Ихтиозавър на 170 милиона години хвърля светлина върху еволюцията на тези морски влечуги през ранния Юрски период:
170-Million-Year-Old Fossil Of Previously Unknown Marine Reptile Found In Scotland
After trawling through a collection of fossil fragments gathered on the Isle of Skye, a team of paleontologists pieced together the remains of a previously unknown species of ancient marine reptile. The now extinct predatory animal, an ichthyosaur, swam the shallow waters around Scotland some 170 million years ago, during the Jurassic Period.
Alongside identifying a new species, the team also found the remains of several known species of ichthyosaur, which are believed to be the first ichthyosaurs from Scotlanddescribed so far. Not only that, but the find is helping scientists slowly fill in a frustrating gapin the fossil record during the Middle Jurassic, a 15-million-year stretch that began around 176 million years ago.
The discovery was made by researchers at the University of Edinburgh who had the laborious task of examining a collection of fragmented skulls, teeth and vertebrae unearthed by different teams of scientists and fossil hunters over the past 50 years. Several different species of ichthyosaur were discovered, which spanned the Early to Middle Jurassic, including the newly described Dearcmhara shawcrossi.
The latter part of the name is in honor of the specimen’s discoverer, Brian Shawcross, who donated the fossils to a museum after recovering them in 1959. Dearcmhara is gaelic for “marine lizard”; ichthyosaur translates to fish lizard. D. shawcrossi represents both a new species and a new genus, making the discovery particularly exciting.
The specimen, which has been described in the Scottish Journal of Geology, was around the size of an average great white shark, measuring 4.3 meters (14 ft) from snout to tail. This animal therefore sits at the smaller end of the ichthyosaur spectrum as some previously described specimens measured up to nine meters (30 ft) in length.
Ichthyosaurs were predatory marine reptiles that swam our oceans while the dinosaurs ruled the land. They lived during the Mesozoic Era, the Age of the Reptiles, first appearing during the Triassic and finally dying out during the Cretaceous. Early ichthyosaurs had long, flexible bodies and probably swam like modern day eels. However, they rapidly diversified from animals that resembled lizards with fins into a more streamlined, fish-like form that was built for speed.
Although a number of ichthyosaur fossils have been unearthed since their discovery along the Dorset coast back in 1809, skeletons from the Middle Jurassic period are rare. “It’s one of a select few specimens of that age in the world,” said paleontologist and study co-author Stephen Brusatte. Furthermore, Brusatte is excited to be able to boast that this is “the first time we’ve found a new species that was uniquely Scottish.”
[Via University of Edinburgh, Scottish Journal of Geology, BBC News and Live Science]
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