Skull Of Refrigerator-Size Ancient Armadillo Finds A Home At UF

Source: Russ McCarty, (352) 392-1721

GAINESVILLE, Fla. --- At more than 6 feet long and weighing as much as 600 pounds, this is one armadillo that likely wouldn't have ended up as road kill.

That's about the size of the armadillo University of Florida researchers say roamed the Sunshine State 10,000 years ago, and now they have a well-preserved skull to prove it.

"The skull belonged to one of two species of giant armadillo that lived in Florida during the Pleistocene Epoch, and its unusually good preservation makes it one of only a handful of its kind in the United States," said Russ McCarty, a University of Florida senior biological scientist.

Found in a limestone quarry west of Gainesville, the skull now is at the Florida Museum of Natural History on the UF campus, where researchers are preserving and restoring the specimen so it can be stored and displayed in the building's collections.

"It's a very important specimen because it is so complete and has all its teeth," McCarty said. "The wear patterns that we're able to see on the teeth may give us some valuable clues about these creatures' diet. We really don't know exactly what they ate. That information would give us a better understanding of the niche they occupied, their relationship to other animals, as well as the whole ecosystem of the time."

Called Holmesina septentrionalis, the beasts, like their smaller modern counterparts, spread to what now is Florida from South America. Ground sloths, tapirs and other exotic creatures followed the same route into the Sunshine State, he said.

Unlike today's armadillos that subsist on termites, ants and beetles, the ancient ones, weighing as much as 600 pounds, likely needed more substantial fare to survive, he said.

Unfused limb bones indicate the specimen was a juvenile, which may give clues about the armadillo's growth sequence, McCarty said. "We don't know much about juveniles or how they develop into adults," he said. "The few skulls that are found tend to be adult."

Scientists also would like to learn more about how the giant armadillos differed in its evolution from the ground sloth and glyptodont, its close relatives, he said.

Richard Hulbert, a geology professor at Georgia Southern College who saw the skull at the museum several months ago, said, "It was evident that it was much more complete than any we've previously had of these species. It certainly will be important for studying how these animals lived and trying to figure out why they became extinct."

Giant armadillos became extinct in Florida about 9,800 years ago, a period of dramatic climate change, McCarty said. But a smaller variety continued to live in South America, as did llamas, large rodents called capybaras, and tapirs, the pig-size animals closely related to horses and rhinoceroses, all of which once roamed Florida, he said.

Because people lived in Florida 11,000 to 12,000 years ago, early humans encountered giant armadillos for a few thousand years before they disappeared, he said.

"We haven't found any evidence that people hunted them, but they were probably considered as possible food sources," he said. "Maybe the heavy armored plates on their bodies were a good defense against spear points."

The skull at UF was discovered in August. Eric Taylor, a Lake City insurance agent, showed the site to Adam Black, a biological illustrator specializing in painting extinct Pleistocene mammals, who found rabbit bones and armadillo shells sticking out of the vertical limestone cliff face in the Haile quarries. Six months later, when the two men returned, a rock slide had exposed more bones, including the skull.

"We were just elated," said Taylor, who also is secretary of the Florida Paleontological Society. "I probably will never see anything like it the rest of the time I'm involved in fossil collecting. We knew right away that it was a significant find because the skulls of these creatures are so rare."

The site may have been a wolves' den because of the presence of a "dire wolf" skull and the bones of hundreds of rabbits, which these robust wolves ate, McCarty said. Because armadillos have armored shells, the armadillo skull probably was not prey but just happened to tumble into the sinkhole cavity, ending up in the wolves' den, he said.

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