| Part of a jaw from a mosasaur--an extinct aquatic reptile--from the upper Cretaceous section of the upper Cretaceous to Paleocene Moreno Formation. Collected by scientific crews from an exposure of the Moreno Formation near the western border of California's Great Central Valley. Scientific name is Plotosaurus bennison. High resolution stratigraphic research disclosed that, locally in California Moreno depositional times, mosasaurs went extinct 158,000 years prior to the Yucatan Peninsula meteorite collision that possibly caused the dinosaurian demise some 66 million years ago. Photograph courtesy a specific web page. |