Ornithomimus are a great dinosaur to learn about. Find out all about how, when and where they lived - and check out some great pictures of them too.
Its dinosaur classification is Theropoda.
They lived 75-65 million years ago during the late Cretaceous period. There were a lot of dinosaurs living in this period of time.
They have long beaks with no teeth in them. Instead, it used its scissor like beak to chop food into smaller pieces.
Scientists think they probably looked like a feathery kangaroo - but they could run as fast as an ostrich. It used this as a defense - it would run to safety if a predator arrived.
It had 3 toes on its hind legs that would dig into the ground when it was running - like spikes on running shoes.
It is thought they could run at speeds of up to 40 mph, which means it would take them only 5.59 seconds to run 100 meters - almost twice as fast as Usain Bolt's 9.58 seconds!
They lived in North America, Mongolia and the East America.
The fossils found so far have been of different sizes - but roughly they were around 4-5 meters long (13-16 feet) and weighed about 158.8kg.
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