The anatomy of the upper cretaceous snake Najash rionegrina Apesteguía & Zaher, 2006, and the evolution of limblessness in snakes Author Zaher, Hussam Author Apesteguía, Sebastián Author Scanferla, Carlos Agustín text Zoological Journal of the Linnean Society 2009 156 801 826 journal article 0024-4082 NAJASH APESTEGUÍA AND ZAHER, 2006 Emended diagnosis: A snake nearly 2 m long with robust hindlimbs and a sacrum, tip of dentaries with a medially projected facet that bears a straight anteroposteriorly directed margin, suggesting a tightly connected mandibular symphysis, lack of dentary shelf, prootic exposed dorsally between the otooccipital and parietal, lack of laterosphenoid, developed laterally projected basipterygoid process, lack of a crista circumfenestralis, robust stapedial footplate, single large parazygantral foramen on vertebrae, arqual ridges on middle and posterior presacral vertebrae, and blunt haemapohyses on caudal vertebrae. It exhibits the following autapomorphies: (1) a thick splenial; (2) strongly concave ventral surface of the parasphenoid rostrum, forming a deep and straight gutter; (3) strongly faceted condition of the neural arch laminae; (4) enlarged and blade-like femoral trochanter.