Late Jurassic – 154 - 150 Mya
Wyoming, Colorado, Utah and Oklahoma
Length: 22.9 meters (75 feet)
Height: 9.1 meters (30 ft)
Weight: 29,937 kg (66,000 lb) as an adult
A vulnerable young Apatosaurus had to be watchful before it found itself as “lunch” for predators like Allosaurus. Fortunately growth was rapid and a young Apatosaurus could increase its size by as much as 6 lbs per day. By the age of 10 – 15 Apatosaurus was full sized. Until then protection by the larger members of the group was the best way to stay alive.