Palaeohypotodus Glueckman , 1964

Ebersole, Jun A., Cicimurri, David J. & Harrell Jr., T. Lynn, 2024, A new species of Palaeohypotodus Glueckman, 1964 (Chondrichthyes, Lamniformes) from the lower Paleocene (Danian) Porters Creek Formation, Wilcox County, Alabama, USA, Fossil Record 27 (1), pp. 111-134 : 111

Genus Palaeohypotodus Glueckman, 1964

Type species.

Otodus rutoti Winkler, 1874, Orp Member of the Heers Formation, Orp-le-Grand (Maret), Belgium.

Emended generic diagnosis.

Lamniform shark with teeth consisting of a triangular main cusp and one to three pairs of lateral cusplets. Enameloid plications occur along the labial crown foot on unworn teeth, and these may coalesce to form transversely oriented ridge-like structures on posterior teeth. Cutting edges are complete on all upper teeth but are incomplete on lower teeth. Although the main cusp is tall and relatively narrow in anterior files, it becomes progressively lower and broader the closer a file is located with respect to the commissure. Upper lateral teeth have a wide triangular and distally hooked main cusp, whereas lower lateral teeth have a narrower and more erect main cusp. Upper third anterior teeth have a basally extended mesial root lobe, the distal cutting edge is more convex than the mesial edge, and the crown appears to be mesially recurved. Teeth have a robust lingual root protuberance that bears a nutritive groove. The root lobes are long and the interlobe area is deep and U-shaped. Upper anterior teeth have shorter and slightly more divergent root lobes compared to those in the lower anterior files.