Tailed frog
genus of amphibians
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.
Taxonomy
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.
“Tailed frog” enters the record as genus of amphibians. Crown Archives preserves that source wording while asking what Tailed, frog and genus can confirm, complicate or overturn.
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“Tailed frog” is worth following because a concise public description often conceals a longer documentary argument. Here, Tailed, frog and genus provides the most credible route into that argument.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated May 18, 2026. The linked authority identifier is Q2925426. The Library of Congress control number is sh85008524. None of the 1 selected statements returned an explicit reference. The first chronological checks are 2001 and 1899.
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This entry incorporates text from “Tailed frog” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.