Plesiomon is a genus of extinct reptiles that lived during the Late Cretaceous period, approximately 70 million years ago. These creatures are part of the larger group known as plesiosaurs, which are characterized by their long necks, small heads, and large bodies. Plesiomons were primarily marine animals, adapted to life in the ocean. Fossils of Plesiomon have been found in various locations, providing insights into their anatomy and lifestyle. They likely fed on fish and other marine organisms, using their long necks to reach prey. Their unique features contribute to our understanding of the diversity of prehistoric marine life.