SHIPWORMS AND CRABS: ICHNOLOGY OF A CRETACEOUS LAGOON

An assortment of trace fossils were examined within an exposure of the Glen Rose Formation in Coryell County, Texas, along Cowhouse Creek. These ichnofossils vary in abundance and variety, providing insight into a complex and thriving ecosystem. Teredolites isp. burrows were found in situ, penetrating into a carbonized tree log. The carbonized log was deposited within a limestone, with layers of sand and chalk interspersed, formed in shallow waters near shore. This interpretation is supported by other associated ichnofossils and invertebrate fossils emplaced within the same beds, including a variety of bivalves, ammonites, and small rudist patch reef structures. An associated plant fragment was similarly carbonized but is much smaller and lacking in evident traces. Additional trace fossils include Thalassinoides isp. in layers upwards of 20cm thick throughout the exposure, several paired sets of Brontopodus isp. in the uppermost layer, as well as two sand lined, flattened, horizontally oriented Psilonichnus isp. (?) burrows that have been preserved intact, lacking infill.