Dromaeosauridae is a family of bird-like carnivorous dinosaurs commonly known as "raptors". There are several known species belonging to this family, three of the most famous being Velociraptor, Deinonychus, and Utahraptor.
Velociraptor (75-71 Million Years Ago): Despite its depiction in the Jurassic Park novels and movies, the Velociraptor was actually a very small dinosaur. Not only that, but Dr. Grant couldn't possibly have been digging for Velociraptor fossils in Montana; they are actually found in Mongolia.
Deinonychus (121-99 Million Years Ago): Dr. Grant actually could have dug up this raptor. Slightly larger than Velociraptor, Deinonychus fossils are found in Montana and Wyoming. The discovery of Deinonychus (an animal clearly built for speed and agility) in 1964 began to change paleontologists' view of dinosaurs. Gradually, the traditional view of dinosaurs as slow, cold-blooded reptiles doomed to extinction began to change to one of fast, warm-blooded, biologically successful animals.
Utahraptor (132-119 Million Years Ago): This raptor is among the largest, most heavily built Dromaeosourids yet discovered.
It now appears that another inaccuracy of Jurassic Park is the absence of feathers on the Velociraptors. Shortly after the release of the movie, many paleontologists began to believe that most, if not all raptors had feathers based on the discovery of feather imprints around fossils of very small members of the Dromaeosauridae family (e.g., the 2-foot long Microraptor). In 2007 this belief was further strengthened by the discovery of quill knobs on the forearms of a well-preserved Velociraptor specimen. Quill knobs are bumps on an animal's bone where ligaments that connect to feathers are attached. Thus, it is even more likely that even the large Dromaeosaurids, such as Utahraptor, sported feathers.