A new species of<i>Enchodus</i>(Aulopiformes: Enchodontidae) from the Cretaceous (Albian to Cenomanian) of Zimapán, Hidalgo, México

Abstract

ABSTRACT A new species of Enchodus (Aulopiformes: Enchodontidae) is described from a quarry exposure of the La Negra facies of the El Doctor Formation (Cretaceous: Albian to Cenomanian) in the state of Hidalgo, central México. It is an elongate fish with many generic and familial characters, including dermal ornamentation of tubercles atop rows of ridges; a palatine with a single, large tooth; and a triangular preopercle. It has a number of unique characters that include the presence of an orbitosphenoid, absence of dorsal scutes, and dorsal fin rays that share common pterygiophores. A phylogenetic analysis places the new species as the sister to Enchodus gladiolus. The new species of Enchodus is the most abundant fish species at the locality. Using mandible length as an indicator of overall size, the range in lengths suggests that this species lived at or near the locality. This is further supported by other species that have individuals of large and small sizes.