A family of ancient animals called Glyptodonts have long been thought of as giant armadillos, and now scientists have the genetic data to back it up: According to a study published Monday in Current Biology, the long-extinct armored beasts were indeed very closely related to modern armadillos.
Scientists led by Hendrik Poinar of McMaster University and Frédéric Delsu of the French National Centre for Scientific Research analyzed the genome of a Glyptodont called Doedicurus. Doedicurus was one of the largest-known species in the family, growing to be over 13 feet long and weighing some 3,000 pounds or more. The hulking animals featured spiked, club-like tails that they probably used in combat. Unlike modern armadillos, their shells were generally made from one solid piece – they didn't have the articulated armor that makes their modern cousins so roly-poly.
The last Doedicurus died about 11,000 years ago, and the tiny fossil sample analyzed for the study was about 12,000 years old – so extracting DNA, which degrades and gets more contaminated over time, was no small feat.
"Ancient DNA has the potential to solve a number of questions such as phylogenetic position -- or the evolutionary relationship -- of extinct mammals, but it is often extremely difficult to obtain usable DNA from fossil specimens," Poinar explained in a statement. "In this particular case, we used a technical trick to fish out DNA fragments and reconstruct the mitochondrial genome."
According to the new analysis, the Glyptodonts are a distinct subfamily in the family Chlamyphoridae, which includes the (absolutely adorable) pink fairy armadillo. The ancient bruisers probably diverged from the rest of the family about 35 million years ago, which is more than 30 million years before modern armadillo species hit the scene.
Based on the fossil record, the researchers believe that this 35 million-year-old common ancestor would have weighed just around 13 pounds, suggesting that Glyptodonts saw a tremendous increase in size as they evolved. It's possible that their unarticulated backs evolved to allow this massive growth.
While their size probably made them much more formidable fighters than their modern cousins, they joined other megafauna in dying off during the last Ice Age. Their lineage is gone, but now we know that their extended family lives on.