Monday, March 21, 2011

Running Lizard

The Dromaeosaurus which had remarkably large eyes and excellent vision resembles the Velociraptor, lived during the Late Cretaceous period.

The name means 'running lizard' and is derived from the Greek dromeus meaning 'runner' and sauros meaning 'lizard'.

Dromaeosaurus was a small carnivore, the size of a wolf, about 2 m in length and 15 kg in weight. Its mouth was full of sharp teeth, and it had a sharp "sickle claw" on each foot.

It lived during the Campanian stage of the Late Cretaceous, however, some fragmentary remains such as teeth which may belong to this genus have been found from the late Maastrichtian age Lance and Hell Creek Formations, dating to 65.5 million years ago.

Although only a few bones are known from the hind limb, they indicate that Dromaeosaurus was a powerfully built animal.

The presence of feathers in closely related animals makes it extremely likely that it was feathered as well.

It also probably had a good sense of smell and hearing. Its neck was curved and flexible and its jaws were solidly built.

The tail was flexible at the base but sheathed in a lattice of bony rods; this allowed it to be carried in a sharply upturned position.

In Dromaeosaurus albertensis, the vena capitis dorsalis "drains the anterior neck muscles through a pair of long canals on the posterior surface of the endocast."

Despite receiving widespread attention in popular books on dinosaurs, and the usage of a complete mounted skeleton cast in museums throughout the world, Dromaeosaurus is surprisingly poorly known from actual fossils.

The first known Dromaeosaurus remains were discovered by paleontologist Barnum Brown during a 1914 expedition to Red Deer River on behalf of the American Museum of Natural History.

The area where these bones were collected is now part of Dinosaur Provincial Park in Alberta; Canada.

The find consisted of a partial skull 24 cm in length, and some foot bones. Several other skull fragments, and about 30 isolated teeth, are known from subsequent discoveries in Alberta and Montana.

Several species of Dromaeosaurus have been described, but Dromaeosaurus albertensis is the most complete specimen.

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