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Dinosaur Trackway Analysis
Objectives:
1. To apply the procedures used to analyze dinosaur track ways
2. To examine dinosaur tracks to determine speed of movement
Introduction
The study of dinosaur tracks is yielding considerable information regarding the
behavior of dinosaurs. To date, thousands of dinosaur track way sites have been found,
and their examination has produced information that has changed the way we think of
dinosaurs. Early in this century, dinosaurs were thought of as slow moving plodding
animals. But in the last three decades, the detailed study of dinosaur trackways has
changed our view of dinosaur behavior to one of rapid moving intelligent animals
capable of parental care and coordinated hunting behavior.
Procedure:
This laboratory will use the details described during the presentations. Don’t let
the math confuse you. You will be able to calculate dinosaur speeds by simply plugging
in the values into the various formulae.
First, you need to know the leg length of the dinosaur. Generally the leg length is
estimated from the length of the footprint. The footprint is 20% the length of the leg, or
you can find the leg length by taking the footprint length times 5.
The leg length is 5 times the length of the track.
Next we need to measure the length of the stride, which is the length between two
consecutive left or right prints.
The stride is measured from the same point on two consecutive right or left prints
Next you must determine your relative stride using the formula:
Relative stride = length of stride / Leg length
Because larger animals can run faster than smaller animals, we must take that into
account. To solve that dilemma we need to determine the dimensionless speed.
Experiments on mammals determined a relationship that relates the length of the relative
stride with dimensionless speed, which can be used in a formula to calculate
dimensionless speed.
The relationship between relative stride and the dimensionless speed is found with
the formula:
dimensionless speed = (relative stride - .72) / 1.19
Once the dimensionless speed of a dinosaur has been found, calculating the actual
speed is easy using the formula:
Actual speed = dimensionless speed times the square root of the (leg length x
gravitational acceleration)
The gravitation acceleration is 10 meters/second2. Therefore the
Actual speed = dimensionless speed times the square root of the (leg length x 10
meters/second2)
Example: First you must measure the various components of the trackway. If a
single track is 0.5 meters long, then the length of the leg should be
Leg length = track length x 5
or
Leg length = 0.5 m x 5 = 2.5 m.
Next you need to find the relative stride. If our example has a stride length of 6.5 m, then
the relative stride would be:
Relative stride =
6.5 m / 2.5 m = 2.6
Now you must determine the dimensionless speed of the dinosaur using the above
formula
Dimensionless speed = relative stride - .72 / 1.19 = (2.6 - .72) / 1.19 = 1.58
Therefore the actual speed would be
Actual speed = 1.58 x square root of (2.5 m x 10 m per sec2) = 7.9 m per second
The conversion to km/hr would require that we do the following conversion.
7.9 m/sec x 3.6 km/hr = 28.44 km/hr.
There are 1.6 km per mile thus to find the dinosaurs speed in mph, divide 28.44 by 1.6.
The dinosaur was running at 17.78 mph! That dinosaur was moving.
At Glen Rose, Texas there is a famous trackway site that will provide a case study for us.
The area has a large number of tracks, but we will use one set. The footprint is
approximately 0.51 m long. It is pictured below.
The trackway can be easily measured using a tape measure. The stride was 6.5 meters.
The length of the pace (the distance between consecutive right and left prints) is shown
below.
Calculate the leg length, relative stride, dimensionless speed and actual speed of the
following five dinosaur examples.
Using the data from the images above of a single track being 0.51 meters long and the
stride being 6.5 meters in length. Calculate the speed at which the dinosaur was moving.
Use the table to see how the calculations are preformed.
Trackway problem sets
1. A T rex with a track of 0.64 m long was found to have a stride of 9 meters. Calculate
the speed of the dinosaur.
2. If the T rex was found to have a stride of 3 meters, then how fast was it moving?
3. A trackway showed a dinosaur with a track of 0.2 meters long and a stride of 5 meters.
How fast was this dinosaur moving?
4. The Oxford Megalosaurus trackway had tracks that were 0.64 m long. The stride of
the tracks was 2.5 m long. How fast was that dinosaur moving?
5. Tracks further along the trackway had a stride length of 4.6 m. At what speed was this
dinosaur moving at that point?
6. A Cetiosaurus trackway had a track size of 0.6 m and a stride length of 2.8 m. How
fast was it moving?
Dinosaur Trackway worksheet
To calculate the dinosaurs speed simply fill in the track size (T) and Stride length (L)
from the above data, and complete the calculations indicated. You will end up with
the speed in mph. The sample trackway from the introduction is included for your
reference. If you are proficient in Excel, you can set up a spread sheet that will
simply do the calculations for you. Make sure you format the numbers for only
two significant digits
track
T
stride
S
T
leg
length
L
Tx5
S
relative
stride
R
S/ L
0.5
2.5
6.5
2.6
dimen.
speed D
km/hr
K
mph
(R-.72)/ 1.19
actual speed
m/sec
A
D x √ (L x 10)
A X 3.6
K/1.6
1.58
7.9
28.44
17.78
Identifying dinosaur tracks is quite easy. Theropod tracks have three slender toes that
often show evidence of a claw. Ornithopod tracks are also three toed, but they are not as
pointed and have a more rounded heel. Sauropod hind tracks are rounder with a fore
track that is half the size. Examples of each of these and others were presented in lecture.
Below is a photograph of a large set of dinosaur tracks. Draw lines along the tracks that
were likely made by the same individual (hint the tracks seem to be moving along the
same path). Try to identify the types of dinosaurs represented, and how many individuals
were present?
Questions:
1. In trackway one, the leg length of the Tyrannosaurus was
A. 2 m
B. 3 m
C. 3.2 m
D. 4 m
E. 6 m
2. In trackway one, the relative stride of the Tyrannosaurus was
A. 2.1 m
B. 2.6 m
C. 3.2 m
D. 4.3 m
E. 6.7 m
3. In trackway two, the speed of the Tyrannosaurus with a stride of 9 m in mph was
A. 12.5
B. 29.1
C. 22.38
D. 31.2
E. 44.2
4. In trackway three, the relative stride of the dinosaur was
A. 2.5 m
B. 2.9 m
C. 3.6 m
D. 5 m
E. 6.4 m
5. In trackway three, the speed in mph of the dinosaur was
A. 25.59
B. 12.9
C. 30.6
D. 16.5
E. 6.4
5. In trackway four, the speed in mph of the Megalosaurus was
A. 2
B. 3.4
C. 1.1
D. 0.66
E. 2.8
6. In trackway five, the speed in mph of the Megalosaurus was
A. 2.33
B. 7.67
C. 9.22
D. 5.32
E. 4.54
7. In trackway six, the speed in mph of the Cetiosaurus was
A. 2.21
B. 3.43
C. 2.77
D. 5.32
E. 7.43
8. Of the six trackway analyzed, which dinosaur was the fastest?
A. Trackway 1
B. Trackway 2
C. Trackway 3
D. Trackway 5
E. Trackway 6
9. In the mixed trackway photograph, were there any theropods?
A. yes
B. no
10. In the mixed trackway photograph, were there any onithopods?
A. yes
B. no
11. In the mixed trackway photograph, were there any sauropods?
A. yes
B. no
12. In the mixed trackway photograph, what type of dinosaur was the most common?
(hint: this the number of trails you found)
A. theropods
B. ornithopods
C. sauropods
D. ceratopsia
E. stegosauria