Tailed frog
| Tailed frogs | |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Anura |
| Suborder: | Archaeobatrachia |
| Family: |
Ascaphidae Fejérváry, 1923 |
| Genus: |
Ascaphus Stejneger, 1899 |
| Species | |
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| Distribution of Ascaphidae (in black) | |
The tailed frogs are two species of frogs in the genus Ascaphus, the only taxon in the family Ascaphidae /æˈskæfᵻdiː/. 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.
Its scientific names 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 coastal tailed frog.
The existence of the visible "tail" appendage makes this frog family distinct from all other frogs. Thus, its wider classification is difficult. It is usually classified in the Archaeobatrachia suborder of ancient frogs, though some say it should be a sister to all other frogs. The "tail" is found only in males, and is actually part of the cloaca, used to insert sperm into the female during mating. This anatomical feature improves breeding success by minimizing loss of sperm in the turbulent, fast-flowing streams inhabited by this species. Thus, the tailed frogs exhibit internal fertilisation, rather than the external fertilisation found in other frogs.
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Wikipedia