She 's a giant , and ancient , jigsaw puzzle : 300 bones , 19 bony plates and four vicious-looking spikes . The world 's most complete stegosaurus skeleton -- nicknamed Sophie -- has gone on display at the Natural History Museum in London . At 5.6m long and 2.9m tall , the Stegosaurus stenops is roughly the size of a 4x4 vehicle -- though it predated such motors by 150 million years . Paleontologists at the museum have spent 12 months studying the skeleton , measuring , photographing and scanning it , as well as practicing putting it together . Now , a year after she arrived in London from the U.S. , Sophie -- named after the daughter of a wealthy financier whose donation allowed the museum to acquire her -- is finally ready to make her public debut . The museum 's lead dinosaur researcher , Professor Paul Barrett , said the stegosaurus was incredibly rare . `` Finding one as complete as this , where only the left arm and base of the tail are missing , is exceptional , '' he said in a statement . `` It 's the only stegosaurus in the world that 's anywhere near this complete . So it 's an amazing find . '' As well as drawing visitors in to the museum , Barrett said the specimen offered many interesting opportunities for research . `` Because the new skeleton is almost complete , and three-dimensional , we can do a lot of things that have not been possible until now , such as looking at how the leg muscles work or how the skull functions during biting . `` Thanks to this fossil , we can begin to uncover the secrets behind the evolution and behavior of this iconic but poorly understood dinosaur species . '' Key to its importance is the fact that the fossil 's skull bones are not fused together , allowing paleontologists the chance to experiment : `` It 's almost like playing with a Meccano set , '' Barrett said . While they do n't actually know whether it was male or female ( despite the name ) , they can tell the dinosaur was relatively young when it died -- adult stegosaurus are known to have measured up to 9m in length . And although its spine plates and spiked tail mean it looks a little threatening , back when it was alive the stegosaurus would have been a vegetarian and a solitary creature . The first stegosaurus was discovered in Colorado in 1877 by paleontologist Othniel Marsh . The Natural History Museum 's specimen was found at Red Canyon Ranch in Wyoming in 2003 -- it took 18 months of painstaking excavation work to free it from the ground it had lain in for so long .
World 's most complete stegosaurus skeleton unveiled at Natural History Museum . Skeleton is 5.6m long and made up of more than 300 bones , 19 plates and four spikes . Found at Red Canyon Ranch in Wyoming , USA , in 2003 , donated to museum in 2013 . Stegosaurus roamed the Earth 156 to 144 million years ago , in late Jurassic period .