However, heaps of rock layers first appeared around 30 to 40 million years ago as a result of the folding of the Alps, which started 95 million years ago when the African tectonic plate started to push on the European tectonic plate. The fossils were "tectonically deformed," or driven to a rock formation at the summit of a mountain, by the tectonic plate movements.
According to lead study author P. Martin Sander, professor of vertebrate paleontology at the University of Bonn in Germany, "you kind of have to be a mountain goat to access the relevant beds." Inconveniently, they don't appear below 8,000 feet (2,438.4 meters), much above the treeline.
The lack of fossil evidence for these animals, despite the fact that they previously dominated the seas, has left paleontologists puzzled. However, the ichthyosaur fossils have revealed new details about these mysterious, extinct creatures.
One massive tooth
Three distinct ichthyosaurs left behind fossils. The difference between the two was roughly 65 feet (20 meters), while the other was 49 feet (15 meters). The largest ichthyosaur tooth ever discovered, however, is the most intriguing discovery connected to these fossils.
The largest specimen from an ichthyosaur with a full skull to date was 20 millimeters and came from a creature that was over 18 meters (59 feet) long, according to Sander. "This is huge by ichthyosaur standards: Its root was 60 millimeters in diameter," he said.
Although most of the larger ichthyosaurs were toothless, scientists believe they fed on cephalopods like squid by suction. Scientists are aware that smaller ichthyosaurs had teeth.
Using their teeth to ensnare prey like gigantic squid, huge ichthyosaurs with teeth were probably similar to sperm whales and killer whales of the present.
The tooth, however, poses a problem because the crown was broken off. Because of distinctive characteristics, such as the infolding of dentin in the tooth root, experts are certain that the tooth belongs to an ichthyosaur, although they cannot be certain that the tooth's size corresponds to the animal's size.
The blue whale, which weighs 150 tons and may grow to 98 feet (30 meters) in length, doesn't have any teeth since, in their opinion, being large and being a predator (with teeth) don't align. Instead, it removes microscopic aquatic organisms through filtration.
Sperm whales, which can grow to be 65 feet (20 meters) long and weigh 50 tons, hunt.
Therefore, Sander concluded, "marine predators probably can't get much bigger than a sperm whale."
Giants in the mountains
The fossils were initially found during the 1976–1990 geological mapping of the Alps. Furrer recalls holding the fossils in his hand as a doctorate student at the University of Zurich. Furrer was a member of the original team that extracted the fossils from the rocks known as the Kössen Formation.
The fossils were virtually forgotten throughout time.