Fossils of a new dromaeosaur date to the end of the Age of Dinosaurs

A wolf-sized warrior, kin to
the fierce, feathered Velociraptor, prowled what is now New Mexico about
68 million years ago.

Dineobellator notohesperus was a dromaeosaur, a group of swift, agile predators
that is distantly related to the much larger Tyrannosaurus rex. The
discovery of this new species suggests that dromaeosaurs were still diversifying, and even becoming better at pursuing
prey
, right up to the end of the Age
of Dinosaurs, researchers say March 26 in Scientific Reports.

That age came to an abrupt close
at the end of the Cretaceous Period about 66 million years ago, when a mass
extinction event wiped out all nonbird dinosaurs. A gap in the global fossil
record for dromaeosaurs near the end of the Cretaceous had led some scientists
to wonder whether the group was already in decline before the extinction, says Steven Jasinski, a
paleontologist at the State Museum of Pennsylvania in Harrisburg (SN:
4/21/16
). The new find suggests otherwise.

D. notohesperus skeleton
A skeletal reconstruction of D. notohesperus shows that the dromaeosaur, one of a group of agile predators, was about the size of a modern wolf. Analyses of over 20 fossil bits revealed that the dinosaur had feathers and was likely stronger than the closely related Velociraptor.S. Jasinski

Since 2008, Jasinski and his
colleagues have recovered more than 20 fossilized pieces of the new species from
the Bisti/De-Na-Zin Wilderness, a rapidly eroding region of barren badlands in
northwestern New Mexico. Analyses of muscle attachment sites on the fossilized
forelimbs suggest the dinosaur was unusually strong for a dromaeosaur, with a
very tight grip in its hands and feet. That grip, Jasinski says, was likely
stronger than that of its
famous kinfolk, Velociraptor and Utahraptor, giving the new
species extra weaponry in its pursuit of prey.

Like many other dromaeosaurs,
D. notohesperus had feathers, evidenced by the presence of quill nobs
bumps indicating where the feathers were attached — on its limbs (SN:
9/19/07
). But, like Velociraptor, it probably used the feathers for purposes
other than flight, Jasinski says, such as sexual selection, camouflage or added
agility while on the hunt.

Paid Content

Read More