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.