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Fossil DNA shows effect of ancient climate change on eastern moa

                                   

The New Zealand extinct eastern moa has given scientists new insights into how species react to climate change, with a recent study finding that during the last Ice Age these large flightless birds changed their distribution as the climate heated and cooled.

Geneticists analysed ancient DNA from moa fossils and found that while the species had been spread across the eastern and southern South Island during the prior warmer Holocene period, their range reduced to just the south during the height of the last Ice Age (25,000 years ago).

“The eastern moa’s response had consequences for its population size and genetic diversity – the last Ice Age led to a pronounced genetic bottleneck which meant it ended up with lower genetic diversity than other moa living in the same areas,” says lead author Dr Alex Verry, a researcher in the Otago Paleogenetics Laboratory at the University of Otago, New Zealand.

The findings are reported in the journal Biology Letters.

https://royalsocietypublishing.org/doi/10.1098/rsbl.2022.0013

 

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Cue the Laos Cobra cave tooth, first clue in the Denisovan hunt down under

The Denisovan chain to PNG and Australia gets another link.

Denisovans, the mysterious archaic humans first identified in a cave in Siberia, also lived down under. We know that because indigenous Papuans and Australians carry their DNA – around 4% was bequeathed by a Denisovan ancestor.

Since that discovery in 2010, the race has been on to find the actual remains of a Denisovan in this part of the world. Now an international team may have found them in the form of a 160,000–130,000-year-old tooth unearthed from Cobra cave in the remote Annamite mountains of northern Laos.

“We have essentially found the ’smoking gun’ – this Denisovan tooth shows they were once present this far south,” says geoarchaeologist Mike Morley, a team member from Flinders University, in Adelaide.

“It’s incredibly exciting; we’ve never seen them in a warm climate before,” says geochronologist Kira Westaway, a team member from Macquarie University, Sydney.

Outside the research team, some remain circumspect about the tooth’s identity. “The authors have done a great job in describing and dating it, but I’d prefer to say it’s a putative Denisovan fossil,” says seasoned anthropologist Chris Stringer, the research leader in human origins at the British Natural History Museum.

Denisovans are the only archaic humans ever to have been identified by DNA alone. The first clue came from a finger bone fragment, one of the middle bones of a pinky, found in a jumble of bone fragments in Denisova Cave near the border of Siberia and China. The pinky bone looked like it came from a human. But its DNA showed that, while human-like, it was not from a modern human or a Neanderthal but something quite distinct.

So distinctive was the DNA, that geneticists could pick out traces of it in modern human populations. The DNA of nearby Eurasians carried only 0.1% but on the other side of the world, the DNA of indigenous Papuans and Australians carried 4%.

The DNA story said the Denisovans most likely interbred with modern people somewhere in South East Asia. So where were their physical remains?

The only other Denisovan remains to date were identified in 2019, when an oversized human-like jaw with huge teeth, originally found by a meditating monk in a Tibetan cave, turned out to be Denisovan. The identification was made after researchers extracted collagen protein from the very large teeth and found it was a match to that predicted by the Denisovan DNA sequence. Denisova Cave later also yield three large Denisovan teeth.

• First complex ecosystems formed in Ediacaran – millions of years earlier than thought

To find Denisovan fossils down under, most pundits placed their bets on the islands that serve as stepping stones between the Asian mainland and Australia/Papua New Guinea. The Annamite mountains were not on the radar of Denisovan hunters. But they were for Fabrice Demeter, a paleoanthropologist at the University of Copenhagen and lead author of the new study. He had gone there to answer a different question: how did modern humans travel from Africa through Asia? Laos turned out to be an important part of the route: in 2012 the ‘cave of monkeys’ aka Tam Pa Ling Cave, delivered the oldest remains of modern humans on mainland southeast Asia, with one jaw dating to around 70,000 years ago.

But adventurous climbers had also found another promising cave nearby, the Cobra cave, or Tam Ngu Hao 2.

Unlike the cave of monkeys it was not habitable. But it served, as limestone caves do, as a trap for fossils swept from surrounding hillsides during floods. Inside, a cemented gravelly deposit turned out to be a treasure trove of fossilised bones, mostly teeth of giant herbivores such as ancient bison, elephants and rhinos. Amidst them was a prize gem: one archaic-looking human molar.

How old was it? Archaeology is plagued by arguments about dates so the researchers deployed independent approaches. Kira Westaway from Macquarie dated the cemented gravel deposit using infra-red stimulated luminescence dating. Jian-Xin Zhao from University of Queensland dated the flowstones above the gravel using a uranium series. Renaud Joannes-Boyau from Southern Cross University, in Lismore, dated the co-cemented animal teeth using a combined uranium series and electron spin resonance technique (the hominin tooth was too precious to drill into).

Finally Mike Morley from Flinders examined hair-thin slices of the cemented deposits under the microscope to check the integrity of the structure. Were the baubles in this cement cake all baked in at the same time, or had some fallen in later, perhaps when a tree root pierced the layer?

The forensic analyses all agreed: the layer was intact and had been deposited between 164,000 and 131,000 years ago. The minimum age for the tooth then, was 131,000 years old. It did not belong to a modern human.

Had the cave been in the northern hemisphere, the key suspect would be a Neanderthal but their kind had never been found this far south. Could it be, at last, a remnant of the long-sought southern Denisovan?

The tooth did not yield any DNA for an ID; no surprise since the tropics are unkind to DNA preservation. So Clément Zanolli, an expert at identifying hominin teeth at the University of Bordeaux, in France, was brought in to adjudicate. His method is akin to the time-honoured approach of identifying species from the molar cusp pattern, but with a high-tech advance. Instead of scanning the outer cusps, which may be worn or broken, he uses a miniature CT scanner to look at the pristine pattern just underneath the enamel layer, the so-called enamel-dentine junction, or EDJ.

Zanolli has used his technique to look at the EDJ of diverse members of the South East Asian archaic human family – including Indonesian Homo erectus and the diminutive Homo luzoneniensis (found on the island of Luzon, in the Philippines) and Homo floresiensis (found on the Indonesian island of Flores). His analysis placed the tooth closest to that of the Denisovan teeth found in the Tibetan cave and Denisova Cave.

Protein traces from the tooth enamel also suggested the owner was a young woman, because no male-specific version of the amelogenin protein was detected.

But to close the case on whether or not she really was a tropical Denisovan, more of her kind will need to be found. Watch this space. There’s surely more to come!

https://cosmosmagazine.com/history/denisovan-tooth-found-in-laos/

Edited May 19, 2022 by CaaC (John)
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Stunning restoration 

 

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First Pompeiian human genome sequenced from a man who died in the Mt Vesuvius eruption

Study shows that he may have had tuberculosis.

The ancient Italian city of Pompeii was destroyed by an eruption of Mt Vesuvius in 79 AD. More than 2,000 people died as a direct consequence of the eruption, and the city was buried under four to six metres of volcanic ash and pumice and seemingly lost to time.

Pompeii was rediscovered in 1748, and human remains have since been excavated from the archaeological dig site.  Now, for the first time, the genome of one of these individuals has been sequenced in full, according to a new study in Scientific Reports.

Scientists have examined the skeletal remains of two humans from the city’s Casa del Fabbro (House of the Craftsman) and extracted their ancient DNA. One set of remains belonged to a male, aged between 35 and 40 years old at the time of his death, and the other belonged to a female over 50 years of age.

Due to the position and orientation of the human remains, the authors suggest they probably died instantly due to the approach of the high-temperature volcanic ash cloud.

They team analysed the ancient DNA extracted from the petrous bone – a wedge-shaped mass of bone within the cranial cavity – and while there were gaps in the sequences recovered from the female’s remains, they were able to sequence the entire genome of the male.

Before now, only short stretches of mitochondrial DNA from human and animal remains had been sequenced from Pompeii, since exposure to high temperatures reduces the quality and quantity of recoverable DNA.

But the authors speculate that the pyroclastic materials – the fast-moving flow of solidified lava pieces, volcanic ash and hot gases – that covered the remains may have also shielded them from environmental factors, such as atmospheric oxygen, that degrade DNA over the years.

They compared the male individual’s DNA with DNA from 1,030 other ancient humans (from Upper Palaeolithic to Medieval periods) and 471 modern western Eurasian individuals and found that his DNA shared the most similarities with modern central Italians and those who lived in Italy during the Roman Imperial age (27 BCE to 476 AD), as you might expect.

Interestingly, his mitochondrial DNA and Y chromosome DNA, in particular, also contains groups of genes that are commonly found in people from the island of Sardinia, but not among other individuals who lived in Italy during the Roman Imperial age.

This suggests there may have been high levels of genetic diversity across the Italian Peninsula during this time.

Further analysis also identified lesions in one of his vertebra, as well as DNA sequences commonly found in the group of bacteria to which Mycobacterium tuberculosis – the pathogen that causes tuberculosis – belongs.

This suggests that the man may have been affected by spinal tuberculosis (Pott’s disease) prior to his death.

According to the researchers, these findings “provide a foundation to promote an intensive analysis of well-preserved Pompeiian individuals” to gain more insight into the genetic history and lives of this population.

https://cosmosmagazine.com/history/first-human-genome-sequenced-pompeii/

 

 

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Ancient humans used Spanish cave for rock art for more than 50,000 years

New research paints a picture of the symbolic value of the cave for prehistoric human culture.

Cueva de Ardales in Málaga, Spain, is a famous site containing more than 1,000 prehistoric cave paintings and engravings. It also includes artefacts and human remains. But since its discovery in 1821, after an earthquake unearthed the entrance, the way ancient humans used the cave has been a mystery.

New research, published in PLoS ONE, on items from the first excavation have shed light on prehistoric Iberia’s human inhabitants.

Archaeologists from Spain, Germany and Denmark collaborated to analyse the paintings, relics and human bones from the cave.

Combining radiometric dating – measuring the presence of radioactive elements such as carbon-14 to determine the age of remains – with other analysis of artefacts from the site, the researchers have determined the first occupants of Cueva de Ardales, arriving more than 65,000 years ago, were likely Neanderthals.

Modern humans came to use the cave around 30,000 years later. This timeframe coincides with the disappearance of Homo neanderthalensis some 40,000 years ago. Homo sapiens used the cave sporadically until as recently as the beginning of the Copper Age, around 7,000 years ago.

Rock art is believed to be an indication of humankind’s first attempts to understand, rationalise and abstract the external world. Our ability to imagine and communicate through language, writing, science, art and abstractions are likely consequences of such leaps in ancient human culture.

• More on archaeology: First Pompeiian human genome sequenced from a man who died in the Mt Vesuvius eruption

The authors write: “Our research presents a well-stratified series of more than 50 radiometric dates in Cueva de Ardales that confirm the antiquity of Palaeolithic art from over 58,000 years ago. It also confirms that the cave was a place of special activities linked to art, as numerous fragments of ochre were discovered in the Middle Palaeolithic levels.”

The oldest examples of cave art in the Málaga site include abstract signs such as dots, finger tips and hand stencils created with red pigment. Later artwork involves more complex paintings and figures such as animals.

Human remains indicate the use of the cave as a burial place in the Holocene – the period of geological time since the end of the last major glacial epoch, or “ice age”, around 12,000 years ago.

There is limited evidence of domestic activities at Cueva de Ardales, suggesting humans were not residing in the cave.

The team’s findings confirm that Cueva de Ardales is a site of immense symbolic value.

The Iberian Peninsula holds more than 30 other caves with similar rock art, making the region a key locality for investigating the history and culture of ancient humans in Europe.

https://cosmosmagazine.com/history/spanish-cave-art-prehistoric/

 

Edited June 3, 2022 by CaaC (John)
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Stone Age “Swiss Army knife” reveals early humans’ connections

Strong social networks allowed early populations to prosper in southern Africa.

Early humans across southern Africa around 65,000 years ago made a particular type of stone tool – called a backed artefact – in the same shape, indicating that the populations must have been in contact with each other, finds a new study in Scientific Reports.

Archaeologists have found that the backed artefact, dubbed the “stone Swiss army knife” of prehistory, was made to look the same in enormous numbers across great distances and multiple biomes.

This indicates that the humans making them must have been sharing information and communicating with one another, and the findings suggest that these strong social networks are what would have allowed early human populations to prosper.

“People have walked out of Africa for hundreds of thousands of years, and we have evidence for early Homo sapiens in Greece and the Levant from around 200,000 years ago. But these earlier exits were overprinted by the big exit around 60-70,000 years ago, which involved the ancestors of all modern people who live outside of Africa today,” says lead author Dr Amy Way, an archaeologist at the Australian Museum and the University of Sydney.

“Why was this exodus so successful where the earlier excursions were not? The main theory is that social networks were stronger at this time. This analysis shows for the first time that these social connections were in place in southern Africa just before the big exodus,” explains Way.

The “Swiss army knife” of early human stone tools

The backed artefact – small, sharp blades likely used as insets in composite tools – has been associated with many different domestic activities, such as cutting and scraping, and with hunting activities as part of projectiles.

These types of tools have been made independently by many different groups of people across the world, including here in Australia.

The particular tools studied in this research are known as Howiesons Poort backed artefacts – named after the stone tool technology period that lasted between 60-65,000 years ago in southern Africa.

Southern Africa and backed artefacts. Credit: Dr Amy Way

Though such tools had been made for thousands of years before, a phenomenal increase in their production occurred during this period. The researchers were interested in whether this dramatic shift could have been due to a social response to changing environmental conditions in early humans.

They investigated this by studying 459 backed artefacts from seven southern African Middle Stone Age sites and comparing them to an Australian outgroup of the same type of tool to determine whether the similarities between the sites were due to randomness or cultural connections.

The Australian outgroup consisted of 95 artefacts from a late-Holocene site in Lake George, New South Wales.

“I compared some of the Australian shapes from 5,000 years ago with the African shapes 65,000 years ago (as they can’t possibly be related), to show the southern African tools all cluster within a much larger range of possible shapes,” explains Way.

“While the making of the stone tool was not particularly difficult, the hafting of the stone to the handle through the use of glue and adhesives was hard, which highlights that they were sharing and communicating complex information with each other,” says co-author Dr Paloma de la Peña, a senior research associate at the McDonald Institute for Archaeological Research, Cambridge University, UK.

Changing environment may have triggered a social response in early humans

They also analysed evidence of changing climate conditions during the time by looking at both global and local (from Sibudu Cave, one of the archaeological sites) environmental data, to see whether there was a correlation between the incidence of backed artefacts and climatic conditions.

“What was also striking was that the abundance of tools made in the same shape coincided with great changes in the climatic conditions. We believe that this is a social response to the changing environment across southern Africa,” adds de la Peña.

In particular, there was a correlation between the numbers of backed artefacts and environmental shifts towards drier and colder conditions.

“Examining why early human populations were successful is critical to understanding our evolutionary path,” adds Professor Kristofer Helgen, chief scientist and director at the Australian Museum.

“This research provides new insights into our understanding of those social networks and how they contributed to the expansion of modern humans across Eurasia.”

The Australian outgroup consisted of 95 artefacts from a late-Holocene site in Lake George, New South Wales.

“I compared some of the Australian shapes from 5,000 years ago with the African shapes 65,000 years ago (as they can’t possibly be related), to show the southern African tools all cluster within a much larger range of possible shapes,” explains Way.

“While the making of the stone tool was not particularly difficult, the hafting of the stone to the handle through the use of glue and adhesives was hard, which highlights that they were sharing and communicating complex information with each other,” says co-author Dr Paloma de la Peña, a senior research associate at the McDonald Institute for Archaeological Research, Cambridge University, UK.

Changing environment may have triggered a social response in early humans

They also analysed evidence of changing climate conditions during the time by looking at both global and local (from Sibudu Cave, one of the archaeological sites) environmental data, to see whether there was a correlation between the incidence of backed artefacts and climatic conditions.

“What was also striking was that the abundance of tools made in the same shape coincided with great changes in the climatic conditions. We believe that this is a social response to the changing environment across southern Africa,” adds de la Peña.

In particular, there was a correlation between the numbers of backed artefacts and environmental shifts towards drier and colder conditions.

“Examining why early human populations were successful is critical to understanding our evolutionary path,” adds Professor Kristofer Helgen, chief scientist and director at the Australian Museum.

“This research provides new insights into our understanding of those social networks and how they contributed to the expansion of modern humans across Eurasia.”

https://cosmosmagazine.com/history/early-humans-backed-artefact-tools/

 

Edited June 9, 2022 by CaaC (John)
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Europe's 'largest ever' predator dinosaur found on Isle of Wight

Remains of Europe's largest ever land-based predator dinosaur have been discovered on the Isle of Wight, scientists say.

Palaeontologists at the University of Southampton identified the remains, which measured more than 32ft (10m) long and lived 125 million years ago.

The prehistoric bones belonged to a two-legged, crocodile-faced, predatory spinosaurid dinosaur.

PhD student Chris Barker, who led the research, said it was a "huge animal".

The remains, which include pelvic and tail vertebrae, were discovered on the south-west coast of the Isle of Wight.

The carnivore has been dubbed the "white rock spinosaurid", after the geological layer in which the remains were found.

FULL REPORT

 

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Giant predatory dinosaur fossils discovered in Egypt

The new fossil expand the list of large meat-eating dinosaurs that roamed around 100 million years ago.

White Rock spinosaurid’s colossal cousin, Spinosaurus aegyptiacus, was discovered in the early 20^th century in the Bahariya Oasis in Egypt’s Western Desert. While the original fossils of the sail-backed fish-eater were destroyed in World War II, the scant remains of the animal have sparked imaginations and debates ever since. The site is also home to one of the largest land animals ever, the long-necked herbivorous sauropod Paralatitan.

Now, US and Egyptian researchers have published in Royal Society Open Science their discovery of a smaller predatory dinosaur that would have lived alongside Spinosaurus.

Found in the same celebrated fossil site in the Sahara Desert, the bones were unearthed in 2016 from the 98 million-year-old Bahariya Formation, placing the dinosaur in the middle Cretaceous.

“This bone is just the first of many important new dinosaur fossils from the Bahariya Oasis,” says Sanaa El-Sayed, who co-led the 2016 expedition.

The new dinosaur is a still unnamed species of abelisaurid – the first found in Bahariya Formation. Abelisaurids are short-faced meat eaters with small teeth, stocky hind limbs, and likely vestigial forelimbs. Commonly found in Europe and southern hemisphere continents, the most famous of the group is the demonic-looking Carnotaurus, which has distinctive horns on each brow.

Identified by a well-preserved neck vertebra, the new abelisaurid would have been roughly six metres long. Despite the single vertebra being found, it is virtually identical to vertebrae found from other abelisaurids, making it easy to identify the new creature as a member of the group.

Along with Spinosaurus, the 13 metre-long Carcharodontosaurus and the 11 metre-long Bahariasaurus, the new abelisaurid fossil adds yet another species to the cadre of large predatory dinosaurs that roamed what is now the Egyptian Sahara in the middle Cretaceous. The area was also home to giant crocodiles.

“During the mid-Cretaceous, the Bahariya Oasis would’ve been one of the most terrifying places on the planet,” says study leader Belal Salem, from Ohio University in the US. “How all these huge predators managed to coexist remains a mystery, though it’s probably related to their having eaten different things, their having adapted to hunt different prey.”

The researchers believe the new find has implications for the biodiversity of Cretaceous dinosaurs in Egypt and the entirety of northern Africa. It is the oldest known fossil of Abelisauridae from north-eastern Africa, and shows that, during the mid-Cretaceous, these carnivorous dinosaurs ranged across much of the northern part of the continent, east to west, from present day Egypt to Morocco, to as far south as Niger and potentially beyond.

“In terms of Egyptian dinosaurs, we’ve really just scratched the surface,” notes study co-author Hesham Sallam. “Who knows what else might be out there?”

Recently, Professor Sallam and others have ensured students from Egypt play lead roles in the research process. Both the field expedition that uncovered the new abelisaurid and the follow-up laboratory work were led by students and contributing authors on the paper from the Mansoura University Vertebrate Palaeontology Centre (MUVP) in Mansoura, Egypt. “Working with MUVP and its faculty and students, like Belal Salem, continues to inspire me, as I see the next generation of palaeontologists taking a prominent role in sharing their views on the history of our planet,” says team member and Ohio University biomedical sciences professor Patrick O’Connor.

https://cosmosmagazine.com/history/new-dinosaurs-england-egypt/

 

Edited June 13, 2022 by CaaC (John)
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Massive public database of over 2,000 languages created to study linguistic diversity and evolution

Linguists, computational scientists and psychologists collaborate to publish the repository.

Apart from their compilation of stories – which have become a pillar of Western culture – the brothers Grimm (Wilhelm and Jacob) were intensely interested in linguistics. Jacob in particular made a significant contribution in his book Deutsche Grammatik, published in 1819, in which he documented the relationships among Indo-European languages.

The similarities between languages have raised the possibility that we might follow the links between linguistic families down the language tree all the way to some root language (see the 1989 essay “Grimm’s Greatest Tale” by Stephen Jay Gould for further discussion). Other questions surround the possible parallel evolution of languages and their diversity.

Now, a team of linguists, computational scientists and psychologists at the Max Planck Institute for Evolutionary Anthropology in Germany have created a massive public database to study these and other questions about the evolution and diversity of language.

They present their research in a paper published in the Scientific Data journa

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“When our Department of Linguistic and Cultural Evolution was founded in 2014, I presented my colleagues with an ambitious goal. There are more than 7,000 languages in the world: create databases with the most extensive documentation of the linguistic diversity as possible,” says the paper’s co-author and Max Planck director Russell Gray.

“Our inspiration came from Genbank – a large genetic database where biologists from all over the world have deposited genomic data,” Gray continues. “Genbank was a game changer. The large amount of freely available sequence data revolutionised the ways we can analyse biological diversity. We hope that the first of our global linguistic databases, Lexibank, will start to revolutionise our knowledge of linguistic diversity in a similar way.”

Lexibank stores data in the form of standardised wordlists for more than 2,000 language varieties.

“The work on Lexibank coincided with a push towards more consistent data formats in linguistic databases. Thus, Lexibank can serve both as a large-scale example of the benefits of standardisation and a catalyst for further standardisation,” reports co-author Robert Forkel, who led the computational part of the data collection. “We decided to create our own standards, called Cross-Linguistic Data Formats, which have now been used successfully in a multitude of projects in which our department is involved.”

“We have designed new computer-assisted workflows that enable existing language datasets to be made comparable,” says co-author Johann-Mattis List, who led the practical data curation. “With these workflows, we have dramatically increased the efficiency of data standardisation and data curation.”

Using new computational techniques, the team showed how languages are alike or differ according to 60 different criteria.

“Thanks to our standardised representation of language data, it is now easy to check how many languages use words like ‘mama’ and ‘papa’ for ‘mother’ and ‘father’,” says List.

“It turns out that this pattern can indeed be found in many languages of the world and in very different regions,” adds Simon J. Greenhill, one of the founders of the Lexibank project. “Since all the languages with this pattern are not closely related to each other, it reflects independent parallel evolution, just as the great linguist Roman Jakobson suggested in 1968.”

Other patterns that the dataset and computational tools have found warrant further probing, say the authors.

“When investigating which languages use the same word for ‘arm’ and ‘hand’, we found that these languages typically also use the same word for ‘leg’ and ‘foot’,” List reports. “While this may seem to be a silly coincidence, it shows that the lexicon of human languages is often much more structured than one might assume when investigating one language in isolation.”

The researchers say the next phase of the project will be the expansion of their dataset, and probing further questions on linguistic diversity and language evolution. “Nobody thinks that the analysis must stop with the examples we give in our paper,” says List. “On the contrary, we hope that linguists, psychologists, and evolutionary scientists will feel encouraged to build on our example by expanding the data and developing new methods,” adds Forkel.

https://cosmosmagazine.com/people/language-database-lexibank/

 

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Were the bones of soldiers that died at the Battle of Waterloo sold as fertiliser? Probably, archaeologists say.

Very few human remains have been found at the site of the conflict despite thousands of soldiers being killed.

Exactly 207 years on from the 19th Century battle that saw the defeat of Napoleon Bonaparte, researchers from the University of Glasgow have published a study suggesting that the bones of the fallen soldiers were later sold for use as fertiliser.

The researchers came to the grisly conclusion after poring over a batch of newly discovered drawings and written descriptions of the battlefield made shortly after Napoleon’s defeat.

In total, these accounts describe the precise locations of three mass graves containing up to 13,000 corpses. However, there is no reliable record of a mass grave ever being found at the site, says lead researcher Prof Tony Pollard.

In fact, only a few remains from the battle have so far been discovered. These include a skeleton found during the building of a museum at the site in 2015 and amputated leg bones found during the excavation of the field hospital in 2019.

As several newspaper articles from the same period mention the gruesome practice of looting human bones from European battlefields to turn into fertiliser, Pollard suspects this may well have happened at Waterloo.

“European battlefields may have provided a convenient source of bone that could be ground down into bone-meal, an effective form of fertiliser. One of the main markets for this raw material was the British Isles,” said Pollard.

“Waterloo attracted visitors almost as soon as the gun smoke cleared. Many came to steal the belongings of the dead, some even stole teeth to make into dentures, while others came to simply observe what had happened.

“It’s likely that an agent of a purveyor of bones would arrive at the battlefield with high expectations of securing their prize.

“Primary targets would be mass graves, as they would have enough bodies in them to merit the effort of digging the bones.”

Pollard now plans to lead an unprecedented geological survey of the area that is likely to last for the next several years.

“The next stage is to head back out to Waterloo, to attempt to plot grave sites resulting from the analysis of early visitor accounts reported here,” he said.

“If human remains have been removed on the scale proposed then there should be, at least in some cases, archaeological evidence of the pits from which they were taken, however truncated and poorly defined these might be.”

https://www.sciencefocus.com/news/were-the-bones-of-soldiers-that-died-at-the-battle-of-waterloo-sold-as-fertiliser-probably-archaeologists-say/

 

Edited June 21, 2022 by CaaC (John)
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The Jurassic world of the vampire squid

How these cephalopods survived across two mass extinction events.

When you think Jurassic Park, you probably imagine a chomping T-Rex, or even a giant snapping Mosasaurus leaping out of the ocean. But how about vampire squid?

Though it didn’t make the cut into any blockbuster movie, the vampire squid is one of the most mysterious creatures of the ocean, with a single species still alive to this day. The vampire squid Vampyroteuthis infernalis,of the Order Vampyromorphida, lives in extreme deep ocean environments that often have little oxygen. They don’t want to suck you blood, but get their name from their cloak-like spooky appearance. They actually live off detritus floating around the abyss.

Using modern 3D imaging techniques, exceptionally preserved fossil specimens of an ancient relative Vampyronassa rhodanica have been re-analysed. Unlike the modern-day species, this Jurassic vampire squid revealed it was well adapted to actively hunt, and had suckers that could hold onto its prey.

“Suckers are really useful for the identification of these animals at high taxonomic levels,” says Dr Patrick Smith, one of Australia’s fossil cephalopod experts based at the Australian Museum. “This study gives us a much better resolution of how those suckers were constructed and how they compare to other living and extinct cephalopod groups.”

This creature lived 164 million years ago, had eight arms and two small fins across their small oval-shaped body of around 10 cm in length. Vampyronassa rhodanica had muscular suckers on the tips of two long arms, used to create a watertight seal, which would aid in the manipulation and retention of prey. It also had conical appendages for sensing prey, indicating it was an active hunter.

“This gives us insight into the evolutionary transition of the vampyromorphs,” says Smith. “The modern-day vampire squid is highly specialised for feeding on plankton in deep cold-water environments. Yet in the fossil record, this species seems to be predators of fish and possibly other cephalopods.”

While the fossil species Vampyronassa rhodanica are from Jurassic deposits of La Voulte-sur-Rhône (France), Australia has its own Vampyromorph species in the Eromanga Basin, Queensland, albeit from the slightly younger Cretaceous period. When piecing together this globally spanning record, we can see how vampire squids and other cephalopods groups changed across two major extinction events – the Triassic-Jurassic, around 200 million years ago, and the Cretaceous-Paleogene extinction, around 66 million years ago.

“We have several groups of Cretaceous cephalopods in Australia. Unfortunately, none of them with soft tissue are preserved quite like the ones from the Jurassic,” says Smith. “We have at least two species of vampyromorphs preserved in the Eromanga basin, which may have reached up to six metres long.”

This research has been published in Scientific Reports. You can also read more about the cephalopods of La Voulte-sur-Rhône (France) and the Eromanga Basin (Australia).

https://cosmosmagazine.com/history/palaeontology/jurassic-vampire-squid/

 

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Megalodon was Earth’s highest-level apex predator – ever

Tooth analysis shows this prehistoric shark ate anything it wanted – including other predators.

Sharks are often described as perfect killing machines. While this sort of negative press certainly doesn’t help conservation efforts today, there is some truth to this lethal impression of these magnificent beasts. And some were far more deadly than others.

In one form or another, sharks have patrolled Earth’s oceans for over 400 million years – since long before even the dinosaurs. The largest predatory shark and biggest fish known to science was megalodon, which ruled the seas until around 3 million years ago.

While its exact size is subject to debate, based on fossil teeth, megalodon may have been 15-18 metres long – three to four times the dimensions of the biggest great white sharks.

These monsters had jaws so wide a human could stand in them. Individual teeth were the size of an adult human hand.

No surprise then that recent research by palaeontologists at Princeton University in the US has shown that megalodon ate whatever it wanted – including other predators. The results of the research, published in Science Advances, indicate this ancient shark was an apex predator with no comparison in all of Earth’s history.

“We’re used to thinking of the largest species – blue whales, whale sharks, even elephants and diplodocuses – as filter feeders or herbivores, not predators,” says the paper’s lead author, geoscientist Emma Kast, now based at the University of Cambridge, UK. “But megalodon and the other megatooth sharks were genuinely enormous carnivores that ate other predators, and Meg went extinct only a few million years ago.”

“If Megalodon existed in the modern ocean, it would thoroughly change humans’ interaction with the marine environment,” adds senior author Danny Sigman, professor of geological and geophysical sciences at Princeton.

Kast and Sigman’s team discovered clear evidence that megalodon and its ancestors occupied the highest rung of the prehistoric food chain – called the highest “trophic level”. So high is their trophic signature that the researchers believe megalodon must have eaten other predators and predators-of-predators in a complicated food web. Helping megalodon on its way to the top of the food web is cannibalism. There is evidence of cannibalism in both megatooth sharks and other prehistoric marine predators.

“Ocean food webs do tend to be longer than the grass-deer-wolf food chain of land animals, because you start with such small organisms,” says Kast. “To reach the trophic levels we’re measuring in these megatooth sharks, we don’t just need to add one trophic level – one apex predator on top of the marine food chain. We need to add several onto the top the modern marine food web.”

The team used a new technique to measure the nitrogen isotopes in fossilised megalodon teeth. The rule of thumb for ecologists is the more nitrogen-15 in an organism, the higher its trophic level. But this is the first time the tiny amounts of nitrogen preserved in these prehistoric teeth have been measured.

“We have a series of shark teeth from different time periods, and we were able to trace their trophic level versus their size,” says co-author Zixuan (Crystal) Rao.

Sometimes, prehistoric food webs can be gauged through bite marks on fossilised bones. But such evidence is scant for extinct sharks. The novel nitrogen isotope method helps paint a picture of an ancient fish-eat-fish world.

“The whole direction of my research team is to look for chemically fresh, but physically protected, organic matter – including nitrogen – in organisms from the distant geologic past,” says Sigman.

Organisms at the bottom of the food web, like plants and algae, absorb nitrogen from the air or water. When other species eat them, the predator species incorporates that nitrogen into their own bodies. But more of nitrogen’s lighter isotope, N-14, gets excreted (sometimes in urine) than the heavier N-15.

So N-15 builds up relative to N-14 as you go up in trophic level.

But there’s an unfortunate drawback. While researchers have had a whale of a time measuring nitrogen levels in animals as old as 15,000 years old, lack of preserved soft tissue in older species has made measuring nitrogen a dead end. Until now.

Luckily, teeth are more easily preserved because they are encased in rock-hard enamel which acts like a barrier to decomposing bacteria. And sharks have a lot of teeth which are constantly being replaced.

“Teeth are designed to be chemically and physically resistant so they can survive in the very chemically reactive environment of the mouth and break apart food that can have hard parts,” Sigman explains. “When you look in the geologic record, one of the most abundant fossil types are shark teeth. And within the teeth, there is a tiny amount of organic matter that was used to build the enamel of the teeth – and is now trapped within that enamel.”

Sigman’s team has been refining methods to measure the tiny amounts of nitrogen in the thin enamel layer of long-extinct sharks to get the ratio of the nitrogen isotopes.

After a bit of work with a dentist drill, cleaning chemicals and microbes turn the nitrogen in the enamel into nitrous oxide to read out the ratio. “This has been a multiple-decades-long quest that I’ve been on, to develop a core method to measure these trace amounts of nitrogen,” Sigman adds.

The team began using their method on microfossils in sediments. From there, they moved on to fossil corals, fish ear bones and shark teeth. “Next, we and our collaborators are applying this to mammalian and dinosaur teeth,” says Sigman.

Kast has built up a record of more than 20,000 marine mammal individuals and more than 5,000 sharks. “Our tool has the potential to decode ancient food webs – what we need now is samples,” she says. “I’d love to find a museum or other archive with a snapshot of an ecosystem – a collection of different kinds of fossils from one time and place, from forams near the very base of the food web to otoliths – inner ear bones – from different kinds of fish, to teeth from marine mammals, plus shark teeth. We could do the same nitrogen isotope analysis and put together the whole story of an ancient ecosystem.”

https://cosmosmagazine.com/history/megalodon-tooth-apex-predator/

 

 

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Pompeii: Ancient pregnant tortoise surprises archaeologists

When Mount Vesuvius erupted nearly 2,000 years ago Pompeii's ancient residents were frozen in place by ash.

So too it turns out were the city's flora and fauna - including a pregnant tortoise with her egg.

Archaeologists found the reptile's remains buried under ash and rock where it had lain undiscovered since 79AD.

The tortoise was sheltering beneath an already-destroyed building when volcanic disaster struck.

Archaeologists found the remains while excavating an area of the city that its ancient inhabitants had been rebuilding after an earlier earthquake devastated Pompeii in 62AD.

Around 2,000 years ago the 14cm (5.5in) tortoise had burrowed into a tiny underground lair beneath a shop destroyed in that earlier quake.

Experts say the fact it was found with an egg suggests it was killed while trying to find somewhere peaceful to lay its offspring.

FULL REPORT

 

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Human ancestor fossils in South African cave may be a million years older than previously thought

New dating technique of famous fossils may force an evolutionary re-evaluation.

In the early 20th century, our perception of ourselves received a massive shake-up when nwe looked eye-to-eye with the ancient hominins who marked the evolutionary separation between modern humans and the great apes like gorillas and chimps.

Discovering these “missing links” between humans and prehistoric primates not only confirmed the Darwinian thesis that humans evolved from apes but began to paint a picture of how we came to be.

A major milestone in the writing of our human story was the 1936 discovery of the first adult specimen of the genus Australopithecus (southern ape). The fossil of the individual, dubbed TM 1511, was found in the Sterkfontein Caves in South Africa.

Since then, the caves have revealed hundreds of australopithecine fossils including several significant finds, like Australopithecus africanus individual “Mrs Ples”, and Australopithecus prometheus specimen “Little Foot”. As such, the Sterkfontein Caves are referred to as the “Cradle of Humankind”.

Sterkfontein is a deep and complex cave system. In its caverns is preserved a long history of hominin activity in the region.

Most of Sterkfontein’s Australopithecus fossils have been excavated from an ancient cave infill called Member 4, which holds the highest density of Australopithecus fossils in the world. Estimates for the age of Member 4 range from about three million years to as young as about two million years ago – younger than the appearance of our genus Homo.

But new research using novel dating techniques suggests that the sediment in which the Australopithecus fossils have been found might be over one million years older, at nearly four million years old. This would place them further back in time than the world’s most well-known Australopithecus specimen, “Dinkinesh”, also known as “Lucy”, of the species afarensis.

The research, published in Proceedings of the National Academy of Sciences (PNAS), was directed by Professor Dominic Stratford from South Africa’s University of Witwatersrand.

“The new ages range from 3.4-3.6 million years for Member 4, indicating that the Sterkfontein hominins were contemporaries of other early Australopithecus species, like Australopithecus afarensis, in East Africa,” says Stratford who co-authored the PNAS paper.

Coming up with accurate dates for fossils formed over millions of years is tricky. In East Africa, where many hominin fossils have been found, the volcanic ash in which fossils are encased can be dated. Cave sediments, however, are especially hard to date as rock and bone tumble to the cave floor.

In caves, palaeontologists usually base their dates on other animal fossils found nearby, or flowstone formed by slow-flowing water trickling down the cave walls.

Previous dating of Member 4 was based on calcite flowstone deposits, but recent observations show that the flowstone is actually younger than the cave fill. Thus, previous ages were underestimates.  

“Sterkfontein has more Australopithecus fossils than anywhere else in the world,” says lead author Darryl Granger, professor at Purdue University in the US. “But it’s hard to get a good date on them. People have looked at the animal fossils found near them and compared the ages of cave features like flowstones, and gotten a range of different dates. What our data does is resolve these controversies. It shows that these fossils are old – much older than we originally thought.”

Using a novel technique involving radioactive decay of the rare isotopes aluminum-26 and beryllium-10 in mineral quartz, the research team obtained the new age range for the fossils.

“These radioactive isotopes, known as cosmogenic nuclides, are produced by high-energy cosmic ray reactions near the ground surface, and their radioactive decay dates when the rocks were buried in the cave when they fell in the entrance together with the fossils,” says Granger.

Aluminum-26 is formed when a rock is exposed to cosmic rays at the surface, but not after it has been deeply buried in a cave. Measuring levels of aluminum-26 in tandem with beryllium-10 allows researchers to date the sediment. This method is more accurate as it involves dating the concrete-like breccia in which the fossils are embedded. 

Placed in a mass spectrometer, the amount of each radioactive nuclide in the rocks was determined. This, coupled with geological mapping and a thorough examination of how sediments accumulate in caves, gave Granger and Stratford’s team their age range.

Because the australopithecines found in Sterkfontein are so old, it may force scientists to rewrite the early chapters of human evolution.

“This reassessment of the age of Sterkfontein Member 4 Australopithecus fossils has important implications for the role of South Africa on the hominin evolution stage. Younger hominins, including Paranthropus and our genus Homo, appear between about 2.8 and 2 million years ago. Based on previously suggested dates, the South African Australopithecus species were too young to be their ancestors, so it has been considered more likely that Homo and Paranthropus evolved in East Africa,” says Stratford.

But the new dates place the “Cradle of Humankind” in South Africa front and centre as the likely location of the evolution of early humans.

“This important new dating work pushes the age of some of the most interesting fossils in human evolution research, and one of South Africa’s most iconic fossils, Mrs Ples, back a million years to a time when, in East Africa, we find other iconic early hominins like Lucy,” says Stratford.

“The redating of the Australopithecus-bearing infills at the Sterkfontein Caves will undoubtably re-ignite the debate over the diverse characteristics of Australopithecus at Sterkfontein, and whether there could have been South African ancestors to later hominins,” adds Granger.

https://cosmosmagazine.com/history/south-africa-cave-fossil/

 

 

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Digging at Arthur’s Stone commences: probably no kings, but plenty of science

And perhaps some coconuts.

Digging has begun at Arthur’s Stone: an ancient tomb in Herefordshire, UK, linked to the mythical King Arthur.

The tomb is actually some 5000 years old – making it about 3500 years older than the supposed age of the fabled king.

So, while they’re not expecting to find a holy grail, the archaeologists excavating the tomb for the first time hope to learn more about the Neolithic people who built it.

“Arthur’s Stone is one of the country’s most significant Stone Age monuments, and this excavation gives a really rare and exciting chance for members of the public to come and see archaeology in action,” Ginny Slade, volunteer manager at English Heritage, said in a statement.

• More on English archaeology: The Stonehenge dead tell their stories

Arthur’s Stone is a tomb made up of nine upright stones. A 25-tonne capstone sits on top.

Similar tombs have yielded skeletal remains, flint flakes, arrowheads and pottery – but presumably no shrubberies (that’s another one for the Monty Python fans out there).

King Arthur has been linked to Arthur’s Stone since at lease the 13^th Century. Legend has it he killed a giant who elbowed one of the stones and left an impression as he fell. (A flesh wound.)

“Arthur’s Stone is one of this country’s outstanding prehistoric monuments, set in a breathtaking location – yet it remains poorly understood,” said Professor Julian Thomas, an archaeologist at Manchester University, who will co-lead the excavation.

“Our work seeks to restore it to its rightful place in the story of Neolithic Britain.”

https://cosmosmagazine.com/history/arthurs-stone-archaeology/

 

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Ancient fossilised brains give insight into the evolution of insects and spiders

These 500 million-year-old arthropods had three eyes and a segmented brain

A cache of new fossils containing the brain and nervous system of a marine predator from half a billion years ago has given evolutionary biologists new insight into the evolution of arthropods – insects, arachnids and crustaceans.

Stanleycaris hirpex belonged to an ancient, extinct offshoot of the arthropod evolutionary tree called Radiodonta. The fossils reveal it was a truly weird animal, with a pair of stalked eyes and a huge third eye in the front of its head – a feature never before seen in a radiodont.

“While fossilised brains from the Cambrian Period aren’t new, this discovery stands out for the astonishing quality of preservation and the large number of specimens,” says lead author Joseph Moysiuk, a PhD candidate in ecology and evolutionary biology at the University of Toronto, Canada.

“We can even make out fine details such as visual processing centres serving the large eyes and traces of nerves entering the appendages. The details are so clear it’s as if we were looking at an animal that died yesterday.”

The research has been published in Current Biology.

Stanleycaris was a bizarre-looking organism

Animation of Stanleycaris hirpex, including transparency to show internal organs. Credit: animation by Sabrina Cappelli © Royal Ontario

MuseumMoysiuk and PhD supervisor Dr Jean-Bernard Caron – Royal Ontario Museum’s curator of invertebrate palaeontology – studied a previously unpublished collection of 268 exceptionally preserved specimens of Stanleycaris.

They had been collected mostly in the 1980s and ’90s from the Burgess Shale in Yoho National Park in Canada.

Stanleycaris was small (for the radiodont group) at no more than 20cm long, but it would have still been an impressive predator at a time when most animals didn’t grow any bigger than a human finger.

It had large, compound eyes, a circular mouth lined with teeth, frontal claws with an array of spines, and a flexible, segmented body with a series of swimming flaps along its sides.

“The presence of a huge third eye in Stanleycaris was unexpected. It emphasises that these animals were even more bizarre-looking than we thought, but also shows us that the earliest arthropods had already evolved a variety of complex visual systems like many of their modern kin,” says Caron.

“Since most radiodonts are only known from scattered bits and pieces, this discovery is a crucial jump forward in understanding what they looked like and how they lived.”

Insights into the evolution of segmented brains in arthropods

In 84 of the fossilised remains, the brain and nerves were still preserved after 506 million years, revealing the Stanleycaris brain was composed of two segments – the protocerebrum and deutocerebrum – that connected with the eyes and frontal claws, respectively.

But today, arthropods have brains composed of three segments including an additional tritocerebrum.

“We conclude that a two-segmented head and brain has deep roots in the arthropod lineage and that its evolution likely preceded the three-segmented brain that characterises all living members of this diverse animal phylum,” explains Moysiuk.

While this might not sound game-changing, it has important scientific implications for understanding how these structures diversified across the group.

“These fossils are like a Rosetta Stone, helping to link traits in radiodonts and other early fossil arthropods with their counterparts in surviving groups.”

https://cosmosmagazine.com/history/stanleycaris-hirpex-fossilised-brains/

 

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Dinosaur dentures: as rare as sauropod teeth

Fossil dinosaur teeth found in Queensland are putting the smile back on the sauropod

Extremely rare sauropod dinosaur teeth found in Queensland have enabled researchers “to put the smile back on the sauropod”, says palaeontologist Dr Stephen Poropat.

Poropat is the lead author of a paper published in the Royal Society Open Science this week, and a researcher at the Australian Age of Dinosaurs Museum in Winton, Queensland.

Sauropods were long-necked dinosaurs, the largest Australian land animals of all time. The fossilised sauropod teeth were found in the Winton Formation in western Queensland. 

And while such teeth are commonly found in fossil deposits elsewhere in the world, in Australia, sauropod teeth are as rare as … well, sauropod teeth. 

Poropat told Cosmos this might be because there aren’t many rocks of Jurassic or Cretaceous age exposed at the surface in Australia, and those that are haven’t been extensively explored. Even the Winton Formation, which has produced several sauropod skeletons including baby Sauropod “Ollie”, examples of teeth and head fragments have been extremely rare. 

That changed in 2019 and 2021 when palaeontologists excavated 17 sauropod teeth at the “Mitchell” site on a sheep station located 60 kilometres west-northwest of Winton. These were analysed together with a dental fragment and tooth from the nearby “Matilda” site, and a single tooth from the “Alex” site, 60km northeast of Winton.

Poropat says that while people might expect a plant-eating animal to have molars for grinding, the sauropod teeth “couldn’t be further from that”.

“The simple fact is that sauropods didn’t chew their food.” 

The teeth from the Winton Formation were all very similar – sort of conical, then curved and pointed at the end; perfect for snipping plants. 

“Then they would use what was presumably a pretty long and muscular tongue […] to then pull the food straight down the gullet,” says Poropat. “Essentially, once they had swallowed their food – basically no processing in the mouth at all, no chewing – they would pass it through to the rest of the digestive system. And it would basically act as giant fermenting vats.

“It’s been hypothesised that sauropods might have actually kept any given meal within their bodies for up to two weeks before excreting.”

Wear markings on five of the teeth allowed the researchers to infer that the dinosaur’s teeth would have been a bit offset. Scratches and pits on the teeth indicated that sauropods probably fed on plants from at least one metre above the ground, up to as much as 10m. That’s as high as a sauropod could reach if it reared on its hind legs, stretched out its neck and reached far up into the canopy.

Its lunch might have included conifers, gingkos and flowering plants given plant fossils found in the area. 

Poropat says horsetails, a plant which is extinct in Australia today but still exist in the northern hemisphere, would have made a “good, nutritious and easily accessible meal”. He thinks these would have been a favourite food for sauropods.

To analyse the wear patterns on the sauropod teeth, the paper’s second author Timothy Frauenfelder made casts of the teeth which were coated in a very thin layer of gold, enabling them to be scanned using an electron microscope.

The researchers have since found even more teeth at the Mitchell site, too late to be included in this paper, but likely to be the focus of further research.

https://cosmosmagazine.com/history/palaeontology/dinosaur-dentures-as-rare-as-sauropod-teeth/

 

Edited July 15, 2022 by CaaC (John)
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Ears burning? Mammal fossils suggest it could be the Late Triassic calling

A study of the inner ears of mammalian ancestors may pinpoint when they evolved to be warm-blooded.

A study of the inner ears of mammalian ancestors may pinpoint when they evolved to be warm-blooded.

Why are reptiles cold-blooded, and mammals warm-blooded? And when did these attributes emerge? Ectotherms – which include amphibians, reptiles, most fish and invertebrates – rely on external sources of heat to regulate their internal body temperatures, whilst endotherms (primarily birds and mammals, although there are some fish that have this capability) have biological processes that provide them with warmth and regulate their body temperatures.

Exactly when mammals evolved to produce internal heat and regulate body temperature has been “one of the great mysteries of palaeontology”, says Kenneth Angielczyk, palaeobiologist at the Field Museum, Chicago, US, and one of the authors of a new Nature paper detailing how fossils of the inner ear structure of mammalian ancestors may provide a crucial clue.

There might not be an immediately obvious connection between warm-bloodedness and inner ear structure, but according to Angielczyk: “The canals in our inner ear are sensors that give the brain information about the position and movement of the head. They work by having a fluid [endolymph] in them that sloshes around when we move our heads, which is detected by cells in the canals and the information is transmitted to the brain for interpretation.”

Warmer temperatures make for sloshier, or less viscous, endolymph fluid. (A highly viscous fluid is thick and doesn’t flow well – think jelly, for instance.) In modern mammals the ear canals are smaller and rounder – better for this less viscous fluid. In contrast, cold-blooded animals’ ear canals are semi-circular and larger to better suit a less runny, more viscous, endolymph fluid.

In the fossil record there’s a sudden [in geologic terms] evolution of the ear canals of animals from the Mammaliamorpha group. According to Angielczyk, there would “be no evolutionary advantage for changes in canal size and shape if there were no changes in body temperature and endolymph viscosity”

The mammaliamorph group “includes mammals, as well as some fairly close extinct relatives that fall outside of Mammalia proper”, says Angielczyk, and it looks like “mammal-like canals (suggestive of endothermy) appear rather abruptly in the Late Triassic Period”, with an indicated increase in body temperature of the mammalian samples of between 5°C and 9°C.

The Late Triassic period is characterised by climatic instability and a time of global environmental changes, including extinction events and climate warming. Although the period marks the extinction of a number of species, it also led to diversification of land and ocean plant and animal life, including the development of many of the characteristic features of mammals today.

Unlike other research in this area – such as studies on bone tissue structure and radioactive isotope ratios – Angielczyk says the shape and sizes of ear canals are a fairly direct indicator of body temperature evolution in mammals, rather than proxies or indirect indicators.

The research team plan to widen the sample of to better pinpoint the exact transition time.

https://cosmosmagazine.com/science/ears-burning-mammal-fossils-triassic/

 

 

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While our ancestors went from sea to land, this 400 million-year old fishapod high-tailed it back into the water

Fossils of the fishapod show it began the transition but was more adapted to water life.

Our ancient ancestors, as with all land-based life on Earth, evolved in our planet’s primordial seas before taking their first steps onto land. For vertebrates like us, the animal commonly associated with this evolutionary stride is the 375 million-year-old Tiktaalik roseae.

For its leap of faith into the Darwinian bible, Tiktaalik has received some tongue-in-cheek flak from internet memesters who blame the amphibious trailblazer for all life’s modern problems.

Memes circulated in the last couple of years bemoan the prehistoric critter’s adventurousness and articulate the not insincere desire to time-travel and coax Tiktaalik back into the water.

FULL REPORT

 

Edited July 22, 2022 by CaaC (John)

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Mayan city collapse over 500 years ago linked to drought and social instability

This interdisciplinary research holds lessons for today amid an ongoing climate crisis.

The Mayan civilisation was among the most advanced on Earth, based in Central America. But it wasn’t all smooth sailing even before the arrival of Europeans in the 16^th century.

Mayapán, 40km to the south-east of the modern city of Merida, in Mexico, was the political and cultural capital of the Maya in the Yucatán peninsula with thousands of buildings and a population of 15,000-17,000 during the city’s peak. Emerging in 1200CE, the city was eventually abandoned in 1450CE after its despotic rulers from the house of Cocom were overthrown.

New research published in Nature Communications suggests that the civil unrest which led to the collapse of Mayapán emerged as a result of climatic changes.

The interdisciplinary team included researchers from Australia’s University of New South Wales, the University of California in the US and the University of Cambridge in the UK. Their findings shed light on the impact of changes in the climate on societies, making use of records from the city from before the Colonial Period.

A prolonged drought, the authors suggest, lasting between 1400 and 1450CE escalated existing social tensions in the city. The effects of the drought on food availability in particular provided the impetus for the civil conflict which eventually led to the city’s abandonment.

“Our data indicate that institutional collapse occurred in the environmental context of drought and conflict within the city,” the authors explain. “Vulnerabilities of this coupled natural-social system existed because of the strong reliance on rain-fed maize agriculture, lack of centralised long-term grain storage, minimal opportunities for irrigation, and a sociopolitical system led by elite families with competing political interests, from different parts of the Yucatán Peninsula. We argue that long-term, climate-caused hardships provoked restive tensions that were fanned by political actors whose actions ultimately culminated in political violence more than once at Mayapán.”

In addition to looking at the climate (political and environmental) during the collapse of Mayapán, the researchers also looked directly at human remains found in the ancient city.

“Direct radiocarbon dates and mitochrondrial DNA sequences from the remains of individuals in the city’s final mass grave suggest they were family members of the heads of state (the Cocoms), ironically and meaningfully laid to rest at the base of the Temple of K’uk’ulkan, the iconic principal temple and ritual centtr of Mayapán.”

The winds of revolution, the authors argue, were fanned by political actors while conditions were worsening for the city’s inhabitants. Chief leaders of the change in political power were the members of the Xiu family house.

“Our results suggest that rivalry among governing elites at Mayapán materialised into action in the context of more frequent and/or severe droughts. Comparatively, such climate challenges present a range of opportunities for human actors, from the development of innovative adaptations to the stoking of revolution. These climate hardships and ensuing food shortages would have undermined the city’s economic base and enabled the Xiu-led usurpation. The unifying and resilient institutions that held the Mayapán state together until approximately 1450CE were ultimately eroded, the confederation dissolved, and the city largely abandoned,” they explain.

But the researchers also note the ability of the Maya to persist despite their difficulties. Those that abandoned Mayapan went to other cities, towns and villages. “Yet economic, social, and religious traditions persevered until the onset of Spanish rule, despite the reduced scale of political units, attesting to a resilient system of human-environmental adaptations.”

Such stories from human history provide food for thought as we face our own self-inflicted climate crisis which is exacerbating hardship for many millions around the world.

The authors conclude: “Our transdisciplinary work highlights the importance of understanding the complex relationships between natural and social systems, especially when evaluating the role of climate change in exacerbating internal political tensions and factionalism in areas where drought leads to food insecurity.”

https://cosmosmagazine.com/history/mayan-city-collapse-drought/

 

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King of the dinosaurs, Tyrannosaurus rex might be one species, not three, after all

New research refutes claims that T. rex was three distinct species.

Is the world’s most famous dinosaur really one species? This question is becoming one of the most hotly debated topics in palaeontology.

Earlier this year, research suggested that Tyrannosaurus rex fossils might actually come from three different species. Now, a new study published by palaeontologists from the American Museum of Natural History and Carthage Collge in Evolutionary Biology refutes this claim.

It is not surprising that classifying animals that lived over 65 million years ago from just their fossilised bones is not that easy. Even animals today can throw up some skeletal doozies. It takes a real expert, to tell the skeleton of a lion apart from that of a tiger, for example (the distinguishing feature, by the way, is the slightly flatter, more upturned skull in lions).

“Tyrannosaurus rex remains the one true king of the dinosaurs,” says co-author Steve Brusatte, paleontologist at the University of Edinburgh. “Recently, a bold theory was announced to much fanfare: what we call T. rex was actually multiple species. It is true that the fossils we have are somewhat variable in size and shape, but as we show in our new study, that variation is minor and cannot be used to neatly separate the fossils into easily defined clusters. Based on all the fossil evidence we currently have, T. rex stands alone as the single giant apex predator from the end of the Age of Dinosaurs in North America.”

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Authors of the March paper suggesting T. rex is actually three separate species reclassified the animal based on the leg bones and teeth of 38 specimens. They believe it is more accurate to group these individuals into the species: the standard T. rex, the bulkier “T. imperator,” and the slimmer “T. regina.”

The new study’s authors revisited the data and added information gathered from 112 bird species (also known as living dinosaurs) and four non-avian extinct theropod (two-legged) dinosaur.

They argue that the multiple species argument breaks down due to limited comparative samples, non-comparative measurements and inadequate statistical techniques.

“Their study claimed that the variation in T. rex specimens was so high that they were probably from multiple closely related species of giant meat-eating dinosaur,” says James Napoli, co-lead author of the rebuttal study. “But this claim was based on a very small comparative sample. When compared to data from hundreds of living birds, we actually found that T. rex is less variable than most living theropod dinosaurs. This line of evidence for proposed multiple species doesn’t hold up.”

“Pinning down variation in long-extinct animals is a major challenge for paleontologists,” adds co-lead author Thomas Carr from Carthage College. “Our study shows that rigorous statistical analyses that are grounded in our knowledge of living animals is the best way to clarify the boundaries of extinct species. In practical terms, the three-species model is so poorly defined that many excellent specimens can’t be identified. That’s a clear warning sign of a hypothesis that doesn’t map onto the real world.”

According to the March paper, variation in the size of the second tooth in the lower jaw and femur robustness indicated multiple species. The new study, however, could not replicate these findings and revealed differing measurements, as well as noting issues in the statistical methods of the study published in March which made assumptions about the number of T. rex groups before running tests.

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“The boundaries of even living species are very hard to define: for instance, zoologists disagree over the number of living species of giraffe,” explains co-author Thomas Holtz, from the University of Maryland and the National Museum of Natural History. “It becomes much more difficult when the species involved are ancient and only known from a fairly small number of specimens. Other sources of variation—changes with growth, with region, with sex, and with good old-fashioned individual differences—have to be rejected before one accepts the hypothesis that two sets of specimens are in fact separate species. In our view, that hypothesis is not yet the best explanation.”

“T. rex is an iconic species and an incredibly important one for both paleontological research and communicating to the public about science, so it’s important that we get this right,” says co-author David Hone, from Queen Mary University of London. “There is still a good chance that there is more than one species of Tyrannosaurus out there, but we need strong evidence to make that kind of decision.”

https://cosmosmagazine.com/history/tyrannosaurus-rex-not-three/

 

 

Edited July 26, 2022 by CaaC (John)

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Bloody Wimpys.

 

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@CaaC (John)