Description
Original diagnosis after Stumpf, Etches, Underwood & Kriwet, 2021 [29802]: Hybodontiform shark-like chondrichthyan that is characterized by the following unique combination of morphological characters: palatoquadrate elongate with low and reduced palatobasal process and well-developed ethmoidal articular surface; Meckel’s cartilage elongate and rather deep with well-developed dental groove extending for approximately one-half its length of the Meckel’s cartilage; medial quadratomandibular joint on Meckel’s cartilage prominent and well-defined; articular cotylus on Meckel’s cartilage moderately well-developed and shallowly recessed; hyomandibular head formed into an anteriorly directed hook-like process; dorsal fin spines ornamented with strong, non-bifurcating costae; body covered by monodontode, thorn-like dermal denticles; dentition includes high-crowned multicuspid teeth that are symmetrical to slightly asymmetrical in labio-lingual view displaying disjunct monognathic heterodonty; tooth crown strongly labio-lingually flattened; main cusp high and fairly wide at its base without sigmoidal profile; main cusp flanked on each side by up to three pairs of low but well-developed lateral cusplets; cutting edges slightly labially displaced, continuous, and sharp without serrations; labial crown base is slightly incised above the crown-root junction and somewhat swollen; crown-root junction straight; lingual and labial crown faces ornamented with very short, inconspicuous vertical folds aligned along the base above the crown-root junction; tooth root prominent, about as high apico-basally as deep labio-lingually, and slightly lingually displaced beneath the tooth crown; basal root face flat with shallow depression extending along the labial edge; lingual and labial root face perforated by numerous small, densely arranged foramina and large, regularly arranged foramina that occur aligned along the bases; morphological variation passing posteriorly through the dentition encompasses distal inclination and reduction of principal cusp; anterior teeth symmetrical in labio-lingual view with moderately robust main cusp and divergent lateral cusplets; lateral teeth asymmetrical in labio-lingual aspect with wide, triangular-shaped and slightly distally inclined main cusp; posterior teeth asymmetrical and low in in labio-lingual view.

Remarks
shark-references Species-ID=16145;
type species of Durnonovariaodus Stumpf, Etches, Underwood & Kriwet, 2021 [29802] by monotypy (Art. 68.3 ICZN);

References