Coastal Tailed Frog

Ascaphus truei

Ascaphus truei is one of two species of frogs in the genus Ascaphus, the only taxon in the family Ascaphidae. The "tail" in the name is actually an extension of the male cloaca. The tail is one of two distinctive anatomical features adapting the species to life in fast-flowing streams. These are the only North American frog species that reproduce by internal fertilization.
Adult male Coastal Tailed Frog (Ascaphus truei) at streamside I had only seen this species once before, many years ago, in this same location. I was looking hard for them around the edges of a stream and found two small individuals. While photographing those, this large adult male came hopping by. These frogs have the most ancient lineage of all frogs, with the possible exception of certain New Zealand species. Ascaphus truei,Coastal Tailed Frog,Geotagged,Summer,United States

Naming

Until 2001, the genus was believed to be monotypic, the single species being the tailed frog (Ascaphus truei Stejneger, 1899). However, in that year, Nielson, Lohman, and Sullivan published evidence that promoted the Rocky Mountain tailed frog (Ascaphus montanus) from a subspecies to its own species. Since then, the former species has been formally called the Coastal Tailed Frog.

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Taxonomy
KingdomAnimalia
DivisionChordata
ClassAmphibia
OrderAnura
FamilyAscaphidae
GenusAscaphus
SpeciesAscaphus truei