The 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

Charente-Maritime, SW France) is a sand quarry exposing a 9-m-thick series of latest Albian-earliest Cenomanian (mid-Cretaceous) age. The uppermost Albian deposits consist of lignitic clay containing fossiliferous amber. The lowermost Cenomanian sand deposits alternate with clay intercalations containing plant remains. One of these clay levels, named P1, shows an outstanding accumulation of conifer and angiosperm macrofossils including delicate reproductive structures such as flowers. Plant remains are associated with invertebrates such as insects (Odonata, Dictyoptera, Diptera), crustaceans (Mecochirus sp.), putative brachiopods (aff. Lingula sp.), and worms. A few vertebrate remains such as shark egg capsules (Palaeoxyris sp.) and a feather are present in the fossil assemblage, as well as an enigmatic specimen tentatively interpreted as a cephalochordate or a petromyzontiform. Various ichnofossils occur in abundance, such as crustacean coprolites and burrows (Ophiomorpha isp.), insect coprolites (Microcarpolithes hexagonalis), and leaves with grazing structures, galls and mines. The sediments have been deposited in a coastal, calm and brackish area.