Paleontologists Find Lost Ice Age World in Flooded Texas Cave
Fossils of a giant tortoise, a ground sloth, a lion-sized armadillo called a pampathere, scimitar-toothed cats, horses, camels and mastodons found in Bender Cave on the Edwards Plateau in Texas may reveal a previously unknown warm period in the region about 100,000 years ago.
An artistic interpretation of the mammals that lived during the Ice Age: Similar species fossils of an armadillo-like pampathere (bottom left) and a giant ground sloth (in background) were among those found in a Texas water cave. Image credit: Jaime Chirinos.
Water caves are conduits for underground waterways. These are important groundwater passages in central Texas and have been anecdotally described by cavers as rich in fossils.
“There were fossils everywhere, just everywhere, in a way that I’ve never seen in any other cave. It was just bones all over the floor,” said John Moretti, a paleontologist at the University of Texas at Austin.
Bender’s Cave is located on private property in Comal County. The bones entered the cave through sinkholes during erosion and flooding events that occurred thousands of years ago, and have remained there ever since.
“There is evidence that the water cave fossils may come from the last interglacial period, a warm period that occurred around 100,000 years ago,” Dr Moretti said.
“Despite extensive paleontological research in the area dating back nearly a century, no fossils from this period have previously been found in central Texas.”
“This site shows us something different, and it’s really important because of all the work that’s been done in this area. »
“If it is interglacial in age, it is a new window into the past and into a landscape, environment and animal community that we have never observed in this part of Texas before.”
Dr. Moretti and local caver John Young collected fossils from 21 different areas of Bender Cave.
To find fossils, you had to crawl along the creek bed with goggles and a snorkel.
Collecting them was as simple as picking them from the bottom of the stream bed – no excavation into the rock was necessary.
Notable finds include giant tortoise bones Hesperotestudo sp., the giant ground sloth Megalonyx jeffersoniithe pampere Holmesina septentrionalisthe scimitar-toothed cat Homotherium serumas well as horses, camels and mastodons.
All of the fossils are polished, rounded, and show a similar degree of rust-red mineralization, suggesting that they were dragged into the cave around the same time.
“Research shows that even in an area as well-documented as central Texas, there are new things to discover,” said Dr. David Ledesma of St. Edwards University, who was not involved in the study.
Team results appear in the journal Quaternary Research.
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John A. Moretti and John Young. 2026. New occurrences of Late Pleistocene megafauna from Bender Cave on the Edwards Plateau of Texas may include evidence of the Last Interglacial. Quaternary Research 131:134-160; doi: 10.1017/qua.2025.10071
