Bignose Shark - Taxonomy and Phylogeny

Taxonomy and Phylogeny

Shark expert Stewart Springer described the bignose shark as Eulamia altima in a 1950 issue of the scientific journal American Museum Novitates. Later authors have regarded the genus Eulamia as a synonym of Carcharhinus. The specific epithet altimus is derived from the Latin altus ("deep"), and refers to the shark's deepwater habits. The type specimen is an immature female 1.3 m (4.3 ft) long, caught off Cosgrove Reef in the Florida Keys on April 2, 1947. An alternate common name for this species is Knopp's shark, originally used by Florida fishery workers since before the species was described.

Phylogenetic studies published by Jack Garrick in 1982 and Leonard Compagno in 1988, based on morphology, placed the bignose shark in the "obscurus group" of Carcharhinus, centered on the dusky shark (C. obscurus) and the Galapagos shark (C. galapagensis). The group consists of large, triangular-toothed sharks with a ridge between the dorsal fins. Gavin Naylor's 1992 study, based on allozyme sequences, upheld and further resolved this "ridge-backed" group. The bignose shark was found to be the sister species of the sandbar shark (C. plumbeus), with the two forming one of the group's two branches.