Dyslocosaurus polyonychius

† Dyslocosaurus polyonychius is a diplodocid sauropod dinosaur from the Late Jurassic Morrison Formation of Wyoming, USA. Its name means 'many-clawed difficult lizard,' referencing the unusual morphology of its foot bones. Estimated at 18 m or more in length, it was a high-browsing herbivore feeding on conifers and tree ferns. Known from fragmentary material described in 1992, it represents the diversity of sauropods in the iconic Morrison fauna alongside Diplodocus and Apatosaurus.