ICHNOLOGY, STRATIGRAPHY AND PALEOENVIRONMENT OF THE BOERNE LAKE SPILLWAY DINOSAUR TRACKSITE, SOUTH-CENTRAL TEXAS

摘要

Record flooding in late June 1997 in south central Texas exposed dinosaur footprints on the Boerne Lake spillway near Boerne, Texas. At least three trackways are present in the upper portion of Unit No. 3 of the Lower Cretaceous Glen Rose Formation. This sequence represents a period of high-frequency depositional cyclicity on a very shallow and partly restricted inner shelf. The track-bearing layer exhibits features characteristic of sabkha-like tidal flats subject to subaerial exposure. It is overlain and underlain by red clay horizons of secondary origin. Those dinosaur prints exhibiting sufficient morphologic preservation to be identifiable appear to have been made by a theropod (carnivorous) dinosaur. Other footprints were too poorly preserved to permit identification of the trackmakers more specifically than as bipedal dinosaurs.