Velociraptor

Velociraptor (/vəˌlɒsɪˈræptər, vəˈlɒsɪræptər/; lit. 'swift thief') is a genus of small dromaeosaurid dinosaurs that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago. It was a bipedal, feathered carnivore with a long tail and an enlarged sickle-shaped claw on each hindfoot, used to tackle and restrain prey.

Two species are currently recognized. The type species is V. mongoliensis, named and described in 1924, with fossils found in the Djadochta Formation, Mongolia. A second species, V. osmolskae, was named in 2008, based on skull material from the Bayan Mandahu Formation, China.

Velociraptor is famous because of its prominent role in the Jurassic Park films. In reality, it was about the size of a turkey, much smaller than the film versions. Today, Velociraptor is well known to paleontologists, with many fossil skeletons discovered, including one particularly famous specimen found locked in combat with a Protoceratops.

History of discovery

The first Velociraptor fossil was found in the Flaming Cliffs in the Gobi Desert by an American Museum of Natural History expedition on August 11, 1923. This fossil, a crushed skull with a claw, was described in 1924 by museum president Henry Fairfield Osborn. He named it Velociraptor mongoliensis because it was swift and from Mongolia.

More fossils were found by Soviet, Polish, and Mongolian scientists, including a famous fossil of a Velociraptor locked in battle with a Protoceratops. In the late 1980s and 1990s, additional fossils were discovered in China and Mongolia, helping scientists learn more about these dinosaurs.

Description

Velociraptor was a small to medium-sized dinosaur that lived in Asia during the Late Cretaceous period, about 75 million to 71 million years ago. Adults were between 1.5–2.07 m (4.9–6.8 ft) long and weighed about 14.1–19.7 kg (31–43 lb). Some estimates suggest they could be larger, up to 2.5 m (8 ft) long and weigh up to 28 kg (60 lb).

The skull of Velociraptor was long and narrow, growing up to 23 cm (9.1 in) long. It had a distinctive up-curved snout and large eye sockets. The lower jaw was long and narrow, equipped with sharp teeth that had serrations along their edges. Velociraptor had a large claw on its second toe, which was used for catching and holding onto prey. Its tail had bony projections and tendons, giving it flexibility and strength.

Classification

Velociraptor belongs to a group called Eudromaeosauria, which is part of the larger dromaeosaurid family. It is often placed in its own subfamily, called Velociraptorinae. This subfamily includes all dromaeosaurs more closely related to Velociraptor than to Dromaeosaurus.

When Velociraptor was first discovered in 1924, it was grouped with other meat-eating dinosaurs in the family Megalosauridae. Later, as more dinosaurs were found, scientists realized it was a dromaeosaurid. Today, the only recognized species of Velociraptor are V. mongoliensis and V. osmolskae.

Paleobiology

Feathers

Scientists found special bumps on the arm bone of a Velociraptor fossil, called quill knobs. These bumps are where feathers would have attached. This discovery suggests that Velociraptor had feathers, even though it couldn’t fly. These feathers might have been used for display, nesting, or to help it run faster up slopes.

Senses

Studies of Velociraptor’s braincase show it could hear a wide range of sounds and track prey easily. This suggests it was a quick and agile hunter.

Feeding

Research shows that Velociraptor likely hunted small, fast animals. Its bite was not as strong as some related dinosaurs, but it could still catch its prey effectively.

Predatory behavior

A famous fossil shows a Velociraptor locked in combat with a Protoceratops, suggesting Velociraptor hunted by ambushing its prey. Instead of slashing with its claw, it might have used it to pierce important body parts like veins or windpipes.

Evidence for pack hunting is limited, though some related dinosaurs may have hunted together. Velociraptor’s claws and body shape suggest it could grip prey tightly and use its jaws to deliver final bites.

Scavenging behavior

Fossils show Velociraptor may have also eaten animals that were already dead, possibly scavenging on Protoceratops or pterosaurs.

Metabolism

Velociraptor was likely warm-blooded, needing lots of energy to hunt. However, its metabolism may have been more moderate than that of modern warm-blooded animals, similar to that of kiwis.

Paleopathology

Fossils show Velociraptor could suffer injuries, such as bite wounds from other Velociraptors or broken ribs, indicating a tough life in the wild.

Paleoenvironment

Velociraptor lived in places called the Bayan Mandahu and Djadochta formations. These areas had many different kinds of dinosaurs. In Bayan Mandahu, Velociraptor osmolskae lived with armored dinosaurs, small meat-eaters, and bird-like dinosaurs. The Djadochta Formation, where Velociraptor mongoliensis was found, was a dry area with lots of sand dunes. It had rivers only sometimes. Fossils from this place show that many dinosaurs, including Velociraptor, were quickly buried in sand during big storms.

Cultural significance

The dinosaur Velociraptor became famous because of the 1990 novel Jurassic Park by Michael Crichton and the 1993 movie directed by Steven Spielberg. In these stories, the "raptors" are based on another dinosaur called Deinonychus, not the real Velociraptor. The filmmakers used ideas from Deinonychus for how the dinosaurs looked and behaved.

Because the movies were made before scientists discovered that these dinosaurs had feathers, the Velociraptors in the films do not have feathers. Later movies in the Jurassic World series kept the same look for Velociraptor, even though real Velociraptor would have had feathers.