Two new species of longirostrine fishes from the Early Cenomanian (Late Cretaceous) of Ein-Yabrud, Israel, with comments on the phylogeny of the Dercetidae

Abstract

A new genus and two new species of Dercetidae, Rhynchodercetis gracilis, sp. nov. and Dercetoides venator, gen. and sp. nov., from Lower Cenomanian (Upper Cretaceous) beds of Israel are described. The caudal endoskeletons of these new species are the first of the family Dercetidae to be described in detail. Rhynchodercetis gracilis is distinguished mainly by having the relatively longest upper jaw of all species, the presence of an interoperculum, a relatively long caudal vertebra in advance of the caudal endoskeleton, and a convoluted suture between the second and third hypurals. Dercetoides venator represents a Dercetis-like fish with upper and lower jaws that terminate anteriorly at the same level. It is distinguished, mainly, by an unroofed post-temporal fossa, the presence of an interoperculum, two pairs of transverse processes on each precaudal vertebra, and a convoluted suture between the second and third hypurals. An analysis of phylogenetic relationships in the family Dercetidae suggests that Dercetidae is a monophyletic group, that Dercetis is the primitive sister-group of all other dercetids, and that the newly described genus Dercetoides is closely related to Rhynchodercetis.