Rocky Mountain Tailed Frog

About the Rocky Mountain Tailed Frog

The tailed frogs are 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. They are among the most primitive known families of frogs.

Its scientific name means 'without a spade', from the privative prefix a- and the Ancient Greek skaphís (σκαφίς, 'spade, shovel'), referring to the metatarsal spade, which these frogs do not have. 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.

The genus Ascaphus, through mtDNA comparisons, has been grouped into a clade with the genus Leiopelma creating a sister taxon to all modern anurans. Wikipedia →