ABSTRACT The purpose of this trip is to visit an internationally famous Quaternary vertebrate paleontology site, Friesenhahn Cave, on the eastern margin of the Edwards Plateau in the heart of the central Texas Hill Country. This site has a very long history of scientific investigations beginning in the early twentieth century and continuing today. The cave has produced the fossil remains of more than 50 vertebrate taxa, including amphibians, reptiles and mammals. However, the abundant remains of an extinct scimitar cat, Homotherium serum, including juvenile individuals along with hundreds of teeth, cranial, and postcranial elements of juvenile mammoths, Mammuthus cf. M. columbi, make it an especially unique site. Our visit to Friesenhahn Cave will focus on its physical setting, cave sediment stratigraphy, potential age and taphonomy as they relate to the adaptations of Homotherium in the late Pleistocene of central Texas and its relationship to its potential prey, juvenile mammoths. We will also discuss recent studies of the cave itself, and its protection for future investigations by Concordia College.

Abstract Riverbluff Cave developed near the southern margin of the Springfield Plateau as a single passage between James River and its tributary, Ward Branch. Portions of the cave preserve a general fining-upward sediment sequence, but with highly fossiliferous gravel beds near the middle. These gravel beds include fragments of various vertebrates, including mammoth and horse. Trackways and claw marks are also preserved atop the sediment in numerous locations. Cosmogenic isotope data provide burial dates for some of the sediment layers and fossil remains. The earliest sediment (reverse magnetic polarity) entered the cave at ~1.1 Ma, while the fossiliferous gravel bed is dated at ~0.74 Ma. The overlying laminated silts and clays have normal polarity with a burial date of ~0.65 Ma at the base. Thus, the sediment sequence spans the Matuyama/Brunhes paleomagnetic datum, and records at least 450 ka of sedimentation within the cave.