Scientists unearth fossil of 150 mln yr old squirrel-sized dino

Sydney, October 25 : Scientists have unearthed the fossil of a 150 million year old tiny dinosaur, which would have weighed less than a kilogram and measured around 70 centimetres long, about the size of a squirrel, making it the second smallest dinosaur ever found.

According to a report in ABC Science, scientists say that Fruitadens haagarorum is the world's smallest known ornithischian dinosaur, a group that included horned, duck-billed and armored dinosaurs, along with many other diverse species.

'The smallest known dinosaurs - just slightly smaller than Fruitadens - are from China and they represent some of the closest relatives of birds,' said co-author Dr Luis Chiappe.

'The new dinosaur may look bird-like because of its size, but in fact it isn't very closely related to birds or Archaeopteryx (the world's first known bird),' said Chiappe, who is director of the Natural History Museum's Dinosaur Institute in Los Angeles.

The dinosaur's name was not inspired by edible fruit, but instead by the Fruita Paleontological Area in Colorado, where its remains were discovered.

Fruits were probably on its menu, however, along with eggs and almost anything else it could get in its mouth.

'The shape of Fruitadens' teeth suggests it was probably eating both plants and small animals, that is insects,' said co-author Dr Laura Porro.

She says that in addition to being an ornithischian dinosaur, it was also a member of a family of dinosaurs called heterodontosaurids, meaning 'different-toothed lizards.'

The teeth of these dinosaurs, like those of fellow omnivore humans, erupted in different shapes, with some resembling canines, others looking like molars and so on.

Relatives of Fruitadens, which have been found in England, South Africa and other countries, lived when 'all continental land masses were connected into a single, giant continent called Pangea,' said Chiappe.

Some of these dinosaurs probably then travelled to North America, explaining how the bones of the tiny dinosaur wound up in Colorado.

'Colorado is the place where the rocks containing the fossils of Fruitadens are exposed, but presumably the species lived elsewhere in North America,' Chiappe said, mentioning that it would have coexisted with other, much larger dinosaurs, such as Diplodocus and Brachiosaurus.

According to Porro, 'Dinosaurs were once thought of as large, lumbering plant or meat eaters.'

'We now know there were lots of small dinosaurs about; that some dinosaurs were specialists that ate primarily fish or insects, that different species of plant-eating dinosaurs may have specialised in different types of plants, and that some dinosaurs may have climbed trees or even dug burrows,' she added.

--ANI