Los Molles Formation

Los Molles Formation is a geological layer sequence in Mendoza Province composed of organic shale, lime-mudstone, and sedimentary rocks. These strata spread across the Neuquén Basin and display the varied depositional history of this ancient landscape.

This formation developed during the Early to Middle Jurassic period, from about 185 to 165 million years ago, through extensive sedimentation processes. That timespan shaped the evolution of the Neuquén Basin and left the layered sequences visible today.

Research teams from universities worldwide conduct field studies at the Los Molles Formation to examine the preserved remains of marine reptiles and dinosaurs.

Access to the formation is available in sections of the Neuquén Basin, though field research areas may have local restrictions. Visitors should prepare for rough terrain and variable access routes while consulting local guides or information centers.

Fossils of two dinosaur species, Isaberrysaura mollensis and Chacaicosaurus cayi, were discovered in these rocks and were previously unknown to science. These finds reveal the variety of life that inhabited this region millions of years ago.