Giant, ancient sea reptiles' fossils have been discovered in the high Swiss Alps, an unexpected location.

According to a recent study, the fossils belonged to three ichthyosaurs, which may have been among the biggest creatures to have ever lived on Earth. The extinct animals were comparable in size and weight to modern sperm whales, reaching 80 tons and 65 feet (20 meters) in length.

About 250 million years ago, these "fish lizards" initially formed in the ocean. They had small heads and elongated bodies, somewhat resembling dolphins. They appeared after more than 95% of marine animals were wiped off during the Permian mass extinction. However, the enormous ichthyosaurs went extinct 200 million years ago, and only the smaller, more dolphin-like species persisted until 90 million years ago.

The discovery was described in a research that was published in the Journal of Vertebrate Paleontology in April 2022.

So how did the skeletal remains of enormous marine animals, including one longer than a bowling alley, end up at a height of 9,186 feet (2,800 meters)?

Those rock formations were the lagoon floor some 200 million years ago.

We believe that the large ichthyosaurs entered the lagoon after following schools of fish. The fossils may also have come from stray animals who perished there, according to research co-author Heinz Furrer, a former curator at the Paleontological Institute and Museum of the University of Zurich.

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.

But recently, more ichthyosaur fossils been surfaced, according to Furrer. Therefore, it appeared worthwhile to us to also conduct a more thorough analysis of the Swiss discoveries.

Although ichthyosaur fossils have been discovered all over the world, North America has produced the majority of the large species' remains. The range of these specimens is widened by their discovery in contemporary Switzerland.

Some of them may grow to be as big as blue whales, the biggest animals on earth, according to earlier evidence.

"In Nevada, we see the beginnings of true giants, and in the Alps, the end," Sander added. "Only the medium-to-large-sized dolphin - and orca-like forms survived into the Jurassic (Period)," which lasted from 145 to 201 million years ago.

Sander ponders whether there are still "giant sea creatures hidden beneath the glaciers." But these remains close an information gap about these enormous marine lizards.

The fact that we know so little about these enormous ichthyosaurs despite the exceptional size of their bones amounts to a tremendous embarrassment for paleontology, according to Sander. "We anticipate meeting this challenge and locating new, superior fossils soon."