RAW STORY
DNA coaxed out of a 12,000-year-old fossil from Argentina is
providing unique insight into one of the strangest Ice Age giants: a
tank-like mammal the size of a small car with a bulbous bony shell and a
spiky, club-shaped tail.
Scientists said on Monday their genetic research confirmed that the
creature, named Doedicurus, was part of an extinct lineage of gigantic
armadillos. Doedicurus was a plant-eater that weighed about a ton and
roamed the pampas and savannas of South America, vanishing about 10,000
years ago along with many other large Ice Age animals.
“With a length of more than three meters (10 feet) from head to tail,
it certainly looks like a small car, like a Mini or Fiat 500,”
evolutionary biologist Frederic Delsuc of France’s Université de
Montpellier, one of the researchers, said.
It was a member of a group called glyptodonts that shared the
landscape with giant ground sloths, sabre-toothed cats and towering,
flightless, carnivorous “terror birds.” Some glyptodonts made it as far
north as southern portions of the United States, from what is now
Arizona through the Carolinas.
The researchers were able to place Doedicurus and the other
glyptodonts into the armadillo family tree after studying small
fragments of DNA extracted from bits of the creature’s carapace. They
used a sophisticated technique to fish mitochondrial DNA out from a soup
of environmental contaminants that had leached into the fossil over the
eons.
They determined the glyptodont lineage originated about 35 million
years ago. The oldest armadillo fossil, from Brazil, was around 58
million years old.
Asked what someone might think upon encountering Doedicurus, another
of the researchers, evolutionary biologist Hendrik Poinar of McMaster
University in Canada said, “That’s the biggest armadillo-looking
creature I’ve ever seen, and it has a tail like an Ankylosaurus. Yikes!”
Doedicurus resembles the dinosaur Ankylosaurus, which also was heavily armored and wielded a club-like tail.
The researchers said the resemblance was an example of “convergent
evolution” in which disparate organisms independently evolve similar
features to adapt to similar environments or ecological niches.
Scientists have debated whether humans contributed to the extinction
of the glyptodonts. Poinar said he believed that humans played a role,
saying most of the large mammals of that time were under pressure not
only from climate change as Ice Age waned but also from human hunting.
The research was published in the journal Current Biology.
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