When Paleontologist David Evans observed the 66-million-year-old jawbones, he realized that he was in search of evidence of dinosaur evolution from a long period of time.

The time when ROM scientist heard about the findings of an important specimen in the Hell Creek Formation, he was travelling through Fort Peck, Mont. This was told to him by his network of dinosaur researchers.

The finding is the youngest-known raptor dinosaur and it lived with Tyrannosaurus rexand triceratops.

On Monday, the scientists said, "This discovery contributes to our understanding of the ecosystem right before the Great Extinction event at the end of the age of dinosaurs". The same jawbones were displayed at the museum.

The newly named Acheroraptor temertyorum is a close cousin of the more common velociraptor. It lived in Asia.

Acheroraptor means `Acheron plunderer' and is derived from Acheron, which is the River of Pain in Greek mythology. It tells about the Hell Creek origin of the fossils.

A new species of dinosaur recently found in the Hell Creek Formation in Montana has been described as the youngest identified dromaeosaurid and was a close relative of the Velociraptor.

The dinosaur, known as Acheroraptor temertyorum, was about nine feet tall and weighed nearly 90 pounds when it was alive.

The Acheroraptor specimens are now put on display through the holiday season in the James and Louise Temerty Galleries of the Age of Dinosaurs at ROM's Michael Lee-Chin Crystal.