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[dinosaur] Elosuchus (Cretaceous crocodyliform) revision and phylogenetic affinities, new species E. broinae




Ben Creisler
bcreisler@gmail.com

A new paper:


Louise M. V. Meunier & Hans C. E. Larsson (2016)
Revision and phylogenetic affinities of Elosuchus (Crocodyliformes).
Zoological Journal of the Linnean Society (advance online publication)
DOI: 10.1111/zoj.12448
http://onlinelibrary.wiley.com/doi/10.1111/zoj.12448/full


Elosuchidae is a clade of longirostrine Crocodyliformes currently confined to Barremian through Cenomanian deposits in north-west Africa and Great Britain. The clade is currently composed of Elosuchus cherifiensis (Lavocat, 1955), Elosuchus felixi de Lapparent de Broin, 2002, Sarcosuchus imperator Broin & Taquet, 1966, Sarcosuchus hartii Buffetaut & Taquet, 1977, Vectisuchus leptognathus Buffetaut & Hutt, 1980 and, by some authors, Stolokrosuchus lapparenti Larsson & Gado, 2000. We redescribe Elosuchus from assigned and new material. This genus occurs in terrestrial Cenomanian deposits in Morocco and Algeria and known from multiple relatively complete skulls. The holotype is unknown but the assigned lectotype in the Muséum National d'Histoire Naturelle (Paris, France) is composed of a fragmentary ventral braincase. Referred paralectotype material housed in the same museum includes multiple fragmentary specimens and two nearly complete skulls. These and additional material in the Canadian Museum of Nature and Royal Ontario Museum were used to re-examine the genus. The original and new material show a number of autapomorphies among crocodyliforms: a unique contribution of the squamosal and jugal to the postorbital anterolateral process and a highly modified suborbital fenestra that displaces the antorbital cavity anteriorly and forms a bony wall separating the cavity from the orbit. Two diagnosable morphotypes are revealed, one from the Kem Kem beds, Morocco, and the other from Gara Samani, Algeria. We retain Elosuchus cherifiensis for the Kem Kem form and erect a new species Elosuchus broinae sp. nov. for the Algerian form. The revised diagnosis for Elosuchus questions the validity of E. felixi. Elosuchus is incorporated into a phylogenetic analysis that includes extensive revisions to character scores for relevant taxa. The resulting topologies recover Elosuchus sister to Meridiosaurus vallisparidisi Mones, 1980, within a complex of ‘Pholidosauridae’ that includes elosuchids and dyrosaurids but excludes Stolokrosuchus. This phylogenetic revision is used to discuss the evolution of this clade and its contribution to crocodyliform diversity during the Cretaceous.