Dromaeosauridae

Dromaeosauridae, whose name means "running lizards," is the sister clade to the avian lineage Avialae. These small-to-medium theropods possessed a distinctive body plan featuring long arms, three-fingered hands, and stiff tails that served as a balance. Most famously, they had a highly extensible second toe equipped with a sickle-shaped claw. Direct evidence from Liaoning specimens such as Microraptor, Sinornithosaurus, and Zhenyuanlong proves that feathers were universal within the group. This is further supported by the presence of quill knobs on the bones of Velociraptor.

The clade is divided into several subfamilies. Microraptorinae consisted of small gliders like Microraptor, Sinornithosaurus, and Changyuraptor. Velociraptorinae included more terrestrial predators such as Velociraptor and Tsaagan. Dromaeosaurinae featured more robust members like Dromaeosaurus, Utahraptor, and Dakotaraptor. Other groups include Eudromaeosauria and the long-snouted Unenlagiinae from Gondwana, which includes Buitreraptor and Austroraptor.

These dinosaurs ranged significantly in size. Utahraptor was a 5–6 m predator weighing around 500 kg, while Microraptor was no larger than a modern crow.

Fossil evidence provides direct support for predatory behaviour. The "Fighting Dinosaurs" specimen from Mongolia preserves a Velociraptor and Protoceratops locked in a struggle, with the dromaeosaur's sickle claw embedded in the prey's neck. Researchers believe this claw was used for grappling and pinning prey, much like the talons of modern birds of prey (Fowler et al. 2011), rather than for slashing.

Whether dromaeosaurs like Deinonychus hunted in packs is still debated. While assemblages of Deinonychus teeth found with Tenontosaurus remains suggest they may have gathered to feed, coordinated pack hunting similar to modern wolves is difficult to prove. Among smaller members, microraptorines were likely capable of gliding or flapping flight. Microraptor, for example, possessed four feathered wings.

• Fighting Dinosaurs (MPC-D 100/25, Velociraptor mongoliensis + Protoceratops andrewsi) — Mongolian Academy of Sciences.
• Microraptor gui holotype (IVPP V13352) — Institute of Vertebrate Paleontology, Beijing; confirms full feathering and four-winged geometry.
• Zhenyuanlong suni holotype (JPM-0008) — Jinzhou Paleontological Museum, China; preserves pennaceous wing feathers on a 1.6 m terrestrial dromaeosaur.
• Deinonychus antirrhopus Yale specimens (YPM 5205) — basis for the modern "raptor" concept.

Sickle-claw function (slashing blade vs grappling/pinning) — current consensus favours grappling, per the "raptor prey restraint" model. Pack hunting in Deinonychus and Utahraptor — likely some form of social cooperation, but precise behaviour debated. Origin of avian flight — dromaeosaurs are the best window into the dinosaurian transition to flapping flight, and microraptorines are key. Phylogenetic position of Unenlagiinae — sometimes recovered outside Dromaeosauridae as basal paravians.

Jurassic Park's scaly, oversized "Velociraptor" (1993, actually based on Deinonychus size and behaviour) reshaped the popular image of small theropods for a generation. The shift in public-facing reconstructions toward fully feathered raptors over the past 20 years is one of paleontology's most visible communication wins.

• velociraptor
• deinonychus
• utahraptor
• microraptor
• theropoda

• Norell, M. A., & Makovicky, P. J. (2004). Dromaeosauridae. In The Dinosauria (2nd ed.).
• Turner, A. H., Makovicky, P. J., & Norell, M. A. (2012). A review of dromaeosaurid systematics and paravian phylogeny. Bulletin of the AMNH, 371, 1–206.
• Fowler, D. W., et al. (2011). The predatory ecology of Deinonychus and the origin of flapping in birds. PLOS ONE, 6, e28964.
• Xu, X., et al. (2003). Four-winged dinosaurs from China. Nature, 421, 335–340.