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A review of Pachyvaranus crassispondylus Arambourg, 1952, a pachyostotic marine squamate from the latest Cretaceous phosphates of Morocco and Syria

Published online by Cambridge University Press:  09 July 2010

CNRS UMR 7207, Département Histoire de la Terre, Muséum National d'Histoire Naturelle, CP 38, 8 rue Buffon, 75005 Paris, France
CNRS UMR 7207, Département Histoire de la Terre, Muséum National d'Histoire Naturelle, CP 38, 8 rue Buffon, 75005 Paris, France
CNRS UMR 7207, Département Histoire de la Terre, Muséum National d'Histoire Naturelle, CP 38, 8 rue Buffon, 75005 Paris, France
Universidad del País Vasco/EHU, Facultad de Ciencia y Tecnología, Departamento de Estratigrafía y Paleontología, Apartado 644, 48080 Bilbao
Office Chérifien des Phosphates, Centre Minier de Khouribga, Khouribga, Morocco
Office Chérifien des Phosphates, Centre Minier de Khouribga, Khouribga, Morocco
Office Chérifien des Phosphates, Centre Minier de Ben Guerir, Ben Guerir, Morocco
Author for correspondence:


The discovery of new specimens of Pachyvaranus crassispondylus Arambourg, 1952 from the Maastrichtian phosphates of Morocco and Syria enables us to (1) redescribe in detail this poorly known varanoid lizard, (2) provide a more detailed diagnosis and (3) re-evaluate the systematic affinities of this taxon within squamates. The latter is placed in Pachyvaranidae nov., considered a new unranked clade of non-pythonomorph Varanoidea. The intense pachyosteosclerosis observed in the vertebrae and ribs suggests a primarily aquatic mode of life for Pachyvaranus. This is in accordance with the sedimentological context (shallow marine environment). As for its palaeobiogeographical distribution, Pachyvaranus is a component of the marine reptile assemblages from the southern margin of the Mediterranean Tethys, around palaeolatitudes 20° N. The osteoderms previously referred to this taxon by Arambourg are reanalysed and assigned to a teleost fish.

Original Article
Copyright © Cambridge University Press 2010

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