Scottishislandisnowawindswepti-考网

Scottishisland is now a windswept island boasting pine martens,red deer and puffins.But 170million years ago,some very different beasts were leaving their mark onthe Isle of Skye.

Researchershave unearthed a new site of about 50 tracks,some as big as a car tyre,from dinosaursthat roamed the island during the Middle Jurassic.

Thestudy,published in the Scottish Journal of Geology,builds on previousdinosaur found on the island--not least a huge array of tracks discovered inthe north of Skye in 2015 by the same team.

Thatsite showed hundreds of footprints,almost all from enormous,long-necked,plant-eating dinosaurs known as sauropods.But the newly discovered site atRubhanam Brathairean,or Brothers Point,reveals that these hefty beasts weresharing their spot with another type of dinosaur:a meat-eater.

“Anytimewe find new dinosaurs it is exciting,especially in Scotland because the recordis so limited and also because these are Middle Jurassic dinosaurs and thereare very few dinosaur fossils of that age anywhere in the world,”said Dr.Stephen Brusatte,a paleontologist and co-author of the study from theUniversity of Edinburgh.

Around 170million years ago,shortly after the supercontinent Pangaea began to break up,the land that is now Skye was part of a smaller subtropical island,far closerto the equator,and replete with beaches,rivers and lagoons.

“Thiswas a subtropical kind of paradise world,probably kind of like Florida orSpain today,”said Brusatte.“These prints were made in a shallowlagoon--dinosaurs walking in very shallow water.”

One ofBrusatte's students stumbled across the tracks in 2016 while on a field tripalong Skye's coast.“The tide went out and we noticed them,”said Brusatte.“Weknew that you could find these things in Scotland and if you were walking ontidal platforms and you saw holes in the rock,they could,possibly,befootprints.”

Mappingthe site with drones and other camera equipment revealed about 50 dinosaurprints at the site in total,including what appears to be two lines of tracks.Brusatte said the conclusion that the depressions were produced by dinosaurscame down to a number of factors.

“Therewas a kind of a left-right,left-right patterning,”he said.“They were allkind of the same shape,they were all generally the same size--they were prettycircular but they had little bits sticking out at the front and those are marksof toes.”

Some ofthe footprints,said Brnsatte,were as big as a car tyre.“There were alsohandprints associated with those tracks--so these were made by.a dinosaurwalking all fours,a big dinosaur,and the dinosaur that fits the bill is asauropod--one of these long-necked,potbellied,brontosaurus-type dinosaurs,”said Brusatte,adding that they would have been up to 15 meters in length and weighedmore than 10 tonnes.“They were the biggest things living on land at the time,”he said.

But theteam also found impressions made by three-toed dinosaurs,probably theropods.“Theseare the tracks of the meat-eaters,”said Brusatte.“There were only footprints,no handprints:this was a dinosaur just walking on its hind legs；”he added,saying thecreature would have weighed about a tonne and was around five or six meters inlength.“Kind of a primitive cousin of a T-Rex,”said Brnsatte.

Brusattesaid the prints back up evidence from the 2015 site that suggests dinosaursspent time pottering around lagoons.

“Wethink of dinosaurs as thundering across the land,which of course they did,butin the Jurassic dinosaurs had become dominant,they had spread all over theworld and they were living in all sorts of environments,even on the beaches,even in the lagoons,”he said.

“These dinosaurslook like they were just lingering;they were just kind of loitering.This seemsto be a snapshot into a day in the life of some dinosaurs and I think that isjust pretty cool.”

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