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Around 12,000 years ago, something scorched a vast swath of the Atacama Desert in Chile with heat so intense that it turned the sandy soil into widespread slabs of silicate glass. Now, a research team studying the distribution and composition of those glasses has come to a conclusion about what caused the inferno. In a study published in the journal Geology, researchers show that samples of the desert glass contain tiny fragments with minerals often found in rocks of extraterrestrial origin. Those minerals closely match the composition of material returned to Earth by NASA's Stardust mission, which sampled the particles...

New research shows 8,000-pound sloths once dug caves, adapted to oceans, and roamed widely—until climate and humans brought their downfall. (Artist’s concept.) Credit: SciTechDaily.com ================================================================= Long before they became tree-hugging symbols of chill, sloths were 8,000-pound giants that roamed deserts, dug caves into cliffs, and even swam like manatees. Scientists have now pieced together the epic story of their evolution, using ancient DNA and hundreds of fossils to explain how sloths once grew to mammoth proportions—bigger than most cars—and why they eventually shrank or vanished altogether. Sloths’ Strange Family Tree Most of us know sloths as the slow-moving, tree-loving creatures...

Prehistoric humans hunt a woolly mammoth. More and more research shows that this species – and at least 46 other species of megaherbivores – were driven to extinction by humans. Credit: Engraving by Ernest Grise, photographed by William Henry Jackson. Courtesy Getty’s Open Content Program ================================================================== Researchers at Aarhus University have concluded that human hunting, rather than climate change, was the primary factor in the extinction of large mammals over the past 50,000 years. This finding is based on a review of over 300 scientific articles. Over the last 50,000 years, many large species, or megafauna, weighing at least 45...

The discovery of butchered bones belonging to a glyptodont, a giant relative of the armadillo, suggests that humans were living in Argentina 20,000 years ago. Ancient humans may have butchered and eaten a giant armadillo-like creature around 20,000 years ago in what is now Argentina, a new study finds. The discovery of the butchered bones supports a growing body of evidence that people spread throughout the Americas much earlier than previously assumed. During the Late Pleistocene epoch (129,000 to 11,700 years ago), ice sheets and glaciers covered much of the planet, particularly during the Last Glacial Maximum, a period around...

When Alex Rodriguez swings for the fences or Venus Williams tries to ace her serve, they do well to connect at the "sweet spot" of their bat or racket. That aim was apparently shared by some unlikely contenders: glyptodonts, armored mammals with clublike tails that roamed the Americas until about 10,000 years ago. The sweet spot, or center of percussion, is the point on a tool where powerful blows should be landed to maximize impact and minimize the risk of injury to the user.

Based on sites excavated in the western United States, archaeologists know Paleo-American Clovis hunter-gatherers who lived around the time of the extinctions at least occasionally [emphasis added] killed or scavenged Ice Age megafauna such as mammoths. There they've found preserved bones of megafauna together with the stone tools used for killing and butchering these animals...Unfortunately, many areas in the Southeastern United States lack sites with preserved bone and associated stone tools that might indicate whether megafauna were hunted there by Clovis or other Paleo-American cultures. Without evidence of preserved bones of megafauna, archaeologists have to find other ways to examine...

Early human foragers may have relied on eating the partially digested vegetable matter, called digesta, found in the stomachs and digestive tracts of bison and other large game herbivores...Folding digesta into these models will allow researchers to better address major questions in evolutionary anthropology. It even calls into question the idea that “hunting and gathering,” which all prehistoric people relied on until about 10,000 years ago, was divided by sex, according to author Raven Garvey, associate professor of anthropology and affiliate of the Research Center for Group Dynamics at the U-M Institute for Social Research.Early foragers may, in some contexts,...

Coprophilous fungi spores, which are integral to the life cycle of large animals weighing over 45 kg, pass through the digestive systems of these creatures. Consequently, the presence of such spores in sediment samples indicates that these sizable animals once inhabited specific locations and time periods.Researchers led by the University of Exeter determined that the local extinction of large animals at Pantano de Monquentiva occurred approximately 23,000 years ago and again around 11,000 years ago, significantly affecting ecosystems. The study relied on samples taken from a peat bog in Pantano de Monquentiva, situated about 60 km from Bogota in the...

...the First Evidence of the Prehistoric Predator Roaming the State at the End of the Ice Age Between 13,605 and 13,460 Years Ago.The sabertoothed cat (Smilodon) is one of the best-known genera of the machairodont, an extinct subfamily of carnivoran mammals of the family Felidae (true cats). They are popularly referred to as "sabertoothed tigers", although they are not closely related to tigers (Panthera).The genus was named in 1842 based on fossils from Brazil; the generic name means "scalpel" or "two-edged knife" combined with "tooth".Researchers discovered the remarkably well-preserved skull in Page County, southwest Iowa...The skull belonged to a subadult...

South Australia's Naracoorte Caves is one of the world's best fossil sites, containing a record spanning more than half a million years. Among the remains preserved in layers of sand are the bones of many iconic Australian megafauna species that became extinct between 48,000 and 37,000 years ago.The reasons for the demise of these megafauna species are intensely debated. But the older the fossils we can find, the better we can understand the species' evolution and extinction.To date, determining the precise age of the caves has been difficult. However our research demonstrates, for the first time, how old Naracoorte's caves...

Species of the horse genus Equus first appeared on the North American continent during the Pliocene era and spread to and across Eurasia beginning around 2.5 million years ago. They disappeared from the Western Hemisphere during the megafauna extinction event at the end of the Pleistocene and the last glacial period. The return of equids to the Americas through the introduction of the domestic horse (Equus caballus) is documented in the historical literature but is not explored fully either archaeologically or genetically. Historical documents suggest that the first domestic horses were brought from the Iberian Peninsula to the Caribbean in...

"Territorial and environmental pressures triggered by climate changes are most probably responsible for these frequent conflicts between what appears to be culturally distinct Nile Valley semi-sedentary hunter-fisher-gatherers groups," the study said. The cemetery holds the remains of 61 people, and it was excavated in the 1960s. "Over 100 previously undocumented healed and unhealed lesions were identified on both new and/or previously identified victims, including several embedded lithic artefacts. Most trauma appears to be the result of projectile weapons and new analyses confirm for the first time the repetitive nature of the interpersonal acts of violence," the study found.

Along with locations in North and South America, Greenland, Western Europe, and the Middle East, we can now add southern Africa to the list of places where scientists have uncovered evidence of a calamitous event that happened 12,800 years ago. This evidence of a 12,800-year-old platinum spike in Africa is the first to be found on the continent, and it’s yet further evidence in support of the Younger Dryas Impact Hypothesis. According to this theory, either a comet or asteroid struck Earth during the Pleistocene, triggering an impact winter that saw temperatures plummet around the globe. The associated loss of...

Following the discovery of the 19.2-mile wide Hiawatha impact crater beneath the northwest margin of the Greenland Ice Sheet, Dr. Joe MacGregor of NASA’s Goddard Space Flight Center and colleagues explored satellite and aerogeophysical data in search of additional such craters and found a possible second impact crater that is 22.7 miles wide and 114 miles southeast of the Hiawatha crater. The discovery is described in a paper in the journal Geophysical Research Letters. ..." Following the finding of that first crater, Dr. MacGregor and co-authors checked topographic maps of the rock beneath Greenland’s ice for signs of other craters....

An international team of geoscientists from the United States, Canada and Europe has discovered a large impact crater beneath the Hiawatha Glacier in remote northwest Greenland. A paper on the discovery was published in the journal Science Advances. The Hiawatha impact crater is approximately 19.2 miles (31 km) wide and lies under an ice sheet that is 0.6 miles (1 km) thick.The scientists believe this crater was formed by a 0.6-mile wide iron asteroid that slammed into the Earth at the end of the Pleistocene epoch, perhaps as recently as 12,000 years ago. ..." “Researchers were looking at the map...

On a bright July day 2 years ago, Kurt Kjær was in a helicopter flying over northwest Greenland—an expanse of ice, sheer white and sparkling. Soon, his target came into view: Hiawatha Glacier, a slow-moving sheet of ice more than a kilometer thick. It advances on the Arctic Ocean not in a straight wall, but in a conspicuous semicircle, as though spilling out of a basin. Kjær, a geologist at the Natural History Museum of Denmark in Copenhagen, suspected the glacier was hiding an explosive secret. The helicopter landed near the surging river that drains the glacier, sweeping out rocks...

New data from Greenland ice cores suggest North America may have suffered a large cosmic impact about 12,900 years ago. A layer of platinum is seen in ice of the same age as a known abrupt climate transition, US scientists report. The climate flip has previously been linked to the demise of the North American "Clovis" people. The data seem to back the idea that an impact tipped the climate into a colder phase, a point of current debate. Rapid climate change occurred 12,900 years ago, and it is proposed that this is associated with the extinction of large mammals...

Greenland ice core analysis shows drastic climate change near end of last ice age Caption: The North Greenland Ice Core Project camp. Credit: NGRIP Temperatures spiked 22 degrees F in just 50 years, researchers say Information gleaned from a Greenland ice core by an international science team shows that two huge Northern Hemisphere temperature spikes prior to the close of the last ice age some 11,500 years ago were tied to fundamental shifts in atmospheric circulation. The ice core showed the Northern Hemisphere briefly emerged from the last ice age some 14,700 years ago with a 22-degree-Fahrenheit spike in just...

About 2.6 million years ago, an oddly bright light arrived in the prehistoric sky and lingered there for weeks or months. It was a supernova some 150 light years away from Earth. Within a few hundred years, long after the strange light in the sky had dwindled, a tsunami of cosmic energy from that same shattering star explosion could have reached our planet and pummeled the atmosphere, touching off climate change and triggering mass extinctions of large ocean animals, including a shark species that was the size of a school bus. The effects of such a supernova—and possibly more than...

"Patagonia turns out to be the Rosetta Stone - it shows that human colonisation didn't immediately result in extinctions, but only as long as it stayed cold," says study leader Professor Alan Cooper, ACAD Director. "Instead, more than 1000 years of human occupation passed before a rapid warming event occurred, and then the megafauna were extinct within a hundred years." The researchers, including from the University of Colorado Boulder, University of New South Wales and University of Magallanes in Patagonia, studied ancient DNA extracted from radiocarbon-dated bones and teeth found in caves across Patagonia, and Tierra del Fuego, to trace...