https://www.vice.com/en_us/article/xgdjmz/remains-of-ancient-giant-sea-creatures-found-in-swiss-alps

Paleontologists have discovered rare fossils from ancient sea creatures that grew to enormous lengths of more than 65 feet—making them among the biggest animals ever to roam our planet—strewn across the slopes of the Swiss Alps, at elevations of nearly two miles above sea level, reports a new study. Remarkably, one of the fossils is the largest tooth ever discovered from these massive creatures, which are called ichthyosaurs. 

Ichthyosaurs are not as famous as the world’s other major behemoths: Whales and the long-necked dinosaurs called sauropods. This is in part because fossils of these Triassic Period giants are so scarce, though their smaller descendants are more commonly found later in the fossil record.