FNR 24150 Herps Final Exam

Why did amphibians move to land?

Why did amphibians move to land?

- Unexploited food and niches - aquatic niches occupied
- Lack of large terrestrial predators
- Low O2 in warm water - unlimited O2 on land

What are the three main diversifications of reptile and amphibian phylogeny? When did they begin to diversify?

Ichthyostega - Paleozoic Devonian
Leptospondyli - Paleozoic Carboniferous
Temnospondyli - Paleozoic Carboniferous

What was the name of the radiation that created the groups of amphibians we see today? When was it?

Lissamphibians
Late Permian in Paleozoic to Mesozoic

What is the most remarkable feature of Tiktaalik?

front pair of fins with wrist like structure

Which fossil was the 1st tetrapod with proper neck, enabling increased flexibility during short bouts on land?

Tiktaalik

Which fossil is called the "roof fish"?

Ichthyostega

Describe Eryops

crocodile-like early amphibian

Which fossil had a boomerang head?

Diplocaulus

Which fossil is called "frogmander"?

Gerobatrachus

What were some characteristics of Gerobatrachus?

2 fused ankle bones, backbone intermediate, large tympanum (external ear), wide frog-like scull

When did the splitting between frogs and salamanders occur?

240-275 MYA

Which fossil is called "proto frog" and was the 1st fossil frog?

Triadobatrachus

Which fossil is the earliest true frog?

Vieraella

List some differences between Vieraella and Triadobatrachus?

Triadobatrachus - sacral vertebrae, small pelvis, tibia and fibula separate, 13-14 presacral vertebrae

Vieraella - urostyle (fused sacral vertebrae), large pelvis, tibiofibula (fused), 9 presacral vertebrae

What are some characteristics of Paleobatrachus?

- Completely aquatic, inhabited swamp basins
- Volcanic gasses preserved soft tissue
- Resembles present day Xenopus - African clawed frog

Salamanders mostly use which kind of fertilization?

internal

Which groups of salamanders do not have internal fertilization?

Sirenidae and Cryptobranchidae

What is the defining characteristic of Sirenidae?

Lacks hinds legs

Why is Sirenidae considered paedomorphic?

all stages aquatic, adults have external gills

Describe the habitat of the lesser siren.

shallow water, swamps, ditches, ponds

What are the 3 species of Cryptobranchidae? List them largest to smallest

Chinese giant salamander
Japanese giant salamander
Hellbender

Why are Cryptobranchidae considered paedomorphic?

paddle-like tail and aquatic

Describe the habitat of the hellbender.

cold, fast-moving rivers and streams

What species are under Proteidae?

Mudpuppies

How are Proteidae paedomorphic?

External gills and fully aquatic

Describe the habitat of the mudpuppy.

rivers, streams, lakes; usually concealed under rocks and debris

What species are under Ambystomidae?

mole salamanders

Describe the habitat of the mole salamanders.

hide under rocks/logs/burrows in summer and winter
aggregate pond breeders

Describe aggregate pond breeding

- Migrate in hundreds to ponds, congregate in large numbers
- Rain and temp stimulates migration
- Males outnumber females 2:1
- Breeding occurs over short period of time (4-5 days)

What is the largest family of salamanders? What portion of salamanders are in this group?

Plethodontidae
2/3 all species of salamanders are in this family

What is a defining characteristic of Plethodontidae?

Nasolabial grooves - run from nostril to lip, found only in this family

Which salamander family has direct development?

Plethodontidae

Describe the habitat of the plethodontid salamanders.

Diverse - can be terrestrial, partly aquatic, fully aquatic, or arboreal

What species are in the Salamandridae family?

Newts

Define aposematic coloration. Which species of salamander has this?

bright color to advertise toxicity

Newts (Salamandridae)

Which family of salamanders has tetradotoxin and an unken reflex?

Salamandridae (newts)

Define tetradotoxin

non-protein toxin used for chemical defense in newts

Define unken reflex

posturing to advertise toxicity and highlight areas with more skin secretions (tail)

Describe the habitat of the newt.

forest settings, shelter under logs/leaves/rocks

Name and describe the additional life stage of Salamandridae species

Red eft

- Only terrestrial life stage
- Lasts 2-3 years then reach sexual maturity, migrate back to pond and become aquatic
- More active during the day (diurnal) so bright colors show up in daylight

List some differences between frogs and toads

Frogs: smooth skin, longer hind legs, leapers
Toads: rough skin, shorter hind legs, jumpers

List and describe the 4 types of Anuran calls

- Advertisement calls - males call to females during breeding
- Aggressive calls - resident males give to approaching males
- Courtship calls - between male and female in close proximity
- Release calls - when being attacked to startle predator

Which type of fertilization is most common in Anurans?

External

What is the defining characteristic of the Scaphiopodidae family?

Circular/sickle shaped hardened keratinaceous structure on each hind foot, forms spade

Why is the Scaphipodidae family considered transitional between frogs and toads?

somewhat warty skin, smooth skin somewhat resembles frog

Describe the habitat of spadefoot toads.

tropical forest floors, burrow rear-first into soil, spend most of year in estivation, temporary ponds to breed

What species are under Hylidae?

Tree frogs

What is the defining characteristic of Hylidae?

toe pads

Describe the habitat of a tree frog.

most arboreal, some aquatic, some fossorial; return to water to breed

savannas, woodlands, floodplain forests

What species are under Bufonidae?

Toads

Describe the Bidder's organ. Which family of Anurans has this?

vestigial ovary on larval testes
Bufonidae

Which group of Anurans has prominent parotid glands?

Bufonidae

Describe the habitat of bufonidae.

terrestrial or fossorial, return to water to breed, found in almost every habitat

burrow to avoid freezing and dry conditions

Which species are under Ranidae?

True frog

What are some characteristics of Ranidae?

- Dorsal-lateral skin folds around tympanum and down back
- Webbed hind feet

Describe the habitat of ranidae.

mainly aquatic, some fossorial, arboreal, terrestrial; inhibit all types of aquatic systems

When did reptiles begin evolving? Why?

- 320-310 MYA in Carboniferous within Paleozoic era
- Drought, arid climate caused reptilian adaptations
- Started proliferating in Permian

List some structures that reptiles evolved

- Increasing brain size (cerebrum and cerebellum)
- More effective jaw
- Skeletal structure improved
- Skin tough, covered with scales
- Well developed lungs allow for increased body size
- AMNIOTE EGG

What is the most important difference between reptiles and amphibians?

Amniotic egg (shelled egg)

What are the 3 main groups of reptile evolution? What did they evolve into?

Synapsids - mammals
Diapsids - birds, crocodilians, dinosaurs, snakes, and lizards
Anapsids - turtles

Describe Casineria

- Resembled small lizards, but mix of reptile and amphibian characteristics
- Salamander like head
- Claws (not amphibian characteristic)

Which fossil was the first to develop amniotic egg?

Casineria

Why is Hylanomus important?

- Perhaps earliest known reptile
- Among 1st amniotes

Which era was the age of reptiles?

Mesozoic

Which group of Diapsids are the "ruling reptiles"?

Archosauromorphs

What do Archosauromorphs evolve into?

crocodilians and birds

Which groups of Diapsids evolve into lizards and snakes?

Lepidosauromorphs

What do Anapsids evolve into?

turtles

What do Synapsids evolve into?

mammals

What is the defining characteristic of Odontochelys?

toothed shell and teeth on lower and upper jaw

What is the most well known turtle fossil?

Proganochelys

Which turtle fossil was called "ruling turtle" and could get up to 12 feet?

Archelon

What is one thing that is unique about the evolution of turtles?

body plan has not changed much over millions of years

Define temperature dependent sex determination

- location and depth of clutch will determine sex of embryo

- Higher temps = more males (depends on species, sometimes swapped)
- Lower temps = more female
- Intermediate temp = 1:1 ration of males to females

T/F: All chelonians lay eggs

true

What species are under Chelydridae? Defining characteristics?

snapping turtles

spiny shells and tails, reduced plastrons, fully aquatic

What species are under Kinosternidae? Defining characteristics?

mud and musk turtles

glands that produce musky odor

What species are under Emididae? Defining characteristics?

basking, marsh, box turtles

long lives, diverse body size/shape

What species are under Trionchidae? Defining characteristics?

soft-shelled turtles

no bony carapace, genetic sex determination

Define genetic sex determination

not changed by temperature, have sex chromosomes

What are some defining characteristics of lizards?

movable eyelids, external ear openings

What species are under Phrynosomatidae? Defining characteristics?

spiny lizards

have spines but wide range of morphology

Describe basking

- bask from 8:30-9:00 in the morning to abt 11:00
- active foragers, quick moving

What species are under Anguidae? Defining characteristics?

glass or alligator lizards

legless, osteoderms, automize tail

Define osteoderms

bony plates under scales; makes them stiff and shiny

What species are under Teiidae? Defining characteristics?

whiptails and racerunners

can move very fast, some parthenogenic, automize tail

What species are under Scinidae? Defining characteristics?

skinks

osteoderms, automize tail

What is the largest lizard family?

Scinidae

What are some defining characteristics of snakes?

Legless, immovable eyelids, no external ears, Jacobson's organ, degenerative/nonexistent left lung

Describe the Jacobson's organ in snakes

6th sense from tongue flicking

What species are under Viperidae? Defining characteristics?

pit vipers

venomous, loreal pit organ on face

What species are under Natricidae? Defining characteristics?

water snakes

associated with aquatic environments

When does brumation occur?

during cold weather

When does estivation occur?

during hot, dry weather

Define exothermic

Primary heat sources is external

Define endothermic

Primary heat source internal

What is the limiting factor that affects the distribution of herps?

temperature

What are the 3 ways heat exchange occurs in ectotherms?

- Radiation - heat from sun
- Convection - air temperature
- Conduction - surface temperature

T/F: Smaller animals lose/gain heat more rapidly.

True

surface area to volume ratio is greater in smaller animals

Define ATR

Activity Temperature Range

temps in which an ectotherm can operate