Chaychanus gonzalezorum gen. et sp. nov.: A damselfish fossil (Percomorphaceae; Pomacentridae), from the Early Paleocene outcrop of Chiapas, Southeastern Mexico

摘要

We describe a new fossil fish, dagger Chaychanus gonzalezorum gen. et sp. nov., from the Belisario Dominguez quarry, a marine Paleocene outcrop of Chiapas, Southeastern Mexico. The single articulated specimen is placed in the family Pomacentridae based on its pharyngognathy and the presence of two anal fin spines in supernumerary association. At approximately 63 Ma, this is the earliest record of the family. The presence of three supraneural with the predorsal formula 0 + 0/0/1 + 1/combined with several diagnostic features indicates this fossil fish as a new genus and species of damselfish. Following the discovery of ancient taxa belonging to dagger Eekaulostomidae and Serranidae, this the third percomorph family with possible coral reef associations to be described from these marine deposits. Its presence on the Western margin of the Tethys region highlights the importance of the Western Atlantic in the early origins of tropical marine taxa.