The term "Paleosaur" refers to a group of prehistoric reptiles that lived during the Mesozoic Era, primarily in the late Triassic to early Jurassic periods. These creatures are often associated with the broader category of archosaurs, which includes modern birds and crocodiles. Paleosaurs were characterized by their elongated bodies, sharp teeth, and adaptations for both land and aquatic environments. Paleosaurs are significant in the study of evolution, as they provide insights into the transition from earlier reptiles to more advanced forms. Fossil evidence suggests that they played a crucial role in the ecosystem of their time, influencing the development of later reptiles, including the well-known dinosaurs.