. Scientific Frontline: Paleontology
Showing posts with label Paleontology. Show all posts
Showing posts with label Paleontology. Show all posts

Monday, October 3, 2022

Jurassic ichthyosaurs divided food resources to co-exist, researchers find

The skull of Ichthyosaurs Hauffiopteryx typicus from the Strawberry Bank Lagerstätt, one of the specimens that were the subject of this study.
Credit: Bath Royal Literary and Scientific Institution Collections

Early Jurassic ichthyosaur juveniles show predatory specializations, scientists at the University of Bristol have revealed.

Their findings, published today in Journal of Anatomy, suggest that physical differences in their snouts show they evolved to have different diets and were not competing for the same resource.

Ichthyosaurs, the classic ‘sea dragons’, were dolphin-shaped marine predators that fed on fish and squid-like swimming shellfish. The ichthyosaurs of the Lower Jurassic, some 185 million years ago, are renowned because the first specimens were found over 200 years ago at Lyme Regis in southern England, by the celebrated fossil collector and paleontologist Mary Anning. Some of her specimens have long, slender snouts and others have short, broad snouts.

“Functional studies need excellent three-dimensional specimens,” said Matt Williams of Bath Royal Literary and Scientific Institution, “and the Lower Jurassic ichthyosaur fossils from Strawberry Bank in Ilminster are just that. Mary Anning’s fossils are amazing, but they are mostly squashed flat.”

Saturday, October 1, 2022

What caused the holes in SUE the T. rex ’s jaw? Probably not an infection

Field Museum paleontologist Jingmai O’Connor with SUE the T. rex’s skull.
Resized Image using AI by SFLORG
Credit: Katharine Uhrich, Field Museum

SUE the T. rex is one of the most complete, best-preserved Tyrannosaurus rex specimens ever found. That level of preservation helps reveal details about SUE’s life. For instance, SUE lived to a ripe old age of about thirty-three, and in those years, suffered their fair share of injuries. SUE’s most mysterious ailment might be the holes in their jawbone. These holes, some the diameter of a golf ball, dot the back half of the left lower jaw. It’s not clear what caused them, but similar injuries have been found in other T. rex fossils. In a new study published in Cretaceous Research, scientists showed that one of the popular theories-- that SUE had suffered an infection from a protozoan parasite-- couldn’t be true.

“These holes in SUE’s jaw have been a mystery for decades,” says Jingmai O’Connor, the associate curator of fossil reptiles at Chicago’s Field Museum and a co-author of the study. “Nobody knows how they formed, and there have been lots of guesses.”

One early hypothesis was that SUE suffered from a fungus-like bacterial infection, but that was later shown to be unlikely. It was re-hypothesized that SUE had a protozoan infection. Protozoans are microbes with more complex cell structures than bacteria. There are lots of protozoan-caused maladies out there; one common such disease is called trichomoniasis, caused by a microbe called Trichomonas vaginalis. Humans can get infected with trichomoniasis as an STD, but other animals can catch it too.

What a reptile’s bones can teach us about Earth’s perilous past

An illustration of how Palacrodon may have looked.
Credit: K.M. Jenkins

An extinct reptile’s oddly shaped chompers, fingers, and ear bones may tell us quite a bit about the resilience of life on Earth, according to a new study.

In fact, paleontologists at Yale, Sam Houston State University, and the University of the Witwatersrand say the 250-million-year-old reptile, known as Palacrodon, fills in an important gap in our understanding of reptile evolution. It’s also a signal that reptiles, plants, and ecosystems may have fared better or recovered more quickly than previously thought after a mass extinction event wiped out most of the plant and animal species on the planet.

“We now know that Palacrodon comes from one of the last lineages to branch off the reptile tree of life before the evolution of modern reptiles,” said Kelsey Jenkins, a doctoral student in Yale’s Department of Earth and Planetary Sciences in the Faculty of Arts and Sciences and first author of the study, which appears in the Journal of Anatomy. “We also know that Palacrodon lived in the wake of the most devastating mass extinction in Earth’s history.”

That would be the Permian-Triassic extinction event, which occurred 252 million years ago. Known as “the Great Dying,” it killed off 70% of terrestrial species and 95% of marine species.

Although a large number of reptile species eventually bounced back from this extinction event, the details of how that happened are murky. Researchers have spent decades trying to fill in the gaps in our understanding of key adaptations that enabled reptiles to flourish after the Permian-Triassic extinction — and what those adaptations may reveal about the ecosystems where they lived.

Friday, September 30, 2022

Paleontologists Found Mammoth Baby, Ancient Bear Teeth, and Lair of Cave Hyenas

Scientists will open a new expedition season in spring.
Photo credit: TASS-Ural Press Center / Vladislav Burnashev

Paleontologists of Ural Federal University and the Institute of Plant and Animal Ecology of Ural Branch of Russian Academy of Sciences during summer expeditions found a large number of ancient bones, teeth, as well as wool and skin of a mammoth baby. The study of remains will allow us to recreate the specifics of the flora and fauna of ancient times in detail and to understand the specifics of animal nutrition. Scientists told about the results of summer expeditions at a press conference in TASS.

On the Gyda Peninsula (Far North), paleontologists found the well-preserved remains of a mammoth baby. The uniqueness of the discovery is its age - it is a six-year-old mammoth baby. If previously only single bones were found, now the researchers have found material that will help study mammoth babies, said Pavel Kosintsev, a leading expert of the Laboratory of Natural Science Methods in Humanities of UrFU, a Senior Researcher of the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences.

Thursday, September 29, 2022

Ancient 'Shark' from China Is Humans' Oldest Jawed Ancestor

Life reconstruction of Fanjingshania renovata.
Image Credit: ZHANG Heming)

Paleontologists discover a 439-million-year-old 'shark' that forces us to rethink the timeline of vertebrate evolution

Living sharks are often portrayed as the apex predators of the marine realm. Paleontologists have been able to identify fossils of their extinct ancestors that date back hundreds of millions of years to a time known as the Palaeozoic period. These early "sharks," known as acanthodians, bristled with spines. In contrast to modern sharks, they developed bony "armor" around their paired fins.

A recent discovery of a new species of acanthodian from China surprised scientists with its antiquity. The find predates by about 15 million years the earliest acanthodian body fossils and is the oldest undisputed jawed fish.

These findings were published in Nature.

Reconstructed from thousands of tiny skeletal fragments, Fanjingshania, named after the famous UNESCO World Heritage Site Fanjingshan, is a bizarre fish with an external bony "armor" and multiple pairs of fin spines that set it apart from living jawed fish, cartilaginous sharks and rays, and bony ray- and lobe-finned fish.

Wednesday, September 28, 2022

Dead fish breathe new life into the evolutionary origin of fins and limbs

The holotype specimen of the fossil Tujiaaspis vividus from 436 million year old rocks of Hunan Province and Chongqing, China.
Credit: Zhikun Gai

A trove of fossils in China, unearthed in rock dating back some 436 million years, have revealed for the first time that the mysterious galeaspids, a jawless freshwater fish, possessed paired fins.

The discovery, by an international team, led by Min Zhu of the Institute of Vertebrate Paleontology and Palaeoanthropology, Bejiing and Professor Philip Donoghue from the University of Bristol’s School of Earth Sciences, shows the primitive condition of paired fins before they separated into pectoral and pelvic fins, the forerunner to arms and legs.

Until now, the only surviving fossils of galeaspids were heads, but these new fossils originating in the rocks of Hunan Province and Chongqing and named Tujiaaspis after the indigenous Tujia people who live in this region, contain their whole bodies.

Theories abound on the evolutionary beginnings of vertebrate fins and limbs – the evolutionary precursors of arms and legs - mostly based on comparative embryology. There is a rich fossil record, but early vertebrates either had fins or they didn’t. There was little evidence for their gradual evolution.

Monday, September 19, 2022

Fossil eggs show dinosaur decline before extinction

Artist’s depiction of Late Cretaceous oviraptorosaurs, hadrosaurs, and tyrannosaurs living in central China
Credit: IVPP 

Nearly 66 million years ago, a large asteroid hit Earth and contributed to the global extinction of dinosaurs, leaving birds as their only living descendants.

Scientists know that a wide variety of dinosaurs lived around the world at the end of the Cretaceous period just before their extinction. However, scientists have debated whether dinosaurs were at their zenith or already in decline prior to their demise. In other words, did dinosaurs go out with a bang or a whimper?

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences, along with their collaborators, now have an answer. They've found evidence to support the hypothesis that dinosaurs were not very diverse before their extinction and had declined overall during the last part of the Cretaceous.

Their findings were published in PNAS on Sept. 19.

Most of the scientific data on the last days of the dinosaurs comes from North America. Although some published studies suggest that dinosaur populations there were thriving quite well before extinction, other more detailed research has suggested that dinosaurs were instead in decline, which set the stage for their eventual mass extinction.

Thursday, September 1, 2022

Scientists discover new ant species

Three-dimensional image of the previously unknown extinct ant species.
Illustration credit: Hammel/Lauströer

An international team of scientists has discovered a previously unknown extinct ant species encased in a unique piece of amber from Africa. Using the X-ray light source PETRA III at the German Electron Synchrotron (DESY) in Hamburg the researchers, from Friedrich Schiller University Jena, the University of Rennes in France, the University of Gdansk in Poland, as well as the Helmholtz-Zentrum Hereon in Geesthacht, Germany, had examined the critical fossil remains from 13 individual animals in the amber and realized that they could not be attributed to any previously known species. The name given to the new species and genus is †Desyopone hereon gen. et sp. nov. In this way, the scientists are honoring the two research institutions involved – DESY and Hereon – which contributed significantly to this find with the help of modern imaging techniques. Ultimately, it was only possible to identify the new species and genus through the combination of extensive phenotype data from scans and recent findings from genome analyses of living ants. The team reports on its discovery in the research journal “Insects”.

Wednesday, August 24, 2022

30-million-year-old amphibious beaver fossil is oldest ever found

A comparison of anklebones from the giant beaver and the newly identified species, Microtheriomys articulaquaticus, at the same scale.
Credit: Jonathan Calede / Ohio State University

A new analysis of a beaver anklebone fossil found in Montana suggests the evolution of semi-aquatic beavers may have occurred at least 7 million years earlier than previously thought, and happened in North America rather than Eurasia.

In the study, Ohio State University evolutionary biologist Jonathan Calede describes the find as the oldest known amphibious beaver in the world and the oldest amphibious rodent in North America. He named the newly discovered species Microtheriomys articulaquaticus.

Calede’s findings resulted from comparing measurements of the new species’ anklebone to about 340 other rodent specimens to categorize how it moved around in its environment – which indicated this animal was a swimmer. The Montana-based bone was determined to be 30 million years old – the oldest previously identified semi-aquatic beaver lived in France 23 million years ago.

"Beavers and other rodents can tell us a lot about mammalian evolution," said Calede, an assistant professor of evolution, ecology and organismal biology at Ohio State’s Marion campus.

Tuesday, August 23, 2022

Study finds that ocean cooling over millennia led to larger fish

Dahiana Arcila in Reykjavík, Iceland. Arcila is the recipient of a National Science Foundation CAREER award to study the evolutionary history of marine fish.
Source: University of Oklahoma

Earth’s geological history is characterized by many dynamic climate shifts that are often associated with large changes in temperature. These environmental shifts can lead to trait changes, such as body size, that can be directly observed using the fossil record.

To investigate whether temperature shifts that occurred before direct measurements were recorded, called paleoclimatology, are correlated with body size changes, several members of the University of Oklahoma’s Fish Evolution Lab decided to test their hypothesis using tetraodontiform fishes as a model group. Tetradontiform fishes are primarily tropical marine fishes, and include pufferfish, boxfishes and filefish.

The study was led by Dahiana Arcila, assistant professor of biology and assistant curator at the Sam Noble Oklahoma Museum of Natural History, with Ricardo Betancur, assistant professor of biology, along with biology graduate student Emily Troyer, and involved collaborators from the Smithsonian Institution, University of Chicago and George Washington University in the United States, as well as the University of Turin in Italy, University of Lyon in France and CSIRO Australia.

The researchers discovered that the body sizes of these fishes have grown larger over the past hundred million years in conjunction with the gradual cooling of ocean temperatures.

Wednesday, August 17, 2022

Scientists are relieved to discover ‘curious’ creature with no anus is not earliest human ancestor

Left to right: Saccorhytus, Saccorhytus dorsal, Saccorhytus side-on.
Credit: Philip Donoghue et al

An international team of researchers have discovered that a mysterious microscopic creature from which humans were thought to descend is part of a different family tree.

Resembling an angry Minion, the Saccorhytus is a spikey, wrinkly sack, with a large mouth surrounded by spines and holes that were interpreted as pores for gills – a primitive feature of the deuterostome group, from which our own deep ancestors emerged.

However, extensive analysis of 500-million-year-old fossils from China has shown that the holes around the mouth are bases of spines that broke away during the preservation of the fossils, finally revealing the evolutionary affinity of the microfossil Saccorhytus.

“Some of the fossils are so perfectly preserved that they look almost alive,” says Yunhuan Liu, professor in Paleobiology at Chang’an University, Xi’an, China. “Saccorhytus was a curious beast, with a mouth but no anus, and rings of complex spines around its mouth.”

The findings, published today in Nature, make important amendments to the early phylogenetic tree and the understanding of how life developed.

Thursday, August 11, 2022

Uncovering the Past: Researchers Create 3D Images of Fossils

Aase mounts one of the fossils in the X-ray microscope for imaging.
Credit: Idaho National Laboratory

Idaho National Laboratory is perhaps best known for innovative research that helps shape the clean energy economies of today and tomorrow – and for good reason. But while much of the laboratory’s work is focused on building a sustainable future, INL is also doing its part to preserve the past.

INL researchers recently imaged several fossils using a powerful X-ray microscope. The 3D images will be used to create exhibits for Wyoming’s Fossil Butte National Monument and help experts gain insight into the origins of these and other relics.

The fossils, found in private quarries around Wyoming, were imaged using a technique known as X-ray microscopy. At INL, researchers typically use high-resolution X-ray microscopy to view specimens – such as samples of irradiated nuclear fuel — at a level of detail not possible with conventional microscopes. The depth and granularity afforded by this technique will help paleontologists learn a great deal about these fossils —including an unknown object resembling an insect egg case or pea pod — and the conditions under which they formed.

“You can see the limestone layers as well as submillimeter and thinner organic materials that have been compressed into waxy, pre-petroleum substances around the specimen,” said Arvid Aase, a paleontologist and the museum curator at Fossil Butte National Monument. “These incredibly detailed images will help us determine the organism’s taxonomy and reveal information about its fossilization process, such as how long it was laying on the bottom of the lake covered in microbes before getting buried by limestone.”

The fossilization process may have occurred over a period of months, though the timing still remains unknown, he added.

Nearly a hundred genes have been lost during the woolly mammoth’s evolution

Tusk from woolly mammoth emerging from the permafrost on Wrangel Island.
Photo Credit: Love Dalén/Stockholm University.

A new study shows that 87 genes have been affected by deletions or short insertions during the course of the mammoth’s evolution. The researchers note that their findings have implications for international efforts to resurrect extinct species, including the woolly mammoth. The study was published in the journal iScience by researchers at the Centre for Palaeogenetics in Stockholm, a collaboration between Stockholm University and the Swedish Museum of Natural History.

One of the most widely discussed methods to resurrect extinct species is to use genome editing techniques such as Crispr-Cas9 to insert key gene variants from an extinct species into a genome from its living relative. However, the results in this new study indicate that one might also need to remove certain genes to preserve important biological traits while reconstructing extinct genomes.

“Editing the genome of a living species to mimic that from an extinct relative was never going to be easy, and these new findings certainly illustrate the complexity and difficulties that lie ahead”, says Love Dalén, a professor of evolutionary genomics at the Centre for Palaeogenetics.

Wednesday, August 10, 2022

How dinos carried their enormous weight

 3D paleoreconstruction of a sauropod dinosaur
Credit: Dr. Andreas Jannel

Scientists have cracked an enduring mystery, discovering how sauropod dinosaurs – like Brontosaurus and Diplodocus – supported their gigantic bodies on land.

A University of Queensland and Monash University-led team used 3D modeling and engineering methods to digitally reconstruct and test the function of foot bones of different sauropods.

Dr. Andréas Jannel conducted the research during his PhD studies at UQ’s Dinosaur Lab and said the team found that the hind feet of sauropod had a soft tissue pad beneath the ‘heel’, cushioning the foot to absorb their immense weight.

“We’ve finally confirmed a long-suspected idea and we provide, for the first time, biomechanical evidence that a soft tissue pad – particularly in their back feet – would have played a crucial role in reducing locomotor pressures and bone stresses,” Dr. Jannel said.

“It is mind-blowing to imagine that these giant creatures could have been able to support their own weight on land.”

Sauropods were the largest terrestrial animals that roamed the Earth for more than 100 million years.

They were first thought to have been semi-aquatic with water buoyancy supporting their massive weight, a theory disproved by the discovery of sauropod tracks in terrestrial deposits in the mid-twentieth century.

Monash University’s Dr. Olga Panagiotopoulou said it had also been thought sauropods had feet similar to a modern-day elephant.

New long-necked dinosaur helps rewrite evolutionary history of sauropods in South America

Panoramic view of the Serranía del Perijá in Colombia, where a vertebra was found in 1943. The vertebra has allowed scientists to identify a new species of sauropod, the Perijasaurus lapaz.
Image Credit: Jeff Wilson Mantilla, University of Michigan

A medium-sized sauropod dinosaur inhabited the tropical lowland forested area of the Serranía del Perijá in northern Colombia approximately 175 million years ago, according to a new study by an international team of researchers published in the Journal of Vertebrate Paleontology.

The new species is a long-necked, plant-eating dinosaur known from a single trunk vertebra that is about a half meter tall and wide. The vertebra bears a distinct pattern of bony struts that identify it as the new dinosaur species Perijasaurus lapaz (pear-EE-hah-SOW-roos la-PAHZ)—named in recognition of the mountainous region where it was found and for the 2016 peace treaty that allowed scientists to pursue their research decades after the fossil remains were found in 1943.

Perijasaurus is the northernmost occurrence of a sauropod in South America and represents an early phase in their evolutionary history.

“This new genus and species in the paleotropics allow us to understand a little more about the origin of the sauropods in the Jurassic, as well as how they set the stage for later sauropods from the Cretaceous,” said study lead author Aldo Rincón Burbano, professor of physics and geosciences at the Universidad del Norte in Colombia.

Neutrons help track down Mammalian Ancestors

Dr. Michael Schulz at the neutron radiography facility ANTARES.
Image Credit: Bernhard Ludewig, FRM II / TUM

Investigations at Research Neutron Source led to the discovery of a previously unknown animal species.

A team of German and Argentinian researchers has used neutrons in the FRM II research neutron source at the Technical University of Munich (TUM) to identify an animal species that has been extinct for 220 million years. Findings on the new species provide surprising insights into the evolution of mammals.

A long snout, a massive jaw and sharp teeth – these are some features of the newly discovered species Tessellatia bonapartei. It belongs to the group of Cynodontia (which literally translates to “dog teeth”), mammal-like animals from which mammals eventually evolved.

Argentinian researchers found the bones of the roughly mouse-sized cynodont species in the desert-like Talampaya National Park in the west of Argentina. “The bones were very fragile and therefore it was not possible to remove the surrounding rock without risking damaging them”, explains Dr. Aureliano Tartaglione of the research neutron source Heinz Maier-Leibnitz at TUM. He worked on the project with Dr. Leandro Gaetano from CONICET (National Scientific and Technical Research Council in Argentina).

Monday, August 1, 2022

New Mexico Mammoths Among Best Evidence for Early Humans in North America

Close up of the bone pile during excavation. This random mix of ribs, broken cranial bones, a molar, bone fragments, and stone cobbles is a refuse pile from the butchered mammoths. It was preserved beneath the adult mammoth’s skull and tusks.
Credit: Timothy Rowe / The University of Texas at Austin.

About 37,000 years ago, a mother mammoth and her calf met their end at the hands of human beings.

Bones from the butchering site record how humans shaped pieces of their long bones into disposable blades to break down their carcasses, and rendered their fat over a fire. But a key detail sets this site apart from others from this era. It’s in New Mexico – a place where most archaeological evidence does not place humans until tens of thousands of years later.

A recent study led by scientists with The University of Texas at Austin finds that the site offers some of the most conclusive evidence for humans settling in North America much earlier than conventionally thought.

The researchers revealed a wealth of evidence rarely found in one place. It includes fossils with blunt-force fractures, bone flake knives with worn edges, and signs of controlled fire. And thanks to carbon dating analysis on collagen extracted from the mammoth bones, the site also comes with a settled age of 36,250 to 38,900 years old, making it among the oldest known sites left behind by ancient humans in North America.

“What we’ve got is amazing,” said lead author Timothy Rowe, a paleontologist and a professor in the UT Jackson School of Geosciences. “It’s not a charismatic site with a beautiful skeleton laid out on its side. It’s all busted up. But that’s what the story is.”

Thursday, July 28, 2022

Ural Scientists Found Earliest Evidence of Hyenas Toxocariasis

Image of a hyena coprolite taken with a microscope. In the center is a toxocara egg.
Credit: Dmitry Gimranov

Ural paleontologists, together with Permian parasitologists, found helminth eggs in coprolites (fossil excrement) of the giant short-faced hyena Pachycrocuta. This is the earliest finding indicating that this species of hyena was infected with parasites and had toxocariasis. A description of the finding and analysis of the specimens is published in Doklady Biological Sciences.

"During excavations in the Tavrida cave we found the remains of large mammals, including at least two dozen individuals of Pachycrocuta hyena, dated to the early Pleistocene (1.5-1.8 million years). We believe that hyenas used the cave Tavrida as a den for quite a long time, because here, in the southern corridor of the cave, there were a huge number of coprolites of hyenas, both single and in large assemblies. The massive teeth and especially strong enamel structure allowed hyenas to gnaw the bones of even large hoofed animals. Therefore, the Pachycrocuta could utilize the carcasses of large herbivores," says Dmitry Gimranov, Senior Researcher at the Institute of Plant and Animal Ecology of Ural Branch of Russian Academy of Sciences and Laboratory of Natural Science Methods in Humanities at Ural Federal University.

Scientists analyzed three samples of coprolites, in one of which they found parasite eggs. Based on the size and morphology, paleontologists determined that these were helminth eggs. Scientists believe that toxocariasis was a widespread disease among extinct hyenas. This is also confirmed by the data of other researchers. Eggs of helminths of 1.2 million years old were found in coprolites of the same hyena species from the Haro site in Pakistan and 0.3-0.5 million years old at the Menez-Dregan site in France. There are also finds in Italy (Costa San Gicomo site) dated at 1.5 million years. The find in Tavrida will not only help to complete the list of parasites of ancient animals and compare it with helminths of modern hyenas, but also to clarify other features of ancient animals.

"Ancient animal coprolites are unique fossils reflecting biological features that cannot be demonstrated by studying bone remains. Coprolites can be a valuable source of paleoclimate data because they may contain pollen and spore remains of ancient plants. Coprolites may also contain remains of ancient parasites, which provides a unique opportunity to obtain additional information about the ecology of extinct species," adds Daniyar Khantemirov, Laboratory of Natural Science Methods in Humanities researcher.

Note that the research team included employees of the Ural Federal University, the Institute of plant and animal ecology Ural Branch of the Russian Academy of Sciences and the Perm State Agro-Technological University named after Academician D.N. Pryanishnikov.

Reference:
Toxocariasis is an infection caused by animal ascarid larvae. Other helminth eggs of toxocarias mature in the soil and infect dogs, cats and other animals. The source of the disease, toxocara was discovered by the German scientist Werner in 1782. Only in 1950 lesion with these helminths was isolated as a separate disease. Eggs from toxocars can be found in the ground and contaminated water.

Source/Credit: Ural Federal University

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Wednesday, July 6, 2022

Underwater cave fossil site gains state protections

A reconstruction of the South Australian cave site which has been heritage listed due to its abundance of megafauna fossils.
Image by Peter Schouten.

A team of researchers and cave divers have successfully lobbied for the protection of a unique fossil site in South Australia, which could pave the way for the future preservation of other important paleontological sites around Australia.

The underwater cave site known as the Green Waterhole in the Mount Gambier region contains the only known extensive underwater vertebrate fossil deposits in Australia, has been listed on the South Australia State Heritage Register.

The unique freshwater depositional environment has ensured the preservation of extinct species of megafauna such as marsupial lions, short-faced kangaroos, and carnivorous kangaroos, with several additional species new to science recovered and awaiting description.

Thursday, June 30, 2022

Wildfires May Have Sparked Ecosystem Collapse During Earth’s Worst Mass Extinction

Credit: Victor O. Leshyk During the worst mass extinction event in Earth’s history, vast wetlands suffered increased wildfires, turning the world’s largest carbon sinks into carbon sources.
Resized Image using AI by SFLORG
Credit: Victor O. Leshyk 

Researchers at University College Cork (UCC) and the Swedish Museum of Natural History examined the end-Permian mass extinction (252 million years ago) that eliminated almost every species on Earth, with entire ecosystems collapsing. The researchers discovered a sharp spike in wildfire activity from this most devastating of mass extinctions. Promoted by rapid greenhouse gas emissions from volcanoes, extreme warming and drying led to wildfires across vast regions that were previously permanently wet. Instead of capturing carbon from the atmosphere, these wetlands became major sources of atmospheric carbon, enhancing the sharp warming trend. The research is published in PALAIOS today (30th June).

Fossils examined in eastern Australia & Antarctica

By studying fossil plant and charcoal records of the Sydney & Bowen basins in eastern Australia and Antarctica (Lambert Graben), the researchers discovered that the wetlands were regularly disturbed by fires leading up to the extinction event. In response, the plants had evolved a range of fire-coping mechanisms. However, the severe climate change and peak in fire activity during the extinction event seems to have pushed even these fire-adapted plants over a tipping point, from which the entire ecosystem could not recover for millions of years.

“Sifting through the fossil plant records of eastern Australia and Antarctica, we found high abundances of burnt, or charcoalified, plants throughout the late Permian Period. From this high baseline, charcoal abundances reached a prominent peak right at the top of the last Permian coal beds, indicating a major but short-lived increase in wildfires. This was followed by low charcoal for the next three million years of the Early Triassic Period. It was an end-Permian burnout, followed by an Early Triassic depression” comments Dr Chris Mays, Lecturer in Paleontology at University College Cork (UCC) and lead author of the study.

Earth on a path to a similar mass extinction?

The researchers highlight that in today’s world, wildfires have caused shocking mass animal die-offs in several regions around the world (e.g. California 2018, 2020, Australia 2019-20). Over the same time, our warming global climate has led to prolonged droughts and increased wildfires in typically wet habitats, such as the peat forests of Indonesia and the vast Pantanal wetlands of South America. These major ‘carbon sinks’―regions of natural capture of carbon from the atmosphere―are crucial in our fight against climate change. As the fossil record reveals, without these regions of carbon capture, the world can stay intolerably warm for hundreds of millennia.

“The potential for wildfires as a direct extinction driver during hyperthermal events, rather than a symptom of climatic changes deserves further examination. Unlike the species that suffered the mass extinctions of the past, we have the opportunity to prevent the burning of the world’s carbon sinks and help avoid the worst effects of modern warming” comments Dr Mays.

Source/Credit: Coláiste na hOllscoile Corcaigh (University College Cork)

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