April 4, 2022 Scott Kraus

Dromaeosaurus was a Small, Cretaceous Theropod

Dromaeosaurus, pronounced “DRO-me-uh-SAWR-us”, was a small theropod dinosaur from the late Cretaceous period, about 76 to 75 million years ago. Its name comes from the Greek words “dromeos” meaning “runner” and “saurus” meaning lizard. The meaning behind the name refers to its long legs which were obviously built for speed. This dinosaur is not well-represented among the fossil records, so paleontologists tend to fill in gaps of information by looking at others in the Dromaeosauridae family, of which Dromaeosaurus was the first member.

Quick Facts

What did Dromaeosaurus look like?

Although Dromaeosaurus was only the approximate height of an average dog, it was a ferocious carnivore. While stalking on its hind feet, this predator hunted in the dense foliage of the late Cretaceous, preying on small animals and scavenging whatever was small or weak enough to kill. It also had very powerful, robust jaws that might have been able to take down bigger prey, especially if two or more hunted together.  Dromaeosaurus was like a small Velociraptor, but its jaws were estimated to be even stronger  It used the iconic sickle claw, located on the first digit of the foot, to help trap and hunt prey.  However, it weighed only about 35lbs, which would have somewhat limited its ability to take medium to large sized game.  Its relatively large head held two large eyes and a blunt snout, with a jaw lined with tiny serrated teeth, and was not a pleasant sight for its prey.

Physical attributes of the Dromaeosaurus

Dromaeosaurus was a highly adapted and evolved predator, with a mix of avian and dinosaur characteristics.  The highly adapted first toe held an inwardly curved claw, or talon.  While the claw was smaller in proportion to the claw wielded by its larger cousin the Velociraptor, it still would have been used in much the same fashion.  Digging the claws into the back of an unsuspecting prey animal, the two talons would be used to grip the prey, and maintain the precarious position to deliver a decisive blow with its jaws. It had adapted jaws and skull specializations as well. The jaw was very powerful, estimated to be several times the strength of Velociraptor. Its teeth were large and there were only nine in its skull, although more probably would not be necessary given the strength of its jaw. There is also speculation as to whether or not Dromaeosaurus had primitive feathers leading to a link between late Theropods and early birds.

What did Dromaeosaurus Eat?

Dromaeosaurus was a carnivore, so it ate meat. Its hands were useful for catching and grasping prey. Like its relative, Velociraptor, Dromaeosaurus had talons on its feet that were used in capturing or tearing prey, but paleontologists believe the dinosaurs relied on these talons differently. When Dromaeosaurus attacked its prey, the talons played a secondary role to its teeth, which were estimated to be three times more powerful than Velociraptor. The fossils also indicate that Dromaeosaurus teeth showed heavy wear and tear, much more than its other relative, Saurornitholestes. That suggested that its jaws were used for crushing and tearing, as opposed to slicing through meat.

How did Dromaeosaurus Move?

Dromaeosaurus was bipedal with long legs that suggested that it was one of the fastest running dinosaur species. Based on what paleontologists know about the physiology of theropods and members of the Dromaeosauridae family, Dromaeosaurus relied on its speed to catch prey. Especially considering it didn’t have the advantage of size.

Where did Dromaeosaurus Live?

Dromaeosaurus lived in what is now western North America and Alberta, Canada during the late Cretaceous period. The fossils discovered to date have been pretty scarce, so paleontologists have estimated the relatively narrow date range of 75-76 million years for when Dromaeosaurus thrived. The habitat of Dromaeosaurus was warmer than it was today, with many flowering plants and trees and lots of herbivores to feed on the foliage. With its strong jaws, Dromaeosaurus probably had many food sources.

The Discovery of Dromaeosaurus

The first Dromaeosaurus specimen was discovered in 1914 by the paleontologist Barnum Brown during an expedition to Red Deer River. The spot where the fossils were found is now in Dinosaur Provincial Park in Alberta, Canada. The place was so named because it is one of the richest sources of dinosaur fossils in the world. The fossil that Brown discovered consisted of a partial skull that was 9.4 inches long, a mandible, two hyoids, foot bones, and a first metacarpal. The skull was missing most of the top part of the snout. Other fossil finds of the dinosaur consist of several pieces of skull and thirty isolated teeth. They were found in subsequent expeditions in Alberta and Montana.

Dromaeosaurus changes Families

Dromaeosaurus was named by Barnum Brown and William Diller Matthew in 1922. They originally categorized Dromaeosaurus within the “Deinodontidae” family because of similarities in the skull, but that would only last until 1969. In that year, John H. Ostrom noticed many similarities between Dromaeosaurus and Velociraptor and Deinonychus, so he placed the dinosaurs into a new family. He called it Dromaeosauridae, named after the dinosaur that sparked the new category.

The Importance of Dromaeosaurus

Dromaeosaurus is important because it was the member for which the Dromaeosaurid family was named and the first of the family with good descriptions of cranial fossils. It is fortunate that the similarity between it and Velociraptor and Deinonychus was found, since Dromaeosaurus seems to be so rare in its time and place compared to other small Theropods. Because of this link, paleontologists have been able to infer what Dromaeosaurus looked like and make reasonable recreations of its skeleton for museums and exhibitions.