The Largest Fossil Ever Found of an Ancient ‘Sea Dragon’

FOSSILS OF ICHTHYOSAURUS, AN ANCIENT creature that swam the oceans before the dinosaurs even existed, were some of the first evidence that humans discovered of prehistoric life on earth. The first complete fossil of one of these reptiles was found in 1810, by a scrappy female paleontologist named Mary Anning, on the cliffs of Britain. So when another specimen of Ichthyosaurus was unearthed on the coast of England in the 1990s, this new “sea dragon” fossil wasn’t considered such an important discovery.

Now, though, two paleontologists report in the journal Acta Palaeontologica Polonica that this fossil is a unique specimen—the largest Ichthyosaurus ever found, with a fossilized embryo in its belly, the third ever on record, the BBC reports.

After the fossil was first discovered, it made its way to the Lower Saxony State Museum, in Hannover, Germany. Recently, Sven Sachs of the Bielefeld Natural History Museum, spotted it there and began to suspect it might be worth taking a closer look at. With ichthyosaur expert Dean Lomax, of the University of Manchester, he examined the specimen and determined that, at more than 10 feet long, this specimen was the largest Ichthyosaurus somersetensis ever found.

This particular reptile would have lived about 200 million years ago; its kind went extinct about 90 million years ago, in the Cretaceous period.

The paleontologists found another surprise when they examined this particular fossil more closely—its tail had been appended from another ichtyosaur entirely, in order to make it look better on the wall of the museum.

The Largest Fossil Ever Found of an Ancient ‘Sea Dragon’

The newly discovered Russian dinosaur named after Mongolian spirit

Nikolay Zverkov, a student from the Department of Paleontology at the Faculty of Geology of the Lomonosov Moscow State University and one of the article authors says: “The new pliosaur – Luskhan itilensis – has got its name from the Mongolian mythology, where Luus-khan stands for a spirit and master of water, and Itil is the ancient Turkic and Mongolian name for the Volga. A pliosaur skeleton was found in 2002 in the Cretaceous deposits (the Hauterivian age of the early Cretaceous Period, about 130 million years ago) on the bank of the Volga River, within 20 kilometers to the north of Ulyanovsk.”

Luskhan itilensis has been included into phylogenic analysis (a taxon-character matrix has been analyzed in the TNT). As the result of this analysis the scientists have recovered a new evolutionary tree for this reptile group. In the pliosaur family tree Luskhan is located in-between the Jurassic and Late Cretaceous pliosaurs since it combines a number of primitive and advanced characters.

Presence of several unique features puzzled the researchers so they had to gather additional data, related to pliosaur morphology, and conduct several additional morphospace analyses. Contrary to all other advanced pliosaurs, traditionally considered to be unexceptionally macropredators, Luskhan had an elongate skull with slender snout and relatively small teeth. The latter denotes adjustment to a diet of medium-sized prey: fish and squid. At the same time, Luskhan shows remarkable resemblance in the form of a skull and snout with representatives of a group of the Cretaceous plesiosaurs (the Polycotylidae family).

Nikolay Zverkov concludes: “So, the new discovery has shown that ecomorphological diversity of pliosaurs was wider and their evolutionary history is more complicated than previously thought. For a long period of time there has been almost no information, concerning the Early Cretaceous pliosaurs. And this period in the pliosaur history is called the “Neocomian gap”. However, the discoveries of the last years allow to close this gap.”

The newly discovered Russian dinosaur named after Mongolian spirit