Dromaeosaurus was a small, fast predatory dinosaur that lived in western North America during the Late Cretaceous Period. Its name means running lizard, which fits its light build, long balancing tail, and powerful hind limbs. It belonged to the dromaeosaurid family, the same group as Velociraptor and Deinonychus.
Studying Dromaeosaurus helps paleontologists understand how feathered theropods hunted, moved, and evolved close to the origin of birds.
The best known species, Dromaeosaurus albertensis, is known from fossil material found in Alberta, Canada, especially skull and jaw bones with sharp, curved teeth. Its famous raised sickle claw on the second toe was likely used to grip prey rather than simply slash it. Feathers on related dinosaurs show that Dromaeosaurus was probably feathered too, even if feathers rarely fossilize directly.
Paleontologists combine bones, comparisons with relatives, muscle attachment evidence, and trackway physics to reconstruct how this animal lived.
Key Facts
- Scientific name: Dromaeosaurus albertensis.
- Time period: Late Cretaceous, about 76 to 74 million years ago.
- Estimated length: about 1.8 to 2.0 m from snout to tail.
- Estimated mass: about 15 kg, similar to a medium-sized dog.
- Speed relationship: speed = distance / time.
- Weight near Earth: W = mg, so a 15 kg Dromaeosaurus would weigh about 147 N when g = 9.8 m/s^2.
Vocabulary
- Theropod
- A group of mostly meat-eating, two-legged dinosaurs that includes Dromaeosaurus, Tyrannosaurus, and modern birds.
- Dromaeosaurid
- A member of the raptor-like dinosaur family known for agile bodies, long tails, grasping hands, and enlarged sickle claws.
- Sickle claw
- An enlarged, strongly curved claw on the second toe that could be held off the ground and used in prey capture.
- Fossil reconstruction
- A scientific model of an extinct organism made by using fossil bones, related species, anatomy, and physical evidence.
- Late Cretaceous
- The final part of the Cretaceous Period, lasting from about 100.5 to 66 million years ago.
Common Mistakes to Avoid
- Calling Dromaeosaurus a Velociraptor is wrong because they were related but separate genera with different fossil records and body details.
- Drawing Dromaeosaurus as a naked scaly lizard is misleading because close relatives preserve feather evidence, so a feathered body covering is the best-supported reconstruction.
- Assuming the sickle claw was only for slicing is too simple because biomechanical studies suggest it may have helped pin, grip, or hold struggling prey.
- Treating every reconstruction as direct fossil evidence is incorrect because soft tissues, colors, and feather patterns often require informed comparison rather than direct preservation.
Practice Questions
- 1 A Dromaeosaurus is estimated to be 2.0 m long. If its tail makes up 45% of its body length, how long is the tail?
- 2 If a 15 kg Dromaeosaurus accelerates at 3.0 m/s^2 during a short sprint, what net force is needed? Use F = ma.
- 3 Explain why paleontologists infer feathers on Dromaeosaurus even though complete feather impressions are not known from this dinosaur.