Dinosaur Central: Velociraptors

I got some cool data from a dinosaur book. While it did have some general dinosaur facts, the book's main focus was on Velociraptors.

Dinosaurs
The Age of Dinosaurs is known as the Mesozoic Era. It started around 228 million years ago, and ended 65 million years ago. Scientists think that a huge asteroid that hit the Gulf of Mexico is what ended the Mesozoic Era by kicking up a huge cloud of dust, which made the Earth cooler (which was normally a warm place, and the book says that extremes were only a few), which killed plants, which made herbivores (plant-eaters) starve, which made meat-eaters starve to death, since they had no prey. Now, some creatures like  mice survived the disaster, but that's what scientists think what happened.
You may know this, but the Mesozoic Era is chomped up into three main sections. The first is the Triassic, whose late ages began 228 million years ago, and ended  206 million years ago, lasting about 42 million years. It was in these late stages that dinosaurs and the small mammals supposedly appeared. The other two is the Jurassic, going from 206-114 millions years ago, lasting 61 million years, and the Cretaceous, which went from 114-65 million years ago, lasting the longest of the three periods with 79 million years.
Dinosaurs supposedly ruled the Earth for 160 million years. But why? Scientists believe that this is because they were able to put their feet and legs directly under their body, giving them an advantage over other reptiles (yes, they were reptiles).
We all know dinosaur means "terrible lizard". But did you know it came from the word dinosauria, which was invented by an English dude named Richard Owen, who was indeed a scientist? The word is made from the Greek words deinos and sauros, which means "terrible lizard".
Scientists classify dinosaurs, of course. But they can chop all dinosaurs into two groups... by the shape of their hipbones! The ones with hips like modern birds are Ornithischians, which were all herbivores. This group includes Thryophorans (which include 4-legged stegosaurians like our friend the Stegosouarus), two other groups (which are ornithopods), which have dinos like Edmontosaurus and marginocephalians. The other hipbone group is the modern-lizard-like group: the Saurischians, which have theropods (which includes the most famous T-Rex, other 2-legged meat-eaters, and possibly have birds for a branch), and sauropods like the other famous dinosaur the Brachiousaurus.
Now, to the Velociraptors!

Velociraptors
I believe this was a great move, but the book clearly stated that the Raptors in the movie Jurassic Park were not Velociratpors. And there are a few pointers in that directions. Velociraptors, unlike the Jurassic Park Raptors, hunted by themselves and not in packs. Also, Jurassic Park takes place in a big jungle-like enviroment with plains, but scientists believe that Velociraptors lived in the desert... more specially, the Gobi Desert in Asia (part of which is China), where their fossils were found.
Velociraptors and Jurassic Park Raptors do share a few commons, though. Both of them have this big, special claw. Scientists aren't overly sure what the Velociraptors did with their crescent-shaped claw. It may have been for slashing throats or guts when hunting, or killing anything that got too close, or it may have helped the Velociraptor in grabbing a prey's back to pull it down and kill it.
Velociraptors weren't overly big. They were only about 6 ft (2 m) long, and weighed from 22-33 lbs (10-15 kg). This limited their hunting options... they hunted only small animals, like mice and shrew, and other small dinosaurs. In fact, there's an interesting story behind a fossil where a Velociraptor and a Protoceratops (Pig-sized dino with beak mouth and bony frill for a neck-guard that lived in same area as Velociraptors) are tangled. Scientists believe that the Velociraptor killed the Protoceratops, which fell on the Velociraptor. The Velociraptor was stuck, and basically starved to death. And then sand covered the two, and they ended up fossilized (which ended up in a museum).
Living in the desert makes things tricky too. Velociraptors have to be careful where they plop their eggs, since it has to be in the shade. And then animals who like shade and come out at night sometimes go after eggs. Speaking of living places, Velociraptors lived in the late Cretaceous.
It was once believed that all dinosaurs were cold-blooded. But Velociraptors are fast. This started scientists to believing that some dinosaurs--at least ones of the Velociraptor's family (Dromeosauride, which includes troodons) are warm-blooded! Part of the Velociraptor's speed is due to its hollow, lightweight bones. Sounds familiar? Members of the Dromeosauride family are similar to birds... scientists believe them to be cousins! Ever since the discovery of a Microraptor (cousin and closest relative to the Velociraptor) fossil with feathers, they even believe that Velociraptors and other similar creatures had feathers!