Tetrapod Characteristics
- 4 walking limbs with toes
- Specialized atlas, 2 occipital condyles
- Hyoid apparatus for tongue muscles
- Middle ear with tympanum, stapes
- Eyelids
|
Amphibia Characteristics
The following apply to Lissamphibia (extant amphibians):
- Glandular skin
- Cutaneous gas exchange
- Short ribs
- Hands with 4 digits
- Reduced or absent dermal armor
- Typically with aquatic larval stage
| |
See also Amphibian Anatomy page
|
Order Caudata — Salamanders, newts
Characteristics
- Generalized, ancestral body plan
- Elongate body, 4 walking limbs, and long tail
- Larvae differ from adults: Have tail fins, external gills, and lateral line
|
Marbled Salamander, Ambystoma opacum, adult; SC
|
Spring Salamander, Gyrinophilus porphyriticus, adult; KY
|
Red-spotted Newt, Notophthalmus viridescens; PA
|
Northwestern Salamander, Ambystoma gracile, larva; WA
|
Spring Salamander, Gyrinophilus porphyriticus, larva; PA
|
Mexican Mushroom-tongue Salamander, Bolitoglossa mexicana; Belize; note reduced legs
|
Lesser Siren, Siren intermedia, an aquatic salamander (note external gills) that lacks hind limbs
|
|
Order Anura — Frogs & Toads
Characteristics
- Body plan specialized for leaping or swimming
- Vertebral column shortened, forms urostyle
- Hind legs greatly elongated
- Fusion of tibia-fibula, ulna-radius
- Loss of tail
- Larvae ("tadpoles"): have tails, lack legs; internal gills, have beak or denticles; lateral line present
|
Maya Mountain Frog, Rana juliani; Belize;
a semiaquatic jumper
|
Fowler's Toad, Bufo (Anaxyrus) fowleri, VA;
a terrestrial hopper
|
Western Spadefoot, Spea hammondii; CA;
a burrower
|
Dyeing Dart-Poison Frog, Dendrobates tinctorius; a terrestrial walker
|
Osorio's Spiny Reed Frog, Afrixalus osorioi; Kenya; a climber
|
Ornate Horned Frog, Ceratophrys ornata;
a sit-and-wait predator
|
African Clawed Frog, Xenopus sp.;
a fully aquatic swimmer
|
Tailed Frog, Ascaphus truei, tadpole (ventral side); CA
|
Bullfrog, Rana catesbeiana, tadpole metamorphosis; IA
|
|
Order Gymnophiona — Caecilians
Characteristics
- Greatly elongated, limbless bodies
- Usually have segmented rings (dermal folds)
- Eyes reduced or absent
- Most are burrowing; some aquatic
|
Rubber Eel, Typhlonectes sp.; preserved specimen
|
|
|
|
