Deinonychus:  A huge curved claw on each foot made Deinonychus a small but particularly deadly dinosaur of the Cretaceous Period. Like modern lions and wolves, Deinonychus is believed to have been a pack hunter that cooperated in tracking much larger animals. 

Genus Name: Deinonychus ("terrible claw")
Type Species: * D. antirrhopus (Ostrom, 1969)
Length: 10 feet (3 meters)
Weight: 150-200 pounds
Time: 115-100 million years ago (Early Cretaceous)
Place: Montana, Oklahoma, Wyoming, Utah
Diet: meat-eater (carnivore)