Garrick (1982) placed the Galapagos shark and the Dusky shark at the center of the "obscurus group", one of two major groupings within "Carcharhinus". The group consisted of the Bignose shark, the Caribbean reef shark, the Sandbar shark, the Dusky shark, and the Oceanic whitetip shark; all large, triangular-toothed sharks. Based on allozyme data, Naylor (1992) changed this group, with the additions of the Silky shark, and the Blue shark. The closest relatives of the Galapagos shark were found to be the Dusky shark, the Oceanic whitetip shark, and the Blue shark. 