 Stegosaurus was the largest stegosaur , possibly weighing up to 5 @,@ 000 kg ( 5 @.@ 5 tons ) . Soon after its discovery , Marsh considered Stegosaurus to have been bipedal , due to its short forelimbs . He had changed his mind , however , by 1891 , after considering the heavy build of the animal . Although Stegosaurus is undoubtedly now considered to have been quadrupedal , some discussion has occurred over whether it could have reared up on its hind legs , using its tail to form a tripod with its hind limbs , and browsing for higher foliage . This has been proposed by Bakker and opposed by Carpenter . 
