Oromobula, Adnet & Cappetta & Guinot & Sciara, 2012

Adnet, Sylvain, Cappetta, Henri, Guinot, Guillaume & Sciara, Giuseppe Notarbartolo Di, 2012, Evolutionary history of the devilrays (Chondrichthyes: Myliobatiformes) from fossil and morphological inference, Zoological Journal of the Linnean Society 166 (1), pp. 132-159 : 145

OROMOBULA GEN. NOV.

Type horizon: Samlat Formation, Gerran member ( Ratschiller, 1967) – late Middle Eocene/Late Eocene.

Etymology: Genus named after the old Spanish spelling of locality ‘Rio del Oro’, ‘Western Sahara’ in south-western Morocco.

Type species: Oromobula dakhlaensis gen. et sp. nov.

Occurrence: Only known on type locality, Late Eocene.

Diagnosis: Mobulid only known by isolated teeth of small (near 3 mm) to moderate size (up to 6 mm). Teeth (crown and root) are quite to strongly flattened labiolingually (according to age and file position) without any possibility of interlocking. Occlusal face rather flat with enameloid layer extremely thin and strongly rippled by numerous deep furrows, partially interlaced on the convex labial face. The labial visor is proportionally high and does not overlap the root– crown boundary. The apical extremity of the labial face is irregularly flat and horizontal because of scouring by functional wear. The transversal crest is always ragged and the notches are toughened by short and scattered lingual folds. The root is medium to high and principally polyaulacorhize in large forms with three to five well-spaced lamellas that can be strongly compressed labiolingually. Their basal face is relatively salient.