Dromaeosaurs

Dromaeosaurs, meaning “running lizards,” are a group of carnivorous theropod dinosaurs within the family Dromaeosauridae, a subset of Paraves that also includes birds. They lived from the Middle Jurassic to the Late Cretaceous, and fossil remains have been found in North America, Asia, and Europe. Well-known members include Velociraptor, Deinonychus, Dromaeosaurus, and Utahraptor.

Anatomically, dromaeosaurs were generally small to medium-sized, highly agile predators with long hind limbs and a relatively short, stiff tail used for balance. A distinctive feature is a large, sickle-shaped claw on the second toe of each foot, which could be curled upward when not in use and likely helped grasping or slashing prey. Their forelimbs were relatively long with grasping hands and three fingers. Many species had sharp, serrated teeth, and their overall build suggests they were capable runners and swift hunters.

Feather evidence is common in dromaeosaurs, including examples of down-like coverings and, in some taxa, wing-like feather arrangements on the arms. This supports a close evolutionary relationship to birds and indicates that plumage played a role in thermoregulation, display, or signaling in addition to potential flight-related function in some lineages.

Ecology and behavior remain topics of study. Dromaeosaurs were active carnivores occupying various ecological niches, and their brains and sensory systems appear advanced for non-avian dinosaurs. The extent of social or cooperative hunting is debated, with limited and contested evidence. Phylogenetically, they are closely related to troodontids and together form a group near the origin of birds.