Herpetology In-Class Notes
Herpetology is the scientific study of reptiles
and amphibians.
Amphibians are in the:
Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Amphibia
Orders:
- Apoda/Gymnophiona
- Anura/Salientia
- Urodela/Caudata
Amphibians are organisms who:
- have internal skeletons, including a backbone
made of vertebrae.
- are ectothermic
- usually have two life stages and go through
metamorphosis
- usually reproduce via external fertilization
- have smooth, scale-less skin that is often slimy
Members of the order Apoda or Gymnophiona
include the caecilians.
“Apoda” means “without feet”.
Caecilians are tropical, legless amphibians that live
in Africa, Asia, Central, and South America.
Caecilians look like worms with a skeleton and
sensory tentacles b/w the eyes and nose.
Caecilians reproduce via internal fertilization and
can give birth to live young.
Members of the order Anura or Salientia include
the frogs and toads.
Adult Anurans lack tails.
Anurans “have well-developed forelimbs, and even
larger hind legs” for hopping.
All adult anurans are carnivorous.
Most frogs and toads are tadpoles with gills as
larvae and breathe with lungs as adults.
Members of the order Urodela or Caudata include
the newts and salamanders.
Salamanders have long, slender bodies and tails.
Most salamanders reproduce via internal
fertilization w/o copulation.
Most salamanders lay eggs in water; others lay
eggs in damp pockets of soil and vegetation.
Most salamanders go through metamorphosis with
an aquatic, gill-using larvae and lungs in adults.
Reptiles are in the:
Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Reptilia
Orders:
- Crocodilia
- Testudines
- Squamata
- Spenodonta
Reptiles are organisms who:
- are fully adapted to life on land
- lay shelled eggs
- have scaly skin
- breathe air via lungs
- have efficient circulatory and respiratory
systems.
Members of the Order Crocodylia include
crocodiles, alligators, caiman, and gavials.
All members of the Order Crocodylia are semi-
aquatic predators that have:
elongated snout
powerful jaws
muscular tail
large protective scales
streamlined body
eyes and nostrils that are positioned on top of head.
• Crocodiles have a long, narrow head that forms a “V” more than a “U” and teeth that are easily visible when the mouth is closed.
• Alligators have a broad, “U”-shaped head and teeth that are more hidden when the mouth is closed.
• Caiman have much narrower bodies than
alligators, have large, bony plates and are
blackish or brownish with various lighter
markings. Caimans are only found in Central and
South America.
• Gavials have very narrow, distinctive snouts and
are found only in the Indian subcontinent. There
are only about 235 total individual gavials left.
• All members of the Testudine Order have a
shell that is fused to the ribcage. The top part
of the shell is called the carapace; the bottom
part of the shell is called the plastron.
• Tortoises typically live on land in drier
climates.
• Turtles typically live in or near water.
• All members of the Order Squamata have
scales, periodically shed their skin, and have
uniquely jointed skulls and jaws.
• Suborder Lacertilia or Sauria: Lizards have
legs, clawed toes, external ears, and movable
eyelids.
• Suborder Serpentes: Snakes have no legs,
are elongated, lack external ears, and have
no eyelids.
• The tuataras are the only members of the
Order Sphenodonta. Tuataras are only found
on a few islands off the coast of New Zealand.
• Tuataras resemble lizards, but lack external
ears and have primitive scales. They also have
a “third eye”, called the parietal eye, that can
sense the level of sunlight.
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