Dr. Ricardo Nestor Martínez (University of San Juan, Argentina)
Dr. Ricardo Néstor Martínez is a distinguished Argentine vertebrate paleontologist whose research has focused on the origin and early evolution of dinosaurs in southwestern Pangea. He obtained his B.Sc. and Ph.D. in Geological Sciences from the Universidad Nacional de San Juan, where he conducted pioneering studies on the stratigraphy, taphonomy, and paleobiology of key Triassic units in western Argentina. His work has been strongly centered on the Ischigualasto Basin, one of the most important regions worldwide for understanding early dinosaur evolution. He has played a central role in fieldwork and discoveries that established this basin as a global reference for Late Triassic faunas. His contributions include fundamental insights into vertebrate diversity, faunal succession, and paleoecology, as well as key studies on early dinosaurs such as Eodromaeus murphi, Panphagia protos, Eoraptor lunensis, and Anteavis crurilongus. Dr. Martínez has led numerous national and international research projects on Triassic-Jurassic faunal evolution, combining detailed anatomical descriptions, phylogenetic analyses of basal dinosaurs, and integrated geological and paleoenvironmental studies of the Ischigualasto Formation. He also discovered and publicized a new Norian fauna in the Marayes-El Carrizal Basin. His work has been widely published in high-impact international journals and has significantly advanced the understanding of early dinosaur diversification and Mesozoic continental ecosystems. He is currently a Full Professor and researcher at the Instituto y Museo de Ciencias Naturales, Universidad Nacional de San Juan, where he also serves as Head of the Vertebrate Paleontology Division and curator of the paleovertebrate collection. He has trained numerous Ph.D. students and fellows within the Argentine scientific system.
Abstract
The origin and early radiation of dinosaurs represent one of the most significant processes in the evolutionary history of terrestrial ecosystems, as they led to the establishment of faunas dominated by this group until the end of the Mesozoic. Despite its importance, the initial stages of this process remain poorly understood, largely due to the scarcity of continuous fossil records from the Late Triassic. In this context, the Ischigualasto Formation (Carnian) constitutes one of the most complete and best-dated records worldwide for studying this critical interval. Its fossil richness, together with its stratigraphic and paleoenvironmental control, allows for the investigation of fundamental questions regarding the origin, diversification, and early ecological history of dinosaurs. This contribution explores the potential of Ischigualasto as an exceptional archive of the dynamics of the earliest dinosaur faunas, with emphasis on community structure, body-size distributions, and their relationships with environmental changes during the Late Triassic. Furthermore, its relevance is discussed within the framework of current models on dinosaur radiation and their progressive ecological expansion across Pangea.
