Diastemapycnodus tavernensis gen. et sp. nov. (Actinopterygii, †Pycnodontiformes) from the marine Maastrichtian (Late Cretaceous) of the Dakhla Formation, Western Desert, Egypt

Based on a single vomer with partial dentition collected from the lower part of the Beris member, Dakhla Formation, dated to the Maastrichtian, we describe the new pycnodont Diastemapycnodus tavernensis gen et sp. nov. The characteristics of the new genus are (i) five rows of teeth and (ii) very large diastema interposed between the primary lateral rows and the medial dental row. The new species has the following combination of characteristics: (i) paired primary lateral rows composed of large, rounded teeth that are not ornamented and are significantly larger than the adjacent teeth in both the medial and secondary lateral rows; (ii) teeth of the primary lateral rows with an elliptical profile, with a major axis normal to the major axis of the vomer, and (iii) they are the largest teeth among those that arm the vomer; and (iv) all of the teeth are mostly not ornamented and are smooth on the unworn occlusal surfaces. Diastemapycnodus tavernensis is a pycnodont with a very reduced vomerine dental floor, which certainly falls within the well-known evolutionary lineage with an almost edentulous vomer (Serrasalmimidae). The authors attribute to the new genus Diastemapycnodus also the species ‘Typodus’ valens.