STUDY OF TWO NEW RAYS SPECIES (RHINOBATIDAE; RAJIFORMS) FROM THE CENOMANIAN LIMESTONE OF LEBANON

Lebanon is worldly renown in Palaeontology for its numerous fossil fish outcrops that constitute a wonderful and unique Konservat-Lagerstätten for the Cenomanian period. The Cenomanian (circa 95 MA) was the most favourable period for trapping fossils of fish and many invertebrates in the sub-equatorial North-East of Gondwana. The climate was tropical, marked by the presence of coral reef in what is today the Mount Lebanon area.

Occurrence of fossil fishes in Lebanon has been documented since 450 B.C. The preservation of these fossils is among the best in the world, and allows the fossilization of complete cartilaginous fishes, which elsewhere are mainly known from isolated teeth. This fact is scientifically of extreme importance as it permits access to anatomical details that are used to complete evolutionary studies through cladistics phylogenies. Since 1845, several scientific studies have been made on Lebanese material. New excavations on several outcrops yielded to the discovery of new material.

We report herein the discovery of two new species belonging to the genus ‘Rhinobatos’, and their taxonomic position is discussed. A cladistic phylogenetic analysis has been conducted in order to determine the position and the evolutionary history of these new species within the Rhinobatoidei. As a result, the genus Rhinobatos appears to be polyphyletic if fossil forms are included. A revision of the genus is thus necessary.