A motorboat-sized beast that was at the top of its food chain 170 million years ago is Scotland's first known native marine reptile.
The formidable ocean predator, described in the latest issue of the Scottish Journal of Geology, might have munched on dinosaurs and sharks, since both also lived at or around what is now the Isle of Skye. The predator was an ichthyosaur, meaning an extinct marine reptile that had a pointy head, four flippers and a vertical tail. Together, these features made such animals look like sinister dolphins.
A group of paleontologists working in Scotland studied the remains of the newly discovered ichthyosaur, named Dearcmhara shawcrossi. Dearcmhara --[/i ]pronounced jark vara -- is Scottish Gaelic for "marine lizard." The species is one of just a handful ever to have been given a Gaelic name.
"Believe it or not, this is the first distinctly Scottish marine reptile species that has ever been described, and our paper is the first paper on ichthyosaurs from Scotland," project leader Steve Brusatte of the University of Edinburgh's School of GeoSciences told Discovery News.
Remains of the animal were found at the Isle of Skye's Bearreraig Bay, where amateur collector Brian Shawcross found them. Instead of keeping or selling them, which often happens, Shawcross donated the specimens to the Hunterian Museum in Glasgow. This allowed researchers to study them, determine their significance and piece together what this animal looked like in the flesh.
"It would have been roughly 14 feet long or so, and probably would have fed on fish and marine invertebrates," Brusatte said.
Much of Skye was under water 170 million years ago. Skye was joined to the rest of the U.K. then, and was part of a large island positioned between land masses that gradually drifted apart and became Europe and North America.
Sharks in the region during the marine reptile's lifetime were generally smaller and more primitive than today's sharks, so it's possible that Dearcmhara ate them.
As for dinos, Brusatte said, "Dinosaurs did live in other parts of Scotland at the same general time as this ichthyosaur was living in the water. We know this from other rare fossils from Skye -- bones, teeth and footprints of very different type of dinosaurs, including big long-necked sauropods and carnivorous theropods."
If any waded or fell into the shallow, warm seas where Dearcmhara lived, they likely would have been dinner for the stealthy ichthyosaur.
Nick Fraser of National Museums Scotland is excited by the discovery, and what it means for his country.
"Scotland is well noted for its geology and geologists, including perhaps the most famous of all, James Hutton (often dubbed the Father of Modern Geology, although he lived from 1726 to 1797)," Fraser told Discovery News. "However, it is not widely noted in the public realm for its fossils, which is unfortunate, as it boasts some incredibly important localities and specimens."
He explained that remains for prehistoric fishes and very early reptiles from the Triassic have been found in Scotland.
"Admittedly, there are not the huge rock exposures in Scotland that permit the excavation of spectacular death-beds of dinosaurs as you might find in the American West," Fraser said. "Yet, even some of the fragmentary remains that we do find are often of great scientific importance, and that is certainly the case with the Skye Jurassic fossils."
Fraser said that the remains represent a time period, the Middle Jurassic, which is rather poorly known worldwide in the fossil record. Evidence, however, from surrounding periods suggests that animal life then, in the seas and on land, was incredibly rich and diverse.
"Skye now seems set to play something of a starring role in shedding light on this window in time," Fraser said.
Both he and Brusatte also have a message for amateur fossil collectors in Scotland.
"If you find fossil vertebrate specimens in Scotland, those of us in the scientific community would love to work with you," Brusatte said. "If you work with us and donate your fossils to a museum, you might also get a new species named after you!"