ABSTRACT
†Erfoudichthys rosae gen. and sp. nov. is described on the basis of a single isolated head found in an unknown locality of the early Cenomanian Kem Kem beds, southeast of Morocco. The new species shows a combination of plesiomorphic and apomorphic characters among ostariophysans, such as a thin and elongated mesethmoid, a nasal formed by a cylindrical unit for the sensory canal extending laterally as a bony lamina, a large lacrimal, a small second infraorbital triangular in shape and wedged between the lacrimal and the third infraorbital, clusters of large conical teeth on the endopterygoids and basibranchial 2, a mandible with a ventral symphysal process and a deep coronoid process. A phylogenetic analysis of †E. rosae among Gonorynchiformes provides two very different patterns, with the new taxon located either as a stem Chanidae (= Chanoidei) or outside the Ostariophysi. This problematic phylogenetic resolution rests on the fragmentary condition of the available material and the lack of nonostariophysan teleosts for comparison, and prevents any analysis of the palaeobiogeographical signal that this taxon can provide.
