Image: Stegosaurus dinosaur footprints in sandstone

Description: Stegosaurus dinosaur footprints in fluvial sandstone from the Jurassic of Colorado, USA (public display, Morrison Natural History Museum, Morrison, Colorado, USA). This sandstone block has the world's finest examples of Stegosaurus dinosaur tracks. The large footprint near & below the center is an adult hind print. This track is artificially elongated - The large depression immediately adjacent to the three toe impressions is the foot itself - the area extending toward the lower right is a slide mark (slip mark). Stegosaurus was a rump-heavy animal, so it was occasionally prone to slipping on wet sediments. The crescent-shaped series of shadowed depressions above the middle and right toes of the hind print is a forefoot track. A juvenile Stegosaurus track occurs between these two adult prints (just above & to the right of the hind print's right toe). Stratigraphy: Morrison Formation, Upper Jurassic Locality: Quarry 5, Dinosaur Ridge, west of Denver, north-central Colorado, USA Trace fossils are any indirect evidence of ancient life. They refer to features in rocks that do not represent parts of the body of a once-living organism. Traces include footprints, tracks, trails, burrows, borings, and bitemarks. Body fossils provide information about the morphology of ancient organisms, while trace fossils provide information about the behavior of ancient life forms. Interpreting trace fossils and determination of the identity of a trace maker can be straightforward (for example, a dinosaur footprint represents walking behavior) or not. Sediments that have trace fossils are said to be bioturbated. Burrowed textures in sedimentary rocks are referred to as bioturbation. Trace fossils have scientific names assigned to them, in the same style & manner as living organisms or body fossils.
Title: Stegosaurus dinosaur footprints in sandstone
Credit: Stegosaurus dinosaur footprints in sandstone (Morrison Formation, Upper Jurassic; Quarry 5, Dinosaur Ridge, west of Denver, north-central Colorado, USA)
Author: James St. John
Usage Terms: Creative Commons Attribution 2.0
License: CC BY 2.0
License Link: http://creativecommons.org/licenses/by/2.0
Attribution Required?: Yes