Oldest Acheulean North Africa Oued Boucherit

The oldest Acheulean evidence in North Africa

The oldest Acheulean evidence in North Africa

The CENIEH in collaboration with CNRPAH leads a study reporting the discovery of the oldest Acheulean lithic assemblage found in North Africa, dated to about 1.7 million years
Oldest Acheulean North Africa Oued Boucherit
View of the valley of Oued Boucherit (Algeria). Photo credits: Mathieu Duval

A new work published in the journal Quaternary Science Reviews, led by the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) in collaboration with the Centre National de Recherches Préhistoriques, Anthropologiques et Historiques (CNRPAH) (Algeria), describes the most recent advances in the current investigation performed in the valley of Oued Boucherit, located about 20 km east of the city of Sétif (Algeria).

There, the sedimentary deposits hosts a unique succession of fossiliferous and archaeological levels ranging from 3.9 Ma to 1.7 Ma. Perhaps the most noticeable outcome of this work is the discovery of the oldest evidence of Acheulean lithic industries in North Africa. Dated to 1.7 million years (Ma), it is about 400,000 years older than those recently reported at Thomas Quarry locality (Casablanca, Morocco).

'This is an exceptional discovery', indicates Dr Mathieu Duval, Ramón y Cajal Researcher at CENIEH and lead author of the work, 'because it could drastically modify our vision and understanding of early human origins and migrations throughout the African continent'.

While the French paleontologist Camille Arambourg already mentioned in the 1950s the presence of Acheulean lithic industries (typically characterized by the presence of tools like handaxes or picks) in that area, their exact origin has remained unclear until now. Field prospections carried out over the last years have allowed to find new lithic pieces, and more importantly, to define a clear stratigraphic context and provide an age.

In 2018, another important discovery from this same area was published in the journal Science: the oldest lithic industries (Oldowan-like; typically characterized by small flakes and pebble tools) in North Africa, dated to 2.4 Ma. ‘Now, Oued Boucherit hosts the oldest Oldowan and Acheulean lithic assemblages found in North Africa’ says Prof. Mohamed Sahnouni, coordinator of the Archaeology Program at CENIEH and co-author of the work. ‘This area allows us to precisely study the emergence and evolution of Acheulean and Oldowan lithic industries, like perhaps very few other localities in Africa,’ adds the researcher who has been actively working in the area since the 1990s.

These discoveries drastically change our current vision about the origin and dispersion of the first lithic industries within Africa. Currently, the oldest Oldowan and Acheulean evidence are located in East Africa, dating to about 2.6 million years (Ma) and 1.8 Ma, respectively. Less than 5 years ago, the evidence was more than half a million years older than those found in North Africa.

Oldest Acheulean North Africa
Biface stone tool from Oued Boucherit (Algeria) dated to 1.7 million years. Photo credits: Mohamed Sahnouni

Now, the recent discoveries made at Oued Boucherit indicate instead that these industries appear in North Africa very close in time to those in East Africa. While these results may suggest in first instance a much faster dispersion of these lithic industries from East Africa than previously anticipated, the plausibility of a multiple African origin scenario for stone tool manufacture and use cannot be discarded.

At the forefront of geochronology

‘This work perfectly illustrates the reason why the Geochronology and Geology Program was designed’ explains Prof. J.M. Parés, Coordinator of this Program and co-author of the article. ‘Thanks to a combination of various dating methods applied at CENIEH, namely palaeomagnetism and Electron Spin Resonance dating, we have been able to provide a solid chronological framework to such an old site, something perhaps unthinkable 20 years ago,’ concludes the researcher.

The Geochronology and Geology Program at CENIEH, Spain, hosts a unique combination of world-class facilities and international researchers fully dedicated to Human Evolutionary studies. One of the main research lines of the program consists in of refining the chronology of the early human occupations in the Mediterranean area, with a special emphasis on the combination of different dating methods in order to obtain more robust chronologies. The work at Oued Boucherit is just the latest example of this investigation carried out for more than a decade since the inauguration of the Centre in 2009.

Full bibliographic information:
Duval M., Sahnouni M., Parés J.M., van der Made J., Abdessadok S., Harichane Z., Chelli Cheheb R., Boulaghraif K., Pérez-González A. (2021). The Plio-Pleistocene sequence of Oued Boucherit (Algeria): a unique chronologically-constrained archaeological and paleontological record in North Africa. Quaternary Science Reviews 271. https://doi.org/10.1016/j.quascirev.2021.107116.
Press release from CENIEH

The shoulders of 'Homo antecessor' and modern humans are similar

The shoulders of 'Homo antecessor' and modern humans are similar

The CENIEH has published a paper in the journal Scientific Reports which concludes that Homo antecessor had a shoulder development analogous to that in H. sapiens, although its growth was faster
Homo antecessor shoulders
Homo antecessor scapulae. Credits: D. Garcia Martínez et al

The shape of our shoulders was already present in the Lower Pleistocene, according to a pioneering study published today in the journal Scientific Reports, carried out by Daniel García Martínez and José María Bermúdez de Castro, paleoanthropologists at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), in collaboration with David Green of Campbell University (USA).

Studying the shoulder (technically known as the "shoulder girdle") furnishes information on points significant for human evolution such as locomotion, body shape, the possibility of climbing with ease or the ability to launch objects like stones or spears with high accuracy.

The authors of this work were able to study for the first time shoulder growth and development in the species Homo antecessor, dated to 850,000 years old, using tools from virtual anthropology and 3D geometric morphometry. The results show that the course of development of the shoulder in this species was very similar to that in H. sapiens, although the growth might have been faster.

Almost one million years ago, our evolution had already attained almost all the biomechanical capacities characterizing the shoulder in modern humans, and it had definitively parted ways from the abilities still then retained by the more archaic species of the human phylogeny, including climbing with great agility.

 To verify the changes undergone by this part of our anatomy, we need a flat bone: the shoulder blade or scapula. But, as the authors of this study state, “The fossil record of our phylogeny contains barely a handful of these highly delicate bones, which has posed enormous difficulties to studying the growth and development of the shoulders during human evolution”.

Two key fossils

By good luck, at level TD6 of the Gran Dolina site, situated in the Sierra de Atapuerca (Burgos), two scapulae have been conserved: one from a child and the other from an individual of age equivalent to a modern adolescent. These fossils were recovered during the excavation in the first decade of the twenty-first century and belonged to the species H. antecessor.

“In an earlier study of these two fossils, it had been noticed that the morphology of the scapulae was similar to our own. But until now, the growth and development model for the shoulders had remained unknown, and this work has now allowed us to check that our shoulder girdle bones have undergone modifications in accordance with different capacities”, says Bermúdez de Castro.

Comparative study

With the scant information available, it was known that the scapulae of Australopithecus species were similar in some ways to those of chimpanzees or gorillas but were different from our own. “We know that the development of our most archaic ancestors was very similar to that of the anthropoid apes, and the morphology of their shoulders shows that they still retained the capacity to climb with ease. We, on the contrary, have lost this ability”, explains García Martínez.

Comparative of scapulae. Credits: D.García Martínez et al

To determine when our anatomical peculiarities arose, in addition to virtual anthropology and 3D geometric morphometry, the researchers used complex statistical methods to study the development of the shoulder girdle in the species H. antecessor, comparing it with other species from the Pliocene and Lower Pleistocene, such as Australopithecus sediba and A. afarensis. A very broad sample from H. sapiens and chimpanzees (Pan troglodytes) was also used.

“This study shows that although there exist slight morphological differences between the scapulae of H. antecessor and H. sapiens, the former were much more similar to modern humans, to H. erectus and even to Australopithecus than to chimpanzees”, comments García Martínez.

With regard to how the scapulae grew, it was also seen that this was very different from what happens in chimpanzees, and comparable with H. sapiens. “However, it is true that the data seem to point to growth being more rapid in H. antecessor, as highlighted by the CENIEH research team on the basis of dental evidence”, emphasizes Bermúdez de Castro.

This paper lays the foundations for how the shoulder girdle developed in Lower Pleistocene species, and opens the door to new research studying shoulder development in fossil species, as it may become possible to expand the timeframe and study this development even in Pliocene species like the genus Australopithecus.

Full bibliographic information

García-Martínez, D., Green, D., Bermúdez de Castro, J.M. 2021. Evolutionary development of the Homo antecessor scapulae (Gran Dolina site, Atapuerca) suggests a modern-like development for Lower Pleistocene Homo. Scientific Reports. DOI: 10.1038/s41598-021-83039

 

Press release from CENIEH


The temporal lobes of Homo erectus were proportionally smaller than in H. sapiens

The temporal lobes of Homo erectus were proportionally smaller than in H. sapiens

The CENIEH has contributed to a paleoneurological study published in the journal Quaternary International, on the brain of Homo erectus, which analyzes its temporal lobes and compares these with other species like H. ergaster and H. sapiens
temporal lobes erectus sapiens ergaster
Pearson at al.

Emiliano Bruner, a paleoneurologist at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has participated in a study published in the journal Quaternary International, on the anatomy of the temporal lobes in the brain of Homo erectus, which establishes that they were proportionally smaller than in modern humans.

In H. sapiens, the temporal lobes are relatively more highly developed than in other primates, although little is known about their anatomy in extinct human species, because they are housed in a very delicate region of the cranium known as the middle cranial fossa, which is often not conserved in fossil individuals.

An earlier study by the same team had shown that the size of the middle cranial fossa can be used to deduce the volume of the temporal lobes. In this new study, three anatomical diameters were analyzed in fossils of H. erectus and H. ergaster, and compared with the corresponding measurements for 51 modern humans. The results suggest that both fossil species had temporal lobes proportionally smaller than in humans today.

Moreover, “The Asiatic individuals, namely Homo erectus, had larger temporal lobes than in the African ones, Homo ergaster, although the scanty fossil record does not allow us to tell whether this is due to chance or a paleoneurological difference between the two species”, says Bruner.

As the temporal lobe is a brain region involved in the integration of many cognitive functions, such as memory, the emotions, hearing, social relations and language, any change in their sizes or proportions is of transcendent importance, as this could reveal variations in the development of their neurons or their connections, and therefore in the cognitive functions associated to this region of the cerebral cortex.

This study has been conducted by Alannah Pearson, a doctoral student of Emiliano Bruner at the Australian National University in Canberra (Australia), in collaboration with Professor David Polly, of Indiana University (USA).

 

Full bibliographic information

Pearson, A., Polly, P. D., & Bruner, E. (2020). Temporal lobe evolution in Javanese Homo erectus and African Homo ergaster: inferences from the cranial base. Quaternary International (0). doi: 10.1016/j.quaint.2020.07.048.

 

Press release from CENIEH


seafood Arabia out of Africa

Seafood helped prehistoric people migrate out of Africa, study reveals

Seafood helped prehistoric people migrate out of Africa, study reveals

Prehistoric pioneers could have relied on shellfish to sustain them as they followed migratory routes out of Africa during times of drought, a new study suggests.

seafood out of Africa Arabia Farasan Islands
Living specimen of the marine mollusc Conomurex fasciatus. Millions of these shells were found on the Farasan Islands in Saudi Arabia as the food refuse of prehistoric fishers. Photo credit: Dr Niklas Hausmann

The study examined fossil reefs near to the now-submerged Red Sea shorelines that marked prehistoric migratory routes from Africa to Arabia. The findings suggest this coast offered the resources necessary to act as a gateway out of Africa during periods of little rainfall when other food sources were scarce.

The research team, led by the University of York, focused on the remains of 15,000 shells dating back 5,000 years to an arid period in the region. With the coastline of original migratory routes submerged by sea-level rise after the last Ice Age, the shells came from the nearby Farasan Islands in Saudi Arabia.

Plentiful

The researchers found that populations of marine mollusks were plentiful enough to allow continuous harvests without any major ecological impacts and their availability would have enabled people to live through times of drought.

Lead author, Dr Niklas Hausmann, Associate Researcher at the Department of Archaeology at the University of York, said: "The availability of food resources plays an important role in understanding the feasibility of past human migrations – hunter-gatherer migrations would have required local food sources and periods of aridity could therefore have restricted these movements.

“Our study suggests that Red Sea shorelines had the resources necessary to provide a passage for prehistoric people.”

Healthy population

The study also confirms that communities settled on the shorelines of the Red Sea could have relied on shellfish as a sustainable food resource all year round.

Dr Hausmann added: “Our data shows that at a time when many other resources on land were scarce, people could rely on their locally available shellfish. Previous studies have shown that people of the southern Red Sea ate shellfish year-round and over periods of thousands of years. We now also know that this resource was not depleted by them, but shellfish continued to maintain a healthy population.”

Fossil reefs

The shellfish species found in the archaeological sites on the Farasan Islands were also found in abundance in fossil reefs dating to over 100 thousand years ago, indicating that these shellfish have been an available resource over longer periods than archaeological sites previously suggested.

Co-author of the study, Matthew Meredith-Williams, from La Trobe University, said: "We know that modelling past climates to learn about food resources is extremely helpful, but we need to differentiate between what is happening on land and what is happening in the water. In our study we show that marine foods were abundant and resilient and being gathered by people when they couldn't rely on terrestrial food."

 

Shellfish resilience to prehistoric human consumption in the southern Red Sea: Variability in Conomurex fasciatus across time and space is published in Quaternary International. The research was funded by the European Research Council.

 

Press release on seafood helping prehistoric people migrate out of Africa from the University of York

 


giant ostrich Crimean cave

Bird three times larger than ostrich discovered in Crimean cave

Bird three times larger than ostrich discovered in Crimean cave

First evidence that giant ostrich-like birds once roamed Europe

giant ostrich Crimean cave
PaleoArt of the bird discovered in a Crimean cave. It weighed three times the largest living bird, the common ostrich. Credit: Andrey Atuchin

A surprise discovery in a Crimean cave suggests that early Europeans lived alongside some of the largest ever known birds, according to new research published in the Journal of Vertebrate Paleontology.

It was previously thought that such gigantism in birds only ever existed on the islands of Madagascar and New Zealand as well as Australia. The newly-discovered specimen, discovered in the Taurida Cave on the northern coast of the Black Sea, suggests a bird as giant as the Madagascan elephant bird or New Zealand moa. It may have been a source of meat, bones, feathers and eggshell for early humans.

"When I first felt the weight of the bird whose thigh bone I was holding in my hand, I thought it must be a Malagasy elephant bird fossil because no birds of this size have ever been reported from Europe. However, the structure of the bone unexpectedly told a different story," says lead author Dr Nikita Zelenkov from the Russian Academy of Sciences.

"We don't have enough data yet to say whether it was most closely related to ostriches or to other birds, but we estimate it weighed about 450kg. This formidable weight is nearly double the largest moa, three times the largest living bird, the common ostrich, and nearly as much as an adult polar bear."

It is the first time a bird of such size has been reported from anywhere in the northern hemisphere. Although the species was previously known, no one ever tried to calculate the size of this animal. The flightless bird, attributed to the species Pachystruthio dmanisensis, was probably at least 3.5 metres tall and would have towered above early humans. It may have been flightless but it was also fast.

While elephant birds were hampered by their great size when it came to speed, the femur of the current bird was relatively long and slim, suggesting it was a better runner. The femur is comparable to modern ostriches as well as smaller species of moa and terror birds. Speed may have been essential to the bird's survival. Alongside its bones, palaeontologists found fossils of highly-specialised, massive carnivores from the Ice Age. They included giant cheetah, giant hyenas and sabre-toothed cats, which were able to prey on mammoths.

Other fossils discovered alongside the specimen, such as bison, help date it to 1.5 to 2 million years ago. A similar range of fossils was discovered at an archaeological site in the town of Dmanisi in Georgia, the oldest hominin site outside Africa. Although previously neglected by science, this suggests the giant bird may have been typical of the animals found at the time when the first hominins arrived in Europe. The authors suggest it reached the Black Sea region via the Southern Caucasus and Turkey.

The body mass of the bird was reconstructed using calculations from several formulae, based on measurements from the femur bone. Applying these formulae, the body mass of the bird was estimated to be around 450kg. Such gigantism may have originally evolved in response to the environment, which was increasingly arid as the Pleistocene epoch approached. Animals with a larger body mass have lower metabolic demands and can therefore make use of less nutritious food growing in open steppes.

"The Taurida cave network was only discovered last summer when a new motorway was being built. Last year, mammoth remains were unearthed and there may be much more to that the site will teach us about Europe's distant past," says Zelenkov.

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Rare fossils provide more detailed picture of biodiversity during Middle Ordovician

Rare fossils provide more detailed picture of biodiversity during Middle Ordovician

Middle Ordovician
Maine fossils from Portugal are shedding light on Middle Ordovician, where there had been a gap in the fossil record. Credit: Julien Kimmig / KU News Service

LAWRENCE -- A clutch of marine fossil specimens unearthed in northern Portugal that lived between 470 and 459 million years ago is filling a gap in understanding evolution during the Middle Ordovician period.

The discovery, explained in a new paper just published in The Science of Nature, details three fossils found in a new "Burgess Shale-type deposit." (The Burgess Shale is a deposit in Canada renowned among evolutionary biologists for excellent preservation of soft-bodied organisms that don't have a biomineralized exoskeleton.)

"The paper describes the first soft-body fossils preserved as carbonaceous films from Portugal," said lead author Julien Kimmig, collections manager at the University of Kansas Biodiversity Institute and Natural History Museum. "But what makes this even more important is that it's one of the few deposits that are actually from the Ordovician period -- and even more importantly, they're from the Middle Ordovician, a time were very few soft-bodied fossils are known."

Kimmig and his KU Biodiversity Institute colleagues, undergraduate researcher Wade Leibach and senior curator Bruce Lieberman, along with Helena Couto of the University of Porto in Portugal (who discovered the fossils), describe three marine fossil specimens: a medusoid (jellyfish), possible wiwaxiid sclerites and an arthropod carapace.

"Before this, there had been nothing found on the Iberian Peninsula in the Ordovician that even resembled these," Kimmig said. "They close a gap in time and space. And what's very interesting is the kind of fossils. We find Medusozoa -- a jellyfish -- as well as animals which appear to be wiwaxiids, which are sluglike armored mollusks that have big spines. We found these lateral sclerites of animals which were actually thought to have gone extinct in the late Cambrian. There might have been some that survived into the Ordovician in a Morocco deposit, but nothing concrete has been ever published on those. And here we have evidence for the first ones actually in the middle of the Ordovician, so it extends the range of these animals incredibly."

Kimmig said the discovery of uncommon wiwaxiids fossils in this time frame suggests the animals lived on Earth for a far greater span of time than previously understood.

"Especially with animals that are fairly rare that we don't have nowadays like wiwaxiids, it's quite nice to see they lived longer than we ever thought," he said. "Closely after this deposit, in the Upper Ordovician, we actually get a big extinction event. So, it's likely the wiwaxiids survived up to that big extinction event and didn't go extinct earlier due to other circumstances. But it might have been whatever caused the big Ordovician extinction event killed them off, too."

According to the researchers, the soft-bodied specimens fill a gap in the fossil record for the Middle Ordovician and suggest "many soft-bodied fossils in the Ordovician remain to be discovered, and a new look at deep-water shales and slates of this time period is warranted."

"It's a very interesting thing with these discoveries -- we're actually getting a lot of information about the distribution of animals chronologically and geographically," Kimmig said. "Also, this gives us a lot of information on how animals adapted to different environments and where they actually managed to live. With these soft-body deposits, we get a much better idea of how many animals there were and how their environment changed over time. It's something that applies to modern days, with changing climate and changing water temperatures, because we can see how animals over longer periods of time in the geologic record have actually adapted to these things."

The fossils were discovered in the Valongo Formation in northern Portugal, an area famed for containing trilobites. Credit: Julien Kimmig / KU News Service

Co-author Couto discovered the fossils in the Valongo Formation in northern Portugal, an area famed for containing trilobites. When the animals were alive, the Valongo Formation was part of a shallow sea on the margin of northern Gondwana, the primeval supercontinent.

"Based on the shelly fossils, the deposit looks like it was a fairly common Ordovician community," Kimmig said. "And now we know that in addition to those common fossils jellyfish were floating around, we had sluglike mollusks roaming on the ground, too, and we had bigger arthropods, which might have been predatory animals. So, in that regard, we're getting a far better image with these soft-bodied fossils of what these communities actually looked like."

According to the KU researcher, scientists didn't grasp until recently that deposits from this period could preserve soft-bodied specimens.

"For a long time, it was just not known that these kinds of deposits survived in to the Ordovician," Kimmig said. "So, it is likely these deposits are more common in the Ordovician than we know of, it's just that people were never looking for them."

Kimmig led analysis of the fossils at KU's Microscopy and Analytical Imaging Laboratory to ensure the fossils were made of organic material. Leibach, the KU undergraduate researcher, conducted much of the lab work.

"We analyzed the material and looked at the composition because sometimes you can get pseudo fossils -- minerals that create something that looks like a fossil," Kimmig said. "We had to make sure that these fossils actually had an organic origin. And what we found is that they contain carbon, which was the big indication they would actually be organic."

 

Press release from the University of Kansas


Neanderthals and modern humans diverged at least 800,000 years ago

Neanderthals and modern humans diverged at least 800,000 years ago

Neanderthals and modern humans diverged at least 800,000 years ago, substantially earlier than indicated by most DNA-based estimates, according to new research by a UCL academic.

Neanderthals diverged teeth
Dental morphology. Credit: Aida Gómez-Robles

The research, published in Science Advances, analysed dental evolutionary rates across different hominin species, focusing on early Neanderthals. It shows that the teeth of hominins from Sima de los Huesos, Spain - ancestors of the Neanderthals - diverged from the modern human lineage earlier than previously assumed.

Sima de los Huesos is a cave site in Atapuerca Mountains, Spain, where archaeologists have recovered fossils of almost 30 people. Previous studies date the site to around 430,000 years ago (Middle Pleistocene), making it one of the oldest and largest collections of human remains discovered to date.

Dr Aida Gomez-Robles (UCL Anthropology), said: "Any divergence time between Neanderthals and modern humans younger than 800,000 years ago would have entailed an unexpectedly fast dental evolution in the early Neanderthals from Sima de los Huesos."

"There are different factors that could potentially explain these results, including strong selection to change the teeth of these hominins or their isolation from other Neanderthals found in mainland Europe. However, the simplest explanation is that the divergence between Neanderthals and modern humans was older than 800,000 years. This would make the evolutionary rates of the early Neanderthals from Sima de los Huesos roughly comparable to those found in other species."

Modern humans share a common ancestor with Neanderthals, the extinct species that were our closest prehistoric relatives. However, the details on when and how they diverged are a matter of intense debate within the anthropological community.

Ancient DNA analyses have generally indicated that both lineages diverged around 300,000 to 500,000 years ago, which has strongly influenced the interpretation of the hominin fossil record.

This divergence time, however, is not compatible with the anatomical and genetic Neanderthal similarities observed in the hominins from Sima de los Huesos. The Sima fossils are considered likely Neanderthal ancestors based on both anatomical features and DNA analysis.

Dr Gomez-Robles said: "Sima de los Huesos hominins are characterised by very small posterior teeth (premolars and molars) that show multiple similarities with classic Neanderthals. It is likely that the small and Neanderthal-looking teeth of these hominins evolved from the larger and more primitive teeth present in the last common ancestor of Neanderthals and modern humans."

Dental shape has evolved at very similar rates across all hominin species, including those with very expanded and very reduced teeth. This new study examined the time at which Neanderthals and modern humans should have diverged to make the evolutionary rate of the early Neanderthals from Sima de los Huesos similar to those observed in other hominins.

The research used quantitative data to measure the evolution of dental shape across hominin species assuming different divergent times between Neanderthals and modern humans, and accounting for the uncertainty about the evolutionary relationships between different hominin species.

"The Sima people's teeth are very different from those that we would expect to find in their last common ancestral species with modern humans, suggesting that they evolved separately over a long period of time to develop such stark differences."

The study has significant implications for the identification of Homo sapiens last common ancestral species with Neanderthals, as it allows ruling out all the groups postdating 800,000 year ago.

Neanderthals diverged teeth
Hominin teeth. Credit: Aida Gómez-Robles

Press release from University College London


Traces of crawling in Italian cave give clues to ancient humans' social behavior

Traces of crawling in Italian cave give clues to ancient humans' social behavior

Using multiple methods of analysis, researchers have identified the movements of a group of humans as they explored an Italian cave system during the late Stone Age

The video shows a virtual exploration of the Bàsura cave, with a reconstruction of the group of ancient humans that proceeded via the 'Corridoio delle Impronte' to reach the inner rooms. Credit: MUSE - Isabella Salvador and Filippo Menolli

cave of Bàsura Toirano Liguria
In the cave of Bàsura, a preliminary survey of fossil traces is carried out on glossy sheets as a reference for more detailed analyses. Credit: Isabella Salvador

Evidence of crawling in an Italian cave system sheds new light on how late Stone Age humans behaved as a group, especially when exploring new grounds, says a study published today in eLife.

The cave of Bàsura at Toirano and its human and animal fossil traces have been known since the 1950s, with the first studies conducted by Italian archaeologist Virginia Chiappella. In the current study, promoted by the Archaeological Heritage Office of Liguria, researchers from Italy, Argentina and South Africa used multiple approaches to analyse the human traces and identified for the first time crawling behaviours from around 14,000 years ago.

"In our study, we wanted to see how ancient humans explored this fascinating cave system," says first author Marco Romano, Postdoctoral Fellow at the University of the Witwatersrand, South Africa. "Specifically, we set out to discover how many people entered the cave, whether they explored as individuals or as a group, their age, gender and what kind of route they took once inside the cave."

To answer these questions, the multidisciplinary team studied 180 tracks from within the cave, including foot and handprints on the clay-rich floor. They applied various modern dating methods, software that analyses the structure of the tracks, and different types of 3D modelling. "Together, these approaches allowed us to construct a narrative of how the humans entered and exited the cave, and their activities once they were inside," Romano explains.

The team determined that five individuals, including two adults, an adolescent of about 11 years old, and two children of three and six years old, entered the cave barefoot and illuminated the way using wooden sticks. This suggests that young children were active group members during the late Stone Age, even when carrying out apparently dangerous activities.

The researchers reported the first evidence of crawling in footprints from a low tunnel - a route that was taken to access the inner part of the cave. Anatomical details in the footprints suggest that the explorers went bare-legged as they navigated this pathway.

When analysing the various handprints, the team found that some of them appear 'unintentional' and relate to exploring the cave only, while others are more 'intentional' and suggest that social or symbolic activities took place within the inner chambers. "Hunter-gatherers may therefore have been driven by fun activities during exploration, as well as simply the need to find food," Romano adds.

"Together, our results show how a varied approach to studying our ancestors' tracks can provide detailed insights on their behaviour," concludes senior author Marco Avanzini, head of the geology department at MUSE - Trento Museum of Science, Italy. "We hope our approach will be useful for painting similar pictures of how humans behaved in other parts of the world and during different periods of time."

cave of Bàsura Toirano Liguria
These are ancient human footprints impressed on different surfaces in the cave of Bàsura. Credit: Marco Avanzini

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Reference

The paper 'A multidisciplinary approach to a unique Palaeolithic human ichnological record from Italy (Bàsura Cave)' can be freely accessed online at https://doi.org/10.7554/eLife.45204.

Press release from eLife


Alcmonavis poeschli

First birds: Archaeopteryx gets company

First birds: Archaeopteryx gets company

Researchers at LMU Munich describe a hitherto unknown bird from the late Jurassic period. It is the second bird capable of flight, after the famous Archaeopteryx, to be identified from this era.

Alcmonavis poeschli
The illustration shows the wing of Alcmonavis poeschli as it was found in the limestone slab. Alcmonavis poeschli is the second known specimen of a volant bird from the Jurassic period. Copyright: O. Rauhut, LMU/SNSB

Archaeopteryx's throne is tottering. Since the discovery of the first fossil of the primal bird in 1861, it had been considered the only bird from the Jurassic geological period. Today's birds are thought to be direct descendants of carnivorous dinosaurs, with Archaeopteryx representing the oldest known flying representative of this lineage. All of the specimens that have been found up to now come from the region of the Solnhofen Archipelago, which during the Jurassic era spanned across what is today the Altmühl Valley, in the area between Pappenheim and Regensburg. Archaeopteryx lived here in a landscape of reef islands about 150 million years ago. A team led by Professor Oliver Rauhut has taxonomically identified a bird unknown until now: Alcmonavis poeschli, the second bird from the era identified as capable of flight. "This suggests that the diversity of birds in the late Jurassic era was greater than previously thought," says Rauhut, paleontologist at the Department of Earth and Environmental Sciences as well as the Bavarian State Collection of Paleontology and Geology.

Only a wing of Alcmonavis poeschli was discovered. "At first, we assumed that this was another specimen of Archaeopteryx. There are similarities, but after detailed comparisons with Archaeopteryx and other, geologically younger birds, its fossil remains suggested that we were dealing with a somewhat more derived bird," says Rauhut. According to the team's taxonomic studies, which are currently featured in the scientific journal eLifeAlcmonavis poeschli was not merely somewhat larger than Archaeopteryx; apparently it could also fly better. "The wing muscles indicate a greater capacity for flying," says Rauhut. Alcmonavis poeschli exhibits numerous traits lacking in Archaeopteryx but present in more recent birds. This suggests that it was adapted better to active, flapping flight.

The discovery of Alcmonavis poeschli has implications for the debate over whether active flapping birds arose from gliding birds. "Its adaptation shows that the evolution of flight must have progressed relatively quickly," says Dr. Christian Foth from the University of Fribourg (Switzerland), one of the co-authors of the study.

The bird now being described for the first time derives its name from the old Celtic word for the river Altmühl, Alcmona, and its discoverer Roland Pöschl, who leads the excavation at the Schaudiberg quarry close to Mörnsheim. A fossil of Archaeopteryx was also discovered in the same unit of limestones. The two primal birds thus apparently lived at the same time in what was then a subtropical lagoon landscape in southern Germany.

 

Press release from the Ludwig-Maximilians-Universität München


ammonite amber

Coastal organisms trapped in 99-million-year-old amber

Coastal organisms trapped in 99-million-year-old amber

ammonite amber
Amber piece showing most large inclusions. Credit: NIGPAS

Most amber inclusions are organisms that lived in the forest. It is very rare to find sea life trapped in amber. However, an international research group led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) reported the first known ammonite trapped in amber in a study in PNAS published on May 13.

The ammonite, a kind of sea animal, was trapped in 99-million-year-old amber from northern Myanmar. The amber is 33 mm long, 9.5 mm wide, 29 mm high and weighs 6.08 g. Besides the ammonite, the amber also encases a diverse assemblage of organisms that today live on land or in the sea, including at least 40 individual animals.

Of the terrestrial fauna found in the amber, mites are the most abundant. Also present are spiders, millipedes, cockroaches, beetles, flies and wasps, most of which would have lived on the forest floor.

Of the marine fauna, in addition to the ammonite itself, sea snails and sea slaters are present. The slaters are like those living on the seashore today.

The researchers used X-ray micro-computed tomography (micro-CT) to obtain high-resolution three-dimensional images of the ammonite including its convoluted sutures, which are important for identifying ammonites.

They found that the ammonite is a juvenile Puzosia (Bhimaites) and its presence in the amber supports a late Albian-early Cenomanian age for the amber deposit. This discovery represents a rare example of dating using amber inclusions.

But how on earth did the ammonite, an extinct sea-dwelling relative of squid, get preserved in a piece of amber that also contains land-based animals? The ammonite and sea snail shells offer possible clues.

The shells are all empty with no soft-tissue, so the organisms were long dead by the time they were engulfed by resin. The outer shell of the ammonite is broken away and the entrance of the shell is full of sand. The amber also contains additional sand.

ammonite amber
(A) Lateral view under light microscopy. (B) Flattened sutures reconstructed by microtomography. (C) Microtomographic reconstruction, apparent view. (D) Microtomographic reconstruction, surface rendering; (E) Microtomographic reconstruction, virtual section. Credit: NIGPAS

The most likely explanation for the appearance of both marine and terrestrial organisms within the amber is that a sandy beach covered with shells was located close to resin-producing trees. The flying insects were trapped in the resin while it was still on the tree. As the resin flowed down the tree trunk, it trapped organisms that lived near the foot of the tree. Reaching the beach, it entombed shells and trapped the slaters living there.

 

Press release from the Chinese Academy of Sciences