The skeletal remains of the euryhaline sclerorhynchoid †<i>Onchopristis</i> (Elasmobranchii) from the ‘Mid’-Cretaceous and their palaeontological implications

Abstract We present the first known cranial remains of fossil batoid †Onchopristis numidus. Based on two exceptionally well-preserved specimens collected from ‘Kem Kem Beds’ (Albian–Cenomanian), south-east Morocco, an almost complete description rostral and portions genus is provided, together with new observations regarding development arrangement denticle series for this genus. The comparison between rostrum length †O. numidus those extant pristids, reveals a relatively large species estimated total four metres. Overall, morphology resembles that other sclerorhynchoids. Its robust hypertrophied rostrum, characteristic wood-like mineralization covering inner layer tessellate cartilage at centre in addition to thick lateral layers densely porous sides cartilages, observed †Ischyrhiza †Schizorhiza, differentiates sclerorhynchoids (e.g. †Libanopristis, †Micropristis †Sclerorhynchus). Aiming determinate phylogenetic relations within sclerorhynchoids, cladistic analysis was carried out based described here; its results suggest taxonomic