Description

A large, stout-bodied, terrestrial salamander. The dorsum is dark brown overlain with fine brown spotting or marbling. In some populations there is no marbling mid-dorsally. Adults reach sizes of 17 - 25 cm total length. The posterior half of the tail is laterally compressed. Some populations have both metamorphosed and gilled adults. Gilled adults may become mature at less than 11 cm total length (Nussbaum 1976). Larvae are the stream type with short, bushy gills and a low tail fin which extends forward to the hindlimb insertion. Larval D. aterrimus are darker than larval D. tenebrosus, with little mottling. A yellow stripe behind the eyes may be indistinct (Nussbaum 1976; Petranka 1998).

Until recently only two species were recognized in the genus Dicamptodon.Recent genetic research (Dougherty et al. 1983; Good 1989) has supported the division of D. ensatus into three species: D. aterrimus, D. ensatus, and D. tenebrosus. The species are also morphologically distinct (Nussbaum 1976). The genus Dicamptodon was historically included as a subfamily (Dicamptodontinae) in the family Ambystomatidae, and was placed in a separate family, Dicamptodontidae, based on features of the spinal nerves (Edwards 1976).