BEETLES, BEES, BURROWS, ROOTS, AND DINOSAURS: DECIPHERING THE ICHNOLOGY OF THE TWIN MOUNTAINS FORMATION

The Twin Mountains Formation sandstone is known to contain a diverse assemblage of plant and animal fossils. From a newly studied site, located on a road cut along Farm to Market Road 1188, east of the community of Bluff Dale, Erath County, Texas, USA, there is abundant petrified gymnosperm wood, large elongate concretions, gastroliths, a large, pronounced boring to a small segment of petrified wood, as well as many smaller borings into a larger log of petrified wood. The distinctive concretion structures, composed of loosely cemented sand, resemble either rhizocretions or perhaps small terrestrial vertebrate burrows. The characterization of this sand as a terrestrial depositional environment for this material and the relative lack of post-maceration boring in the wood suggests rapid burial in the sands of the Twin Mountains Formation. The identification of both the nature of the concretion structures, the trace maker associated with both the solitary as well as the smaller wood borings are the focus of this study, providing a more complex picture of the ecology of this locality in the Lower Cretaceous.