Giant Armadillos the Size of Cars Once Roamed Texas – New Fossils Just Proved How Many There Were.

The picture of two adult men wearing wetsuits and goggles crawling through a flooded, dark cave in the Texas Hill Country and reaching down into the streambed to retrieve ancient bones like someone gathering shells on a beach is subtly disorienting. Not a shovel. No brushes. There are only ancient remnants in the water, polished and rust-colored by thousands of years of mineral flow, just waiting to be retrieved.

In March 2023, University of Texas paleontologist John Moretti and explorer John Young made their first descent into the subterranean system at Bender’s Cave in Comal County, just north of San Antonio. Scientists’ preconceived notions about the animals that once roamed central Texas some 100,000 years ago are being altered by what they discovered, which was dispersed throughout 21 survey zones over the course of six different visits. Mastodons are enormous ground sloths. cats with saber teeth. Camels from the past. And a pampathere, a massive ancestor of armadillos that weighed up to 440 pounds and was about the size of a large male lion.

“There were fossils everywhere, just everywhere, in a way that I haven’t seen in any other cave,” Moretti declared in a statement that was made public. “It was just bones all over the floor.” That statement is significant coming from a paleontologist with training who has spent years crawling through limestone formations in Texas.

Numerous cave systems can be found throughout Central Texas, which were gradually sculpted over millions of years by water and erosion. Both cities and farms rely on the groundwater that flows through them, which is constantly watched. However, these same subterranean rivers also serve as long-term storage systems for anything that the landscape above them has shed, such as animal bones that perished during extinct climatic periods. Situated on private land and largely untouched, Bender’s Cave had quietly amassed an amazing archive.

Because of what it symbolizes, the pampathere is arguably the collection’s most striking animal. These armored mammals originated in South America and moved northward into North America about 2.7 million years ago when the Panama Isthmus formed, creating a land bridge between the continents. The pampathere was designed to grind coarse vegetation; its jaw structure excluded any taste for insects or meat, in contrast to the small, omnivorous armadillos that now shuffle across Texas highways at dusk. It wasn’t risky. It was just huge. Then it disappeared some 12,000 years ago.

The pampathere appears almost insignificant in contrast to its distant relative, the glyptodont. Originally thought to be merely cousins of modern armadillos, glyptodonts are shelled herbivores that first appeared about 35 million years ago. However, they have since been reclassified as essentially gigantic armadillos themselves, a subfamilly rather than a distinct lineage.

The biggest of them could grow up to thirteen feet in length and weighed about two tonnes, or about the same as a Volkswagen Beetle. Unlike modern armadillos, they did not roll into a ball for protection. They were unable to. Rather, they relied on their thick, club-like tails and enormous, stiff shells, which scientists think they swung at both rivals and predators. A two-ton armadillo with a spiked tail doesn’t need much more defense tactics.

The time period that the fossils from Bender’s Cave seem to represent is just as important as the species that were discovered. The combination of species strongly suggests an interglacial warm period about 100,000 years ago, although dating the bones has proven challenging because they were exposed directly on the streambed without any encasing sediment to examine.

Warmth was essential for the survival of giant tortoises and their enormous armadillo relatives. Mastodons and ground sloths favored wooded areas. This combination points to a particular climatic window, a short break between ice ages when central Texas was wetter and warmer than it is now. Despite almost a century of excavation activity in the area, if verified, these would be the first fossils of interglacial animals ever found in this area.

It’s difficult to ignore the discovery’s peculiar intimacy. This was not a spectacular journey to a far-off part of the globe. Bender’s Cave is located on a private ranch in the Texas Hill Country, a region with outcrops of limestone and cedar where people go deer hunting on the weekends and ride horses. Moretti was careful to note that the landowners cooperated with the researchers. “These connections and partnerships make possible a lot of the natural science that gets done in Texas,” he said. “It takes contributions from everyone — not just scientists at universities — to learn about the natural world we live in.”

It’s worth pausing to consider that. In central Texas, the fossil record is still being written, and much of it is under private property that may or may not permit access. There might be dozens more caverns similar to Bender’s, full of bones from animals that once roamed a landscape that is now unrecognizable, just waiting for someone to arrive with a snorkel and the courage to swim into the dark.

It probably depends on your point of view whether that image of ancient Texas—warm, damp, and home to massive, sluggish herbivores in armored shells—feels more like a different planet or just an earlier iteration of the same one. However, the bones, which have been there for 100,000 years, are real, rust-colored, and heavy on the cave floor. All that was needed were two individuals who were willing to get their hands dirty.