Dromaeosauridae

Lore & Background

Dromaeosaurids were bipedal dinosaurs with a distinctive body plan: a relatively large skull, serrated teeth, forward-facing eyes, a moderately long S-curved neck, and long arms with three-fingered hands ending in large claws. Their most famous feature is the enlarged, sickle-shaped claw on the second toe, which was held off the ground when walking and used in capturing prey and climbing. Their tails were long and could bend side to side, possibly serving as a stabilizer or counterweight.

Reader's Guide

Dromaeosaurids are significant for rekindling theories that dinosaurs were active, fast, and closely related to birds. Robert Bakker's illustration of Deinonychus in a fast run is among the most influential paleontological reconstructions. The discovery of feathers in many dromaeosaurids, including Sinornithosaurus, Microraptor, and Velociraptor, provided strong evidence that dinosaurs evolved into birds. Their fossils show pennaceous feathers on arms and tail, and some even have quill knobs, indicating that even large ground-dwelling species retained feathers. The group's classification has been debated, with some paravian fossils reinterpreted as belonging to a separate family, Unenlagiidae. Their legacy in popular culture, especially as 'raptors' in Jurassic Park, has emphasized their bird-like appearance and behavior.

Did You Know?

• The name Dromaeosauridae means 'running lizards', from Greek words for 'running at full speed' and 'lizard'.
• The enlarged second toe claw was held off the ground when walking, a condition called functional didactyly.
• Some dromaeosaurids, like Microraptor, show evidence of a second pair of wings on the hind legs.
• Isolated teeth from the Isle of Wight suggest a possible third lineage of giant dromaeosaurids, the size of Utahraptor.