Revision of the fossil batomorphs from the Cretaceous of Lebanon, and their impact on our understanding of the early step of the evolution of the clade

Abstract

Lebanon is endowed with its outstanding preservation lagerstätten of fossil fish from the Upper Cretaceous. The batomorphs are represented by 16 species of Rajiformes belonging to 9 genera and 4 families however, their phylogeny remains poorly understood. Also, their diversity is possibly underestimated, compared to the great diversification event observed in the Upper Cretaceous, by lumping the majority of Lebanese rhinobatids in the genus Rhinobatos, whereas their relationships with the modern species of this genus are unclear. We discuss herein the attribution of three lebanese shark-like “Rhinobatids” species included into two new genera to Rhynchobatidae. These species together with Rhynchobatus possess a combination of primitive characters such as propterygium failing to reach the level of the nasal capsules and pectoral fin posterior corner not reaching the level of the pelvic fin. Three additional characters are supporting this clade in the present analysis together with two plesiomorphies. The remaining guitarfishes present a closer relationship with Rajidae than to Pristidae and so the order Rhinopristiformes recently erected by Naylor et al., (2012) is not recovered in our analysis.

Keywords

• batomorpha
• upper cretaceous
• rhinobatidae
• cladistics