The Validity of Lagosuchus Talampayensis Romer, 1971 (Archosauria, Dinosauriformes), from the Late Triassic of Argentina

A reassessment of the fossil record from the Ischigualasto / Talampaya Natural Parks, Argentina, reveals that Lagosuchus talampayensis, a key 'proto-dinosaur' species, is not distinct but shares critical anatomical traits with Marasuchus lilloensis. This finding, based on new observations of the holotype's femoral head morphology, suggests L. talampayensis is a senior synonym of M. lilloensis. The study challenges previous classifications and sheds light on early dinosauromorph diversity in the Late Triassic Chañares Formation, refining our understanding of dinosaur precursors' evolutionary relationships.

Agnolin, F. L. (2019). THE VALIDITY OF LAGOSUCHUS TALAMPAYENSIS ROMER, 1971 (ARCHOSAURIA, DINOSAURIFORMES), FROM THE LATE TRIASSIC OF ARGENTINA. Breviora, 565(1), 1. https://doi.org/10.3099/0006-9698-565.1.1