Fossilized Footprints Show Ice Age Hunters Ganged Up on Giant Sloths

Courtesy of Bournemouth University
Courtesy of Bournemouth University

They just don't make sloths like they used to. Giant ground sloths from the Ice Age wielded razor-sharp claws and stood 7 feet tall, and new evidence suggests that humans—even children—stalked and hunted them.

By analyzing fossilized footprints found in the salt flats of New Mexico, researchers at Bournemouth University in the UK figured out how prehistoric humans managed to outsmart these furry behemoths. The tracks, which are between 10,000 and 15,000 years old, show two overlapping sets of footprints belonging to both man and beast. Researchers deduced that these early hunters aligned their footprints with the sloth's to avoid detection and sneak up on their prey. The findings were published in the journal Science Advances.

Human footprints inside of a larger sloth footprint
Courtesy of Matthew Bennett, Bournemouth University

"Getting two sets of fossil footprints that interact, that show you the behavioral ecology, is very, very rare," Matthew Bennett, one of the researchers at Bournemouth, told Reuters.

They also found another set of human footprints, leading researchers to believe that hunters traveled in packs and ganged up on the sloth, with one group distracting the animal from a safe distance while another attempted to land a fatal blow. The clue was in marks they dubbed "flailing circles," which suggested that the sloth rose on its hind legs and swung around to defend itself. Anywhere they found flailing circles, human footprints followed.

The presence of children's tracks also showed that hunting was a family affair, but it probably wasn't as fun (or as safe) as going to a modern-day zoo. The prints were taken from New Mexico's White Sands National Monument, which has the "largest concentration of human and Ice Age giant megafauna prints in the Americas," according to researchers. The remote part of the park where they conducted their research is not open to the public.

Modern sloths are related to the giant ground sloth, which went extinct about 11,000 years ago, likely due to over-hunting by humans, scientists say. The fossilized footprints were digitized and preserved for future research using 3D modeling techniques.

Fossilized Fat Shows 550-Million-Year-Old Sea Creature May Have Been the World's First Animal

Ilya Bobrovskiy, the Australian National University
Ilya Bobrovskiy, the Australian National University

A bizarre sea creature whose fossils look like a cross between a leaf and a fingerprint may be Earth's oldest known animal, dating back 558 million years.

As New Scientist reports, researchers from the Australian National University (ANU) made a fortunate find in a remote region of Russia: a Dickinsonia fossil with fat molecules still attached. These odd, oval-shaped creatures were soft-bodied, had rib structures running down their sides, and grew about 4.5 feet long. They were as “strange as life on another planet,” researchers wrote in the abstract of a new paper published in the journal Science.

Another variety of fossil
Ilya Bobrovskiy, the Australian National University

Although Dickinsonia fossils were first discovered in South Australia in 1946, researchers lacked the organic matter needed to classify this creature. "Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran biota were: giant single-celled amoeba, lichen, failed experiments of evolution, or the earliest animals on Earth,” senior author Jochen Brocks, an associate professor at ANU, said in a statement.

With the discovery of cholesterol molecules—which are found in almost all animals, but not in other organisms like bacteria and amoebas—scientists can say that Dickinsonia were animals. The creatures swam the seas during the Ediacaran Period, 635 million to 542 million years ago. More complex organisms like mollusks, worms, and sponges didn’t emerge until 20 million years later.

The fossil with fat molecules was found on cliffs near the White Sea in an area of northwest Russia that was so remote that researchers had to take a helicopter to get there. Collecting the samples was a death-defying feat, too.

“I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone, and repeat this process until I found the fossils I was after,” lead author Ilya Bobrovskiy of ANU said. Considering that this find could change our understanding of Earth’s earliest life forms, it seems the risk was worth it.

[h/t New Scientist]

Endeavour, Captain Cook's Lost Ship, Might Have Been Found—Solving a Centuries-Old Mystery

Wellcome Images, Wikimedia Commons // CC BY-SA 4.0
Wellcome Images, Wikimedia Commons // CC BY-SA 4.0

The exact location of the final resting place of Captain James Cook’s HMS Endeavour, which was sunk off the coast of Rhode Island 200 years ago, is considered one of maritime history’s greatest mysteries. Now, after a 25-year effort to pinpoint its remains among 13 sunken vessels, The Age reports that the Endeavour might have finally been identified.

British explorer James Cook left England on the Endeavour in 1768 headed for the South Pacific. He and his crew became the first European expedition to map the entire coast of New Zealand, and later, the first to reach Australia’s east coast. Along the way, they collected hundreds of previously unknown plant species, became the first Europeans to record a kangaroo sighting, and gathered evidence that would help disprove the existence of the long-speculated southern continent, Terra Australis, that hypothetically extended all the way up to the equator.

A replica of the 18th-century 'Endeavour' in the ocean
A replica of the Endeavour in 2004
Dennis4trigger, Wikimedia Commons // CC BY-SA 3.0

After that three-year journey, Cook and his crew returned to England. Though Cook became a legend, the Endeavour didn’t receive the star treatment. The British Royal Navy used it to ferry supplies to and from the Falkland Islands for several years before selling it to a private buyer. The ship was renamed the Lord Sandwich, and was eventually put into service transporting German mercenaries to fight on Britain's side in the American Revolution.

That’s how the ship ended up in Rhode Island, where it was stationed as part of the Royal Navy’s fleet in Newport Harbor and used as a prison ship for captured American soldiers. When French reinforcements came to assist American revolutionaries in Rhode Island, the British decided to sink their ships rather than allow them to be captured, creating a blockade out of scuttled vessels to block the French from getting into the harbor. They sank 12 transport vessels and set another on fire. Over the ensuing years, locals and French forces took equipment from the wrecks, but it’s never been entirely clear what happened to the remains.

The Rhode Island Marine Archaeology Project began to try to map and identify those remains starting in the early 1990s, and eventually figured out that the Lord Sandwich was the same ship as the HMS Endeavour. As the ship played a vital role in Australian history, the Australian National Maritime Museum then got involved with the project.

The two organizations have announced that they have lowered the number of potential wrecks that could be the Endeavour from 14 to five—and perhaps down to just one—by inspecting the area and measuring the wrecks against historic information about Cook's vessel. The researchers think the final resting place of the ship is located off the coast of Goat Island in Narragansett Bay, but to be absolutely certain, they’ll have to excavate the remains of the ship and examine its timbers. The researchers hope to have that work done by the 250th anniversary of Cook’s arrival in Australia’s Botany Bay—and his claiming of Australia as British territory—in 2020.

And there may be a battle over the remains. While the ship is considered a vital artifact of Australian history, the state of Rhode Island claimed ownership of all of the sunken ships in 1999, and they are overseen by the Rhode Island Historical Preservation and Heritage Commission.

[h/t The Age]

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