Ancient Filipino human relatives discovery

This 10 April 2019 video says about itself:

New human species found in the Philippines

Scientists have found a few bones and seven teeth belonging to a previously unknown species of human. They’ve named the new species Homo luzonensis, after the island of Luzon in the Philippines where it was found. The bones are tiny, suggesting that Homo luzonensis was under 4 feet tall. That would make it the second species of diminutive human to be found in south-east Asia; in 2007 scientists announced the discovery of Homo floresiensis, found on the island of Flores in Indonesia and nicknamed the hobbit.

Both species lived around 50,000 years ago, at a time when Asia was also home to our species, the Neanderthals and a group called the Denisovans. The new species raises many questions, including who were its ancestors and how did it move?

Read the research paper here.

See also here. And here. And here.


Woolly mammoths’, Neanderthals’ Ice Age adaptations

This 2013 video is called A group of Neanderthals attack a herd of woolly mammoths.

From the American Friends of Tel Aviv University:

Woolly mammoths and Neanderthals may have shared genetic traits

Findings point to molecular resemblance in climate adaptation traits of the two species

April 8, 2019

A new Tel Aviv University study suggests that the genetic profiles of two extinct mammals with African ancestry — woolly mammoths, elephant-like animals that evolved in the Arctic peninsula of Eurasia around 600,000 years ago, and Neanderthals, highly skilled early humans who evolved in Europe around 400,000 years ago — shared molecular characteristics of adaptation to cold environments.

The research attributes the human-elephant relationship during the Pleistocene epoch to their mutual ecology and shared living environments, in addition to other possible interactions between the two species. The study was led by Prof. Ran Barkai and Meidad Kislev of TAU’s Department of Archaeology and Ancient Near Eastern Cultures and published on April 8 in Human Biology.

“Neanderthals and mammoths lived together in Europe during the Ice Age. The evidence suggests that Neanderthals hunted and ate mammoths for tens of thousands of years and were actually physically dependent on calories extracted from mammoths for their successful adaptation,” says Prof. Barkai. “Neanderthals depended on mammoths for their very existence.

“They say you are what you eat. This was especially true of Neanderthals; they ate mammoths but were apparently also genetically similar to mammoths.”

To assess the degree of resemblance between mammoth and Neanderthal genetic components, the archaeologists reviewed three case studies of relevant gene variants and alleles — alternative forms of a gene that arise by mutation and are found at the same place on a chromosome — associated with cold-climate adaptation found in the genomes of both woolly mammoths and Neanderthals.

The first case study outlined the mutual appearance of the LEPR gene, related to thermogenesis and the regulation of adipose tissue and fat storage throughout the body. The second case study engaged genes related to keratin protein activity in both species. The third case study focused on skin and hair pigmentation variants in the genes MC1R and SLC7A11.

“Our observations present the likelihood of resemblance between numerous molecular variants that resulted in similar cold-adapted epigenetic traits of two species, both of which evolved in Eurasia from an African ancestor,” Kislev explains. “These remarkable findings offer supporting evidence for the contention regarding the nature of convergent evolution through molecular resemblance, in which similarities in genetic variants between adapted species are present.

“We believe these types of connections can be valuable for future evolutionary research. They’re especially interesting when they involve other large-brained mammals, with long life spans, complex social behavior and their interactions in shared habitats with early humans.”

According to the study, both species likely hailed from ancestors that came to Europe from Africa and adapted to living conditions in Ice Age Europe. The species also both became extinct more or less at the same time.

“It is now possible to try to answer a question no one has asked before: Are there genetic similarities between evolutionary adaptation paths in Neanderthals and mammoths?” Prof. Barkai says. “The answer seems to be yes. This idea alone opens endless avenues for new research in evolution, archaeology and other disciplines.

“At a time when proboscideans are under threat of disappearance from the world due to the ugly human greed for ivory, highlighting our shared history and similarities with elephants and mammoths might be a point worth taking into consideration.”

Prehistoric African Homo sapiens, new study

This is a map showing early African archaeological sites with evidence for symbolic material and microlithic stone tools. Credit: NASA Goddard Space Flight Center. Image by Reto Stöckli

From the University of Huddersfield in England:

New light on origins of modern humans

March 20, 2019

Summary: The work confirms a dispersal of Homo sapiens from southern to eastern Africa immediately preceded the out-of-Africa migration.

Researchers from the University of Huddersfield, with colleagues from the University of Cambridge and the University of Minho in Braga, have been using a genetic approach to tackle one of the most intractable questions of all — how and when we became truly human.

Modern Homo sapiens first arose in Africa more than 300,000 years ago, but there is great controversy amongst scholars about whether the earliest such people would have been ‘just like us’ in their mental capacities — in the sense that, if they were brought up in a family from Yorkshire today, for example, would they be indistinguishable from the rest of the population? Nevertheless, archaeologists believe that people very like us were living in small communities in an Ice Age refuge on the South African coast by at least 100,000 years ago.

Between around 100,000 and 70,000 years ago, these people left plentiful evidence that they were thinking and behaving like modern humans — evidence for symbolism, such as the use of pigments (probably for body painting), drawings and engravings, shell beads, and tiny stone tools called microliths that might have been part of bows and arrows. Some of this evidence for what some archaeologists call “modern human behaviour” goes back even further, to more than 150,000 years.

But if these achievements somehow made these people special, suggesting a direct line to the people of today, the genetics of their modern “Khoi-San” descendants in southern Africa doesn’t seem to bear this out. Our genomes imply that almost all modern non-Africans from all over the world — and indeed most Africans too — are derived from a small group of people living not in South Africa but in East Africa, around 60,000-70,000 years ago. There’s been no sign so far that southern Africans contributed to the huge expansion of Homo sapiens out of Africa and across the world that took place around that time.

That is, until now. The Huddersfield-Minho team of geneticists, led by Professor Martin Richards at Huddersfield and Dr Pedro Soares in Braga, along with the eminent Cambridge archaeologist Professor Sir Paul Mellars, have studied the maternally-inherited mitochondrial DNA from Africans in unprecedented detail, and have identified a clear signal of a small-scale migration from South Africa to East Africa that took place at just that time, around 65,000 years ago. The signal is only evident today in the mitochondrial DNA. In the rest of the genome, it seems to have been eroded away to nothing by recombination — the reshuffling of chromosomal genes between parents every generation, which doesn’t affect the mitochondrial DNA — in the intervening millennia.

The migration signal makes good sense in terms of climate. For most of the last few hundred years, different parts of Africa have been out of step with each other in terms of the aridity of the climate. Only for a brief period at 60,000-70,000 years ago was there a window during which the continent as a whole experienced sufficient moisture to open up a corridor between the south and the east. And intriguingly, it was around 65,000 years ago that some of the signs of symbolism and technological complexity seen earlier in South Africa start to appear in the east.

The identification of this signal opens up the possibility that a migration of a small group of people from South Africa towards the east around 65,000 years ago transmitted aspects of their sophisticated modern human culture to people in East Africa. Those East African people were biologically little different from the South Africans — they were all modern Homo sapiens, their brains were just as advanced and they were undoubtedly cognitively ready to receive the benefits of the new ideas and upgrade. But the way it happened might not have been so very different from a modern isolated stone-age culture encountering and embracing western civilization today.

In any case, it looks as if something happened when the groups from the South encountered the East, with the upshot being the greatest diaspora of Homo sapiens ever known — both throughout Africa and out of Africa to settle much of Eurasia and as far as Australia within the space of only a few thousand years.

Professor Mellars commented: “This work shows that the combination of genetics and archaeology working together can lead to significant advances in our understanding of the origins of Homo sapiens.”

Saber-toothed cats, other La Brea, USA fossils

Cats, from left to right: Dantheman9758/Wikimedia Commons (CC BY 3.0); Charles R. Knight; Charles R. Knight; C. Chang; Dantheman9758/Wikimedia Commons (CC BY 3.0); DiBgd/Wikimedia Commons (CC BY-SA 4.0); Iconographia Zoologica; Jean Charles Werner; Reichenbach, Der Naturfreund, 11-12; Jean Charles Werner; Richard Lydekker; C. Chang. Source: A.D. Rincón et al/J. of Vertebrate Paleo. 2011

By John Pickrell in the USA, 6:00am, March 24, 2019:

Saber-toothed cats were fierce and family-oriented

A freshly detailed picture shows Smilodon helping the injured and the young

The adolescent saber-toothed cat on a summertime hunt realized too late that she had made a terrible miscalculation.

Already the size of a modern-day tiger, with huge canine teeth, she had crept across grassy terrain to ambush a giant ground sloth bellowing in distress. Ready to pounce, the cat’s front paw sank into sticky ground. Pressing down with her other three paws to free herself, then struggling in what has been called “tar pit aerobics”, she became irrevocably mired alongside her prey.

Scenarios much like this played out repeatedly over at least the last 35,000 years at California’s Rancho La Brea tar pits. Entrapped herbivores, such as the sloth, attracted scavengers and predators — including dire wolves, vultures and saber-toothed Smilodon cats — to what looked like an easy meal. Eventually the animals would disappear into the muck, until paleontologists plucked their fossils from the ground in huge numbers over the last century.

THE BADDEST CAT On countless occasions over thousands of years, predator and prey alike — such as saber-toothed cats and giant ground sloths — became mired in the tar at what is now Rancho La Brea in southern California, leaving loads of fossils for researchers to study. Picture by Sergio de la Rosa

Five million or so fossils have been found at the site. But “it’s not like there was this orgy of death going on”, says Christopher Shaw, a paleontologist and former collections manager at the La Brea Tar Pits and Museum in Los Angeles. He calculates that such an entrapment scenario, dooming 10 or so large mammals and birds, would have needed to occur only once per decade over 35,000 years to account for that bounty of fossils.

At La Brea, the collection of Smilodon fatalis fossils alone includes more than 166,000 bones, from an estimated 3,000 of the ill-fated prehistoric cats. Famed for their fearsome canines, which grew up to 18 centimeters long, S. fatalis weighed as much as 280 kilograms, bigger than most of today’s largest lions and tigers.

Fossils of S. fatalis, the second largest of three Smilodon species that roamed the Americas during the Pleistocene Epoch, have been found across the United States and in South America, west of the Andes as far south as Chile. And a recent study put S. fatalis in Alberta, Canada, about 1,000 kilometers north of its previously known range.

But the La Brea fossil site, unique in offering up so many specimens, is the source of the vast majority of knowledge about the species. There, fossils of dire wolves and saber-toothed cats together outnumber herbivores about 9-to-1, leading scientists to speculate that both predators may have formed prides or packs, similar to modern lions and wolves. Yet a small number of experts argue against cooperative behavior for Smilodon, reasoning that pack-living animals would have been too intelligent to get mired en masse.

New studies may help settle the debate about Smilodon’s sociality, and answer questions about how the cat lived and why it died out 10,000 to 12,000 years ago.

“We have an innate curiosity to understand what it was doing and why it went extinct”, says Larisa DeSantis, a vertebrate paleontologist at Vanderbilt University in Nashville. Now, she says, “we can answer these questions.”

DeSantis is studying microscopic wear on fossil teeth and chemical signatures in the enamel to reveal Smilodon’s diet. Other scientists are doing biomechanical studies of the skull, fangs and limbs to understand how the powerful cat captured and killed its prey. Some researchers are extracting DNA from fossils, while others are gathering data on the paleoclimate to try to piece together why Smilodon died out.

“It’s the T. rex of mammals … a big, scary predator”, says Ashley Reynolds, a paleontology Ph.D. student and fossil cat researcher at the University of Toronto. She presented the Alberta fossil find in October in Albuquerque at the Society of Vertebrate Paleontology conference. Explaining why Smilodon cats continue to excite researchers, she says, “They’re probably the baddest of all the cats that have ever existed.”

Safety in numbers

Whether Smilodon was a pack hunter has long been debated (SN: 10/28/17, p. 5) because living in groups is rare among large cats today. But an unusual number of healed injuries in the Smilodon bones at La Brea makes it unlikely that these cats were solitary, DeSantis and Shaw reported in November in Indianapolis at a meeting of the Geological Society of America.

More than 5,000 of the Smilodon bones at La Brea have marks of injury or illness: tooth decay, heavily worn arthritic joints, broken legs and dislocated elbows that would have occurred before the animals’ tar burial. Dramatic examples include crushed chests and spinal injuries, which the cats somehow survived. “You would actually wince to see these horribly, traumatically injured specimens”, says Shaw, who is also coeditor of the 2018 book Smilodon: The Iconic Sabertooth.

One particularly debilitating injury was a crippled pelvis, but evidence of new bone growth shows that the animal lived long enough for healing to occur. “There was a lot of infection, pain and smelly stuff, and just a really awful situation for this animal, but it survived well over a year”, Shaw says. “To me that indicates [the injured cat] was part of a group that helped it survive by letting it feed at kills and protecting it.”

Shaw and DeSantis looked at a series of specimens with what were probably agonizing maladies in the teeth and jaws, including fractured canines and massive infections that left animals with misshapen skulls.

“These animals probably couldn’t have gone out … to kill anything”, Shaw says. “You know how it is when you have a toothache. This is like that times 100.”

DeSantis compared microscopic pits and scratches on the surface of the teeth of injured animals with microwear on the teeth of seemingly healthy Smilodon cats. The injured cats’ dental surfaces indicated that the animals were eating softer foods, which would have been less painful to chew, “likely a higher proportion of flesh, fat and organs, as opposed to bone”, she says.

The findings are consistent with the interpretation that Smilodon was a group-living animal, she says, and that the cats “allowed each other access to food when [injured pack members] couldn’t necessarily take down their own prey.”

Reynolds agrees that the healed injuries are persuasive evidence that Smilodon lived in groups. “When you see an animal with really nasty injuries that healed somehow, it does make you wonder if they were cared for.”

Not everyone is convinced, however. Ecologist Christian Kiffner of the Center for Wildlife Management Studies in Karatu, Tanzania, has studied modern carnivores such as African lions and spotted hyenas. “Relatively long survival of Smilodon fatalis individuals after dental injuries had occurred does not necessarily provide airtight evidence for a specific social system in this species”, he says. “It is very, very difficult to use patterns in Pleistocene carnivore [fossil] assemblages to make inferences about behavior of an extinct species.”

Even if the saber-toothed cats did live in groups, the animals’ exact social structure remains an open question, Reynolds says. Modern lion prides have numerous females and several younger males led by an alpha male, with intense competition between male lions. As a result, males are much bigger than females, as the males must work hard to defend their positions.

Despite searching, scientists have not found obvious evidence of a size difference between the sexes in Smilodon; researchers can’t even tell which La Brea fossils are male or female. Size differences between the sexes, if they existed, may have been small.

“That lack of sexual dimorphism is odd”, says Blaire Van Valkenburgh, a UCLA paleontologist who studies fossil carnivores. Sex-related size differences are seen in many big cats today, most particularly lions. She thinks the lack of sexual dimorphism in Smilodon might hint at a different social structure. Perhaps males weren’t competing quite so intensely for access to females. Maybe there was no single alpha male preventing the majority of males from making a move.

Family affair

Perhaps Smilodon groups had an alpha female rather than an alpha male, or an alpha pair. Such is the case in modern wolves and coyotes, which have less pronounced size differences between sexes than lions do. The prehistoric cats “could have had extended family structures [similar to wolves] where uncles and aunts hung around, because it probably took a while to raise the young saber-toothed cats”, Van Valkenburgh suspects.

Kittens may have taken a long time, as long as 22 months, to get most of their adult teeth, she says. The upper canines took even longer, as much as three years or more, to reach their massive size, researchers reported in PLOS ONE in 2015. Modern lions, in contrast, typically have all of their adult teeth by 17 months, Van Valkenburgh says.

Smilodon kittens also probably went through a substantial learning curve before attempting to take down large prey. “It took longer for them to learn how to safely kill something without breaking their teeth or biting in the wrong place and hurting themselves”, Van Valkenburgh speculates.

Pack living would enable this slower development: “If you’re a social species, you can afford to grow at a slower rate than a nonsocial species because you have a family safety net,” Reynolds says. She is studying Smilodon fossils from Peru’s Talara tar pits for evidence of slow bone development using bone histology, examining thin cross sections under a microscope to determine such things as age and growth rate.

To understand how saber-toothed cats eventually took down prey, Van Valkenburgh joined paleobiologist Borja Figueirido of the University of Málaga in Spain and others. The group studied the biomechanics of Smilodon’s killing bite and how the animal used its sabers. That work, published in the October 22, 2018 Current Biology, adds to a consensus that the cat used its powerful forelimbs, which existed even in the youngsters (SN Online: 9/27/17), to pin prey before applying a lethal bite to the neck.

“The specialization of being a saber-toothed appears to have been partly to effectively take prey larger than yourself and to do that very quickly,” Van Valkenburgh says. With the prey tightly gripped, a Smilodon cat would position itself so that one or two really strong canine bites would rip open the pinned animal’s throat.

In contrast, lions suffocate prey — one lion may clamp its jaws around the neck, crushing the windpipe, while another uses its mouth to cover the victim’s nose and mouth. Using this slower method would have increased Smilodon’s chances of injuring or damaging those precious canine teeth.

Diverging senses

Smilodon and its extinct saber-toothed relatives are on a branch of the cat family tree that is far from today’s cats. Scientists think Smilodon’s branch diverged from the ancestors of all living cats about 20 million years ago. Given the evolutionary distance, researchers are still trying to determine how similar — or different — Smilodon was from its living feline cousins. A recent focus has been the cat’s sounds and senses.

At the October vertebrate paleontology conference, Shaw presented evidence that Smilodon may have roared, as do lions, tigers, leopards and their close relatives. The clues come from 150 La Brea fossils that were once part of the hyoid arch, or larynx, in the Smilodon throat. (Tar pits stand out for preserving tiny bones rarely found elsewhere.) The small fossils are very similar in shape and style to those of roaring cats. House cats and others that purr have a different arrangement of bones.

Smilodon may have “used this type of communication as an integral part of social behavior”, Shaw says. Roaring, however, is not a sure sign of pack living, Reynolds notes; most roaring cats today do not live in large groups.

How Smilodon’s sense of smell compared with living cats’ is something else researchers wonder about. To probe this part of the extinct animal’s biology, a team lead by Van Valkenburgh looked at Smilodon’s cribriform plate — a small, perforated bone inside the skull. Smell-sensing nerve cells pass through holes in the plate from the olfactory receptors in the nose to the brain. The size and number of holes are thought to correlate with the number of receptors and, therefore, the extent of an animal’s sense of smell.

To confirm this link, Van Valkenburgh’s team combined CT scans and 3-D images of skulls from 27 species of living mammals with information on the number of olfactory receptor genes. A CT scan of a skull revealed that Smilodon may have had slightly fewer olfactory receptor nerve cells than a domestic cat, the researchers reported at the paleontology conference. Smilodon’s sense of smell was perhaps 10 to 20 percent less keen than a modern lion’s, says Van Valkenburgh, whose team reported the findings in the March 14, 2018 Proceedings of the Royal Society B.

Smilodon “might have relied more heavily on their eyes and their ears”, she says. Perhaps, in an ancient evolutionary divergence, Smilodon’s level of reliance on smell went in a slightly different direction than in modern big cats.

Saber-toothed swan song

As the pieces of the Smilodon puzzle fall into place, perhaps the biggest remaining mystery is why the animal disappeared 10,000 to 12,000 years ago. Debate about the extinction of some of North America’s large mammal species swings between blaming humans and climate change (SN: 11/10/18, p. 28). While humans, who probably arrived on the continent more than 15,000 years ago, and Smilodon certainly knew one another in the Americas, they may not have overlapped at La Brea, Shaw says. The earliest evidence of people in the Los Angeles Basin is about 11,000 years ago, by which time Smilodon may or may not already have gone. Nevertheless, human hunting of large prey elsewhere in the Americas could have led to a scarcity of food for the big cats, he says.

One theory holds that Smilodon went through tough times at La Brea when lack of prey forced the saber-toothed cats to consume entire carcasses including bones. This has been posited as the reason for all those broken teeth among the La Brea fossils. But DeSantis isn’t convinced; she thinks breakages happened during scuffles with prey. She says dental microwear suggests that Smilodon was not eating great quantities of bone.

Some opportunistic carnivores, such as cougars, did eat bone and managed to survive to the modern day. Perhaps Smilodon couldn’t adapt to hunting smaller prey when larger herbivores disappeared, also around 10,000 to 12,000 years ago (SN: 11/24/18, p. 22).

“A lot of the large prey on the landscape go extinct,” DeSantis says. “You lose out on the horses, camels, giant ground sloths, mammoths and mastodon. That’s got to have had an impact.”

The challenge of dating fossils from the tar pits has been one hurdle to understanding exactly what was going on with Smilodon over time. Bones deposited over many thousands of years get jumbled by movement in the tar, for reasons experts don’t fully understand. Plus, the tar itself becomes embedded in each specimen, complicating carbon dating.

However, new methods of chemically pretreating fossils to remove the tar have made carbon dating much easier and cheaper — and a multi-institutional project is now dating hundreds of Smilodon and other bones. Researchers will soon be able to track changes in Smilodon over the 35,000 years of prehistory recorded at La Brea and correlate fossil changes to known changes in climate over that time.

“We’re going to have a much better handle”, Van Valkenburgh says, “on what was going on towards the end of their existence.”

Hobbit hominins of Flores island, why extinct?

This video is a 2017 documentary on the hobbit hominins of Flores island in Indonesia.

From National Geographic, 12 March 2019:

‘Hobbit’ human story gets a twist, thanks to thousands of rat bones

An abundance of rodent remains adds new clues to the fate of the tiny human relative Homo floresiensis on the Indonesian island of Flores

By Paige Madison

The limestone cave of Liang Bua, on the Indonesian island of Flores, is widely known as the hobbit cave, the site where the surprisingly tiny and enormously controversial extinct human relative Homo floresiensis was discovered. But to the scientists who excavate there, the site is known as something else entirely: the rat cave.

“The first time I went to the excavations at Liang Bua, I remember watching the bones coming out of the ground and being amazed at how it was almost all rat”, recalls Matthew Tocheri, the Canada Research Chair in Human Origins at Lakehead University.

Now, Tocheri and an international team of scientists have examined the rat bones and found evidence for major shifts in their past populations—including one around 60,000 years ago, when hobbit remains started vanishing from the cave.

“Sixty-thousand years ago is precisely when the hobbits’ presence began to decline, before disappearing from the site altogether,” says Wahyu Saptomo, head of conservation and archeometry at the Indonesian National Research Centre for Archaeology.

That means the discovery, which is being reported in the Journal of Human Evolution, not only paints a previously unknown picture of the paleoecology around Liang Bua, it also could help answer some of the biggest lingering questions concerning what happened to the hobbits.

Measuring rats

When H. floresiensis burst onto the paleoanthropological scene in 2003, its small brain and strange, primitive traits sparked debates about where it fit within the human family tree. As scientists hunted for clues to this mystery, the hobbit’s environment began to come into focus, with digs at the site revealing a cast of prehistoric characters almost as bizarre as the hobbit itself, from giant storks to cow-sized elephant relatives and ancient komodo dragons.

Yet, the most plentiful creatures found beneath the surface of the cave floor by far are rats, which make up 80 percent of the identifiable bones at the site.

The rats of Flores aren’t your average rodents; this is as true today as it was when H. floresiensis roamed the landscape. One of the rat species alive today is as large as a small dog, and while this giant rat usually garners the spotlight, it is only one of many species preserved at Liang Bua, each one varying in size, behavior, and food preference.

Of all the species on Earth, “rodents are the most diverse group of mammals”, remarks study leader Elizabeth Veatch, a graduate student at Emory University who is affectionately known by the research team as Miss Tikus (Indonesian for “rat lady”). And in paleoanthropology sites, these variations can convey information about the local ecology and environment through time.

Rats are exceptionally useful for painting the picture of prehistoric life at Liang Bua because their bones appear continuously in the cave sequence. While hobbits, stegodons, and others come and go, the rats persist throughout the roughly 190,000-year stretch preserved under the cave floor.

“Homo floresiensis and modern humans are simply occasional guests that check in and check out for limited stays,” Tocheri points out. (Find out more about the hunt for hobbit DNA.)

Using the rats’ diversity and temporal persistence, and with partial funding from the National Geographic Society, Veatch and Tocheri measured more than 12,000 rat bones, grouped them in size classes, and tracked the relative abundances of each class throughout the stratigraphic sequence. That’s when a striking signal emerged: Medium-size rats that prefer more open habitats dominated the site until about 60,000 years ago, when the bones give way to smaller, more forest-adapted rats.

This shift, the team hypothesizes, reflects a change in the environment surrounding the cave with “more open habitats giving way to more closed ones”, says Jatmiko, a study coauthor and researcher at the Indonesian National Research Centre for Archaeology.

Hobbit migration?

This ecological shift doesn’t just effect only the hobbits, the team suggests: “H. floresiensis wasn’t alone in this departure—the remaining large species followed suit. By 50,000 years ago, all traces of hobbit, stegodon, vulture, stork, and komodo dragon were gone from the cave,” Saptomo says.

Previously, scientists hypothesized that the large fauna on Flores went extinct. “The signal from the rats, however, suggests H. floresiensis’ departure from Liang Bua may simply be because they—and the others—left in search of more open environments,” Veatch says. (On the neighboring island of Sulawesi, scientists also found stone tools that may have belonged to a hobbit relative.)

In essence, the hobbits and their giant animal neighbors didn’t necessarily die out at that time, but may have moved on to more hospitable parts of the island, says coauthor Thomas Sutikna of Wollongong University.

“There is the possibility that some of them still survive after that time somewhere on Flores,” he says.

The team’s analysis is “elegant and careful”, says Bernard Wood, director of the Center for the Advanced Study of Human Paleobiology at George Washington University, who adds that it showcases the need to take many possible interpretations of a given fossil record into account. “This study is yet another example of the folly of equating the end of the fossil record of a taxon at a local site, or sites, with its extinction across a much larger region,” he says.

For instance, the results could mean that the hobbit species lingered into the more recent past—and may have even come into contact with our ancient ancestors. Modern humans (Homo sapiens) appear to have arrived on the island by about 46,000 years ago, and a possible extension of the hobbits’ presence on Flores suggests that they might have encountered modern humans elsewhere on the island.

Resolving such questions will require additional discoveries—in this case, at Liang Bua and elsewhere on Flores. If scientists are fortunate, they will find more caves and sites containing the bones of H. floresiensis. And if they are even luckier, they will also uncover lots and lots of rat bones to help flesh out what exactly happened in the last days of this lost human relative.

Birds in prehistoric rock art

This 2014 video is called Paleolithic Art.

From the University of Barcelona in Spain:

Palaeolithic art featuring birds and humans discovered

An exceptional milestone in European Palaeolithic rock art

March 11, 2019

Summary: A new article tells how researchers found — in the site of Hort de la Bequera (Margalef de Montsant, Priorat) — an artistic piece from 12,500 years ago in which humans and birds try to interact in a pictorial scene with exceptional traits: figures seem to [tell]a narration on hunting and motherhood.

It is not very common to find representations of scenes instead of individual figures in Palaeolithic art, but it is even harder for these figures to be birds instead of mammals such as goats, deer or horses. So far, historians have only found three scenes of Palaeolithic art featuring humans and birds in Europe.

Now, an article published in the journal L’Anthropologie tells how University of Barcelona researchers found -in the site of Hort de la Bequera (Margalef de Montsant, Priorat)-, an artistic piece from 12,500 years ago in which humans and birds try to interact in a pictorial scene with exceptional traits: figures seem to star a narration on hunting and motherhood. Regarding the Catalan context in particular, this is an important finding regarding the few pieces of Palaeolithic art in Catalonia and it places this territory within the stream of artistic production of the upper Palaeolithic in the Mediterranean.

The piece they found is a 30-centimeter long limestone which shows two human figures and two birds, which the researchers identified as cranes. Since they found the piece in 2011, they underwent all cleaning, restoration and 3D copying procedures to study it in detail. Those figures were engraved in the stone board with a flint tool so that they created an organized composition compared to the other pieces of the same period.

“This is one of the few found scenes so far which suggest the birth of a narrative art in Europe, and this theme is unique, since it combines an image of hunting and a motherhood one: a birth with its young one,” says the first signer of the article, ICREA researcher and lecturer at the UB Inés Domingo. “In the represented scene the birds catch the attention, they are copied or chased by two human figures,” continues Domingo. “We do not know the meaning of the scene for prehistoric peoples, but what it says is that not only they were regarded as preys but also as a symbol for European Palaeolithic societies,” she continues.

“We do not doubt this is an exceptional milestone in European Palaeolithic rock art due its singularity, its excellent conservation and the chances to study it within a general context of excavation,” say the authors of the article; members of the Prehistoric Studies and Research Seminar (SERP). Apart from Domingo, other signers are the UB lecturers of Prehistory Pilar García Argüelles, Jordi Nadal, directors of the excavation in Host de la Boquera, Professor Josep Maria Fullola, director of SERP, and José L. Lerma and the researcher Miriam Cabrelles, from Universitat Politècnica de València, who worked on the 3D reproduction of this piece.

Palaeolithic art in Montsant valley

The other sites in Europe researchers had found so far with human and bird figures are rock paintings in the site of Lascauz, a perforated baton in Abri Mege (Teyjat, Dordogne), and the Great Hunter plaque in the site of Gönnersdorf (Germany).

SERP researchers have been excavating in the valley of Montsant since 1979, an exceptional area regarding findings of this period of the late upper Palaeolithic. In particular, excavations have taken place in Host de la Boquera since 1998 and it provided a great amount of flint tools and structure such as rooms for a fireplace.

The director of the excavation, Pilar García Argüelles notes that “the findings of the engraved scene are exceptional, and proves the importance of the site and the area regarding Palaeolithic art in the peninsular north-east area; where we can find nearby the only Palaeolithic cave engraving in Catalonia, the deer in the cave of Taverna (Margalef de Montsant), and about 40 kilometres away there is Molí del Salt (Vimbodí), with an interesting series of stone blocks with engraved animals and a representation of huts.”

The first to identify the engraving was the co-director of the excavation, Jordi Nadal, who remembers that moment with excitement: “Since the first moment I was aware of the importance of this finding, of its uniqueness; these things do not happen very often, this is seeing a figure that has been forgotten and buried for 12,500 years.”

Giant sloth fossil discovery in Belize

This 2017 video on North America in the Pleistocene is called Short-faced bear vs ground sloth.

From the University of Illinois at Urbana-Champaign in the USA:

Ancient extinct sloth tooth in Belize tells story of creature’s last year

February 27, 2019

Summary: Some 27,000 years ago in central Belize, a giant sloth was thirsty. It eventually found water in a deep sinkhole, but it was the creature’s last drink. A new analysis of its tooth offers insight into the landscape it inhabited and what it ate its last year of life.

Some 27,000 years ago in central Belize, a giant sloth was thirsty. The region was arid, not like today’s steamy jungle. The Last Glacial Maximum had locked up much of Earth’s moisture in polar ice caps and glaciers. Water tables in the area were low.

The sloth, a beast that stood up to 4 meters tall, eventually found water — in a deep sinkhole with steep walls down to the water. That is where it took its final drink. In 2014, divers found some of the sloth‘s remains — parts of a tooth, humerus and femur — while searching for ancient Maya artifacts in the pool, in Cara Blanca, Belize.

Though partially fossilized, the tooth still held enough unaltered tissue for stable carbon and oxygen isotope analysis, which provided clues to what the sloth ate in the last year of its life. This, in turn, revealed much about the local climate and environment of the region at the time. The findings, reported in the journal Science Advances, will aid the study of similar fossils in the future, the researchers said.

“We began our study with the hopes of gaining a better understanding of the landscape within which large mammals went extinct and humans emerged in central Belize,” said University of Illinois graduate student Jean T. Larmon, who led the research with U. of I. anthropology professors Lisa Lucero and Stanley Ambrose. “In the process, we discovered which part of the tooth had best maintained its integrity for analysis. And we refined methods for studying similar specimens in the future.”

The new findings “add to the evidence that many factors, in addition to a changing climate, contributed to the extinction of megafauna in the Americas,” said Lucero, who studies the ancient Maya of central Belize. “One of those potential factors is the arrival of humans on the scene 12,000 to 13,000 years ago.”

The teeth of giant sloths like the one found in Belize, Eremotherium laurillardi, differ from those of other large mammals, like mammoths, that went extinct between 14,000 and 10,000 years ago, Larmon said.

“Giant sloth teeth have no enamel, the hard, outer layer of human and some animal teeth that can be analyzed to learn about their diet,” she said.

Other factors have limited scientists’ ability to study the teeth of ancient sloths. Most are fossilized, with minerals replacing much or all of the original tissue and bone.

By using cathodoluminescence microscopy, a technique that causes minerals to glow and can detect the extent of mineralization in fossils, the researchers discovered that one type of tooth tissue, the dense orthodentin, was largely intact.

Larmon drilled 20 samples of orthodentin for isotopic analysis along the 10-centimeter-long tooth fragment, spanning more than a year of tooth growth.

“This allowed us to trace monthly and seasonal changes in the sloth’s diet and climate for the first time, and also to select the best part of the tooth for reliable radiocarbon dating,” Ambrose said.

The isotopic analysis revealed that the giant sloth lived through a long dry season, which lasted about seven months, sandwiched between two short rainy seasons. The analysis also revealed that the creature lived in a savanna, rather than a forest, and consumed a variety of plants that differed between wet and dry seasons.

“We were able to see that this huge, social creature was able to adapt rather readily to the dry climate, shifting its subsistence to relying upon what was more available or palatable,” Larmon said.

“This supports the idea that the sloths had a diverse diet,” Lucero said. “That helps explain why they were so widespread and why they lasted so long. It’s likely because they were highly adaptable.”

The National Science Foundation and the University of Illinois supported this research.