Fossils of three large marine reptiles, ichthyosaurs that lived about 205 million years ago, have been discovered in the Swiss Alps, including the largest teeth found from this animal, according to a study published Thursday.
Weighing up to 80 tons and measuring more than 20 meters, ichthyosaurs, with elongated bodies and small heads, are considered among the largest animals in existence.
Appearing about 250 million years ago, some smaller, dolphin-like representatives survived until 90 million years ago. But most died 200 million years ago, especially those that evolved to become very large.
They will rival our current large sperm whale, while remaining smaller than the largest living animal on Earth today, the blue whale (up to 30 meters long).
Several fossils of this prehistoric giant have been discovered so far, forming a great mysteryaccording to Professor Martin Sander, lead author of this work published in Journal of Vertebrate Paleontology.
The specimens in question were excavated between 1976 and 1990, in the canton of Grisons in Switzerland, but have only recently been studied in detail.
Funny fact: they were found at an altitude of 2800 m. The seabed at that time, surrounding the single supercontinent (Pangea), was gradually found, due to plate tectonics, at the top of these mountains.
From an early ichthyosaur was found a series of ten rib fragments, along with a vertebra, suggesting an animal about 20 meters long. Or more or less equal to the largest specimen ever discovered (21 meters), named Shonisaurus sikanniensis and found in Canada.
The second animal measured approximately 15 meters, according to the seven vertebrae examined.
But the highlight of the show is the tooth very large, even for an ichthyosaur: its root is 60 millimeters in diameterdetailed in a press release by Martin Sander, of the University of Bonn.
The specimen found in Canada appears to have no teeth. Ichthyosaurs with teeth and without teeth may be together, according to the study.
The largest tooth discovered so far (and the only other for a giant ichthyosaur) measures 20 millimeters in diameter, from an animal nearly 18 meters long.
Most of the crown of this new tooth is unfortunately missing. The size of its host cannot be known.
According to researchers, it is difficult to know if the tooth is from a large ichthyosaur with giant teeth, or a giant ichthyosaur with standard sized teeth.
Source: Radio-Canada
