Apatosaurus right femur (thigh bone)! This average-sized adult #Apatosaurus cast leg bone is on display at the Utah Geological Survey. #Paleontology works so well because we can take properties we know about living animals and apply them to those long deceased, in this case 150 mya in the Late #Jurassic of Utah. Terrestrial vertebrate bones are #homologous, meaning they derive from the same embryological structures and follow similar, if not identical, neurological, vascular, and muscular pathwa