; class Amphibia, order Anura)
A monotypic family (Ascaphus truei) of amphibians, found in mountain streams in western N. America, that, like Leiopelmatidae, have nine amphicoelous vertebrae and free ribs. A muscular extension of the cloaca (‘tail’) is used in copulation. Tadpoles cling to rocks with a sucking mouth.
Subjects: Zoology and Animal Sciences.