Reassessment of Cosmodus Sauvage, 1879, a poorly known genus of large pycnodont fish (Actinopterygii, Pycnodontiformes) from the Cenomanian (Upper Cretaceous) of Western Europe

Abstract

International audienceThe large pycnodontiform fish genus Cosmodus Sauvage, 1879 is redescribed on the basis of both historical material and new specimens, and a formal diagnosis is proposed. The vomerine and prearticular dentitions of Cosmodus show a unique combination of characters, including the morphology and ornamentation of the tooth crowns and the number of tooth rows. Cosmodus is thus recognized as a valid distinct genus, restricted to the middle–upper Cenomanian of Western Europe (France, England, Spain, and possibly Germany) and including a single species, C. carentonensis (Coquand, 1859). Cosmodus shares some peculiar dental features with Coccodus (e.g., vomerine dentition with three rows of subtriangular teeth) and is therefore tentatively interpreted as a gigantic member of the Coccodontidae, a family of highly specialized pycnodont fishes so far known only from the middle–upper Cenomanian of Lebano