Scientists have determined that the modern-day armadillo had an interesting ancestor — an animal the size of a Volkswagen Beetle.

Researchers have determined that glyptodonts, which lived for millions of years before the ice age 10,000 years ago killed them off, had a clublike armored tail and a bony shell that make them appear similar to armadillos, according to a CBS News report.

The remarkable creature fascinated none other than Charles Darwin when he collected the first known specimens back in the 1830s.

Scientists had long suspected glyptodonts were related to armadillos, but weren’t sure exactly where they were situated in the family tree of that animal. Before, they thought it might be a strange offshoot from the armadillo family, but the research has indicated that they are probably close relatives to the modern armadillo based on genetic analysis.

Glyptodonts are believed to have originated about 35 million years ago.

Scientists used a 12,000-year-old shell of a Doedicurus, which is one of the largest glyptodonts scientists have ever found. They extracted DNA from the specimen and then analyzed it, comparing it to DNA from living mammals in the group Xenarthra.

The findings indicated that the last common ancestor the glyptodont and armadillo shared was just 13 lbs, so the glyptodont certainly exploded in growth, reaching up to 4,400 lbs before the ice age wiped them out.

Modern-day armadillos have a leathery armor shell and belong in the same family as anteaters and sloths. Scientists have described about 9 extant genera and 21 extant species of armadillo.

The findings were published in the journal Current Biology.