New specimen of the enigmatic, Late Cretaceous crocodyliform Neuquensuchus universitas sheds light on the anatomy of the species

LIO, GABRIEL; AGNOLIN, FEDERICO L.; MARTINELLI, AGUSTÍN G.; EZCURRA, MARTÍN D.; NOVAS, FERNANDO E.

CRETACEOUS RESEARCH (PRINT)

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2018 vol. 83 p. 62 - 74

0195-6671

Neuquensuchus universitas is an enigmatic crocodyliform known by a single, incomplete postcranialskeleton collected in the Upper Cretaceous (Santonian) Bajo de la Carpa Formation, Neuquen province, Patagonia, Argentina. Here we describe a second specimen of N. universitas that adds important featuresrelated to the neck and limb anatomy. The new specimen allows recognizing several convergent featureswith dinosaurs, including a roughly S-shaped neck in lateral view and extremely gracile limb bones. Inaddition, the anatomy of the neural arch of the available cervical and dorsal vertebrae possesses a uniquecombination of traits not seen in any other crocodylomorph, including a laterally concave, fan-shapedprezygodiapophyseal lamina that overlaps most of the anterior half of the base of the neural arch andcentrum in lateral view and a conspicuous, horizontal prezygopostzygapophyseal lamina. The phylogenetic analysis conducted here found an unresolved position for Neuquensuchus among early branchingnon-mesoeucrocodylian crocodyliforms.