Fossilized remains of small dinosaur rediscovered in Canada

Tuesday, March 17, 2009

Model of the "sickle claw" of a dromaeosaurid, NHM.
Image: Ballista..

Scientists in Alberta, Canada have discovered a new species of dinosaur in remains left untouched for 25 years. The find has been published in the Proceedings of the National Academy of Sciences.

The measurements put the fossil, the smallest discovered in North America, at one and a half feet (50 centimetres) tall, weighing in at an estimated 4 to 5 pounds (1.8-2.2 kilograms) when it was alive, about the size of today's modern domesticated cat. Scientists believe it ate things like insects and other smaller dinosaurs. It is estimated to have roamed earth during the late Cretaceous Period about 75 million years ago in what is known as present day Alberta.

The fossil was discovered in 1982 by Elizabeth "Betsy" Nicholls, a Canadian paleontologist who died in 2004. The fossils went largely unstudied since their discovery in the 80's and were later located in 2007 at an archive in the University of Alberta.

"Hesperonychus is currently the smallest dinosaur known from North America. [This] raises the possibility that there are even smaller ones [dinosaurs] out there waiting to be found," said Nick Longrich, paleontology research associate with the University of Calgary's Department of Biological Sciences, and one of the scientists publishing the report. He added that the creature spent most of its time on the ground.

Hesperonychus elizabethae is a species of the family Dromaeosauridae and is a cousin of Velociraptor . This fully feathered, warm blooded bird of prey was believed to have walked upright on two legs with claws like the Velociraptor. Its second claw was larger, giving rise to the name Hesperonychus which means "western claw." elizabethae was chosen in honor of Nicholls.