Raptors

Raptors

Rarely has a single movie so permanently twisted peoples’ views of an entire family of dinosaurs. In Steven Spielberg’s Jurassic Park, Velociraptor is presented as a man-sized, scaly-skinned predator smart enough to turn doorknobs. In real life, though, this dinosaur was only the size of a small toddler, probably covered in feathers, and not quite as intelligent as the average hummingbird. (For the record, what are called Velociraptors in Jurassic Park were really much bigger Deinonychuses, but let’s not quibble.) See a gallery of raptor pictures.

The time has clearly come to set the record on raptors straight. For one thing, you might be surprised to learn that “raptor” itself is a mass-market, Hollywood-type name: paleontologists prefer to speak of “dromaeosaurs” (Greek for “running lizards”), which isn’t quite as catchy. And for another, the raptor roster extends far beyond the popular Velociraptor and Deinonychus, as explained below. (By the way, not all dinosaurs with “raptor” in their names are true dromaeosaurs; examples are Oviraptor and Eoraptor.)

What Is a Raptor?

Technically, paleontologists define dromaeosaurs as dinosaurs that share certain obscure anatomical features. Broadly speaking, though, raptors can be classified as small- to medium-sized, bipedal carnivores equipped with grasping, three-fingered hands and relatively big brains. Most distinctively, raptors had huge, solitary claws on each of their hind feet, which they probably used to slash (and sometimes disembowel) prey.

Then there’s the issue of feathers. While it can’t be flatly stated that all dromaeosaurs had feathers, enough fossils have been found bearing evidence of this unmistakeably bird-like trait to lead paleontologists to conclude that feathered raptors were the norm, rather than the exception. Some genera (such as Microraptor) were capable of gliding, and some experts even speculate that raptors descended from flying (non-bird) ancestors. In any case, dromaeosaurs are closely related to modern birds; the name “raptor” also embraces modern eagles and falcons.

The Rise of the Raptors

Raptors came into their own during the late Cretaceous period (about 90 to 65 million years ago), but they may have roamed the earth a hundred million years before (paleontologists have yet to dig up any fossils, but they have found distinctly dromaeosaur-like teeth dating from this time). It’s likely that these early raptors were relatively tiny, scurrying under the feet of the larger sauropods of the middle to late Jurassic.

In the Cretaceous, raptors could be found all over the planet, with the exception of modern-day Australia and southern Africa. These creatures varied enormously in size and sometimes in anatomical features: Microraptor weighed only a few pounds and had four feathered proto-wings, while the fierce, two-ton Utahraptor could have whomped a Deinonychus with one claw tied behind its back. In between were standard-issue raptors like Dromaeosaurus and Saurornitholestes, swift, fierce predators that made quick meals out of lizards, bugs, and smaller dinosaurs.

Raptor Behavior

While even the brainiest raptor couldn’t outwit a siamese cat, much less a human being, it’s clear that dromaeosaurs were slightly smarter than their fellow dinosaurs (this increase in brain size can be directly linked to the eye-hand coordination required for active predation, since swifter reflexes translate into more frequent meals).

As to whether or not raptors hunted in packs, that debate has yet to be settled conclusively one way or the other. The fact is, very few modern birds engage in cooperative hunting; since birds are tens of millions of years farther down the evolutionary line, that can be taken as evidence that raptor packs are a figment of a Hollywood producer’s imagination. Still, the recent discovery of multiple dromaeosaur tracks shows that at least some of these dinosaurs lived in small herds, so pack hunting is certainly within the realm of possibility.

Here’s a list of the most notable raptors; just click on the links for more information.

Achillobator – This fierce raptor was discovered in modern-day Mongolia.
Bambiraptor – Yes, this tiny raptor was named after you-know-who.
Buitreraptor – The oldest raptor ever discovered in South America.
Deinonychus – One of the most fearsome predators of the Cretaceous era.
Dromaeosaurus – This “running lizard” was probably covered with feathers.
Microraptor – This tiny proto-bird had four wings rather than two.
Pyroraptor – This “fire thief” prowled the plains of prehistoric France.
Rahonavis – Was it a raptor-like bird, or a bird-like raptor?
Saurornitholestes – A close cousin of Velociraptor.
Unenlagia – This bird-like raptor was native to South America.
Utahraptor – Probably the biggest raptor that ever lived.
Velociraptor – This dino was vicious–but a lot smaller than you thought.

Thanks to Jurassic Park, Velociraptor is one of the world’s most famous dinosaurs–but there’s a big difference between the Hollywood version of Velociraptor and the one familiar to paleontologists. Here are 10 facts you may or may not have known about this small but vicious predator. (See a gallery of Velociraptor pictures.)

10 Facts About Velociraptor
By Bob Strauss, About.com Guide

1. That wasn’t really a Velociraptor in Jurassic Park.

The sad fact is, Velociraptor’s claim to pop-culture fame is based on a lie: the movie’s special-effects wizards have long since confessed that they modeled their Velociraptor after the much bigger (and much more dangerous-looking) raptor Deinonychus, whose name isn’t quite as catchy or easy to pronounce.

2. Velociraptor was about the size of a big chicken…

For a dinosaur that’s often mentioned in the same breath as Tyrannosaurus Rex, Velociraptor was remarkably puny: this carnivore weighed only about 30 pounds fully grown (about the same as a good-sized human toddler) and achieved an awe-inspiring height of two or three feet, max.

3. …and it looked like a big chicken, too.

Based on the the smaller, more primitive, feathered raptors that predated it by millions of years, paleontologists believe Velociraptor sported feathers, too, though the direct evidence for this is slim. Artists have pictured this dinosaur with everything from wan, chicken-like tufts to bright green plumage worthy of a South American parrot.

4. Velociraptor lived in central Asia, not North America.

Based on its Hollywood treatment, you might expect Velociraptor to be as American as apple pie, but the fact is that this dinosaur was native to modern-day Mongolia (the most famous species is Velociraptor mongoliensis). America Firsters have to settle for its much bigger, and much more deadly, cousins Deinonychus and Utahraptor.

5. There’s no evidence that Velociraptor hunted in packs.

To date, all of the dozen or so Velociraptor skeletons found in Mongolia have been of solitary individuals. The idea that Velociraptor ganged up on its prey probably stems from the discovery of associated Deinonychus remains in North America; this raptor may have hunted in packs to bring down large hadrosaurs like Tenontosaurus.

6. Velociraptor wasn’t the smartest dinosaur of the Cretaceous period…

While we’re on the subject: that scene in Jurassic Park where a Velociraptor figures out how to turn a doorknob? Pure fantasy. Even the smartest dinosaur of the Mesozoic Era, Troodon, was dumber than a newborn kitten, and it’s a safe bet that no reptiles (ancient or modern) have ever learned to use tools.

7. …and it wasn’t the fastest, either.

Not to beat up on poor little Velociraptor, but this “speedy thief” (that’s what Velociraptor’s name means) wasn’t nearly as fast as contemporary ornithomimids, or “bird mimics,” some of which could attain speeds of 50 miles per hour. Even the fastest Velociraptors would have been severely hampered by their short, turkey-sized legs.

8. A Velociraptor was fossilized in the act of attacking a Protoceratops.

So Velociraptor didn’t hunt in packs, and it wasn’t particularly big or speedy. How did it survive? Well, by attacking comparably small dinosaurs like the pig-sized Protoceratops: one famous fossil shows a Velociraptor and Protoceratops locked in combat as both were buried alive by a sudden sandstorm.

9. Velociraptor’s main weapons were its single, oversized hind claws.

Although its sharp teeth were certainly unpleasant, the primary weapons in Velociraptor’s arsenal were the curved, three-inch-long claws on its hind feet, which it used to slash and jab at prey. It’s possible that this raptor stabbed its prey in sudden, surprise attacks, then withdrew to a safe distance as its victim bled to death.

10. Velociraptor was probably warm-blooded.

Cold-blooded lizards don’t excel at pursuing and savagely attacking their prey (think of crocodiles, which are content to lay patiently in wait). That fact, combined with its probable coating of feathers, leads paleontologists to believe that Velociraptor had a warm-blooded metabolism comparable to that of modern birds and mammals.