Modern Amphibians

Modern Amphibians• Anura/Salientia (frogs & toads) ~ 3500

sp; Triassic

• Caudata/Urodela (salamanders) ~ 350 sp; Jurassic

• Apoda/Gymnophiona (caecelians) ~ 60 sp

general features• 'amphibious' life cycle (metamorphosis)

• smooth, glandular skin

• three chambered heart

• carnivorous

Cutaneous Respiration

Order Anura/Salientia1. distribution cosmopolitan except

Antarctica; tropics especially2. elongate hind limbs & powerful

leg muscles3. strong pelvis fused to the

vertebral column; posterior vertebrae

fused into a urostyle4. sticky, protrusible tongue5. species specific vocalizations6. external fertilization; amplexus

“spades”

Bufo americanus, American Toad

Bufo cognatus, Great Plains Toad

Gastrophryne carolinensis, Eastern Narrowmouth Toad

Pseudacris crucifer, Spring Peeper

Hyla sp., Gray Treefrog complex

Acris crepitans,Blanchard’s Cricket Frog

Rana blairi,Plains Leopard Frog

Rana utricularia, Southern Leopard Frog

Rana catesbeiana, Bullfrog

Rana clamitans,Green Frog

Order Caudata/Urodela1. distribution: primarily northern

hemisphere

2. neoteny- adult retains juvenile features

3. Family Plethodontidae- loss of lungs; cutaneous respiration

4. troglodytes- cave dwellers

reproduction1. courtship: species specific displays

(visual, tactile, & chemical cues)

2. internal fertilization; spermatophore transfer

3. eggs laid in water or moist soil

4. larvae; aquatic & gilled in many

5. territoriality

Ambystoma texanum, Smallmouth Salamander

Ambystoma maculatum, Spotted Salamander

Ambystoma opacum, Marbled Salamander

Ambystoma tigrinum,Barred Tiger Salamander

Courtship in Plethodontids

Nasolabial Groove

Plethodon ouachitae, Rich Mountain Salamander

Plethodon serratus, Southern Redback

Salamander

Eurycea multiplicata,Many-ribbed Salamander

Desmognathus brimleyorum, Ouachita Dusky Salamander

Notopthalmus viridescens, Central Newt

Order Apoda/Gymnophiona

•  legless & fossorial

• distribution: tropics