectis moschata
1
-
-
1
Arctonyx collaris
1
-
-
1
Lutrinae
Lutra canadensis
brevipilosus
canadensis
Total
Enhydra lutris
Mustelinae
Mustela putorius
Mellivorinae
Mellivora sagulata
Melinae
110
MALES
FEMALES
?
TOTAL
Lutrinae
Amblonyx cinerea
1
Pteronura brasiliensis
1
Total Old World
3
Total North America
GRAND TOTAL
1
-
1
4
0
7
380
160
11
551
383
164
11
558
APPENDIX 2
CONTRIBUTING INSTITUTIONS
American Museum of Natural History (AMNH)
Mustela nigripes
1
Eira barbara
1
Martes pennanti
3
California Academy of Science (CAS)
Mephitis mephitis
3
Carnegie Museum of Natural History (CMNH)
Mustela frenata
19
Field Museum of Natural History (FMNH)
Eira barbara
3
Martes pennanti
2
Conepatus mesoleucus
2
Taxidea taxus
4
Humboldt State University MVZ (HSU)
Mustela frenata
1
Mustela putorius
1
Martes pennanti
1
Lutra canadensis
1
Enhydra lutris
1
Los Angeles County Museum of Natural History (LACMNH)
Eira barbara
1
112
(LACMNH)
Martes pennanti
3
Spilogale putorius
1
Conepatus mesoleucus
1
Taxidea taxus
5
Lutra canadensis
2
Michigan State University, the Museum (MSU)
Taxidea taxus
5
National Museum of Natural History (NMNH)
Mustela nigripes
2
Eira barbara
6
Martes pennanti
3
Gulo luscus
2
Enhydra lutris
1 -
Mellivora sagulata
1
Meles meles
1
Helectis moschata
1
Arctonyx collaris
1
Amblonyx cinerea
1
Pteronura brasiliensis
1
San Diego Natural History Museum (SDNHM)
Gulo luscus
2
University of California, Berkeley, MVZ (UCB)
Mustela frenata
71
Mustela vison
43
113
(UCB)
Mustela nigripes
3
Martes americana
58
Martes pennanti
12
Eira Barbara
1
Gulo luscus
9
Spilogale
28
Mephitis mephitis
20
Conepatus mesoleucus
3
Taxidea taxus
9
Lutra canadensis
Enhydra lutris
10
9
University of California, Los Angeles (UCLA)
Enhydra lutris
1
University of Kansas Museum of Natural History (KU)
Spilogale putorius
22
Mephitis mephitis
27
University of Michigan Museum of Zoology (UMich)
Martes americana
10
Martes pennanti
10
Gulo luscus
Lutra canadensis
8
28
University of Montana Department of Zoology (UMont)
Martes americana
21
Martes pennanti
9
114
(UMont)
Spilogale
18
University of Puget Sound, Puget Sound Museum of
Natural History (UPS)
Mustela frenata
1
Mustela vison
5
Martes americana
13
Gulo luscus
6
Taxidea taxus
1
Lutra canadensis
2
Enhydra lutris
6
Appendix 3. -- Groupings of samples for descriptive statistics. Groupings are listed
taxonomically and divided by sex and side.
RIGHT
Mustela frenata
males
LEFT
munda
munda
nevadensis
nevadensis
nigriauris
nigriauris
noveboracensis
both sexes
All subspecies
All subspecies
nevadensis
nevadensis
All subspecies
All subspecies
nevadensis
nevadensis
All save nev.
All save nev.
All subspecies
All subspecies
Mustela nigripes
males
All
All
Mustela vison
males
aestuarina
aestuarina
energumenos
energumenos
115
females
-
RIGHT
Mustela vison
males
females
both sexes
LEFT
ingens
All subspecies
aestuarina
aestuarina
energumenos
energumenos
All subspecies
All subspecies
aestuarina
aestuarina
energumenos
energumenos
All subspecies
All subspecies
abietinoides
abietinoides
116
All subspecies
Martes americana
males
actuosa
females
-
caurina
caurina
sierrae
sierrae
All save abi.
All save abi.
All subspecies
All subspecies
abietinoides
abietinoides
RIGHT
Martes americana
females
both sexes
males
caurina
-
sierrae
-
All save abi.
-
All subspecies
All subspecies
abietinoides
abietinoides
caurina
-
sierrae
-
All save abi.
All save abi.
All subspecies
All subspecies
columbiana
pacifica
pacifica
pennanti
-
All subspecies
females
-
columbiana
All subspecies
-
pacifica
pacifica
All subspecies
All subspecies
117
Martes pennanti
LEFT
RIGHT
Martes pennanti
Eira barbara
both sexes
LEFT
columbiana
-
pacifica
pacifica
pennanti
All subspecies
males
All subspecies
All subspecies
females
All subspecies
All subspecies
both sexes
All subspecies
All subspecies
males
luscus
luscus
All subspecies
All subspecies
118
All subspecies
Gulo luscus
females
both sexes
luscus
-
All subspecies
All subspecies
luscus
luscus
luteus
All subspecies
All subspecies
RIGHT
Spilogale gracilis
LEFT
latifrons
-
All subspecies
-
females
All subspecies
-
both sexes
latifrons
-
phenax
-
males
All subspecies
males
females
both sexes
Spilogale all species
interrupta
-
All subspecies
-
interrupta
-
All subspecies
-
interrupta
-
putorius
-
All subspecies
-
males
All subspecies
females
All subspecies
All subspecies
-
119
Spilogale putorius
RIGHT
LEFT
Spilogale all species
both sexes
All subspecies
-
Mephitis mephitis
males
avia
-
major
major
occidentalis
occidentalis
nigra
females
All subspecies
occidentalis
occidentalis
All subspecies
avia
occidentalis
nigra
Conepatus mesoleucus
All subspecies
occidentalis
-
All subspecies
All subspecies
males
All subspecies
All subspecies
females
All subspecies
both sexes
All subspecies
All subspecies
120
All subspecies
avia
both sexes
-
RIGHT
Taxidea taxus
Lutra canadensis
males
males
berlanderi
berlanderi
taxus
taxus
All subspecies
All subspecies
canadensis
All subspecies
females
canadensis
males
All subspecies
-
All subspecies
All subspecies
brevipilosus
brevipilosus
canadensis
Enhydra lutris
-
-
periclyzomae
periclyzomae
All subspecies
All subspecies
nereis
-
lutris
-
All subspecies
All subspecies
12 1
both sexes
LEFT
RIGHT
Enhydra lutris
females
nereis
All subspecies
both sexes
LEFT
All subspecies
nereis
-
lutris
-
All subspecies
All subspecies
122
Appendix 4. -- Groups of samples used to generate histograms
of frequency distributions for each ratio. Groups are
listed taxonomically. Groups are either entire
species samples or well represented subspecies. Groups
are also separated into males, females, and male +
females samples.
Mustela frenata
nevadensis only, males
nevadensis only, females
nevadensis only, males + females
noveboracensis only, males
all subspecies, males
all subspecies, females
all subspecies, males + females
Mustela vison
all subspecies, males
all subspecies, males + females
Martes americana
abietinoides only, males +
females
abietinoides + actuosa, males
abietinoides + actuosa, males +
females
all subspecies save abietinoides +actuos,mle
124
Martes americana
all subspecies save abietinoides
+ actuosa, males + females
all subspecies,
all
subspecies,female
males
sl subspecies,emales
all subspecies, males + females
Martes pennanti
all subspecies, males
all subspecies, males + females
Gulo luscus
all subspecies, males + females
Spilogale gracilis
all subspecies, males
all subspecies, males + females
Spilogale putorius
all subspecies, males
all subspecies, males + females
Spilogale gracilis + putorius all subspecies, males + females
Mephitis mephitis
avia only, males + females
all subspecies, males
all subspecies, males + females
Taxidea taxus
all subspecies, males
125
Lutra canadensis
canadensis only, males + females
all subspecies, males
all subspecies, males + females
Enhydra lutris
all subspecies, males + females
Appendix 5. -- Dimensions (number of species, number of
ratios) for Prim networks. Sexes were examined
separately and in a male + female sample. Prim networks
were generated for nine combinations of ratios. Those
nine combinations of ratios are the major subdivisions
of this appendix.
Number
of spp.
Number of ratios
NO SKULL
males + females
15,24
ratios: 1, 2, 3, 4, 5, 7, 8,
13,24
10, 14, 16, 18, 20, 21, 24,
11,24
25, 26, 27, 30, 31, 38, 39,
46, 49, 50.
15,24
males only
13,24
11,24
females only
13,24
11,24
LENGTH RATIOS
males + females
15,27
ratios: 5, 6, 9, 10, 12, 15,
13,27
16, 17, 19, 20, 22, 23, 25,
27, 28, 29, 30, 32, 37, 38,
40, 41, 44, 45, 46, 47, 48.
127
LENGTH RATIOS (cont.)
males
15,18
ratios:
6, 9, 12, 15, 17, 19,
males + females
13,18
22, 23, 28, 29, 32, 37, 40,
11,18
41, 44, 45, 47, 48.
15,18
males only
13,18
11,18
females only
13,18
11,18
FORELIMB RATIOS, NO SKULL
males + females
13,15
ratios:
5, 6, 9, 10, 11, 12,
13, 15, 16, 17, 19, 20, 22,
23, 25.
males + females
males only
ratios:
11,10
17, 19, 22, 23.
13,10
11,10
females only
6, 9, 11, 12, 13, 15,
13,10
11,10
128
FORELIMB LENGTHS
males + females
15,13
ratios:
5, 6, 9, 10, 12, 15,
13,13
16, 17, 19, 20, 22, 23, 25.
11,13
males + females
15,8
ratios:
13,8
22, 23.
6, 9, 12, 15, 17, 19,
11,8
15,8
males only
13,8
11,8
females only
13,8
11,8
HINDLIMB
males + females
males + females
27, 28, 29, 30, 32,
15,14
ratios:
13,14
37, 38, 40, 41, 44, 45, 46,
11,14
47, 48.
15,10
ratios:
13,10
41, 44, 45, 47, 48.
11,10
28, 29, 32, 37, 40,
129
HINDLIMB (cont.)
15,10
males only
13,10
11,10
females only
13,10
HINDLIMB RATIOS, NO SKULL
males + females
13,19
ratios:
27, 28, 29, 30, 32,
33, 34, 35, 36, 37, 40, 41,
42, 43, 44, 45, 46, 47, 48.
males + females
13,16
ratios:
11,16
35, 36,
28, 29, 32, 33, 34,
40, 41, 42, 43,
44, 45, 47, 48.
males only
13,16
11,16
females only
11,16
females only
11,16
130
ROBUSTICITY
males + females
15,11
ratios:
11, 12, 13, 23, 29,
13,11
33, 34, 35, 36, 42, 43.
11,11
15,11
males only
13,11
11,11
females only
13,11
11,11
SKULL ONLY
males + females
12,11
9,11
males only
ratios:
3, 4, 7, 8, 14, 18,
21, 24, 26, 31, 39.
11,11
9,11
females only
9,11
SIX SKULL RATIOS
males + females
15,6
ratios:
13,6
39.
11,6
9, 14, 18, 21, 31,
Appendix 6. -- Descriptive statistics for species comparisons
Range
Mean
SD
SE
n
CV
.003
65
3.676
1) Length of body/Total length
Mf
.57- .69
Mn
.639
.023
.761
1
My
.64- .69
.669
.014
.003
25
2.076
Ma
.64- .71
.769
.020
.003
35
2.915
Mp
.58- .63
.601
.021
.009
6
3.500
G1
.73- .81
.775
.026
.008
10
3.400
Eb
.602
1
S
.57- .73
.652
.046
.008
32
7.082
Mm
.43- .62
.544
.045
.011
17
8.250
Cm
.59- .60
.594
.005
.002
4
.802
Tt
.78- .86
.819
.025
.007
12
3.850
Lc
.59- .64
.623
.016
.005
12
2.521
El
.73- .79
.766
.020
.007
9
2.558
60
9.503
2) Length of hindfoot/Length of body
Mf
.15- .27
Mn
.178
.017
.002
.145
1
My
.15- .19
.174
.009
.002
24
4.890
Ma
.19- .24
.212
.014
.003
26
6.480
Mp
.19- .22
.203
.013
.006
5
6.563
G1
.21- .24
.224
.016
.006
7
6.951
Eb
.175
1
S
.14- .20
.167
.013
.002
31
7.920
Mm
.18- .31
.210
.032
.008
17
15.265
133
Range
Mean
SD
SE
n
CV
Cm
.19- .21
.196
.012
.006
4
6.031
Tt
.17- .20
.187
.011
.003
12
6.102
Lc
.12- .20
.176
.021
.006
12
12.218
El
.21- .25
.222
.011
.004
9
5.156
.002
61
8.188
3) Length of skull/Length of body
Mf
.17- .29
Mn
.191
.016
.171
1
My
.16- .18
.170
.005
.001
23
3.116
Ma
.18- .20
.191
.006
.001
32
3.161
Mp
.18- .20
.188
.007
.003
6
3.702
G1
.19- .21
.195
.006
.002
9
3.026
S
.18- .24
.201
.011
.002
30
5.533
Mm
.17- .32
.213
.035
.009
14
16.324
Cm
.18- .21
.186
.017
.009
4
9.290
Tt
.19- .22
.209
.009
.003
11
4.436
Lc
.15- .17
.157
.008
.002
12
5.205
El
.12- .14
.131
.006
.002
9
4.238
Eb
4) Length of scapula/Length of skull
Mf
.45- .54
.494
.019
.002
83
3.858
Mn
.53- .58
.544
.018
.007
6
3.223
My
.51- .62
.546
.024
.004
41
4.366
Ma
.48- .56
.524
.017
.002
79
3.291
Mp
.53- .66
.570
.029
.005
36
5.044
134
Range
Mean
SD
SE
n
CV
G1
.67- .71
.689
.016
.004
18
2.282
Eb
.57- .64
.609
.034
.013
7
5.578
S
.51- .63
.583
.025
.003
55
4.302
Mm
.64- .80
.704
.040
.006
48
5.633
Cm
.63- .84
.762
.074
.030
6
9.759
Tt
.55- .66
.616
.031
.007
18
5.014
Lc
.59- .69
.648
.027
.004
41
4.140
El
.79-1.00
.899
.049
.011
21
5.394
5) Length of scapula/Length of forelimb
Mf
.32- .37
.348
.009
.001
38
2.553
Mn
.35- .35
.354
.002
.001
3
.432
My
.35- .39
.368
.010
.002
16
2.669
Ma
.29- .32
.302
.007
.001
27
2.470
Mp
.30- .34
.316
.012
.002
27
3.660
G1
.31- .33
.320
.007
.002
8
2.203
Eb
.32- .34
.329
.006
.002
7
1.701
S
.36- .43
.387
.016
.003
26
4.124
Mm
.37- .45
.410
.019
.003
32
4.614
Cm
.374
1
Tt
.34- .40
.373
.019
.006
12
5.160
Lc
.41- .46
.439
.012
.003
22
2.833
El
.49- .54
.512
.016
.006
6
3.066
135
Range
Mean
SD
SE
n
CV
6) Height of scapula/Length of scapula
Mf
.48- .61
.531
.024
.003
86
4.446
Mn
.49- .54
.515
.017
.006
7
3.288
My
.50- .60
.564
.020
.003
38
3.568
Ma
.50- .60
.546
.019
.002
78
3.500
Mp
.49- .63
.574
.027
.004
42
4.727
G1
.57- .67
.604
.024
.005
27
3.937
Eb
.56- .62
.580
.016
.005
10
2.739
S
.35- .62
.559
.037
.005
60
6.611
Mm
.44- .64
.518
.039
.005
51
7.487
Cm
.50- .57
.532
.027
.010
7
5.089
Tt
.57- .68
.623
.031
.006
24
4.922
Lc
.57- .69
.619
.026
.004
37
4.193
El
.57- .71
.627
.038
.008
.21
0.138
7) Height of scapula/Length of skull
Mf
.22- .29
.263
.015
.002
81
5.858
Mn
.27- .29
.279
.008
.003
6
3.001
My
.26- .35
.307
.019
.003
34
6.186
Ma
.25- .31
.287
.014
.002
75
4.720
Mp
.27- .50
.330
.035
.006
35
G1
.38- .45
.415
.019
.004
20
4.584
Eb
.32- .37
.353
.017
.006
7
4.807
S
.28- .37
.329
.021
.003
55
6.404
Mm
.31- .41
.365
.025
.004
47
6.811
Cm
.34- .45
.409
.038
.015
6
9.185
136
Range
Mean
SD
SE
n
CV
Tt
.33- .41
.377
.025
.006
18
6.578
Lc
.34- .45
.402
.024
.004
38
5.900
El
.49- .63
.564
.045
.010
21
7.938
8) Length of humerus/Length of skull
Mf
.60- .73
.663
.024
.003
79
3.668
Mn
.70- .72
.710
.009
.004
6
1.282
My
.65- .75
.699
.026
.004
39
3.671
Ma
.66- .84
.782
.028
.003
78
3.557
Mp
.76- .91
.823
.024
.004
36
2.867
G1
.86- .97
.930
.025
.005
21
2.701
Eb
.83- .90
.866
.031
.011
8
3.548
S
.64- .76
.707
.027
.004
57
3.849
Mm
.75- .87
.800
.030
.004
48
3.710
Cm
.79- .89
.839
.034
.014
6
4.020
Tt
.69- .87
.757
.048
.011
18
6.344
Lc
.65- .76
.697
.025
.004
42
3.645
El
.77- .92
.846
.044
.010
21
5.183
9) Length of humerus/Length of scapula
Mf
1.24-1.45
1.342
.040
.004
82
2.969
Mn
1.29-1.34
1.317
.020
.008
7
1.537
My
1.20-1.38
1.290
.035
.005
42
2.699
Ma
1.30-1.55
1.488
.035
.004
81
2.327
Mp
1.30-1.55
1.447
.051
.008
43
3.517
G1
1.24-1.42
1.358
.037
.007
27
2.729
139
Range
Mean
SD
SE
n
CV
13) Ellipticity of humerus
Mf
.65- .96
.799
.058
.006
89
7.282
Mn
.74- .90
.829
.055
.021
7
6.661
My
.63- .84
.730
.054
.008
47
7.338
Ma
.71- .95
.856
.049
.005
84
5.746
Mp
.71- .92
.811
.048
.007
43
5.890
G1
.70- .86
.775
.039
.007
28
5.014
Eb
.74- .89
.815
.057
.017
11
7.037
S
.60- .86
.699
.056
.007
62
8.051
Mm
.53- .85
.639
.058
.008
53
9.074
Cm
.52- .64
.576
.041
.016
7
7.199
Tt
.66- .84
.734
.043
.009
24
5.922
Lc
.50- .69
.574
.039
.006
42
6.748
El
.49- .65
.576
.044
.010
21
7.634
14) Length of ulna/Length of skull
Mf
.54- .65
Mn
.600
.025
.003
78
4.168
.681
.001
.001
2
.208
My
.58- .74
.654
.031
.005
39
4.705
Ma
.68- .82
.756
.031
.004
69
4.128
Mp
.78- .91
.819
.021
.004
34
2.537
G1
.91-1.01
.973
.025
.005
22
2.577
Eb
.82- .88
.844
.022
.008
7
2.623
S
.64- .76
.713
.026
.004
52
3.639
Mm
.77- .93
.846
.028
.004
45
3.346
Cm
.86- .97
.918
.034
.014
6
3.650
140
Range
Mean
SD
SE
n
CV
Tt
.81- .95
.864
.038
.009
17
4.415
Lc
.65- .76
.704
.023
.004
39
3.232
El
.80- .98
.872
.044
.010
20
5.054
15) Length of ulna/Length of humerus
Mf
.86- .95
.903
.020
.002
81
2.225
Mn
.95- .99
.971
.024
.014
3
2.428
My
.81- .97
.930
.027
.004
39
2.867
Ma
.92-1.01
.956
.022
.003
73
2.304
Mp
.96-1.07
.998
.021
.003
41
2.101
Gl
1.01-1.15
1.049
.026
.005
28
2.521
Eb
.94- .99
.968
.016
.005
10
1.639
S
.96-1.08
1.011
.021
.003
57
2.067
Mm
1.01-1.13
1.061
.028
.004
49
2.683
Cm
1.05-1.12
1.094
.024
.010
6
2.210
Tt
1.04-1.19
1.146
.034
.007
22
2.983
Lc
.93-1.06
1.009
.024
.004
39
2.412
El
1.00-1.06
1.034
.016
.004
20
1.569
16) Length of ulna/Length of forelimb
Mf
.41- .44
.428
.006
.001
38
1.407
Mn
.45- .46
.449
.005
.003
3
1.142
My
.40- .44
.431
.009
.002
17
2.095
Ma
.40- .45
.438
.009
.002
28
1.945
Mp
.44- .46
.452
.004
.001
27
.946
G1
.46- .46
.459
.002
.001
9
.361
141
Range
Mean
SD
SE
n
CV
Eb
.44- .46
.452
.006
.002
7
1.372
S
.40- .51
.459
.031
.006
27
6.771
Mm
.40- .50
.477
.034
.006
32
7.045
Cm
.510
1
Tt
.51- .54
.530
.010
.003
12
1.907
Lc
.45- .50
.469
.010
.002
22
2.041
El
.48- .50
.492
.006
.003
6
1.249
17)Length of olecranon process/Length of ulna
Mf
.11- .17
.146
.012
.001
84
8.100
Mn
.17- .18
.171
.006
.004
3
3.566
My
.14- .20
.162
.011
.002
43
6.731
Ma
.11- .14
.121
.007
.001
74
5.891
Mp
.11- .14
.127
.007
.001
41
5.779
G1
.10- .14
.120
.009
.002
28
7.311
Eb
.12- .15
.129
.011
.003
10
8.230
S
.13- .17
.150
.008
.001
57
5.347
Mm
.13- .18
.163
.011
.002
50
6.585
Cm
.21- .23
.218
.011
.005
6
5.276
Tt
.21- .24
.222
.011
.002
22
4.828
Lc
.19- .25
.215
.016
.003
39
7.367
El
.13- .16
.146
.008
.002
20
5.449
18)Length of ulna minus length of olecranon process/Length
of skull
Mf
.46- .57
.512
.025
.003
78
4.815
142
Range
Mean
SD
SE
n
CV
Mn
.56- .57
.564
.007
.005
2
1.254
My
.46- .61
.547
.028
.005
39
5.138
Ma
.60- .73
.664
.030
.004
69
4.535
Mp
.68- .78
.717
.021
.004
34
2.866
G1
.80- .90
.857
.026
.006
22
3.082
Eb
.70- .77
.734
.025
.009
7
3.403
S
.53- .65
.607
.024
.003
52
3.965
Mm
.65- .79
.709
.028
.004
45
3.889
Cm
.67- .76
.718
.033
.013
6
4.457
Tt
.63- .74
.670
.033
.008
17
4.890
Lc
.46- .60
.550
.026
.004
39
4.759
El
.68- .83
. 47
.038
.008
20
5.044
19) Length of ulna minus length of olecranon process/Length
of humerus
Mf
.73- .81
.771
.020
.002
81
2.625
Mn
.78- .82
.804
.025
.014
3
3.820
My
.65- .82
.778
.029
.005
39
3.729
Ma
.81- .91
.848
.025
.003
73
2.961
Mp
.83- .95
.871
.023
.004
41
2.607
G1
.88- .95
.920
.019
.004
28
2.065
Eb
.82- .86
.843
.014
.004
10
1.629
S
.80- .92
.860
.020
.003
57
2.267
Mm
.84-1.03
.889
.033
.005
49
3.748
Cm
.83- .89
.857
.026
.011
6
3.093
Tt
.83- .93
.889
.026
.006
22
2.975
143
Range
Mean
SD
SE
n
CV
Lc
.64- .84
.789
.035
.006
39
4.480
El
.86- .91
.883
.015
.003
20
1.641
20) Length of ulna minus length of olecranon process/Length
of forelimb
Mf
.35- .44
.394
.033
.005
38
8.326
Mn
.37- .38
.373
.006
.004
3
1.640
My
.32- .37
.361
.010
.003
17
2.888
Ma
.37- .40
.387
.006
.001
28
1.508
Mp
.38- .41
.394
.005
.001
27
1.311
G1
.40- .41
.404
.003
.001
9
.743
Eb
.39- .40
.395
.003
.001
7
.758
S
.38- .43
.403
.010
.002
27
2.524
Mm
.40- .43
.411
.006
.001
32
.1.452
Cm
.393
1
Tt
.40- .43
.410
.008
.002
12
1.850
Lc
.32- .38
.366
.013
.003
22
3.490
El
.42- .43
.419
.004
.001
6
.865
21) Length of radius/Length of skull
Mf
.43- .52
.471
.021
.002
77
4.512
Mn
.51- .53
.522
.013
.010
2
2.576
My
.45- .54
.500
.021
.003
40
4.281
Ma
.56- .68
.619
.028
.003
68
4.502
Mp
.64- .74
.672
.018
.003
34
2.710
G1
.75- .83
.797
.021
.004
22
2.598
144
Range
Mean
SD
SE
CV
n
Eb
.65- .72
.681
.026
.009
8
3.815
S
.50- .61
.569
.023
.003
52
3.993
Mm
.62- .74
.675
.025
.004
46
3.642
Cm
.64- .73
.696
.033
.013
6
4.745
Tt
.61- .70
.647
.025
.006
17
3.817
Lc
.48- .54
.514
.016
.003
40
3.113
El
.63- .73
.679
.031
.003
19
4.576
22) Length of radius/Length of humerus
Mf
.67- .75
.709
.018
.002
81
2.526
Mn
.73- .76
.744
.015
.008
3
1.958
My
.67- .75
.712
.016
.003
40
2.270
Ma
.75- .84
.793
.022
.003
72
2.818
Mp
.78- .87
.818
.019
.003
41
2.356
G1
.83- .89
.856
.015
.003
28
1.749
Eb
.76- .81
.787
.017
.005
11
2.126
S
.77- .86
.807
.020
.003
57
2.494
Mm
.81- .90
.846
.023
.003
50
2.690
Cm
.80- .85
.832
.019
.007
7
2.328
Tt
.77- .90
.863
.026
.006
22
3.029
Lc
.71- .77
.739
.018
.003
40
2.387
El
.77- .83
.807
.015
.003
19
1.877
23) Distal width of radius/Length of radius
Mf
.14- .81
.178
.011
.001
81
6.442
Mn
.19- .20
.196
.005
.003
3
2.297
145
Range
Mean
SD
SE
n
CV
My
.15- .23
.194
.014
.002
44
7.065
Ma
.15- .18
.164
.007
.001
73
4.086
Mp
.15- .23
.166
.013
.002
41
7.724
G1
.18- .21
.195
.008
.001
29
4.043
Eb
.18- .22
.200
.017
.005
11
8.322
S
.17- .23
.194
.013
.002
57
6.442
Mm
.18- .23
.202
.012
.002
51
5.992
Cm
.20- .24
.211
.015
.006
7
6.925
Tt
.22- .26
.232
.011
.002
22
4.908
Lc
.21- .25
.234
.011
.002
40
4.509
El
.18- .23
.207
.012
.003
19
6.003
24) Length of third metacarpal/Length of skull
Mf
.19- .26
.224
.013
.002
39
5.614
Mn
.25- .26
.253
.004
.003
3
1.723
My
.23- .27
.250
.014
.003
19
5.618
Ma
.26- .31
.284
.012
.002
28
4.303
Mp
.26- .30
.277
.010
.002
21
3.637
G1
.31- .33
.323
.006
.003
5
1.893
Eb
.23- .27
.250
.016
.008
4
6.258
S
.19- .25
.207
.014
.003
25
6.979
Mm
.19- .23
.211
.011
.002
32
5.213
Cm
.237
1
Tt
.19- .22
.205
.007
.002
9
3.595
Lc
.24- .26
.248
.007
.002
22
2.866
El
.17- .20
.187
.012
.005
6
6.153
146
Range
Mean
SD
SE
n
CV
25) Length of third metacarpal/Length of forelimb
Mf
.15- .17
.159
.005
.001
38
3.314
Mn
.16- .17
.164
.003
.002
3
1.956
.16- .19
.170
.007
.002
17
3.893
Ma
.15- .17
.162
.004
.001
28
2.242
Mp
.14- .17
.153
.005
.001
27
3.251
G1
.15- .17
.154
.007
.002
9
4.706
Eb
.13- .14
.137
.004
.002
7
3.111
S
.13- .16
.136
.007
.001
27
4.866
Mm
.11- .14
.122
.006
.001
32
5.167
Mv
Cm
.140
1
Tt
.11- .14
.123
.007
.002
12
5.631
Lc
.15- .17
.165
.005
.001
22
3.081
El
.10- .11
.105
.004
.002
6
3.929
26) Length of pelvis/Length of skull
Mf
.52- .67
.599
.028
.003
82
4.647
Mn
.68- .69
.682
.009
.004
5
1.298
My
.64- .76
.702
.028
.004
43
4.035
Ma
.57- .73
.656
.030
.003
97
4.541
Mp
.71- .82
.741
.025
.004
35
3.307
G1
.82- .90
.863
.019
.004
20
2.173
Eb
.71- .85
.794
.040
.015
7
4.999
S
.63- .83
.744
.043
.005
62
5.729
Mm
.85-1.00
.911
.032
.005
48
3.544
Cm
.85-1.07
1.009
.084
.035
6
8.282
147
Range
Mean
SD
SE
n
CV
Tt
.74- .85
.789
.034
.008
17
4.343
Lc
.89-1.09
1.001
.053
.008
43
5.340
El
1.25-1.50
1.397
.061
.014
20
4.396
27)Length of pelvis/Length of hindlimb
Mf
.31- .35
.330
.009
.001
42
2.797
Mn
.37- .38
.378
.008
.004
3
1.987
My
.34- .47
.389
.041
.010
18
10.498
Ma
.27- .31
.293
.010
.002
40
3.243
Mp
.31- .35
.330
.010
.002
27
3.159
G1
.35- .38
.365
.012
.003
13
3.302
Eb
.34- .39
.360
.020
.009
5
5.682
S
.37- .43
.403
.013
.002
31
3.213
Mm
.38- .45
.421
.015
.003
33
3.591
1
.416
Cm
Tt
.45- .49
.473
.012
.004
9
2.598
Lc
.48- .55
.525
.020
.004
27
3.765
El
.56- .58
.568
.006
.002
7
.998
28)Length of pubic symphysis/Length of pelvis
Mf
.22- .34
2.81
.019
.002
86
6.622
Mn
.24- .27
.260
.011
.005
6
4.304
Mv
.19- .27
.231
.023
.005
23
9.857
Ma
.27- .37
.328
.021
.003
53
6.268
Mp
.21- .33
.307
.025
.005
23
8.169
G1
.24- .28
.254
.013
.003
16
5.296
148
Range
Mean
SD
SE
n
CV
Eb
.29- .34
.314
.016
.006
8
5.076
S
.10- .19
.142
.022
.003
42
15.722
Mm
.06- .11
.092
.012
.002
37
12.870
Cm
.09- .12
.104
.012
.005
6
11.238
Tt
.11- .15
.127
.010
.002
22
7.655
Lc
.16- .20
.180
.017
.008
5
9.421
El
.16- .24
.213
.022
.008
16
10.155
29)Preacetabular length of pelvis/Length of pelvis
Mf
.50- .57
.541
.015
.002
88
2.685
Mn
.53- .55
.542
.006
.002
6
1.116
Mv
.50- .59
.529
.017
.002
47
3.220
Ma
.50- .55
.523
.011
.001
102
2.113
Mp
.50- .57
.539
.016
.002
41
2.886
G1
.48- .54
.520
.013
.002
27
2.428
Eb
.50- .54
.522
.014
.004
10
2.706
S
.48- .57
.527
.016
.002
66
3.008
Mm
.50- .76
.573
.033
.004
54
5.762
Cm
.51- .57
.539
.019
.008
6
3.592
Tt
.47- .50
.487
.009
.002
23
1.917
Lc
.42- .45
.438
.009
.001
43
2.138
El
.43- .48
.448
.011
.003
20
2.569
62
6.289
30)Length of femur/Length of hindfoot
Mf
Mn
.62- .86
.754
.875
.047
.006
1
149
Range
Mean
SD
SE
n
CV
My
.69- .83
.733
.032
.006
24
4.340
Ma
.72- .90
.778
.046
.009
25
5.881
Mp
.78- .90
.811
.043
.018
6
5.295
G1
.76- .92
.844
.067
.025
7
7.968
Eb
.987
1
S
.83-1.20
.942
.077
.013
35
8.137
Mm
.87-1.02
.936
.043
.010
17
4.587
Cm
.95-1.01
.991
.030
.015
4
3.024
Tt
.74- .99
.882
.100
.032
10
11.373
Lc
.57- .63
.603
.023
.007
12
3.825
El
.47- .54
.504
.022
.008
8
4.336
31) Length of femur/Length of skull
Mf
.64- .80
.706
.034
.004
82
4.771
Mn
.73- .90
.809
.078
.030
7
9.684
My
.66- .86
.750
.036
.006
41
4.820
Ma
.79- .93
.872
.028
.003
95
3.195
Mp
.83- .99
.913
.028
.005
35
3.118
Gl
.93-1.02
.983
.021
.005
21
2.148
Eb
.84-1.03
.954
.066
.022
9
6.926
S
.71- .88
.794
.034
.004
64
4.271
Mm
.86-1.02
.925
.036
.005
47
3.849
Cm
.89-1.06
.999
.058
.024
6
5.829
Tt
.73- .86
.783
.036
.009
17
4.574
Lc
.66- .77
.706
.028
.004
44
3.946
E1
.77- .94
.852
.043
.009
21
5.076
150
Range
Mean
SD
SE
n
CV
32) Length of femur/Length of hindlimb
Mf
.38- .40
.392
.005
.001
42
1.264
Mn
.41- .42
.411
.004
.002
4
.888
My
.38- .40
.393
.005
.001
20
1.327
Ma
.38- .41
.394
.007
.001
40
1.811
Mp
.40- .41
.402
.004
.001
28
.891
G1
.42- .43
.422
.004
.001
13
.835
Eb
.42- .45
.440
.013
.005
6
2.960
S
.42- .44
.427
.005
.001
31
1.263
Mm
.42- .44
.428
.006
.001
33
1.412
Cm
.43- .43
.433
.001
.001
2
.327
Tt
.46- .48
.471
.004
.001
9
.769
Lc
.36- .37
.364
.005
.001
27
1.246
El
.33- .36
.340
.011
.004
9
3.137
33) Anteroposterior width of femoral condyles/Mediolateral
width of femoral condyles
Mf
.72- .96
.871
.041
.004
89
4.716
Mn
.82- .94
.866
.042
.016
7
4.823
My
.82- .96
.895
.034
.005
44
3.755
Ma
.74- .93
.844
.035
.004
101
4.178
Mp
.76- .95
.863
.032
.005
42
3.684
G1
.77- .90
.833
.032
.006
28
3.812
Eb
.74- .92
.803
.046
.014
11
5.772
S
.70- .89
.792
.043
.005
68
5.371
Mm
.74- .93
.827
.033
.004
53
3.951
151
Range
Mean
SD
SE
n
CV
Cm
.75- .94
.807
.062
.023
7
7.634
Tt
.76- .89
.827
.033
.007
22
3.988
Lc
.79- .91
.837
.030
.005
43
3.570
El
.79- .93
.877
.029
.007
20
3.324
34)Mediolateral width of femoral condyles/Length of femur
Mf
.18- .22
.198
.009
.001
89
4.595
Mn
.20- .21
.205
.003
.001
7
1.704
My
.21- .26
.223
.012
.002
45
5.317
Ma
.17- .20
.182
.006
.001
101
3.181
Mp
.17- .21
.188
.007
.001
42
3.948
G1
.20- .24
.217
.011
.002
28
4.959
Eb
.18- .23
.198
.016
.005
11
7.996
S
.19- .24
.208
.012
.001
68
5.808
Mm
.20- .26
.225
.012
.002
53
5.366
Cm
.21- .25
.225
.014
.005
7
6.447
Tt
.22- .26
.235
.010
.002
22
4.325
Lc
.27- .32
.297
.012
.002
43
4.067
El
.29- .35
.310
.016
.003
21
5.168
35)Anteroposterior width of femoral condyles/Length of femur
Mf
.14- .19
.173
.009
.001
89
4.936
Mn
.17- .19
.178
.008
.003
7
4.241
My
.17- .24
.199
.010
.002
44
5.247
Ma
.14- .18
.154
.007
.001
100
4.242
Mp
.14- .18
.162
.007
.001
42
4.380
152
Range
Mean
SD
SE
n
CV
G1
.17- .20
.180
.009
.002
28
4.742
Eb
.14- .20
.160
.020
.006
11
12.527
S
.15- .18
.164
.008
.001
68
4.573
Mm
.16- .21
.186
.010
.001
53
5.497
Cm
.17- .21
.181
.019
.007
7
10.294
Tt
.18- .21
.194
.008
.002
22
4.354
Lc
.23- .28
.248
.010
.002
43
4.110
El
.24- .31
.271
.014
.003
21
5.051
36) Ellipticity of femur
Mf
.75- .96
.867
.043
.005
90
4.942
Mn
.74- .82
.784
.023
.009
7
2.958
My
.73- .96
.835
.047
.007
46
5.637
Ma
.79- .95
.877
.031
.003
102
3.510
Mp
.86- .97
.926
.021
.003
42
2.313
G1
.86- .95
.913
.024
.005
28
2.649
Eb
.78- .91
.857
.039
.011
12
4.587
S
.68- .88
.781
.047
.006
68
6.041
Mm
.63- .91
.821
.054
.007
53
6.553
Cm
.73- .92
.816
.075
.028
7
9.234
Tt
.71- .88
.815
.051
.011
23
6.302
Lc
.68- .88
.783
.046
.007
43
5.932
El
.68- .81
.749
.041
.009
21
5.435
153
Range
Mean
SD
SE
CV
n
37) Length of tibia minus length of medial malleolus/Length
of tibia
Mf
.93- .98
.952
.007
.001
82
.698
Mn
.93- .95
.994
.006
.003
6
.679
My
.90- .95
.941
.009
.001
46
.934
Ma
.95- .97
.959
.004
.000
92
.456
Mp
.94- .97
.953
.005
.001
40
.503
G1
.95- .97
.954
.007
.001
29
.717
Eb
.95- .96
.955
.005
.001
11
.487
S
.94- .97
.952
.007
.001
65
.736
Mm
.94- .97
.953
.007
.001
51
.755
Cm
.93- .96
.947
.009
.003
7
.975
Tt
.88- .96
.939
.014
.003
23
1.499
Lc
.92- .95
.937
.007
.001
43
.727
El
.91- .94
.926
.007
.002
21
.293
55
5.866
38) Length of tibia/Length of hindfoot
Mf
.67- .92
Mn
.824
.048
.007
1
.891
My
.77- .91
.812
.030
.006
23
3.680
Ma
.76-1.01
.839
.054
.011
25
6.407
Mp
.82- .96
.872
.051
.021
6
5.861
G1
.24- .91
.839
.063
.024
7
7.495
Eb
1
.923
S
.85-1.20
.961
.078
.013
34
8.139
Mm
.93-1.06
.992
.042
.010
17
4.186
154
Range
Mean
SD
SE
n
CV
Cm
.96-1.01
.974
.026
.013
4
2.703
Tt
.61- .85
.749
.074
.022
11
9.893
Lc
.71- .78
.747
.023
.007
12
3.142
El
.61- .69
.649
.025
.008
9
3.908
39) Length of tibia/Length of skull
Mf
.70- .85
.772
.035
.004
74
4.564
Mn
.76- .77
.763
.005
.002
5
.664
My
.75- .94
.829
.034
.005
42
4.101
Ma
.85-1.03
.951
.037
.004
88
3.859
Mp
.92-1.07
.968
.027
.005
33
2.839
G1
.91-1.02
.966
.025
.005
22
2.564
Eb
.88- .97
.926
.036
.013
8
3.840
S
.73- .90
.814
.037
.005
60
4.581
Mm
.89-1.07
.969
.040
.006
46
4.077
Cm
.90-1.07
1.014
.060
.025
6
5.966
Tt
.60- .73
.653
.033
.008
18
5.007
Lc
.82- .93
.872
.025
.004
43
2.907
El
.99-1.18
1.091
.050
.011
21
4.624
40) Length of tibia/Length of femur
Mf
1.03-1.14
1.092
.023
.003
81
2.103
Mn
1.01-1.04
1.027
.013
.005
6
1.311
My
1.07-1.17
1.106
0.22
.003
44
1.984
Ma
1.01-1.13
1.089
.024
.002
92
2.176
Mp
1.03-1.10
1.065
.016
.002
40
1.464
155
Range
Mean
SD
SE
n
CV
Gl
.96-1.03
.983
.015
.003
28
1.541
Eb
.91-1.07
.967
.052
.017
10
5.405
S
.98-1.08
1.026
.022
.003
65
2.171
Mm
1.01-1.11
1.049
.022
.003
50
2.143
Cm
1.00-1.05
1.020
.019
.007
7
1.858
Tt
.81- .87
8.34
.014
.003
21
1.699
Lc
1.17-1.31
1.240
.027
.004
43
2.196
El
1.18-1.33
1.282
.034
.007
21
2.615
41) Length of tibia/Length of hindlimb
Mf
.39- .47
.415
.020
.003
42
4.869
Mn
.42- .43
.422
.008
.002
4
.895
My
.42- .44
.432
.005
.001
20
1.062
Ma
.41- .45
.431
.007
.001
40
1.686
Mp
.42- .44
.430
.004
.001
28
.894
G1
.41- .42
.415
.002
.001
13
.506
Eb
.41- .44
.421
.012
.005
6
2.773
S
.42- .46
.442
.006
.001
31
1.366
Mm
.43- .46
.446
.005
.001
33
1.148
Cm
.44- .46
.446
.013
.009
2
2.854
Tt
.39- .40
.393
.005
.002
9
1.180
Lc
.44- .48
.452
.008
.001
27
1.709
El
.43- .44
.433
.005
.002
9
1.065
156
Range
Mean
SD
SE
n
CV
42) Anteroposterior width of head of tibia/Mediolateral
width of head of tibia
Mf
.79- .95
.868
.031
.003
90
3.601
Mn
.85- .94
.880
.034
.013
7
3.851
My
.77- .93
.862
.035
.005
47
4.038
Ma
.77- .90
.838
.027
.003
95
3.281
Mp
.82- .93
.878
.023
.004
42
2.611
G1
.88-1.01
.933
.031
.006
29
3.279
Eb
.79- .91
.840
.037
.011
12
4.453
S
.74- .90
.821
.037
.005
64
4.472
Mm
.77- .90
.841
.030
.004
53
3.571
Cm
.81- .90
.853
.029
.011
7
3.372
Tt
.89- .92
.851
.034
.007
23
4.005
Lc
.66- .80
.746
.033
.005
42
4.376
El
.65- .85
.782
.039
.008
21
4.936
43) Ellipticity of tibia
Mf
.54- .95
.694
.071
.008
89
10.250
Mn
.70- .76
.731
.024
.009
7
3.283
My
.67- .89
.775
.050
.007
47
6.458
Ma
.63- .90
.783
.053
.005
95
6.724
Mp
.70- .83
.773
.036
.006
40
4.647
G1
.67- .82
.742
.044
.008
29
5.945
Eb
.70- .83
.777
.043
.013
11
5.482
S
.55- .92
.749
.080
.010
65
10.706
Mm
.59- .85
.707
.061
.008
52
8.660
157
Range
Mean
SD
SE
n
CV
Cm
.70- .79
.752
.042
.016
7
5.651
Tt
.57- .73
.651
.038
.008
23
5.769
Lc
.53- .72
.624
.047
.007
43
7.511
El
.54- .78
.671
.062
.013
21
9.186
44)Length of fibula/Length of tibia
Mf
.87- .96
.919
.012
.001
78
1.343
Mn
.70- .91
.816
.110
.049
5
13.441
My
.72- .93
.894
.047
.007
42
5.257
Ma
.92- .96
.936
.008
.001
91
.833
Mp
.89-1.00
.924
.017
.003
39
1.811
G1
.87- .94
.918
.014
.003
28
1.488
Eb
.91- .94
.924
.010
.003
10
1.032
S
.87- .99
.928
.021
.003
64
2.231
Mm
.87- .94
.913
.012
.002
43
1.331
Cm
.89- .94
.910
.017
.006
7
1.869
Tt
.86- .93
.894
.018
.004
20
2.008
Lc
.87- .91
.890
.010
.002
39
1.152
El
.85- .89
.870
.012
.003
20
1.368
45)Postastragalar length of calcaneus/Length of third
metatarsal
Mf
.28- .37
.337
.021
.003
43
6.252
Mn
.40- .48
.432
.034
.017
4
7.794
My
.38- .53
.439
.040
.009
21
9.159
Ma
.33- .41
.359
.018
.003
40
5.084
158
Range
Mean
SD
SE
n
CV
Mp
.38- .48
.411
.022
.004
27
5.246
G1
.51- .60
.551
.025
.007
13
4.463
Eb
.45- .56
.509
.036
.013
8
7.065
S
.48- .64
.537
.035
.007
25
6.464
Mm
.55- .77
.646
.046
.008
34
7.064
Cm
.69- .73
.709
.028
.019
2
3.887
Tt
.62- .74
.700
.036
.011
10
5.571
Lc
.47- .58
.503
.024
.005
27
4.854
El
.32- .37
.347
.013
.004
9
3.867
46) Postastragalar length of calcaneus/Length of hindfoot
Mf
.10- .14
Mn
.117
.009
.001
.155
40
7.641
1
My
.13- .17
.142
.010
.002
22
7.267
Ma
.12- .15
.128
.009
.002
19
7.083
Mp
.13- .16
.145
.012
.005
6
8.059
G1
.16- .21
.185
.020
.008
7
11.043
Eb
.136
1
S
.14- .20
.161
.018
.005
13
11.406
Mm
.18- .20
.185
.009
.003
10
4.678
Cm
.17- .19
.178
.009
.005
3
4.993
Tt
.16- .20
.183
.012
.004
11
6.815
Lc
.14- .23
.162
.023
.007
12
13.973
El
.10- .13
.117
.006
.002
9
5.445
159
Range
Mean
SD
SE
n
CV
47)Postastragalar length of calcaneus/Length of hindlimb
Mf
.05- .07
.061
.004
.001
42
6.560
Mn
.07- .08
.072
.005
.002
4
6.529
My
.07- .09
.076
.006
.001
20
8.290
Ma
.06- .07
.064
.003
.000
40
3.946
Mp
.06- .08
.068
.003
.001
28
4.798
G1
.08- .10
.090
.003
.001
13
3.334
Eb
.06- .08
.070
.006
.002
6
8.132
S
.07- .08
.071
.004
.001
25
6.217
Mm
.06- .09
.077
.009
.002
33
11.281
Cm
.08- .09
.086
.004
.003
2
4.933
Tt
.08- .10
.095
.006
.002
9
6.413
Lc
.09- .10
.094
.003
.001
27
3.294
El
.07- .08
.078
.003
.001
9
4.219
48)Length of third metatarsal/Length of hindlimb
Mf
.17- .19
.180
.006
.001
42
3.224
Mn
.16- .17
.167
.003
.002
4
1.914
My
.17- .18
.174
.005
.001
20
2.587
Ma
.17- .19
.177
.005
.001
40
2.935
Mp
.16- .18
.168
.004
.001
28
2.314
G1
.16- .17
.163
.004
.001
13
2.199
Eb
.13- .15
.139
.005
.002
6
3.344
S
.13- .14
.131
.004
.001
31
2.965
Mm
.12- .14
.127
.005
.001
33
3.967
Cm
.11- .13
.121
.011
.008
2
9.350
160
Range
Mean
SD
SE
n
CV
Tt
.13- .15
.136
.006
.002
9
4.293
Lc
.17- .19
.186
.006
.001
27
2.980
El
.21- .24
.225
.011
.004
9
4.769
49) Length of hindfoot/Length of hindlimb
.48- .59
.529
.076
.006
23
5.132
My
.48- .55
.523
.021
.007
10
3.985
Ma
.52- .53
.524
.007
.004
4
1.397
Mp
.44- .51
.475
.044
.031
2
9.230
Mf
Mn
G1
.564
1
Eb
.452
1
S
.39- .49
.453
.029
.009
11
6.328
Mm
.42- .48
.449
.022
.009
6
4.835
Tt
.49- .64
.543
.058
.026
5
10.760
Lc
.39- .60
.535
.097
.048
4
18.071
El
.65- .69
.675
.022
.011
4
3.212
Cm