Janusaurus

Janusaurus is a genus of mosasaur, an extinct group of marine reptiles. It lived during the Late Cretaceous period, approximately 85 to 80 million years ago. The type species, Janusaurus walkeri, was described in 2021 based on fossil remains found in the Niobrara Formation of Kansas, United States. Janusaurus is notable for its relatively small size compared to other giant mosasaurs, with an estimated length of around 4 meters (13 feet). Its skull features a unique combination of characteristics, including a relatively short snout and prominent crests above the eyes, which may have been used for display or species recognition. The dentition suggests a diet of fish and other small marine organisms. The discovery of Janusaurus adds to our understanding of mosasaur diversity and evolution during the Late Cretaceous in North America. Its presence in the Niobrara Formation, a well-studied Lagerstätte, provides valuable insights into the ecosystem of the Western Interior Seaway. Further research on its skeletal anatomy and phylogenetic relationships is ongoing to clarify its position within the mosasaur family tree.