Upper Jurassic Carnegie Quarry Dinosaur Bone Site

The Carnegie Quarry Exhibit Hall, situated in Dinosaur National Monument, spans 585 square meters of steeply inclined fluvial sandstone. Within, 1500 in-situ dinosaur bones from nine dinosaur species and freshwater bivalves offer insights into the biodiversity and an ecosystem in the Upper Jurassic Morrison Formation. A recent Pb/U date of 150.77 Ma places the bone deposit near the top of the Kimmeridgian.
Sedimentological and taphonomic analyses attribute the three bone layers to drought periods, when decaying carcasses accumulated in a braided river system. Various bone configurations, from complete skeletons to scattered parts, reveal fluvial transport. Significantly, many bones display evidence of upstream scour, indicating a novel finding that bones within dynamic depositional settings facilitated their own burial.
The deposit showcases diverse Late Jurassic dinosaur species, including sauropods, theropods, stegosaurs, and ornithopods and has long been used as representing Late Jurassic dinosaurs to the public. Furthermore, the Quarry produced the Apatosaurus louisae type specimen, unveiling the first evidence of a whip-like tail in sauropods. Size variation in Camarasaurus provides insights into growth changes. Dinosaurs from the quarry are displayed in various North American museums, some as the sole skeletons of their species, highlight the Quarry’s paleontological significance.