New Specimen Sheds Light on the Anatomy and Taxonomy of the Early Late Triassic Dinosauriforms from the Chañares Formation, NW Argentina

A new partial skeleton from the Chañares Formation, Ischigualasto / Talampaya Natural Parks, provides critical insights into the anatomy and taxonomy of early Late Triassic dinosauriforms. The specimen (CRILAR-Pv 552) includes previously unknown anatomical features such as a premaxilla, inner ear, and anterior zeugopodium, which clarify debates surrounding the synonymy of two species: Lewisuchus admixtus and Pseudolagosuchus major. Analysis confirms that Pseudolagosuchus major is a junior synonym of Lewisuchus admixtus, resolving a 20-year-old controversy. Phylogenetic analysis positions Lewisuchus admixtus at the base of Silesauridae, contributing to our understanding of early dinosaur evolution.

Ezcurra, M. D., Nesbitt, S. J., Fiorelli, L. E., & Desojo, J. B. (2019). New Specimen Sheds Light on the Anatomy and Taxonomy of the Early Late Triassic Dinosauriforms from the Chañares Formation, NW Argentina. The Anatomical Record, 303(5), 1393–1438. Portico. https://doi.org/10.1002/ar.24243