ZOOL 406 - Introduction to Herpetology

lectures from Dr. Alison Murray

What is herpetology?

Study of amphibians and reptiles

What are “herps”?

Encompassing term to refer to amphibians and reptiles

How does herpetology get its name?

Latin “herpos” → to slither or crawl

What is the difference between reptilia and reptiles?

Reptilia - taxa including extinct ancestors and birds

Reptiles - focus of the course on extant reptiles

Are herps monophyletic?

No, they are linked by the shared basal trait of ectothermy, but are not monophyletic

Is Lissamphibia monophyletic?

Only if you’re only looking at extant species. Once fossils are included, it is no longer monophyletic

How many living herps are there?

• ~7300 species of amphibians

• >10700 species of reptiles

  • 22 species of crocs

  • 260 species of turtles

  • 10200 species of squamates

How diverse are herps in comparison to other animal groups?

More species diversity than mammals, significantly less species diversity than fishes or birds

What variation can be seen in herps?

Diverse set of behaviours, ecologies, and physiologies

• Highly modified frogs and turtles

• Legless wormlike caecilians, amphisbaenians, snakes

Why is there so much diversity amongst herps?

It’s a reflection of a long and complex evolutionary history and adaptations to a multitude of environment and lifestyles

Why do some herps not have limbless wormlike bodies?

Limb loss adapts for fossorial/burrowing lifestyles

What is ectothermy?

The physiological condition in which an animal’s body temperature depends on heat derived from an external source

Is ectothermy derived?

No, it is the ancestral state of life

Is ectothermy inherently better or worse than endothermy?

Neither, both ectothermy and endothermy constrain what an animal can do for immediate survival, how a species could evolve, and what adaptive modes have been possible

Etymological breakdown of amphibia?

amphi - both

bios - life

• Amphibia refers to the organisms that are aquatic in developmental stages and terrestrial in the adult life stage