DNA study: Ancient glyptodonts were gigantic armadillos

HAMILTON, Ontario, Feb. 23 (UPI) -- Glyptodonts are an extinct group of animals from South America that looked like large armadillos. According to a new study, glyptodonts were large armadillos.

DNA analysis confirms that prior to the group's divergence from the lineage that spawned today's armadillo species, some 35 million years ago, glyptodonts and armadillos shared a common ancestry.

"Glyptodonts in fact represent an extinct lineage that likely originated about 35 million years ago within the armadillo radiation," Hendrik Poinar, an evolutionary biologist at McMaster University in Canada, said in a press release.

"Glyptodonts should probably be considered a subfamily of gigantic armadillos," explained Frederic Delsuc, a researcher at CNRS in France. "We speculate that the peculiar structure of their unarticulated carapace might have evolved as a response to the functional constraint imposed by the size increase they experienced over time."

One of the largest glyptodont species was Doedicurus, which weighed up to a ton and lived alongside giant sloths and saber-toothed tigers during the latest ice age.

Researchers were able to pull fragments of Doedicurus DNA from fossil samples, helping scientists properly position the Glyptodontinae subfaimly within the Chlamyphoridae family, which includes the modern dwarf pink fairy armadillo and giant armadillo.

Their findings suggest glyptodonts evolved larger and larger body sizes after the group's evolutionary split from armadillos. The earliest glyptodonts were moderate in size, while later species like Doedicurus adopted the gigantism of South American megafauna during the Pleistocene. Like other megafauna, glyptodonts became extinct at the end of the latest ice age.

Researchers published their latest findings in the journal Current Biology.