T157 Sigma Gamma Epsilon Undergraduate Research (Posters)

Updates to the Taphonomy of the Aaron Scott Dinosaur Site (Jurassic, Morrison Formation) in Central Utah

Paper number: T157-21
Program: Technical Sessions
Time: 8:00 AM – 4:45 PM

Authors

Abstract

The Aaron Scott Site is a rich accumulation of vertebrate remains in the Jurassic Morrison Formation of central Utah. The site is dominated by a partially articulated skeleton of a Diplodocid sauropod, including cervical and caudal vertebrae. In addition to the sauropod, disarticulated remains of Allosaurus, Ceratosaurus, and an ornithopod dinosaur as well as a rich accumulation of microfauna including turtle, crocodile and sphenodonts are found.

The majority of the bones in the quarry, aside from the sauropod, are fragmented. Although the sauropod shows little directional orientation, the disarticulated remains of the other animals show exhibit orientation that is consistent with both river current and wave activity.

Stratigraphy and sedimentology suggest that the bones accumulated on a delta plain during a period of drought. The bones were disarticulated and broken by wreathing processes and possibly by trampling. Bones were then reworked and oriented in distributary channels or by wave activity along the lake margin. Following the drought, the lake level rose and the bones are capped by a mudstone containing molluscs from the lake.