7 Paleontology Society Session (Posters): Regional Topics in Paleontology

Wednesday, 7 May 2003
1:00 PM - 5:00 PM

UPPER CRETACEOUS ORNITHOPOD TRACKS FROM THE IRON SPRINGS FORMATION, SOUTHWESTERN UTAH

Paper number: 7-7
Program: THEME SESSIONS
Time: 1:00 PM – 5:00 PM

Authors

Abstract

A well preserved assemblage of 24 ornithopod tracks has been located in the upper 50 meters of the late Cretaceous, Iron Springs Formation. This section has been dated as Late Santonian-Early Campanian, and is located in Parowan Gap, Iron County, Utah. This is the first evidence of tracks found in this formation. The tracks are all casts and represent at least seven individuals based on foot morphology and range from 32 to 56 cm in length. The casts formed in the base of three different sandstone beds that covered and in-filled the original molds, formed in non-resistant muddy sandstone and mudstone. The original molds have eroded away exposing the casts on the underside of the sandstone beds and in talus blocks. Most of the tracks are isolated foot prints. A single trackway has been found consisting of three casts. The individual that made this trackway had an 85 cm stride.

These tracks are in sediments that have been interpreted as channel deposits with related over bank deposits. The Iron Springs Formation probably represents an alluvial plain, adjoining the western most incursion of the Cretaceous Interior Seaway the existence of which has been documented in this area.