|A vintage photograph from 1939. A mosasaur (extinct aquatic reptile) skeleton excavated by scientific teams in the upper Cretaceous phases of the upper Cretaceous to Paleocene Moreno Formation, near the western edge 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 technical publication.