Cabindachanos dartevellei gen. and sp. nov., a new chanid fish (Ostariophysi, Gonorynchiformes) from the marine Paleocene of Cabinda (Central Africa)

Abstract

The osteology of Cabindachanos dartevellei gen. and sp. nov., a fossil fish from the marine Danian or early Selandian deposits of Landana (Cabinda Territory, Central Africa), is here studied in detail. This fish is known by only one partially preserved specimen that shows typical characters. The opercle is greatly hypertrophied. The preopercle has a very broad dorsal limb and a long narrower ventral limb. There is a wide plate-like suprapreopercle. The lower jaw is deep, with a well-marked coronoid process formed by the dentary. The articulation between the quadrate and the mandible is located before the orbit. The first supraneurals are enlarged. These characters indicate that C. dartevellei belongs to the family Chanidae (Teleostei, Gonorynchiformes). Cabindachanos dartevellei differs from all the other known fossil or recent chanid fishes by the gigantic development of its opercle and by the loss of the subopercle. The straight angle formed by the two limbs of the preopercle and the well-developed posterior median crest of the supraoccipital indicate that C. dartevellei belongs to the subfamily Chaninae and the tribe Chanini.