A two-acre dig site in Utah, United States of America, has revealed the fossils of hundreds of bird-like dinosaurs of a species new to science. Named Falcarius utahensis, the discovery has been published in the journal Nature. As yet, the scientists are not sure if it ate meat or plants or both, but Falcarius belongs to a group of dinosaurs called therizinosaurs.
This group of dinosaurs was previously enigmatic, with only bits and pieces of specimens being found, but "their anatomy was so different from that of any other dinosaur that we didn't know what to make of them" says Lindsay Zanno, one of the authors of the article.
The new species is special not only for providing expanded knowledge of therizinosaur anatomy, but also for showing signs of features associated with plant-eating dinosaurs. Most other therizinosaurs are sharpclawed meat eaters, related to the ravenous Velociraptor that terrorised people in the movie 'Jurassic Park'.
Falcarius "is the most primitive known therizinosaur, demonstrating unequivocally that this large-bodied group of bizarre herbivorous dinosaurs came from Velociraptorlike ancestors" says Zanno. Co-author Scott Sampson says, "This little beast is a missing link between smallbodied predatory dinosaurs and the highly specialised and bizarre plant-eating therizinosaurs."
An adult Falcarius walked on two legs, was about four metres long and 1.4 metres tall. It had sharp, curved claws about 10cm long, with leaf-shaped teeth designed for shredding plants. The fossil graveyard was revealed to scientists by a commercial fossil collector who was collecting dinosaur bones for sale.
When he realised he had unearthed a new species he told scientists where to find the fossil bed. He was sentenced to five months in jail and a US$15,000 fine. Fossil theft has become a global problem that often removes valuable and unique specimens from the hands of scientists into hidden, private collections.