A SLIPPERY SITUATION: THEROPOD TRACKS AT CARRIZO CREEK, CIMARRON COUNTY, OKLAHOMA

Tracks and trackways can provide us with information that other fossils cannot. One of the most obvious advantages that tracks have over body fossils is that they are able to provide direct evidence of the behavior of extinct organisms. The Cimarron Valley is situated in parts of Union County, New Mexico, Baca County, Colorado, and Cimarron County, Oklahoma. Dinosaur tracks have been known to occur in the Cimarron Valley of Colorado, Oklahoma, and New Mexico since the 1940s. Tracks in Carrizo Creek were first mapped, described, and assigned to the ichnogenus Megalosauripus in 1986. However, tracks and trackways from this region have not been discussed in terms of dinosaur behavior. At the site in Carrizo Creek, Cimarron County, Oklahoma it appears that a dinosaur walking across a mudflat slipped and may have nearly fallen down. Data supporting this conclusion includes a relatively shallow track 7.6 centimeters with a rim of mud pushed up to the right hand side. Additionally, the next track in the series is noticeably deeper 10.2 centimeters than the other tracks in the series. The stratigraphic position of the site has been in dispute. However I can now say that the site sits in lower Morrison Formation. This conclusion is supported by two observations 1) a lack of chert that marks the lower boundary of the Morrison Formation in the Cimarron Valley region, and 2) a predominance of limestone which is a lithology found in the Lower Morrison.