Small vertebrates were recovered from the matrix encasing specimens of giant sauropod dinosaurs (Supersaurus, Ultrasaurus, Dystylosaurus) collected from the "Dry Mesa' Quarry (Brushy Basin Member, Morrison Formation, western Colorado). Most of the remains appear to pertain to a single form of pterodactyloid pterosaur, Mesadactylus ornithosphyos, n.gen. and sp. the holotype of which is a
... [Show full abstract] synsacrum. A bone end from this quarry, first identified as an avian proximal tibia and named Palaeopteryx thomsoni, is reidentified as the distal radius of a small deinonychosaur or bird. A small femur of a small deinonychosaur or bird and additional material of other small vertebrates from this quarry are figured and described. -Authors