Image: Infant Apatosaurus dinosaur tracks

Description: Infant Apatosaurus dinosaur tracks from the Jurassic of Colorado, USA (public display, Morrison Natural History Museum, Morrison, Colorado, USA). This rock is a channel sandstone, deposited in an ancient river or stream. The sandstone block has dinosaur bones in it, plus some remarkable dinosaur tracks on its top surface. The large depression at the top left part of the block (below the head of the model) is an adult sauropod dinosaur footprint, attributed to Apatosaurus. The row of shadowed depressions below the adult track is a set of infant Apatosaurus footprints. Claw impressions are present. No tail drag marks are present (dinosaur tail traces are very rare everywhere on Earth - dinosaurs didn't want to drag their tails, because friction would slow them down, plus it would cause pain). 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: Infant Apatosaurus dinosaur tracks
Credit: Infant Apatosaurus dinosaur tracks (Morrison Formation, Upper Jurassic; Quarry 5, Dinosaur Ridge, west of Denver, north-central Colorado, USA) 2
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