Reptiles and Amphibians
What Makes a Reptile a Reptile?
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Air-breathing
Ectothermic (cold-blooded)
Vertebrates
Skin covered in scales and/or scutes (bony
outside part, like a shell).
• Tetrapods (four limbed)
• Lays eggs with shells
• Inhabit every continent with the exception of
Antarctica.
• Originated around 320-310 million years ago
4 Main Groups of Reptiles
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1) Crocodilia- 23 Species
Crocodiles
Gavials
Caimans
Alligators
Difference Between Crocodiles and
Alligators
• You can't see an alligator's teeth when it's mouth is closed;
its lower teeth fit snugly into pits in the upper jaw. In
contrast, a crocodile's lower teeth are always visible.
• Alligators have a broad snout, while crocodiles have a
thinner snout.
• Alligators tend to be grayish black in color, whereas
crocodiles have a light tan appearance.
• Alligators can only be found in the southeastern United
States and in some parts of China. Crocodiles can be found
all over the world.
• In the wild, alligators tend to run away while crocodiles
prefer to fight.
4 Main Groups of Reptiles
• 2) Sphenodontia – 2 species
• Tuataras
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3) Squamata -approximately 9,150 species
Lizards
Snakes
Worm lizards
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4) Testudines - over 300 species
Turtles
Terrapins
Tortoises
Size Range of Reptiles
• Extant reptiles range in size from a tiny gecko,
Sphaerodactylus ariasae, which can grow up
to 17 mm to the saltwater crocodile,
Crocodylus porosus, which may reach 6 m in
length and weigh over 2,200 lb.
What Makes an Amphibian an
Amphibian?
• Ectothermic (cold-blooded)
• Vertebrates
• Eggs are not surrounded by membranes
(shells)
• Eggs are layed in water
• Tetrapods (4 limbs)
• Born with gills – some retain gills for life, while
others have gills that mature into adult lungs.
• Skin is used for respiration or exchange of
gases.
• 6,500 species
• Evolved out of fish over time.
3 Main Groups of Amphibians
• 1) Anura - frogs and toads
Differences Between Frogs and Toads
Frogs
• two bulging eyes
• strong, long, webbed hind
feet that are adapted for
leaping and swimming
• smooth or slimy skin
(generally, frogs tend to like
moister environments)
• Frogs tend to lay eggs in
clusters.
Toads
• stubby bodies with short hind
legs (for walking instead of
hopping)
• warty and dry skin (usually
preferring dryer climates)
• paratoid (or poison) glands
behind the eyes
• The chest cartilage of toads is
different also.
• Toads tend to lay eggs in long
chains.
• 2) Caudata - salamanders and newts
• 3) Gymnophiona
caecilians
limbless amphibians that resemble snakes
Caribbean Amphibian!
• http://www.youtube.com/watch?v=tCDshh48
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Differences Between Reptiles and
Amphibians
• Reptiles
include
alligators,
crocodiles,
turtles, and
snakes.
• Amphibians
include
salamanders,
toads, and frogs.
• Reptiles are
covered with
scales, shields,
or plates, and
their toes have
claws.
• Amphibians, on
the other hand,
have moist,
glandular skins,
and their toes
lack claws.
• The eggs of
reptiles have a
thick, hard shell
that protects the
developing
embryo from
moisture loss,
even on dry land.
• In contrast, the
eggs of
amphibians lack a
hard outer
covering and,
thus, must be laid
in water or in
damp places.
• Finally, young
reptiles are
miniature replicas of
their parents in
general appearance,
although not always
in coloration and
pattern.
• Juvenile amphibians,
however, pass
through a larval
(wormlike), usually
aquatic, stage before
they metamorphose
(change in form and
structure) into the
adult form.