Pterosaurs are an extinct group of highly modified flying reptiles that thrived during the Mesozoic. This group has unique and remarkable skeletal adaptations to powered flight, including pneumatic bones and an elongate digit IV supporting a wing-membrane. Two major body plans have traditionally been recognized: the primitive, primarily long-tailed paraphyletic “rhamphorhynchoids” (preferably currently recognized as non-pterodactyloids) and the derived short-tailed pterodactyloids. These two groups differ considerably in their general anatomy and also exhibit a remarkably different neuroanatomy and inferred head posture, which has been linked to different lifestyles and behaviours and improved flying capabilities in these reptiles. Pterosaur neuroanatomy, is known from just a few three-dimensionally preserved braincases of non-pterodactyloids (as Rhamphorhynchidae) and pterodactyloids, between which there is a large morphological gap. Here we report on a new Jurassic pterosaur from Argentina, Allkaruen koi gen. et sp. nov., remains of which include a superbly preserved, uncrushed braincase that sheds light on the origins of the highly derived neuroanatomy of pterodactyloids and their close relatives. A µCT ray-generated virtual endocast shows that the new pterosaur exhibits a mosaic of plesiomorphic and derived traits of the inner ear and neuroanatomy that fills an important gap between those of non-monofenestratan breviquartossans (Rhamphorhynchidae) and derived pterodactyloids. These results suggest that, while modularity may play an important role at one anatomical level, at a finer level the evolution of structures within a module may follow a mosaic pattern.

 

Codorniú L, Paulina Carabajal A, Pol D, Unwin D, Rauhut OWM. (2016) A Jurassic pterosaur from Patagonia and the origin of the pterodactyloid neurocranium. PeerJ 4:e2311 https://doi.org/10.7717/peerj.2311

 

 

El pasado fin de semana, el MAU, Museo Municipal Argentino Urquiza, Rincón de los Sauces, Neuquén, Argentina,  realizó la evaluación de una denuncia de hallazgo de restos fósiles en el área La Invernada. Después de transitar por un camino de muy dificil acceso, se pudo dar con el lugar exacto de donde provenian los restos recuperados. Los materiales entregados al Museo correspondían a tres de los cinco huesos metacarpianos de una pata delantera de un dinosaurio saurópodo. La evaluación realizada en el lugar permitió determinar que el resto de los huesos faltantes aún estaban in situ, los cuales se encontraban muy bien preservados y articulados con el resto de dicha pata. En futuras salidas, el resto de los huesos serán recuperados y se evaluará si puede que el resto del dinosaurio se encuentre bajo la roca.