Salutations, PauLO Not all sloths were fuzzy, slow-moving creatures that lived in trees. They had enormous claws when they were startled, and their prehistoric ancestors weighed up to four tons.
Along with many other large species that previously roamed North and South America, such as mastodons, saber-toothed cats, and dire wolves, scientists have thought that the first people to arrive in the Americas quickly drove off these huge ground sloths through hunting.
However, recent studies from a number of locations are beginning to imply that humans arrived in the Americas far earlier than previously believed. These discoveries suggest that these early Americans led a very different life, possibly coexisting with massive animals for millennia on prehistoric wetlands and savannas.
According to Daniel Odess, an archaeologist at White Sands National Park in New Mexico, there was a theory that people soon wiped everything out, a phenomenon known as Pleistocene overkill. However, recent findings indicate that humans coexisted with these species for at least 10,000 years without causing their extinction.
The bones of enormous ground sloths at the Santa Elina archaeological site in central Brazil contain some of the most intriguing hints of human manipulation. In the past, sloths like these lived from Alaska to Argentina. Some species had osteoderms, which are bony projections on their backs that resemble the plates of contemporary armadillos and may have been utilized as decorations.
At the University of São Paulo, Brazil, on September 2, 2024, researcher Marian Pacheco holds a round, penny-sized sloth fossil that dates to approximately 27,000 years ago. He notes that, in contrast to most other specimens, the surface is surprisingly smooth, the edges seem to have been purposefully polished, and there is a tiny hole near one edge. (Photo by Christina Larson for AP)
A spherical, penny-sized sloth fossil is held in the palm of researcher Marian Pacheco at a lab at the University of Sao Paulo. She observes that there is a little hole close to one edge, the surface is astonishingly smooth, and the edges seem to have been purposefully polished.
According to her, we think that ancient people purposefully changed it and used it as jewelry or ornament. Unworked osteoderms on a table, which have rough surfaces and no holes, are clearly distinct from three identical pendant fossils.
These Santa Elina artifacts date back to 27,000 years, which is more than 10,000 years before experts previously believed that people had reached the Americas.
At first, scientists questioned whether the artisans were working on fossils that were already quite old. However, it appears from Pacheco’s research that ancient people were carving fresh bones soon after the animals died.
The story of how humans first arrived in the Americas and how they affected the ecosystem they found there may be altered by her findings and other recent discoveries.
According to Pacheco, there is still a lot of disagreement.
Researchers have shared this image of prehistoric artwork at the Santa Elina excavation site in Brazil’s Mato Grosso state. (via AP) Gueda Vilhena Vialou, Denis Vialou
According to scientific knowledge, humans initially appeared in Africa, then spread to Europe and Asia-Pacific, and ultimately arrived in the Americas, the final continental boundary. However, there are still unanswered concerns regarding the last part of the beginnings of humans.
The theory that the majority of archaeologists believed throughout the 20th century was taught to Pacheco in high school. Clovis was first, she continued, according to what I had learnt in school.
Archaeologists discovered unique projectile points and other artifacts dating from 11,000 to 13,000 years ago at the Clovis site in New Mexico in the 1920s and 1930s.
An idea of how early humans arrived in North America after crossing the Bering Land Bridge from Asia was born on this date, which also happens to be the end of the last Ice Age. During this period, an ice-free corridor most likely formed in North America.
Furthermore, many experts hypothesized that the introduction of people caused mass extinctions since the fossil record demonstrates the widespread collapse of American megafauna beginning at the same time as South America lost more than 80% of its huge mammals and North America lost 70%.
Paleoanthropologist Briana Pobiner of the Smithsonian Institution’s Human Origins Program remarked that when everything fell into place, it was a pleasant story for a while. However, it no longer functions as effectively.
On July 11, 2024, Thas Pansani is shown in the Smithsonian’s National Taphonomy Reference Collection in Washington, D.C., holding a huge sloth rib bone from central Brazil that is believed to have been charred by man-made fire and dates to between 13,000 and 15,000 years ago. (Photo by Mary Conlon/AP)
The old narrative has been upended and new questions, particularly regarding timing, have been raised over the past 30 years by new research methods, such as ancient DNA analysis and new laboratory techniques, as well as by the examination of more archaeological sites and the participation of more diverse scholars from across the Americas.
Richard Fari, a paleontologist at the University of the Republic in Montevideo, Uruguay, stated that anything older than roughly 15,000 years is still subject to close examination. However, increasingly strong evidence from earlier sites continues to surface.
Pacheco investigates the chemical alterations that take place when a bone turns into a fossil in Sao Paulo and at the Federal University of Sao Carlos. This makes it possible for her team to determine when the sloth osteoderms were most likely altered.
We discovered that the osteoderms were carved in fresh bones prior to the fossilization process, which suggests that the sloths perished a few days to a few years later, but not thousands of years later.
Additionally, her team analyzed and ruled out a number of natural processes, such as animal chewing and erosion. The study was released in the Proceedings of the Royal Society B journal last year.
Paleontologist Tha s Pansani, who was recently stationed at the Smithsonian Institution, is one of her partners. He is examining whether the sloth bones discovered at Santa Elina were burnt by man-made fires, which burn at a different temperature than natural wildfires.
It’s unclear from her initial findings if the fresh sloth bones were burned intentionally during cooking or were just close to human campsites. In order to rule out other potential explanations for the black spots, like natural chemical discoloration, she is also conducting tests.
Monte Verde, Chile, was the first location generally acknowledged to be older than Clovis.
Researchers have found fragments of preserved animal hides, a variety of edible and medicinal plants, and 14,500-year-old stone tools buried beneath a peat bog.
The surprise was Monte Verde. Archaeologist Tom Dillehay of Vanderbilt University, a longstanding researcher at Monte Verde, stated, “You’re here at the end of the world, with all this organic stuff preserved.”
Even earlier dates for human presence in the Americas are suggested by other archeological sites.
Among the oldest sites is Arroyo del Vizca no in Uruguay, where researchers are studying apparent human-made cut marks on animal bones dated to around 30,000 years ago.
Researchers have discovered human footprints at New Mexico’s White Sands that date from between 21,000 and 23,000 years ago, along with enormous mammal footprints of a similar age. However, other archaeologists claim that it is difficult to comprehend how people could frequently visit a location and not leave behind any stone implements.
“They’ve presented a compelling argument, but I’m still confused about a few aspects of that site,” Southern Methodist University archaeologist David Meltzer said. Why would people never leave any artifacts but leave footprints over a long time?
According to Odess at White Sands, he anticipates and enjoys these kinds of obstacles. He stated, “We really just followed the evidence where it leads; we didn’t set out to find the oldest anything.”
Although the precise date of human arrival in the Americas is still up for debate and may never be established, it is obvious that if early humans arrived, they did not immediately annihilate the enormous animals they came across.
And the White Sands footprints preserve a few moments of their early interactions.
According to Odess’ interpretation, one set of tracks depicts a big ground sloth moving on four feet after coming across the footprints of a small person who has just sprinted past. After halting and standing up on its hind legs, the massive beast shuffles around before continuing on in a different direction.
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