Elaphrosaurus was a very light weight ceratosaur. Although it was nearly 16 feet long, it only weighed about 500 pounds. That means this ceratosaur would have been very fast. It could have hit speeds of over 30 miles per hour. It was previously thought Elaphrosaurus was an early ornithomimid, but this theory has been dismissed. Elaphrosaurus lived around 150 million years ago in Africa.