Fossil Vertebrates from the Late Pleistocene Ingleside Fauna, San Patricio County, Texas

Fresh-water pond deposits at Ingleside, San Patricio County, Texas, have yielded a large Pleistocene vertebrate fauna. The bones are derived from calcareous sands and marls which overlie a marine lagoonal clay. The locality is located just west of the axis of Live Oak Ridge. This ridge, along with the Ingleside Terrace to the east, was formed as a barrier island and lagoon when sea level was higher than at present. The Ingleside barrier and lagoon are correlated with the Pamlico Terrace of the east coast of the United States, which is currently correlated with the Sangamon interglacial stage. The fresh-water pond formed after the barrier and lagoon, probably by wind deflation during a time when the water table was low, corresponding to a period of lowered sea level. The fauna contains a diverse assemblage of Pleistocene mammals, birds, reptiles, amphibians, and fish; it consists of two principal elements:(1) extinct forms such as Tanupolama, Camelops, Mammuthus, Mammut, Paramylodon, Megalonyx, Equus complicatus, Canis dirus, Platygonus, Bison antiquus, Geochelone crassiscutata, and Gopherus hexagonata; and (2) extant forms such as Odocoileus virginianus, Canis latrans, Peromyscus leucopus, and Mephitis mephitis. A third element usually well represented in Pleistocene faunas—extant forms no longer found in the area—is represented by a very few forms such as Cynomys. The scarcity of this element is a result of the poor representation of the small-sized animals in the fauna. Several species, such as Tanupolama mirifica and Paramylodon harlani, are represented by samples large enough to give information on variability. The diversity of the large mammalian fauna indicates the presence of diverse habitats in the Ingleside area. The presence of large tortoises, such as Geochelone and Gopherus hexagonata, indicates mild winters. The age structure of the Tanupolama mirifica sample indicates the existence of seasonality of some climatic factor, probably rainfall.