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Archaeology NWT_Animals SCI

Baby snake from dinosaur age found frozen in amber

For the first time ever, scientists discovered an ancient snake embryo contained in 105-million-year-old amber. The discovery reveals important information on the evolution of modern snakes.

“This snake is linked to ancient snakes from Argentina, Africa, India and Australia,” said paleontologist Michael Caldwell, lead author of the study and professor in the Department of Biological Sciences. “It is an important—and until now, missing—component of understanding snake evolution from southern continents, that is Gondwana, in the mid-Mesozoic.”

Caldwell and his team, which includes researchers from China, Australia, and the United States, tracked the migration of the ancient Gondwanan snakes all the way back to 180 million years ago when they were transported by tectonic movements created by continents and their parts.

The team also gained information from the amber fragment that encased the specimen.

“It is clear that this little snake was living in a forested environment with numerous insects and plants, as these are preserved in the clast,” Caldwell said. “Not only do we have the first baby snake, we also have the first definitive evidence of a fossil snake living in a forest.”

The team used computerized tomography (CT) scans to study the ancient snake and compare it with the children of modern snakes, shedding light on the embryology and development of the ancient specimen.

“All of these data refine our understanding of early snake evolution, as 100-million year-old snakes are known from only 20 or so relatively complete fossil snake species,” Caldwell said. “There is a great deal of new information preserved in this new fossilized baby snake.”

The findings were published in Science Advances.

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Archaeology NWT_Biology SCI TECH

Experts say ‘alien’ mummy study was flawed, crossed ethical line

Experts are now saying that a 2013 paper by Stanford University immunologist Garry Nolan, which examined the Atacama Mummy, was both flawed and unethical. The study examined the mummy and determined that—contrary to rumors—it was not of extraterrestrial origin, and its strange features were the result of genetic mutations.

But the Chilean National Monuments Council quickly suggested that the mummy’s remains might have been obtained through grave robbing and illegal smuggling. Not only that, many scientists suggested the study was inappropriate.

Now, a new paper headed by a led by Sian Halcrow from the University of Otago, New Zealand claims that the research is riddled with misinterpretations and errors, and suggests there is “no evidence” of the skeletal anomalies described in the original paper.

“We are experts in developmental human anatomy and archaeology, and the mummy looks normal for a fetus around 15-16 weeks gestation,” said Kristina Killgrove, a co-author of the new study. “To the average person, I understand how Ata could look odd, but that’s because the average person doesn’t see developing fetuses or mummies.”

“Unfortunately, there was no scientific rationale to undertake genomic analyses of Ata because the skeleton is normal, the identified genetic mutations are possibly coincidental, and none of the genetic mutations are known to be strongly associated with skeletal pathology that would affect the skeleton at this young age,” Halcrow said.

“Given the fact that the mummified fetus was clearly human, the geneticists did not need to do further testing,” Killgrove said. “But more problematic than that was, once they did test and find it was human, they didn’t immediately stop and question the forensic or archaeological ethics.”

“Whether the fetus mummy was ancient or more recent, Chile requires permits for this sort of testing,” she added. “We believe that these geneticists should have involved a specialist in developmental skeletal biology from the beginning as they would not have made rookie mistakes. But we also want to use this as a cautionary tale going forward—genetics experts need to be informed about ancient and modern laws and ethics surrounding testing.”

The original paper was published in Genome Research.

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Archaeology NWT_Climate SCI

Cold climates contributed to Neanderthal extinction, study says

A new study suggests that climate change likely played a bigger role in the extinction of Neanderthals than we thought. The effort was a collaboration between many American and European research institutions and created detailed new natural records from stalagmites that reveal changes in the European climate over 40,000 years ago.

In particular, many of the cold periods coincide with many of the periods with no archaeological Neanderthals artifacts, which suggests that climate changes impact the long-term survival of the species.

“The Neanderthals were the human species closest to ours and lived in Eurasia for some 350,000 years,” said Vasile Ersek, co-author of the study. “However, around 40,000 years ago — during the last Ice Age and shortly after the arrival of anatomically modern humans in Europe — they became extinct.”

“For many years we have wondered what could have caused their demise,” he added. “Were they pushed ‘over the edge’ by the arrival of modern humans, or were other factors involved? Our study suggests that climate change may have had an important role in the Neanderthal extinction.”

The team believes that modern humans were able to survive these cold periods due to better adaptation to the environment.

“The comparable timing of stadials and population changes seen in the archaeologic and genetic record suggests that millennial-scale hostile climate intervals may have been the pacesetter of multiple depopulation-repopulation cycles” Ersek said. “These cycles ultimately drew the demographic map of Europe’s Middle-Upper Paleolithic transition.”

The findings were published in the Proceedings of the National Academy of Sciences.

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Archaeology NWT_Animals SCI

‘First giant’ dinosaur fossil discovered in Argentina

Researchers just discovered the “first giant” dinosaur fossil in Argentina, which should shed light on evolutionary process that helped dinosaurs become some of the largest creatures to ever traverse the Earth. Researchers are calling the discovery “a huge evolutionary finding.”

“We could see that it was a new species that we named Ingentia prima,” said Cecilia Apaldetti, first author of the study from the Universidad Nacional de San Juan in Argentina.

The fossil in question dates all the way back to the Triassic period approximately 30 million years prior to the arrival of the long-neck Jurassic Brachiosaurus. Scientists believe that the finding is important because it reshapes the conversation surrounding dinosaur evolution.

“We used to think that the first giant dinosaurs arose in the early part of the Jurassic Period, after supervolcanoes caused a global extinction at the end of the Triassic,” Steve Brusatte of the University of Edinburgh, who wasn’t involved in the study, said in a BBC analysis. “But the lessemsaurids tell us that at least some dinosaurs were able to attain giant sizes during the latest part of the Triassic, before the extinction.”

Before the discovery, researchers believed that Triassic dinosaurs were significantly smaller in size..

“What is really unexpected is that the lessemsaurids achieved their huge bodies independently of the gigantic sauropods like Brontosaurus and Diplodocus, which did indeed evolve later during the Jurassic,” Brusatte said in his BBC analysis.

“The development of huge size wasn’t just a one-off event for the sauropods, but rather different types of dinosaurs were able to become colossal, which speaks to just how incredible these animals were,” he added.

The findings were published in Nature Ecology and Evolution.

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Archaeology NWT_Animals SCI

Scientists suggest that winged reptiles existed before dinosaurs

Researchers just discovered a new species of pterosaur, which is the family of prehistoric flying reptiles that includes the pterodactyl. Interestingly, the specimen is approximately 210 million years old, which pre-dates its relatives by 65 million years.

The bones of the new species, named Caelestiventus hanseni, were preserved in desert oasis remains. They suggest that the species thrived on Earth prior to the evolution of dinosaurs.

The pterosaurs are the oldest flying vertebrates and a close relative of Dimorphodon. And since they were the first to evolve powered flight, their bird-like skeletons are often delicate and in a crushed state.

“Most of them are heavily distorted; literally like roadkill,” said lead author Brooks Britt, from Brigham Young University in Utah.

“The bones are so delicate, you can’t take them all the way out of the rock because they would just fall apart,” he added.

The team created a digital profile of the skull using a computed tomography (CT) scan and then printed a 3D model, which revealed a complex set of teeth.

“This one site we’ve pulled out 18,000 bones from an area the size of a good sized living room,” Britt said. “And there’s only one pterosaur.”

Although the specimen hadn’t reached adulthood, it had a wingspan of one-and-a-half meters.

“It was probably the biggest of its day,’ Britt said. “Among its peers, we have no evidence that any rival came close to that.”

The team plans to continue conducting research on the fossil in order to better understand what it ate and how it lived.

The findings were published in Nature Ecology & Evolution.

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Archaeology NWT_Biology SCI TECH

Human prehistoric ancestors mated with each other, study says

A new study reveals an inter-species prehistoric human ancestor with a Denisovan father and Neanderthal mother. The unique lovechild was named Denisova and was at least 13 years old when she died of unknown causes.

“There was earlier evidence of interbreeding between different hominin, or early human, groups,” said Vivian Slon, lead author of the study. “But this is the first time that we have found a direct, first-generation offspring.”

The team analyzed the remains of a bone fragment discovered in 2012 by Russian archaeologists, which revealed chromosomes that were half Denisovan and half Neanderthal. Both of these early human species split apart approximately 400,000 to 500,000 years ago.

“I initially thought that they must have screwed up in the lab,” said senior author Svante Paabo.

Less than two dozen human genomes from before 40,000 years ago have been sequenced. Not only that, but the chances of discovering a half-and-half hybrid is already very small.

“The very fact that we found this individual of mixed Neanderthal and Denisovan origins suggests that they interbred much more often than we thought,” Slon said.

“They must have quite commonly had kids together, otherwise we wouldn’t have been this lucky,” Paablo agreed.

“Part of the story of these groups is that they may simply have been absorbed by modern populations,” he added. “The modern humans were more numerous, and the other species might have been incorporated.”

The study highlights the possibility that Denisovans and Neanderthals might have mated more if not for the fact that the former typically settled in Europe.

The findings were published in Nature.

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Archaeology NWT_Biology Research SCI TECH

Laziness likely helped kill off Homo erectus, study says

A new study examining archaeological research suggests that the extinct species of primitive humans, Homo erectus, met their end in part because they were “lazy.”

The conclusion stems from an archaeological excavation of an ancient population of the species in the Arabian Peninsula that lived during the Early Stone Age. The data suggests that they used “least-effort strategies” to create tools and gather resources.

In combination with an inability to adapt to an evolving climate, this “laziness” most likely played a role in the species’ extinction.

“They really don’t seem to have been pushing themselves,” said Ceri Shipton, lead author of the study from The Australian National University (ANU).

“I don’t get the sense they were explorers looking over the horizon,” he said. “They didn’t have that same sense of wonder that we have.”

Shipton says this was clear from the way that the species created their tools and gathered resources.

“To make their stone tools they would use whatever rocks they could find lying around their camp, which were mostly of comparatively low quality to what later stone tool makers used,” he said. “At the site we looked at there was a big rocky outcrop of quality stone just a short distance away up a small hill.

“But rather than walk up the hill they would just use whatever bits had rolled down and were lying at the bottom,” he added. “When we looked at the rocky outcrop there were no signs of any activity, no artefacts and no quarrying of the stone.”

“They knew it was there, but because they had enough adequate resources they seem to have thought, ‘why bother?'”.

Conversely, other stone tool makers in later time periods, including Neanderthals and early Homo sapiens, climbed mountains to find the best quality stones and carried them over long distances.

The findings were published in PLOS One.

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Archaeology NWT_Animals SCI

British workers discover 140-million-year-old dinosaur footprints

British workers at Purbeck quarry in Swanage along the Jurassic Coast just discovered a set of 140-million-year-old dinosaur footprints that are believed to originate from a herd of massive sauropods that roamed the landscape years ago.

Sauropods are the first successful herbivorous dinosaurs and lived as long as 120 years. Researchers believe they likely resided along Britain’s south coast from the late Triassic through to the late Cretaceous periods

Interestingly, the site was the location of a similar discovery of 52 dinosaur prints back in 1997.

“The footprints are like giant saucer-shaped depressions which are up to three-foot in diameter but only half an inch deep,” said Matthew Bennett from Bournemouth University, who guided the extraction. “They belonged to the Sauropods which were very large dinosaurs the size of double-decker buses and very gregarious, travelling in groups.”

The team used special equipment called DigTrace to create three-dimensional documentation of the tracks.

“This technology is now being used by the police to help track criminals via their footprints, but we can also use it to record and preserve rare footprints like these,” Bennett said.

“The beauty of capturing the tracks in 3D is that they can be analysed digitally and even printed in the future, with no need to hold up the quarrying for long,” he added.

Bennett said now that the footprints have been extracted intact, the team will focus on readying them for a museum display.

“I’ve spent my life travelling the world to look for fossil footprints so it is nice to find some on our doorstep,’ he said.

The quarry was shut down for 10 days to make way for the excavation.

“It became apparent that we had come across something of historical interest, so working closely with the National Trust and Professor Matthew Bennett of Bournemouth University, we were able to move forward in the best way without stopping progress in the quarry itself,” said David Moodie from Lewis Quarries.”

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Archaeology NWT_Animals SCI Science

Study uncovers mystery of ancient vegetarian cave bear diet

One of the two bears species that roamed Europe during the Late Pleistocene period was the extinct and mostly vegetarian Ursus spelaeus cave bear. And now, a new study sheds light on the evolution of cave bear diets and the vegetarian species’ unique morphology.

The study suggests that the the Deninger’s bear (Ursus deningeri), which is the direct ancestor of the vegetarian cave bear, had unique morphology in is mandible, teeth, and cranium, which is likely due to its consumption of vegetables.

“There is an ongoing discussion on the extent to which the classic cave bear was a vegetarian,” said Mikel Arlegi, doctoral candidate at the Universities of the Basque Country and Bordeaux and co-author of the study. “And, this is especially why the new information on the diet of its direct ancestor is so important, because it teaches us that a differentiation between the diet of cave bears and brown bears was already established by 500 thousand years ago and likely earlier.”

“The analyses showed that Deninger’s bear had very similarly shaped mandibles and skull to the classic cave bear”, said Anneke van Heteren, lead-author of the study and Head of the Mammalogy section at the Bavarian State Collection of Zoology. The findings imply that they were adapted to identical food types and were mostly vegetarian.

The team also found shape variations between the Deninger’s bears that lived on the Iberian Peninsula and those that lived in the rest of Europe, and have come up with numerous hypotheses to explain them.

“However, more fossils are necessary to test these three hypotheses,” said Asier Gómez-Olivencia, an Ikerbasque Researcher at the University of the Basque Country.

The findings were published in Historical Biology.

Categories
Archaeology SCI

Hunters burned patches of prairie to entice bison

In north-central Montana, pre-Columbian hunters built mile-long stretches of drivelines. They used the drivelines to funnel buffalo herds from fertile grazing patches towards the edge of a steep bluff.

Archaeologists have radiocarbon dated bison bones to between 900 and 1650 CE at two different driveline sites. The majority of kills occurred in the final 250 years of that period.

Evidence suggests that those hunters burned patches of the prairie to spur the growth of fresh grass in the gathering basins to entice herds of ravenous bison. Southern Methodist University archeologist Christopher Roos and his team studied layers of sediment exposed in the riverbed walls of two tributaries of the Two Medicine River.

The team, including members of the Blackfeet Tribe, found between five and eight layers of charcoal residue at each site. It is a sure sign of nearby prairie fires.

They radiocarbon dated them to between 1100 and 1650 CE – the height of the bison jumps. They did not look like the result of natural wildfires, but rather fires that hunters deliberately set.

The fires were most likely spring burns to prepare for fall hunts. Their goal could have been to stimulate new growth to attract bison.

They seemed to have set them in carefully chosen spots. “Burning of this kind in fescue prairies changes the composition of the grasses and forbs,” Roos said.

That means that a hunter-gatherer society with a comparably low population density had an important impact on the environment.