When Jurassic Park was first released there was some controversy about the size of the Velociraptors in the movie- Spielberg had been unhappy with the true scale of these prehistoric monsters and had his SFX people make them much larger than they really were. Of course, it turns out that at around the same time a new breed of raptor was discovered, a species which was actually a little bigger than Spielberg's made-up raptors; these were Utahraptors.
The Velociraptor itself was fairly small, about two feet high and six feet long, weighing in anywhere between 30lbs and 200lbs depending on your internet source. It's spring-loaded, killing toe-claw was about five inches long. The Utahraptor on the other hand was a much bigger specimen- eight feet tall and twenty three feet long, it weighted roughly a ton. It's killing claw was ten inches long. It's fore-claws were also much better developed than its small relation and it most likely used these big sickle claws in its attacks too. Talk about dangerous game!
I've just begun reading an account by paleontologist Robert Bakker of the life of a Utahraptor, Raptor Red. I picked this up for next to nothing on Amazon ages ago and I wish I hadn't left it sitting gathering dust for so long because- three chapter in- it's a gripping read full of the sort of details about life in the Cretaceous that I've always longed to know. If you like the Jurassic Park movies or dinosaurs in general, then this work of fiction makes for an essential purchase, it's much better than working through a dry textbook. Bakker's a very entertaining writer and his real love of the subject matter comes through everything of his I've read.
As impressive as the thought of the Utahraptor is, it is surpassed by the aptly named Megaraptor. This is an even bigger beast- ten feet tall and twenty six feet long. Most impressive though is the powerful toe-claw, it measured 14 inches in length. To get an idea of the scale of this monstrous dinosaur have a look here to see how it compares to man. Pretty scary.