Deinonychus, the "Terrible Claw," is a famous dinosaur that was at the forefront of paleontologist John  Ostrom's "dinosaur renaissance."  Ostrom lead the charge in reforming dinosaurs from slow, cold-blooded lizards to the swift, warm-blooded  birds we know today, effectively revolutionizing dinosaur knowledge. With a maximum length of three  meters and height of about a meter,  Deinonychus was a strong creature with a powerful body ready to  attack. Like its fellow  dromaeosaurids, it possessed a  sickle-shaped claw on its second toe and likely had feathers covering its  entire body.   Living during the early Cretaceous  Period, Deinonychus made its home in North America's tropical climates.  Deinonychus' limbs could grasp and  clutch objects well. They may have allowed for tree climbing, leading  to possible arboreal behavior. The  Deinonychus hunted small- and  medium-sized dinosaurs with a  technique called "raptor prey  restraint," in which it attacked  prey, held it down, and ate it alive. Although many people believe they hunted in packs to tackle  large prey like Tenontosaurus, a  different hypothesis states that  Deinonychus may have "mobbed" prey, similar to how Komodo dragons hunt alone but gather in groups to feast on recent kills.