How just one set of animal tracks can provide a wealth of information

Namibian tracking experts enable researchers from FAU and the University of Cologne to analyze images of animal tracks in rock art

Peer-Reviewed Publication

FRIEDRICH-ALEXANDER-UNIVERSITÄT ERLANGEN-NÜRNBERG

Rock faces in Namibia are decorated with hundreds of stone-age images not only of animals and human footprints, but also of animal tracks. These have been largely neglected to date as researchers lacked the knowledge required to interpret them. Archaeologists from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and the University of Cologne have now worked together with animal tracking experts from the Nyae Nyae Conservancy in Tsumkwe, Namibia, to investigate the engraved animal tracks on six rock faces in more detail, and were able to determine detailed information on the species, age, sex, limbs, side of the body, trackway and relative direction of the tracks.

In the Doro !nawas mountains in the Namib desert in northwest Central Namibia, vegetation is sparse, trees and bushes generally only grow along small dry river beds. Thanks to various permanent waterholes, however, there is an unusually high occurrence of different animals: springboks, giraffes, elephants, lions and leopards all cross the area.  The area remains untouched by humans at the current time. It is not inhabited or exploited in any other way. It was a different story in the past, however. Numerous instances of rock art representing animals as well as human footprints and animal tracks show that stone age hunters and gatherers lived here in the past.

Until now, archaeologists have only been able to interpret the species of the animals depicted in the rock art. Animal tracks tended to be classified together with the abstract symbols. “Researchers have until now completely neglected the fact that traces and tracks are also a valuable source of information,” explains PD Dr. Andreas Pastoors from the Institute for Prehistory and Protohistory at FAU. Together with his FAU colleagues Prof. Dr. Thorsten Uthmeier and Dr. Tilman Lenssen-Erz from the African Research Institute at the University of Cologne, Pastoors has therefore taken a new approach, merging western archaeological science with indigenous knowledge in an innovative research project. The project began in 2013, when San tracking experts from Namibia read human footprints on the floor of caves in France decorated with rock art from the Ice Age. Now together with the Namibian tracking experts Tsamgao Ciqae, Ui Kxunta and Thui Thao from the Nyae Nyae Conservancy in Namibia, the three researchers set up camp for approximately one week in the Doro !nawas mountains, and investigated six rock faces depicting a particularly large number of human footprints and animal tracks.

The investigated rock faces are at the edge of an area resembling a crater with a diameter of approximately one kilometer in the Doro !nawas mountains. “At the upper edge there are large boulders with flat surfaces which people in the Stone Age decorated with rock art,” explains Pastoors. The rock art shows various different motifs, ranging from human footprints to people and animals such as elephants, giraffes, rhinoceroses and ostriches. “These images are easily recognizable by western archaeologists,” says Pastoors. However, they also depict animal tracks that have until now only been classified together with the abstract symbols. “Seen from the perspective of western art history, researchers are unable to recognize anything in these images, as they are lacking the relevant expertise. For this reason, the tracks have not yet been assessed as a legible source of information, which has in turn led to misleading hierarchies being created with regard to the value of the various images.”

Stone age illustrations of animal tracks prove to be a valuable source of information

The study that has now been published counteracts this trend. Tsamgao Ciqae, Ui Kxunta und Thui Thao have discovered surprising details in the rock art. In more than 90 percent of the analyzed 513 images they were able to determine the species, age range, sex, specific limbs, side of the body and the direction of the animal tracks or human footprints. Interestingly, the animal tracks indicated a larger variety of species than those in the pictures of animals illustrated in profile in rock art in neighboring regions. The team of researchers was able to identify 20 further animal species in the animal tracks, ranging from bushpig, buffalo, monkey and caracal to various different types of antelopes (duiker, bushbuck, roan antelope, ibex), to bird species such as red-crested korhaan and marabou. One rather surprising aspect is that some of these species require damper conditions than those found in this part of Namibia, at least at the current time. But then why did the stone-age artists draw them? How did they know about them? “We cannot answer these questions with the state of research as it stands at present,” admits Pastoors. However, it is plausible that the artists knew other regions with damper environmental conditions, as the Doro !nawas mountains were similarly dry as they are today.”

In addition, the analyses show patterns that are obviously the result of cultural preferences. This includes, for example, the relative direction of the individual animal tracks that the tracking experts were able to decipher from the images. “We beamed a virtual clock onto the rock face and then noted the direction of the tracks according to the hours on the clock face.” The result: Most tracks pointed upwards towards 12 o’clock, only a few pointed down towards 6 o’clock. The one exception were the zebra tracks. They were depicted traveling in all directions. “It’s really exciting to see that the animal tracks can give us far more information that we originally thought,” summarizes Pastoors.

For him, the study is also a “further confirmation of the fact that indigenous knowledge with its extensive insights in a number of different subject areas has a valuable contribution to make towards driving archaeological research forward.”

---

JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0289560 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Animal tracks and human footprints in prehistoric hunter-gatherer rock art of the Doro !nawas mountains (Namibia), analysed by present-day indigenous tracking experts.

ARTICLE PUBLICATION DATE

13-Sep-2023

 

The solarEV city concept: A sustainable option for the city of lights?

Peer-Reviewed Publication

TOHOKU UNIVERSITY

 

IMAGE: A MAP OF ILE-DE-FRANCE INCLUDING THE CITY OF PARIS. view more 

CREDIT: TOHOKU UNIVERSITY

The iconic city of Paris is synonymous with climate change, thanks in part to it being where the landmark 2015 Paris Climate Change agreement was adopted. Now, a research group has investigated the potential of integrating rooftop photovoltaics (PVs) with electric vehicles (EVs) as an effective and scalable solution for supplying clean, affordable, and reliable electricity in urban environments, with a focus on Paris and its surrounding areas.

Findings from the study were published in the journal Applied Energy on August 25, 2023.

CO2 emissions from urban areas account for 71 - 76% of global CO2 emissions, making decarbonizing cities a top priority if countries are to realize net zero emissions.

The SolarEV City Concept is a new idea that combines solar panels on rooftops with electric vehicles. By doing this, electric vehicles not only reduce carbon emissions from gasoline and diesel but also store extra electricity from the solar panels, powering the home when the sun is not shining. Yet the effectiveness of such a concept varies widely from city-to-city.

For example, the first study, which was done on Kyoto, discovered that if 70% of the city's rooftops were covered with solar panels and all cars became electric, Kyoto could reduce its CO2 emissions from electricity and gasoline-powered cars by 60-74% and save 22-37% on energy costs by 2030. But for more densely urban areas in Japan, like Kawasaki and Tokyo, these reductions were less.

Other variables that vary from country-to-country include electricity tariffs, climate conditions, and urban structures. Similar studies conducted in South Korea, China, and Indonesia have reported significant emissions reductions and energy cost savings in different urban contexts.

However, until now, no studies have explored PV + EV systems in high-latitude cities with hourly supply-demand balance, where solar insolation and electricity demand exhibit seasonal variations, particularly influenced by winter heating demand. With this in mind, the researchers examined the benefits of bringing the SolarEV City Concept to Paris. The analysis also included the surrounding region of Ile-de-France and draws comparisons with the reference city of Kyoto.

"As Paris is a highly urbanized area, we found the city could only supply approximately 30% of its electricity needs through rooftop PVs," points out Associate Professor Takuro Kobashi, who co-led the research and is based at Tohoku University's Graduate School of Environmental Studies. "And also, since most PV generation is consumed inside the city, the impact of EVs as storage batteries is limited."

However, in the surrounding Paris region, which comprises many low-rise buildings, the researchers discovered that covering 71% of the rooftops could meet 78% of the annual electricity demand in 2019. When incorporating EVs as storage batteries into the fold, even when accounting for the supply demand of the EVs themselves, it was possible to supply approximately 60% of the electricity. Ultimately, this could lead to a 23% reduction in energy costs by 2030.

"Our study not only highlights the carbon reduction potential of implementing a SolarEV City in Paris and the Ile-de-France, but it shows the need to consider regional variations," adds Kobashi. With achieving carbon neutrality by 2050 top of the agenda for governments across the globe, SolarEV Cities could go a long way to ensuring this happens.

---

JOURNAL

Applied Energy

DOI

10.1016/j.apenergy.2023.121762 

ARTICLE TITLE

SolarEV City Concept for Paris

 

Evolution wired human brains to act like supercomputers

Now, scientists have a mathematical model that closely matches how the human brain processes visual information

Peer-Reviewed Publication

UNIVERSITY OF SYDNEY

 

IMAGE: DR REUBEN RIDEAUX view more 

CREDIT: REUBEN RIDEAUX

Scientists have confirmed that human brains are naturally wired to perform advanced calculations, much like a high-powered computer, to make sense of the world through a process known as Bayesian inference. 

In a study published in the journal Nature Communications, researchers from the University of Sydney, University of Queensland and University of Cambridge developed a specific mathematical model that closely matches how human brains work when it comes to reading vision. The model contained everything needed to carry out Bayesian inference.

Bayesian inference is a statistical method that combines prior knowledge with new evidence to make intelligent guesswork. For example, if you know what a dog looks like and you see a furry animal with four legs, you might use your prior knowledge to guess it's a dog.

This inherent capability enables people to interpret the environment with extraordinary precision and speed, unlike machines that can be bested by simple CAPTCHA security measures when prompted to identify fire hydrants in a panel of images.

The study’s senior investigator Dr Reuben Rideaux, from the University of Sydney’s School of Psychology, said: “Despite the conceptual appeal and explanatory power of the Bayesian approach, how the brain calculates probabilities is largely mysterious.”

“Our new study sheds light on this mystery. We discovered that the basic structure and connections within our brain's visual system are set up in a way that allows it to perform Bayesian inference on the sensory data it receives.

“What makes this finding significant is the confirmation that our brains have an inherent design that allows this advanced form of processing, enabling us to interpret our surroundings more effectively.”

The study’s findings not only confirm existing theories about the brain’s use of Bayesian-like inference but open doors to new research and innovation, where the brain’s natural ability for Bayesian inference can be harnessed for practical applications that benefit society.

“Our research, while primarily focussed on visual perception, holds broader implications across the spectrum of neuroscience and psychology,” Dr Rideaux said.

“By understanding the fundamental mechanisms that the brain uses to process and interpret sensory data, we can pave the way for advancements in fields ranging from artificial intelligence, where mimicking such brain functions can revolutionise machine learning, to clinical neurology, potentially offering new strategies for therapeutic interventions in the future.”

The research team, led by Dr William Harrison, made the discovery by recording brain activity from volunteers while they passively viewed displays, engineered to elicit specific neural signals related to visual processing. They then devised mathematical models to compare a spectrum of competing hypotheses about how the human brain perceives vision.

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-023-41027-w 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Neural tuning instantiates prior expectations in the human visual system

 

Uncover the“black box” of developmental failure of implanting cloned embryos by 3D in vitro culture system

Peer-Reviewed Publication

SCIENCE CHINA PRESS

 

IMAGE: IN THE UPPER OF THE PICTURE, THE NORMAL EMBRYO GOES THROUGH A KEY MORPHOGENETIC STEP DURING THE TRANSITION FROM BLASTOCYST TO EGG CYLINDER THAT EPIBLAST CELLS MARKED BY RED ARE TRANSFORMED INTO A CUP-SHAPED EPITHELIUM. AT THE BOTTOM OF THE PICTURE, THE SCNT BLASTOCYST FAILS TO FORM PROPER EGG CYLINDER WITH A DISORGANIZED EPIBLAST STRUCTURE. view more 

CREDIT: ©SCIENCE CHINA PRESS

Somatic cell nuclear transfer (SCNT), the currently unique reproductive engineering technique that produce new individuals from single differentiated somatic cell nuclei, has been successfully applied to clone more than 20 mammalian species, including cloned monkeys.The truth is, the broad usage of SCNT remains limited due to its low efficiency in generating live offspring, which mainly displays most cloned embryos dying during pre- and peri-implantation periods of gestation and abnormal placentas in full-term offspring.

Over the past decades, huge efforts have been made into understanding the reprogramming barriers and improving cloning efficiency during mammalian pre-implantation and post-implantation development.

However, during the peri-implantation stage, the implanting blastocysts invade the maternal uterine tissues and thus hidden from view. How do the morphogenetic and signaling events of SCNT happen during this stage? The developmental “black box” is previously difficult to study due to lack of proper culture systems.

Recently, a team from China led by Dr. Shaorong Gao have used an improved 3D in-vitro embryonic culture system to permit the visualization of the peri-implantation development of SCNT embryos and observed an abnormal morphogenetic step and pluripotency state in epiblast structure during the transition from blastocyst to egg cylinder. By conducting in-depth experiments and analysis, they characterized a new epigenetic mediated barriers-persistent Wnt signaling activity that can prevent the peri-implantation development of SCNT. Importantly, they presented a rescue approach that can attenuate the pluripotency transition and abnormal epigenetic remodeling and further improve cloning efficiency.

This study provides an important theoretical basis for understanding the development of peri-implantation embryos and will contribute to the expansion of the application of cloning technology in development biology, regenerative medicine and animal breeding industry.

 

See the article: Inhibition of Wnt activity improves peri-implantation development of somatic cell nuclear transfer embryos

---

JOURNAL

National Science Review

DOI

10.1093/nsr/nwad173 

A schematic model showing the defective lineage specification reprogramming in SCNT embryos at the preimplantation stage. Persistent Wnt activity blocks the naïve-to-primed pluripotency transition of epiblast in peri-implantation cloned embryos, which accompanied by the aberrant H3K27me3 reprogramming. The barriers can result in the epiblast disorganization and implantation failure. Wnt manipulation can drive pluripotency transitions of epiblast cells to a considerable degree, further improving the peri-implantation development of cloned embryos.

CREDIT

©Science China Press

 

Isle of Wight fossil shows Europe had different herbivorous dinosaurs to Asia and America

New species is the second member of the hypsilophodont family found on the island, suggesting Europe had a distinct family of small herbivorous dinosaurs from those found in Asia and North America.

Peer-Reviewed Publication

UNIVERSITY OF BATH

 

IMAGE: VECTIDROMEUS INSULARIS WAS DISCOVERED ON THE ISLE OF WIGHT. IMAGE: EMILY WILLOUGHBY view more 

CREDIT: EMILY WILLOUGHBY

Scientists have discovered a new species of small plant-eating dinosaur on the Isle of Wight in southern England (UK). The new species, Vectidromeus insularis, is the second member of the hypsilophodont family to be found on the island, suggesting that Europe had its own family of small herbivorous dinosaurs, distinct from those found in Asia and North America.

Hypsilophodonts were a group of nimble, bipedal herbivores that lived around 125 million years ago. The animals lived alongside early tyrannosaurs, spinosaurs, and Iguanodon. The new fossil represents an animal about the size of a chicken but was a juvenile and may have grown much larger.

Vectidromeus is a close relative of Hypsilophodon foxii, a dinosaur originally described in the Victorian era, and one of the first dinosaurs to be described from relatively complete remains. Small and with gracile, with bird-like hindlimbs, hypsilophodonts were used by famous scientist Thomas Henry Huxley as evidence that birds were related to dinosaurs.

Hypsilophodon is also found on the Isle of Wight, but was found higher up in the rocks, perhaps two or three million years younger than Vectidromeus. Vectidromeus differs in details of the hip bones, suggesting it's a closely related but distinct species.

Dr Nicholas Longrich, from the Milner Centre for Evolution at the University of Bath, led the study. He said: “Paleontologists have been working on the Isle of Wight for more than a century, and these fossils have played an important role in the history of vertebrate paleontology, but we’re still making new discoveries about the dinosaur fauna as the sea erodes new fossils out of the cliffs.”

The Cretaceous strata on the Isle of Wight are hundreds of metres thick and may span several million years - scientific consensus is still not entirely clear how old they are - so the fossils may be sampling a whole series of evolving ecosystems, each with a different set of species.

The discovery was made as part of a collaboration led by the University of Bath, along with the University of Portsmouth, the Isle of Wight Dinosaur Museum in Sandown, and local fossil collectors.

“Working with the amateur community is really important,” said Longrich. “It’s good to have a diverse team; everyone brings something different to the table. These guys have spent their lives collecting and preparing these fossils, they know details about the rock, the geology, and the bone that nobody else does. Everyone sees different pieces of the puzzle.”

Co-author on the study Professor Dave Martill from the University of Portsmouth said: “It is utterly bizarre that so many new dinosaurs are being discovered on the Isle of Wight.

“Vectidromeus is the seventh new species of dinosaur to be discovered in the last four years. This is all down to the amateur collectors.”

Over the years, dozens of small plant-eating dinosaurs have been put into the hypsilophodont family, but revisions to the dinosaur family tree have resulted in reclassifying them to other branches of the tree, leaving Hypsilophodon as the only species left in the family.

Dr Longrich said: “We had a curious situation where one of the first dinosaur families to be recognised had just one species. And now, we have two.

“What’s intriguing is that they’re not particularly closely related to anything found in North America, Asia, or the southern hemisphere.

“We’re still piecing together how all these dinosaurs are related, and how dinosaurs moved between continents. After Pangaea broke up, there was a lot of isolation, leading to different kinds of dinosaurs evolving on each continent.”

Co-author, and curator of Dinosaur Isle Museum Dr Martin Munt said: “This exciting new find is the latest in a line of new discoveries from the Isle of Wight.

“We are enjoying an amazing time of collaboration between collectors, researchers and the museum. New finds are being made on the coast, in private collections, and the museum stores.

“The museum’s mission is to try and ensure as many new finds remain here on the Island for the benefit of our Island community; we anticipate this dinosaur to be on display at the museum for the October school holidays.”

The new study is by Nick Longrich, David Martill, Martin Munt, Mick Green, Mark Penn, and Shaun Smith, and  is published in Cretaceous Research

Ends

For further information, please contact the University of Bath press office on +44(0) 1225 383941 or email press@bath.ac.uk

Notes
 

Paper reference

Longrich, N., Martill, D. & Munt, M. (2023) “Vectidromeus insularis, a new hypsilophodontid dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, England” is published in Cretaceous Research.

 

Milner Centre for Evolution

The Milner Centre for Evolution is a world-class research facility which bridges disciplines of biology, health and education. The Centre, part of the University of Bath, United Kingdom, is helping answer some of the most fundamental evolutionary questions of biology, and using this insight to find new technological and clinical research applications. Research into educational methods, and a novel outreach programme, is helping to improve public understanding of genetics and the importance of the process of evolution in all of life on Earth.

The Milner Centre for Evolution is named after University of Bath alumnus, Dr Jonathan Milner, who provided founding capital to establish and build the Centre.  @MilnerCentre

https://www.bath.ac.uk/research-centres/milner-centre-for-evolution/

 

University of Bath

The University of Bath is one of the UK's leading universities for high-impact research with a reputation for excellence in education, student experience and graduate prospects. 

We are named ‘University of the Year’ in the The Times and The Sunday Times Good University Guide 2023, and ranked among the world’s top 10% of universities, placing 148th in the QS World University Rankings 2024. We are ranked 5th in the UK in the Complete University Guide 2024 and 7th in the Guardian University Guide 2023. 

Bath is rated in the world’s top 10 universities for sport in the QS World University Ranking by Subject 2023. We produce some of the world’s most job-ready graduates, ranking as one of the world’s top 90 universities for employer reputation according to the QS World University Rankings 2024. In the National Student Survey 2022, our overall student satisfaction was rated 10% above the national average and ranked in the UK’s top three:  https://www.bath.ac.uk/corporate-information/rankings-and-reputation/

Research from Bath is helping to change the world for the better. Across the University’s three Faculties and School of Management, our research is making an impact in society, leading to low-carbon living, positive digital futures, and improved health and wellbeing. Find out all about our Research with Impact: https://www.bath.ac.uk/campaigns/research-with-impact/

 

Dinosaur Isle Museum

At the Isle of Wight's top dinosaur family attraction, you can see, hear, touch, and smell the dinosaurs. Learn all about their stories and how they lived. www.dinosaurisle.com

The museum will show you fossils, rocks, minerals, and lots of other interesting natural history items. All of them collected or discovered on the Isle of Wight and its surrounding waters.

Dinosaur Isle is a family-friendly museum. The whole exhibition is inside which makes it an ideal place to visit come rain or shine!

The museum collection comprises approximately 40,000 specimens. The collections contain fossil and mineral specimens from across the Island and includes Type and figured insects, Molluscs and Dinosaurs.

Dinosaur Isle welcome requests to visit the collections for research or study. Students will need to provide the contact details of either their tutor or head of department. To request a visit, contact the curator by emailing martin.munt@iow.gov.uk

---

JOURNAL

Cretaceous Research

DOI

10.1016/j.cretres.2023.105707 

ARTICLE TITLE

Vectidromeus insularis, a new hypsilophodontid dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, England

ARTICLE PUBLICATION DATE

13-Sep-2023

 

How Europe’s forests regenerate – without any human interference

Peer-Reviewed Publication

ETH ZURICH

 

IMAGE: TARICHE BOIS BANAL NATURAL FOREST RESERVE, SWITZERLAND view more 

CREDIT: PHOTOGRAPH: MARKUS BOLLIGER

Yannek Käber, a doctoral student in the Professorship of Forest Ecology at ETH Zurich, and his colleagues from ETH and WSL together with the European Forest Research Initiative (EuFoRIa, www.euforia-​project.org), have taken a look at regeneration in protected European forests for the first time.

In a new study recently published in Journal of Ecology, the researchers show how natural regeneration develops without human influence. To this end, they investigated the emergence of young trees in just under 300 natural forest reserves all across Europe. They analysed how regeneration of the forest works under a wide range of environmental conditions. This involved examining the complex interplay between the different features of the tree species, forest density, disturbances and climate.

Water scarcity leads to fierce competition

One of the most important processes for forest regeneration is competition. What strategies trees use depends on their species. This study shows that positive interactions between trees only occur in a few species, and are therefore rarer than previously assumed. The features of the species concerned and the varying stress factors determine whether trees protect each other from cold or dry conditions during regeneration or whether they compete with each other instead.

Cold stress tends to lead to more protective interactions from other trees than drought stress does. The researchers explain this result by pointing out that low temperatures do not trigger competition for limited resources. Scarcity of water, on the other hand, leads to fierce competition. This can lead to smaller trees being suppressed.

Waiting for gaps

The study also shows what strategies the various tree species use to regenerate. Some are particularly successful in dense forests. Others wait for disturbances such as fire or storms that create gaps in the canopy. As soon as enough light becomes available, these species grow quickly.

In mixed forests, the varying strategies of the different species interact. This means these forests are better placed to react to climatic stress, in that more species emerge that can cope with drought and heat, for example. This changes not only the composition of the forest, but also its structure – in other words, the mix of trees of different sizes and ages. And forest structures form that can only arise in undisturbed and protected forests.

---

JOURNAL

Journal of Ecology

DOI

10.1111/1365-​2745.14181 

ARTICLE TITLE

Sheltered or suppressed? Tree regeneration in unmanaged European forests

 

Shell life species not competitors as they adjusted to Earth’s largest extinction

Peer-Reviewed Publication

UNIVERSITY OF BRISTOL

 

IMAGE: LEFT, DEVONIAN BRACHIOPOD FOSSILS FROM OHIO, USA. RIGHT, RECENT BIVALVE SHELLS FROM SHELL BEACH, WESTERN AUSTRALIA. view more 

CREDIT: (WIKIMEDIA COMMONS; CREATIVE COMMONS CC0 1.0 UNIVERSAL PUBLIC DOMAIN DEDICATION) FOR IMAGE ON THE LEFT. IMAGE ON RIGHT BY ZHONG-QIANG CHEN.

One of the biggest crises in Earth history was marked by a revolution in the shellfish – brachiopods, sometimes called ‘lamp shells’ were replaced everywhere ecologically by the bivalves, such as oysters and clams. This happened as a result of the devastating end-Permian mass extinction which reset the evolution of life 250 million years ago.

Research conducted by palaeontologists based in Bristol, UK and Wuhan, China has shed new light on this crucial turnover when ocean ecosystems changed from ancient-style to modern-style

Life on land and in the sea is rich and forms particular ecosystems. In modern oceans, the seabed is dominated by animals such as bivalves, gastropods, corals, crustaceans, and fishes. But these ecosystems all date back to the Triassic when life came back from the brink. During that crisis, only one in twenty species survived, and there has been long debate about how the new ecosystems were constructed and why some groups survived, and others did not.

Brachiopods dominated shelled animals before the extinction, however bivalves thrived after, better adapting to their new conditions.

“A classic case has been the replacement of brachiopods by bivalves,” explained Zhen Guo at Wuhan and Bristol, who led the project. “Palaeontologists used to say that the bivalves were better competitors and so beat the brachiopods somehow during this crisis time. There is no doubt that brachiopods were the major group of shelled animals before the extinction, and bivalves took over after.”

“We wanted to explore the interactions between brachiopods and bivalves through their long history and especially around the Permian-Triassic handover period,” said Joe Flannery-Sutherland, a collaborator. “So we decided to use a computational method called Bayesian analysis to calculate rates of origination, extinction, and fossil preservation, as well as testing whether the brachiopods and bivalves interacted with each other. For example, did the rise of bivalves cause the decline of brachiopods?”

“We found that in fact both groups shared similar trends in diversification dynamics right through the crisis time,” said Professor Michael Benton from Bristol’s School of Earth Sciences. “This means that they weren’t really competing or preying on each other, but more probably both responding to similar external drivers such as sea temperature and short-lived crises. But the bivalves eventually prevailed and the brachiopods retreated to deeper waters, where they still occur, but in reduced numbers.”

Professor Zhong-Qiang Chen of Wuhan commented: “It was great to see how modern computational methods can tackle such a long-standing question.

“We always thought that the end-Permian mass extinction marked the end of the brachiopods and that was that. But it seems that both brachiopods and bivalves were hit hard by the crisis, and both recovered in the Triassic, but the bivalves could adapt better to high ocean temperatures. So, this gave them the edge, and after the Jurassic, they just rocketed in numbers, and the brachiopods didn’t do much.”

Zhen Guo said: “I had to check and compile records of over 330000 fossils of brachiopods and bivalves through the study interval, and then run the Bayesian analysis which took weeks and weeks on the Bristol supercomputer. I like the method though because it repeats everything millions of times to take account of all kinds of uncertainties in the data and gives a great deal of rich information about what was going on.”

“The end-Permian mass extinction was the biggest of all time, and it massively reset evolution,’ concluded Professor Benton. “In fact the 50 million years after the crisis, the Triassic, marked a revolution in life on land and in the sea. Understanding just how life could come back from near-annihilation and then set the basis for modern ecosystems is one of the big questions in macroevolution. I’m sure we haven’t said the last word here though!”

The paper:

‘Bayesian analyses indicate bivalves did not drive the downfall of brachiopods following the Permian-Triassic mass extinction’ by Zhen Guo, Joseph T. Flannery-Sutherland, Michael J. Benton, and Zhong-Qiang Chen. Nature Communications, https://doi.org/10.1038/s41467-023-41358-8

Diversities of brachiopods and bivalves over the past 500 Myr, showing the brachiopod-bivalve switch near the Permian-Triassic boundary.

Diversities of brachiopods and bivalves through the time of the brachiopod-bivalve switch near the Permian-Triassic boundary.

CREDIT

Zhen Guo et al

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-023-41358-8 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Bayesian analyses indicate bivalves did not drive the downfall of brachiopods following the Permian-Triassic mass extinction