New Triassic crocodile relative reveals ostrich-like body plan and early archosaur evolution

Scientists have identified a newly described prehistoric species, Labrujasuchus expectatus, an unusual crocodile relative from the Late Triassic period that challenges traditional ideas about early archosaur evolution. The fossil was analyzed in research published in the Journal of Vertebrate Paleontology and reveals a creature that looked strikingly different from modern crocodiles. Instead of a sprawling, four-legged body with sharp teeth, Labrujasuchus likely walked on two legs, had small forelimbs, and possessed a toothless beak, giving it a superficial resemblance to ostrich-like dinosaurs. Despite its dinosaur-like appearance, the species belongs to the archosaur lineage that ultimately gave rise to crocodiles. It is part of a group known as shuvosaurids, which independently evolved bipedal locomotion and other features similar to theropod dinosaurs, demonstrating a clear case of convergent evolution. This means different evolutionary branches developed similar traits to adapt to comparable ecological roles. The discovery is especially significant because only a handful of shuvosaur species are currently known. Labrujasuchus expectatus helps fill a predicted gap in the fossil record, linking previously known species from older and younger rock layers and improving scientists’ understanding of how this group evolved over time. The species name “expectatus” reflects the idea that researchers anticipated finding such an intermediate form. The fossils were found in the Ghost Ranch region of New Mexico, a well-known Late Triassic site that has produced many important discoveries. The ecosystem of that time was highly diverse, featuring unusual reptiles with a wide range of body plans and lifestyles. The study highlights how early archosaurs experimented with different evolutionary strategies long before modern crocodiles and birds emerged. Overall, the find provides important insight into how flexible early reptile evolution was and how some crocodile relatives briefly evolved body plans that closely resembled dinosaurs, despite being on a completely different evolutionary branch.