To find fossilized remains of dinosaurs in Antarctica is quiet difficult not only due to the conditions. Because of the glaciation that had started 40 million years ago, most of any fossils have been washed into the ocean. Ironically, also remains of marine dinosaurs also found their way back into their original habitat. However, near the Argentine station Marambio on the eastern side of the Antarctic Peninsula, scientists now found the fossil of a huge plesiosaur.

The Argentine station Marambio is situated at the eastern side of the Antarctic Peninsula and is the largest of the 13 Argentine stations. It has an airfield on which planes can land by using their normal landing gear.
The Argentine station Marambio is situated at the eastern side of the Antarctic Peninsula and is the largest of the 13 Argentine stations. It has an airfield on which planes can land by using their normal landing gear.

During the Jurassic era, 150 million years ago, various types of dinosaurs roamed the oceans. Amongst them, plesiosaurs were the true giants, fast and agile with their four flippers. Back then, Antarctica had been part of Gondwana and laid much further north than nowadays. Due to the geological time span, the conditions, and the glaciation, fossils from this time had been scarce. Thus, the discovery of this new fossil has a large significance because it is the first remains of a plesiosaur in the Antarctic from that time period. It was found 113 km southwest of Marambio station, the largest Argentine base, by scientists from the University of La Matanza. José Patricio O’Gorman, paleontologist at the Museo de la Plata, said that the remains were 80 million years older than any what was initially known for Antarctica. “It was the first paleontological campaign that we carried out in this outcrop, which is like a frozen, 150 million-year-old sea in a excellent state of conservation.”

The fossilized remains of the newly discovered plesiosaur consisted of a few vertebrae, ribs, and flipper bones (red). The finding spot had been a species-rich seabed 150 million years ago. Credit: CTyS
The fossilized remains of the newly discovered plesiosaur consisted of a few vertebrae, ribs, and flipper bones (red). The finding spot had been a species-rich seabed 150 million years ago. Credit: CTyS

The scientists found the petrified remains by coincidence. “when walking through the deposit we found a great diversity of fish, ammonites, some bivalves, but we did not expect to find a plesiosaurus of such antiquity; it was amazing, “ said Dr. Soledad Gouiric Cavalli, specialist for Jurassic creatures. “The find is quite extraordinary because the site does not have the type of rocks in which you can find materials preserved in three dimensions, as is the case of the vertebrae of this marine reptile,” explained the researcher. The site is situated 113 km southwest of the Argentine base of Marambio. By using helicopters from the base the researchers had valuable logistic support.

Besides the fossilized dinosaur remains, the scientists also found numerous organisms from the Jurassic, like fish, bivalves, and ammonites. Credit: CTyS
Besides the fossilized dinosaur remains, the scientists also found numerous organisms from the Jurassic, like fish, bivalves, and ammonites. Credit: CTyS

According to the researchers, the archeological site had been part of Gondwana, the large Southern continent consisting of Antarctica, Australia, New Zealand, India, Madagascar, Africa, and South America. The finding also serves the hypothesis of a possible passage between Africa and Antarctica, which had been newly separated back in the mid-Jurassic. Plesiosaurs once had roamed many parts of the ancient oceans and seemed absent from Antarctica. They went extinct at the end of the Cretaceous period, together with the rest of the dinosaurs.

Plesiosaurs ruled the oceans for more than 140 million years. With their four flippers and their flexible spine, the giants had been very fast and agile despite their size. Credit: Dmitry Bogdanov
Plesiosaurs ruled the oceans for more than 140 million years. With their four flippers and their flexible spine, the giants had been very fast and agile despite their size. Credit: Dmitry Bogdanov

Source: Agenic Ciencia, Technologia y Sociedad / Spektrum der Wissenschaft