Dagon avendanoi gen. and sp. nov., an Early Cenomanian Enchodontidae (Aulopiformes) fish from the El Chango quarry, Chiapas, southeastern Mexico

Dagon avendanoi gen. and sp. nov. is described based on a single specimen from the Early Cenomanian marine deposits of the Cintalapa Formation at El Chango quarry, near Ocozocoautla de Espinosa, Chiapas, southeastern Mexico. This species is identified as a new member of Enchodontidae because it shows the predorsal scute series, a distinctive unique character of the family. Among enchodontids, Dagon is unique because its palatine bone has two large fang-like teeth longitudinally ordered; contrary, the palatine in other enchodontids has only one large terminal tooth (i.e. Enchodus) or many small teeth (i.e. Unicachichthys). The inclusion of the new genus within a phylogenetic analysis reveals that the family Enchodontidae is a natural group (Unicachichthys (Dagon (Palaeolycus (Eurypholis + Saurorhamphus) + (Parenchodus + Enchodus)))). This new fish represents the third enchodontid species described from Mexico; this, together with Enchodus zimapanensis and Unicachichthys multidentata, allows to recognize the early diversification of enchodontids during the lower limit of Late Cretaceous throughout the North American domain of the Tethys Sea.