Category Archives: Paleontology

A Shocking Discovery in Excavations in Israel: A New Type of Ancient Man Unfamiliar With Science Has Been Discovered (Paleontology)

The bones of an ancient man who lived in our area until about 130,000 years ago were discovered in excavations at the prehistoric site “Nesher Ramla

Researchers from Tel Aviv University and the Hebrew University have identified a new type of ancient man at the Nesher Ramla site, who lived in Israel until 130,000 years ago. According to the researchers, the morphology of the human type “Eagle Ramla” is a general morphology, and it shares features both with the Neanderthals (mainly in the teeth and jaw) and with older humans such as Homo erectus (mainly in the skull). At the same time, it is very different from modern man – the structure of the skull is completely different, it has no chin and the teeth are very large. Following the findings of the study, the researchers believe that the ancient human group “Nesher Ramla” is the origin population from which most human populations in the Middle Pleistocene evolved, including the Neanderthals from Europe, and they mated with Homo sapiens who arrived in the area 200,000 years ago. .

Behind the exciting discovery, published in the prestigious journal Science, are two research teams: an anthropological team led by Prof. Israel Hershkovitz, Dr. Hila May and Dr. Rachel Sarig of the Sackler Faculty of Medicine , Dan David Center for Human History Research and the Shmonis Institute of Anthropology, Sitting at the Steinhardt Museum of Nature at Tel Aviv University, and an archeological team led by Dr. Yossi Zeidner of the Institute of Archeology at the Hebrew University of Jerusalem. The excavations at the site were conducted by the Zinman Institute of Archeology, University of Haifa.

The “new” ancient man

“The scientific importance of finding a new type of human allows us to put the fossil world in order, put together another piece in the puzzle of ancient human evolution and understand the journeys he went through around the old world,” says Prof. Hershkovitz. “The” Nesher Ramla “human type is the bridge between the Asian and European populations in the Middle Pleistocene and shows that some of the fossils of the time classified into different species are in fact local geographical orientations of the same group – the Nesher Ramla group.”   

The human fossil was discovered by Dr. Zeidner of the Hebrew University in rescue excavations conducted at the prehistoric site “Nesher Ramla”. This site is located in the mining area of ​​the Nesher cement plant (owned by Len Belvatnik) near the city of Ramla. Many animals such as horses, donkeys and wild bulls, stone tools as well as human bones. Among the bones were also the bones of the “new” ancient man. Was known to science.This is the first type of person defined in the country, and as is customary, the new person was named based on the place of his discovery – “person type Nesher Ramla”.

Dr. Zeidner further noted that “the discovery is extraordinary, we did not imagine that alongside the ancient Homo sapiens, another group of people roamed here who survived to such a late stage in human history. If so far there have not been enough findings regarding this type of person, now a window is opened for us to know more about his lifestyle and culture that were very close to those of Homo spines. “Findings regarding his lifestyle, culture and cultural connections between” Adam Nesher Ramla ” They too are today in the scientific journal Science in a parallel article.

Prof. Hershkovitz adds that the discovery of the ancient man “Nesher Ramla” challenges the accepted view that Neanderthal man originated in Europe. “Until the new findings were revealed, most researchers believed that the Neanderthals were a ‘European story’, with small groups of them having to migrate south with the spread of glaciers in Europe and even arriving in Israel about 70,000 years ago. The man from Nesher Ramla challenges this theory. “Neanderthals in Europe lived in Israel about 400,000 years ago, and from here they migrated (in repeated migrations) west to Europe and east to Asia. The famous Neanderthals of Western Europe are nothing but the remnants of a much larger population living here in the Levant – and not the other way around.”

The research team © Tel Aviv University

According to Dr. May, although unfortunately no DNA has been preserved in the Ramla fossil fossil, the findings could offer a solution to a very big question in human history: how Homo sapiens genes entered the Neanderthal population living in Europe long before Homo sapiens arrived there. In previous studies geneticists studying the DNA of Neanderthals in Europe assumed the existence of a Neanderthal-like population, which they called the “missing population” or “X population”, which mated with the Homo sapiens population at least 100,000 years ago, and its descendants migrated to Europe. -Science, the researchers claim that the person from “Nesher Ramla” represents the same population that is missing in the human fossil evidence. Moreover, the researchers claim that the person from “Nesher Ramla” is not a single find in our area, Like the human fossils from the Tabun Cave that are about 160,000 years old,

The Land of Israel as a melting pot in the old world

“People think in paradigms,” explains Dr. Sarig, “so to this day attempts have been made to associate these fossils with known human groups such as Homo sapiens, Homo erectus, Homo heidelbergensis or Neanderthals, and now we come and say: No – they are a group in themselves with characteristics And special markers. At a later stage small groups of the Nesher Ramle human type also migrated to Europe (in interglacial periods) – where they are known as pre-Neanderthals, and evolved, over time, to become the ‘classic Neanderthals’ we know. Similarly, the archaic Asian populations that carry Neanderthal characteristics (and were considered an evolution from the local Homo erectus) are probably the descendants of populations that migrated from our region (human type Nesher Ramla) eastward towards Asia. Being a crossroads between Africa, Europe and Asia, the Land of Israel was a melting pot in which the various human populations mingled with each other and spread throughout the Old World.

Dr. Sarig believes that this discovery of a new type of man with primordial (archaic) and Neanderthal features, with similarities to fossils from both Europe and East Asia, will lead to the history of Neanderthals being studied differently. More, European-Asian, where the Levant is the starting point or connection point between the two continents.

“The discovery from the Nesher Ramla site writes a new and fascinating chapter in the story of human evolution,” says Dr. Sarig. “A common perception among anthropologists,” says Prof. Hershkovitz, is that “the past changes (according to the findings), only the future is certain.”


Provided by Tel Aviv University

Skull of 340 Million Year Old Animal Digitally Recreated Revealing Secrets of Ancient Amphibian (Paleontology)

Researchers from the University of Bristol and University College London have used cutting-edge techniques to digitally reconstruct the skull of one of the earliest limbed animals.

Tetrapods include mammals, reptiles and amphibians – everything from salamanders to humans. Their origin represents a crucial time in animal evolution, from the development of limbs with digits and the shift from water on to land. The study, which was recently published in the Journal of Vertebrate Paleontology, depicts the reconstructed skull of a prehistoric amphibian, the 340-million year old Whatcheeria deltae, to reveal what this animal looked like and how it may have fed.

First discovered in Iowa in 1995, the fossils of Whatcheeria were originally squashed flat after being buried by mud at the bottom of an ancient swamp, but palaeontologists were able to use computational methods to restore the bones to their original arrangement. The fossils were put through a CT scanner to create exact digital copies, and software was used to separate each bone from the surrounding rock. These digital bones were then repaired and reassembled to produce a 3D model of the skull as it would have appeared while the animal was alive.

The authors found that Whatcheeria possessed a tall and narrow skull quite unlike many other early tetrapods that were alive at the time. Lead author James Rawson, who worked on this project alongside his undergraduate degree in palaeontology and evolution, said: “Most early tetrapods had very flat heads which might hint that Whatcheeria was feeding in a slightly different way to its relatives, so we decided to look at the way the skull bones were connected to investigate further.”

By tracing the connecting edges of the skull bones, known as sutures, the authors were able to figure out how this animal tackled its prey. Professor Emily Rayfield, of the University of Bristol’s School of Earth Sciences, who also worked on the study, said: “We found that the skull of Whatcheeria would have made it well-adapted to delivering powerful bites using its large fangs.”

Co-author Dr Laura Porro said: “There are a few types of sutures that connect skull bones together and they all respond differently to various types of force. Some are better at dealing with compression, some can handle more tension, twisting and so on. By mapping these suture types across the skull, we can predict what forces were acting on it and what type of feeding may have caused those forces.”

The authors found that the snout had lots of overlapping sutures to resist twisting forces from struggling prey, while the back of the skull was more solidly connected to resist compression during biting.

Mr Rawson added: “Although this animal was still probably doing most of its hunting in the water, a bit like a modern crocodilian, we’re starting to see the sorts of adaptations that enabled later tetrapods to feed more efficiently on land.”

Paper:

‘Osteology and digital reconstruction of the skull of the early tetrapod Whatcheeria deltae’ in Journal of Vertebrate Paleontology by James Rawson, Dr Laura Porro, Dr Elizabeth Martin-Silverstone and Professor Emily Rayfield.

Featured image: Skull fossils of amphibian. Credit: Field Museum of Natural History, Chicago


Provided by University of Bristol

Bird Brains Left Other Dinosaurs Behind (Paleontology)

Today, being “birdbrained” means forgetting where you left your keys or wallet. But 66 million years ago, it may have meant the difference between life and death – and may help explain why birds are the only dinosaurs left on Earth.

Research on a newly discovered bird fossil led by The University of Texas at Austin found that a unique brain shape may be why the ancestors of living birds survived the mass extinction that claimed all other known dinosaurs.

A fossil skull of Ichthyornis, a bird that lived 70 million years ago during the late Cretaceous Period.
A fossil skull of Ichthyornis, a bird that lived 70 million years ago during the late Cretaceous Period. Credit: Christopher Torres / The University of Texas at Austin

“Living birds have brains more complex than any known animals except mammals,” said lead investigator Christopher Torres, who conducted the research while earning a Ph.D. from the UT College of Natural Sciences and is now a National Science Foundation postdoctoral fellow at Ohio University and research associate at the UT Jackson School of Geosciences. “This new fossil finally lets us test the idea that those brains played a major role in their survival.”

The fossil is about 70 million years old and has a nearly complete skull, a rare occurrence in the fossil record that allowed the scientists to compare the ancient bird to birds living today.

The findings were published July 30 in the journal Science Advances.

The fossil is a new specimen of a bird named Ichthyornis, which went extinct at the same time as other nonavian dinosaurs and lived in what is now Kansas during the late Cretaceous Period. Ichthyornis has a blend of avian and nonavian dinosaur-like characteristics – including jaws full of teeth but tipped with a beak. The intact skull let Torres and his collaborators get a closer look at the brain.

Bird skulls wrap tightly around their brains. With CT-imaging data, the researchers used the skull of Ichthyornis like a mold to create a 3D replica of its brain called an endocast. They compared that endocast with ones created for living birds and more distant dinosaurian relatives.

The researchers found that the brain of Ichthyornis had more in common with nonavian dinosaurs than living birds. In particular, the cerebral hemispheres – where higher cognitive functions such as speech, thought and emotion occur in humans – are much bigger in living birds than in Ichthyornis. That pattern suggests that these functions could be connected to surviving the mass extinction.

“If a feature of the brain affected survivorship, we would expect it to be present in the survivors but absent in the casualties, like Ichthyornis,” said Torres. “That’s exactly what we see here.”

The ancestors of living birds had a brain shape that was much different from other dinosaurs (including other early birds). This suggests that brain differences may have affected survival during the mass extinction that wiped out all nonavian dinosaurs. Credit: Christopher Torres / The University of Texas at Austin.

The search for skulls from early birds and closely related dinosaurs has been challenging paleontologists for centuries. Bird skeletons are notoriously brittle and rarely survive in the fossil record intact in three dimensions. Well-preserved skulls are particularly rare – but that’s exactly what scientists need in order to understand what their brains were like in life.

Ichthyornis is key to unraveling that mystery,” said Julia Clarke, a professor at the UT Jackson School of Geosciences and co-author of the study. “This fossil helps bring us much closer to answering some persistent questions concerning living birds and their survivorship among dinosaurs.”

Mark Norell, the curator and division chair of paleontology at the American Museum of Natural History, co-authored the study. This work was funded by the Howard Hughes Medical Institute Science Education Program, the Jackson School of Geosciences and the American Museum of Natural History.

Featured image: A transparent 3D model of the fossil bird skull and brain (in pink). Christopher Torres / The University of Texas at Austin.


Reference: Christopher R. Torres et al, Bird neurocranial and body mass evolution across the end-Cretaceous mass extinction: The avian brain shape left other dinosaurs behind, Science Advances (2021). DOI: 10.1126/sciadv.abg7099


Provided by University of Texas at Austin

Prehistoric Hunting Dogs May Have Lived Alongside Early Humans in Europe (Paleontology)

Remains of a prehistoric hunting dog recently discovered in Dmanisi, Georgia may be the earliest evidence that hunting dogs moved to Europe. The findings, which suggest that hunting dogs may have lived alongside early humans found in the same location, are published in Scientific Reports.

An international research team coordinated by the professor of the University of Florence Saverio Bartolini-Lucenti, with the participation of the researcher Joan Madurell, from the UAB Department of Geology and from the Institut Català de Paleontologia Miquel Crusafont (ICP)  analysed the remains of a large dog, dated to between 1.77 and 1.76 million years ago. The specimen is the earliest known case of a hunting dog near Europe, preceding the widespread movement of hunting dogs from Asia to Europe and Africa during the Calabrian stage (1.8 to 0.8 million years ago) of the Pleistocene Epoch.

The authors identified distinct dental structures that suggest the Dmanisi dog belonged to the species Canis (Xenocyon) lycaonoides, the Eurasian hunting dog, which originated in East Asia and may be the ancestor of African hunting dogs alive today. The dog’s dental features also match other wild dog-like species (Canids) from the same era and today that have been identified as highly carnivorous (over 70% meat in their diet). These features include narrower and shorter third premolars than those of omnivores and an enlarged and sharp carnassial (tooth in the middle of the jaw that shreds food). The authors did not find significant wear on the teeth, suggesting the dog was a young but large adult, estimating its weight at around 30kg. 

As human remains found previously in Dmanisi are the earliest direct evidence of early humans moving out of Africa approximately 1.8 million years ago, the current findings suggest that hunting dogs and early humans lived alongside each other in Dmanisi. The Eurasian hunting dogs may have then moved dispersed across Africa, Asia and Europe in line with other studies, becoming one of the most widespread carnivores of the fossil record.

Featured image credit: Mauricio Antón


Reference paper:

Bartolini-Lucenti, S., Madurell-Malapeira, J., Martínez-Navarro, B. et al. The early hunting dog from Dmanisi with comments on the social behaviour in Canidae and hominins. Sci Rep 11, 13501 (2021). https://doi.org/10.1038/s41598-021-92818-4


Provided by UAB

Bronze Age Cemetery Reveals History Of A High-status Woman And Her Twins (Paleontology)

Ancient urn graves contain a wealth of information about a high-ranking woman and her Bronze Age Vatya community, according to a study published July 28, 2021 in the open-access journal PLOS ONE by Claudio Cavazzuti from the University of Bologna, Italy, and Durham University, UK, and colleagues.

People of the Vatya culture that flourished during the Hungarian Early and Middle Bronze Ages (approximately 2200-1450 BCE) customarily cremated the deceased—making the human remains difficult to analyze from a bioarchaeological perspective. In this study, the authors used new osteological sampling strategies to learn more about the people buried in the urnfield cemetery at Szigetszentmiklós-Ürgehegy, one of the largest Middle Bronze Age urn cemeteries in Central Hungary.

Cavazzuti and colleagues analyzed human tissues from 29 graves (three whole burials, or inhumations, and 26 urn cremations) and applied strontium isotope comparison techniques to test if sampled individuals were local to the geographic area. For the majority of sampled graves, each contained the remains of a single individual and simple grave goods made of ceramic or bronze; however, gravesite 241 was of special interest: this grave contained an urn with the cremated remains of an adult woman and two fetuses, buried alongside prestigious grave goods including a golden hair-ring, a bronze neck-ring, and two bone hairpin ornaments.

Though the three inhumed individuals were poorly preserved, the authors were able to confirm these had been adults, though they couldn’t determine the sex. Of the 26 cremated individuals, seven appeared to be adult males, 11 adult females, and two appeared to be adults whose sex couldn’t be determined. They also identified children’s remains: two individuals likely 5-10 years of age, and four individuals ranging from 2-5 years of age—the youngest present aside from the twin fetuses buried with the adult woman in grave 241, which were approximately 28-32 gestational weeks of age. The authors believe the woman in grave 241 may have died due to complications bearing or birthing these twins. Her remains indicate she was 25 to 35 years old at her time of death and the remains were especially carefully collected post-cremation, as her grave exhibited a bone weight 50 percent higher than the average sampled grave. The strontium analysis also revealed she was likely born elsewhere and moved to Szigetszentmiklós in early adolescence, between the ages of 8-13. One other adult woman also appeared non-local to Szigetszentmiklós, with the adult women in general featuring a more varied strontium isotope composition than the adult men, whose isotopes were concentrated in an especially small range—even narrower than those of the children analyzed in the study.

The authors note their findings at the Szigetszentmiklós urnfield reinforce evidence that women, especially of high rank, commonly married outside their immediate group in Bronze Age Central Europe—and confirm the informative potential of strontium isotope analyses even for cremated remains.

The authors add: “Thanks to a wide spectrum of new bioarchaeological methods, techniques and sampling strategies, it is now possible to reconstruct the life-histories of cremated people of the Bronze Age. In this case, the authors investigate the movements and the tragic events of a high-status woman’s life, settled along the Danube 4000 years ago, in the territory of modern-day Hungary.”

Featured image: Szigetszentmiklós-Ürgehegy ‘urnfield’ during excavation and a typical Vatya burial. © doi:10.1371/journal.pone.0254360.g002


Reference: Cavazzuti C, Hajdu T, Lugli F, Sperduti A, Vicze M, Horváth A, et al. (2021) Human mobility in a Bronze Age Vatya ‘urnfield’ and the life history of a high-status woman. PLoS ONE 16(7): e0254360. doi.org/10.1371/journal.pone.0254360


Provided by Public Library of Science

Researchers Explored Blood Types Of Neanderthal and Denisovan Individuals (Paleontology)

An analysis of the blood types of one Denisovan and three Neanderthal individuals has uncovered new clues to the evolutionary history, health, and vulnerabilities of their populations. Silvana Condemi of the Centre National de la Research Scientifique (CNRS) and colleagues at Aix-Marseille University, France, present these findings in the open-access journal PLOS ONE on July 28, 2021.

Neanderthals and Denisovans were ancient humans who lived across Eurasia, from Western Europe to Siberia, from about 300,000 to 40,000 years ago. Previous research efforts have produced full-genome DNA sequences for 15 of these ancient individuals, greatly enhancing understanding of their species. However, despite being encoded in DNA, these ancient individuals’ blood types have received little attention.

In the new study, Condemi and colleagues investigated the previously sequenced genomes of one Denisovan and three Neanderthal individuals (ranging from 100,000 to 40,000 years ago)in order to determine their blood types and analyze the implications. While 43 different systems exist for assigning blood types, the researchers focused on seven systems that are often used in medical settings for blood transfusions.

This analysis of the four individuals’ blood types revealed new information about their species. For instance, the ancient individuals had blood type alleles—different versions of the same gene—in combinations that are consistent with the idea that Neanderthals and Denisovans originated in Africa.

Neandertal and Denisovan blood groups deciphered
Rh blood group system analysis (+ = full Rh(D) antigen ; + partial = partial Rh(D) antigen / – = missing Rh(D) antigen) suggested risk of haemolytic disease of the fetus and newborn among Neandertals and revealed interbreeding (possibly in the Levant), traces of which might be found in modern humans from Australia and Papua New Guinea. In three of the individuals, the presence of a ‘non-secretor’ allele, associated with protection from certain viruses, suggests selective pressure exerted by the latter. Credit: © Stéphane Mazières (photos: Douka et al. / Mafessoni et al. / Prüfer et al. / Green et al.)

In addition, a distinct genetic link between the Neanderthal blood types and the blood types of an Aboriginal Australian and an indigenous Papuan suggests the possibility of mating between Neanderthals and modern humans before modern humans migrated to Southeast Asia.

The Neanderthal individuals also had blood type alleles associated with increased vulnerability to diseases affecting fetuses and newborns, as well as reduced variability of many alleles compared to modern humans. This pattern is in line with existing evidence that links low genetic diversity and low reproductive success with the eventual demise of Neanderthals.

Overall, these findings highlight the relevance of blood types in understanding humans’ evolutionary history.

The authors add: “This work identifies the blood group systems in Neandertals and Denisovans in order to better understand their evolutionary history and to consolidate hypotheses concerning their dispersal in Eurasia and interbreeding with early Homo sapiens.

The results of the Groups system analysis of Neandertals and Denisovans confirm their African origin as well as the weakness in their fertility and susceptibility to virus infection leading to a high infant mortality rate.”

Featured image: Comparison of Modern Human and Neanderthal skulls from the Cleveland Museum of Natural History. Credit: DrMikeBaxter/Wikipedia


Reference: Condemi S, Mazières S, Faux P, Costedoat C, Ruiz-Linares A, Bailly P, et al. (2021) Blood groups of Neandertals and Denisova decrypted. PLoS ONE 16(7): e0254175. doi.org/10.1371/journal.pone.0254175


Provided by Public Library of Science

Icy Waters Of ‘Snowball Earth’ May Have Spurred Early Organisms To Grow Bigger (Paleontology)

A new study from CU Boulder finds that hundreds of millions of years ago, small single-celled organisms may have evolved into larger multicellular life forms to better propel themselves through icy waters.

The research was led by paleobiologist Carl Simpson and appears today in the journal The American Naturalist. It hones in on a question that’s central to the history of the planet: How did life on Earth, which started off teeny-tiny, get so big?

“Once organisms get big, they have a clear ecological advantage because the physics around how they capture food become totally different,” said Simpson, assistant professor in the Department of Geological Sciences and the CU Museum of Natural History. “But the hard part for researchers has been explaining how they got big in the first place.”

In his latest study, Simpson draws on a series of mathematical equations to argue that this all-important shift may have come down to hydrodynamics—or the pursuit of a more efficient backstroke.

Two fossils lay out on a table
Several colonies of Volvox shaped like spheres
Top: Two fossils of Brooksella alternata;bottom: Sphere-shaped colonies of Volvox algae seen under a microscope. (Credits: Glenn Asakawa/CU Boulder; CC photo via Wikimedia Commons)

Roughly 750 million years ago, and for reasons that scientists are still debating, the planet became suddenly and dramatically colder—a period of time called “Snowball Earth.” To adapt to these frigid conditions, which can make swimming more difficult, small organisms like bacteria may have begun to glom together to form larger and more complex life.

Simpson still has a lot of work to do before he can prove his theory. But, the geologist said, the results could help to reveal how the ancestors of all modern multicellular life, from flowers to elephants and even people, first arose on Earth. 

“By swimming together, these cells could remain small on an individual level but still produce more power,” Simpson said. “They become both bigger and faster as a group.”

Snowball Earth

Those successes took place at a seemingly inhospitable time in the planet’s past.

During “Snowball Earth,” the globe may have been all but recognizable. Ice sheets a half-mile thick or more may have blanketed the planet for as much as 70 million years, while temperatures in the oceans plummeted to less than 32 degrees Fahrenheit. 

But even amid those frigid conditions, something spectacular happened: The first organisms made up of many different cells, not just one, began to emerge around the planet. Scientists still aren’t sure what those ancient multicellular organisms might have looked like. One theory suggests that they resembled Volvox, a type of algae that are common in oceans today and are shaped like a hollow sphere or snow globe.

“That’s something that has lodged in my mind for years,” Simpson said. “How do Snowball Earth and the rise of multicellular organisms go together?”

The answer to that counterintuitive problem may hinge on a little-known property of water.

Simpson explained that when saltwater gets colder, it also becomes several times thicker, or more viscous. Humans are too big to notice the change. But for organisms the size of modern-day bacteria, the difference can be huge. 

“When you’re small, you’re stuck,” he said. “The water moves you.”

Taking a swim

The geologist ran a series of calculations to gauge how organisms of various shapes and sizes might fare in the oceans of Snowball Earth. And, in this case, bigger might be better. 

Simpson said that modern-day bacteria and other single-celled organisms move around in aquatic environments using two different sets of tools: There are cilia—which are wavy, hair-like projections—and flagella—think the “tails” on sperm cells. Both of these tools would have been painfully slow in frigid ocean conditions, his results show.

If individual cells joined forces to make a bigger organism, in contrast, they could produce a lot more swimming power while keeping the energy needs of each cell low. 

“The advantage of the multicellular strategy is that each cell stays small and has low metabolic requirements, but these cells can swim together,” Simpson said.

He’s currently testing the theory using experiments with modern algae in a lab and by digging deeper into Earth’s fossil record. One thing is clear, Simpson said: Once life forms got big, a whole new world of possibilities became available to them. Primitive animals like sponges, for example, survive not by floating in the ocean but by actively pumping water through their bodies. 

“When you’re big, you now can move the water rather than the other way around,” Simpson said.

Banner image: Carl Simpson inspects a fossil of Brooksella alternata, an invertebrate animal that swam in the ocean roughly 500 million years ago. (Credit: Glenn Asakawa/CU Boulder)


Provided by University of Colorado Boulder

Levantine Crested Rat And Early Human Dispersals (Paleontology)

Crested rat fossils suggest that ecological corridors once connected Africa to the Levant, according to a study.

Early humans and other hominins dispersed out of Africa through the Levant multiple times, but whether these journeys relied on technology to cross the Saharo-Arabian deserts or followed ecological corridors created by climate change is unclear.

Ignacio Lazagabaster and colleagues analyzed rodent fossils discovered in the Cave of the Skulls in the southern Judean Desert as a proxy for the paleoenvironment of the Dead Sea region during the Late Pleistocene.

Phylogenetic analyses of a sequenced mitochondrial genome and morphological comparisons suggest that the fossils, which were dated to between 42,000 and more than 103,000 years ago, belong to a now-extinct subspecies, Lophiomys imhausi maremortum subsp. nov., of the eastern African crested rat, an enigmatic large rodent equipped with a poisonous pelt and a helmet-like skull. Because extant crested rats live in habitats with relatively dense vegetation, the authors used species distribution models to estimate the timing and location of previously suitable habitats in the region.

View of the Dead Sea and the southern Judean Desert from the Cave of the Skulls. Ignacio A. Lazagabaster

The results* suggest a brief period during the Last Interglacial when green habitat corridors connected eastern Africa to the Levant across the present-day Judean Desert, facilitating the dispersal of crested rats and humans out of Africa, according to the authors.

“Rare crested rat subfossils unveil Afro-Eurasian ecological corridors synchronous with early human dispersals,” by Ignacio A. Lazagabaster et al.

Featured image: A skull of the Dead Sea crested rat subspecies found in situ in the Cave of the Skulls in the southern Judean Desert. Ignacio A. Lazagabaster.


Provided by PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES 

Decoding the Secrets Of A 310 Million-year-old Brain (Paleontology)

Unlike bones and shells, which can endure for millions of years, soft tissues are rarely preserved as fossils.

Indeed, the fossil record of animal soft tissues, such as brains and other internal organs, is so limited that there are significant gaps in our understanding of the evolution and fossilization processes of these important anatomical features.

A new study published today in the prestigious journal Geology has now closed some of these knowledge gaps. The study—by an international team of scientists, including UNE palaeontologists Dr. Russell Bicknell and Professor John Paterson—describes the delicate brain of an ancient aquatic arthropod and how it was preserved in such remarkable detail.

Lead author, Dr. Bicknell, explains what makes the discovery of a 310-million-year-old horseshoe crab with its brain intact so special.

“Most of our limited knowledge on prehistoric arthropod brains is derived from amber inclusions or Cambrian Burgess Shale-type fossil deposits.”

“Amber, or fossilized tree resin, often contains a variety of trapped organisms such as insects, preserving the most intricate details. Using sophisticated imaging technology, scientists are able to study these entombed creatures, including their tiny brains.

Decoding the secrets of a 310 million-year-old brain
(A) The fossil and (B and C) interpretive drawings of the Euproops danae brain, and (D) the brain of a modern juvenile horseshoe crab, Limulus polyphemus. Credit: Russell Bicknell, (D) and Steffen Harzsch.

“However, we are somewhat limited when studying these particular fossils, as the oldest arthropods in amber only date back to the Triassic Period, around 230 million years ago.”

Burgess Shale-type deposits from the Cambrian Period—typically around 500 to 520 million years in age—are much older than the amber and also preserve spectacular brain structures as carbon films in mudstone.

“These Burgess Shale-type fossils are very important as they represent some of the oldest animals on Earth, and can inform us on their origins and earliest evolutionary history,” Dr. Bicknell said.

The team’s new fossil effectively demonstrates that arthropod brains can be preserved in an entirely different way.

Their specimen of the horseshoe crab, Euproops danae, comes from the world-famous Mazon Creek deposit of Illinois in the U.S.. Fossils from this deposit are preserved within concretions made of an iron carbonate mineral called siderite.

Decoding the secrets of a 310 million-year-old brain
A centipede and a neighbouring ant suspended in roughly 23 million-year-old Mexican amber. Credit: Greg Edgecombe

“We have shown, for the first time, that the Mazon Creek animals were not only molded by the rapid formation of siderite that entombed their entire bodies, but also that the siderite quickly encased their internal soft tissues before they could decompose,” co-author Professor Paterson said.

“In our fossil, the brain of Euproops is replicated by a white-colored clay mineral called kaolinite. This mineral cast would have formed later within the void left by the brain, long after it had decayed. Without this conspicuous white mineral, we may have never spotted the brain.”

The study also reveals that the brain anatomy of horseshoe crabs has remained essentially unchanged throughout most of their evolutionary history.

“The fossil’s central nervous system is closely comparable to that of living horseshoe crabs and match up in their arrangement of nerves to the eyes and appendages. It also shows the same central opening for the esophagus to pass through. This is quite remarkable, given the substantial morphological and ecological diversification that has taken place in the group over the intervening 310 million years,” Prof. Paterson said.

Decoding the secrets of a 310 million-year-old brain
The Cambrian arthropod Chengjiangocaris kunmingensis from China. See the bead-like ventral nerve cord preserved in the fossil (A) and its central position in the reconstruction (B). Credit: Javier Ortega-Hernández.

“We have been given a rare glimpse into the prehistoric past, allowing us to further our understanding of the biology and evolution of these long-extinct animals.”

The research “Central nervous system of a 310-m.y.-old horseshoe crab: Expanding the taphonomic window for nervous system preservation” was published in Geology today.

Featured image: (A) Specimen of the fossil horseshoe crab Euproops danae from Mazon Creek, Illinois, USA, preserved with its brain intact. (B) Close-up of brain, as indicated by box in image (A). (C) Reconstruction of Euproops danae, including the position and anatomy of the brain. Credit: Russell Bicknell


Reference: Russell D.C. Bicknell et al, Central nervous system of a 310-m.y.-old horseshoe crab: Expanding the taphonomic window for nervous system preservation, Geology (2021). DOI: 10.1130/G49193.1


Provided by University of New England