RNR 3018 Chapter : Amphibians
Document Summary
Liss = smooth (greek referring to skin) Amphibia = double life (greek referring to metamorphosis) Shared derived characteristics of amphibians: smooth, moist skin, absence of bony / keratinized scales (exception = caecilians, absence of keratinized, true claws, mucous glands (prevent desiccation / slippery / disease-free) Other methods for controlling water loss: behavioral modifications: Warm, dry nights: pelvic patch, permeable bladder: Diversity: first appearance in fossil record = jurassic. * (~ 245 sp. : primarily holarctic distribution: North american = 9 of 10 families (5 endemic: neotropic = greatest # of species. All from single family (plethodontidae ~ 145 sp. ) Morphology / locomotion: presence of tail (larvae / juveniles / adults, 4 equally-sized limbs (extend at right angle from body, size range = 3 cm to >1 m. Respiration: aquatic = primarily gills (some cutaneous, cryptobrachidae = large skin folds, terrestrial = lungs (50%) / skin (50%)
