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.

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).

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.”

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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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.

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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Shrimps and worms among first animals to recover after largest mass extinction

Reconstructed sea bed scenes (A) Pre-extinction, (B-D) Induan (early Early Triassic), (E) Smithian, (F) Spathian
Credit: Yaqi Jiang

Researchers studying ancient sea bed burrows and trails have discovered that bottom burrowing animals were among the first to bounce back after the end-Permian mass extinction.

In a new study, published today in the journal Science Advances, researchers from China, the USA and the UK, reveal how life in the sea recovered from the event, which killed over 90 percent of species on Earth, from their observations of trace fossils.

Life was devastated by the end-Permian mass extinction 252 million years ago, and recovery of life on Earth took millions of years for biodiversity to return to pre-extinction levels. But by examining trails and burrows on the South China sea bed, the international team were able to piece together sea life’s revival by pinpointing what animal activity was happening when.

Professor Michael Benton from the University of Bristol’s School of Earth Sciences, a collaborator on the new paper, said: “The end-Permian mass extinction and the recovery of life in the Early Triassic are very well documented throughout South China.

“We were able to look at trace fossils from 26 sections through the entire series of events, representing seven million crucial years of time, and showing details at 400 sampling points, we finally reconstructed the recovery stages of all animals including benthos, nekton, as well as these soft-bodied burrowing animals in the ocean.”

New Kangaroo Described from Papua New Guinea

Artist's impression of Nombe Rockshelter Megafauna, showing the Nombe kangaroo on the Right.
Image resized using AI by SFLORG
 Credit: Artwork Courtesy Peter Schouten

Australian paleontologists from Flinders University have described a new genus of giant fossil kangaroo from the mountains of central Papua New Guinea.

The new description of the fossil kangaroo has found that, rather than being closely related to Australian kangaroos, it most likely belongs to a unique genus of more primitive kangaroo found only in PNG.

The kangaroo, first described in 1983 by Professor Tim Flannery, is known from fossils around 20,000-50,000 years old. They come from the Nombe Rockshelter, an archaeological and paleontological site in Chimbu Province, Papua New Guinea.

Nombe is already known for multiple extinct species of kangaroo and giant four-legged marsupials called diprotodontids.

Flinders University researchers have renamed the animal Nombe nombe, after the location of its discovery – and plan to return to PNG for further excavations and research next year.

The squat, muscular Nombe lived in a diverse montane rainforest with thick undergrowth and a closed canopy. Here, it evolved to eat the tough leaves from trees and shrubs, with a thick jaw bone and strong chewing muscles.

Fossils in the ‘Cradle of Humankind’ may be more than a million years older than previously thought

Darryl Granger of Purdue University developed the technology that updated the age of an Australopithecus found in Sterkfontein Cave. New data pushes its age back more than a million years, to 3.67 million years old.
Purdue University photo/Lena Kovalenko

The earth doesn’t give up its secrets easily – not even in the “Cradle of Humankind” in South Africa, where a wealth of fossils relating to human evolution have been found.

For decades, scientists have studied these fossils of early human ancestors and their long-lost relatives. Now, a dating method developed by a Purdue University geologist just pushed the age of some of these fossils found at the site of Sterkfontein Caves back more than a million years. This would make them older than Dinkinesh, also called Lucy, the world’s most famous Australopithecus fossil.

The “Cradle of Humankind” is a UNESCO World Heritage Site in South Africa that comprises a variety of fossil-bearing cave deposits, including at Sterkfontein Caves. Sterkfontein was made famous by the discovery of the first adult Australopithecus, an ancient hominin, in 1936. Hominins includes humans and our ancestral relatives, but not the other great apes. Since then, hundreds of Australopithecus fossils have been found there, including the well-known Mrs. Ples, and the nearly complete skeleton known as Little Foot. Paleoanthropologists and other scientists have studied Sterkfontein and other cave sites in the Cradle of Humankind for decades to shed light on human and environmental evolution over the past 4 million years.

Darryl Granger, a professor of earth, atmospheric, and planetary sciences in Purdue University’s College of Science, is one of those scientists, working as part of an international team. Granger specializes in dating geologic deposits, including those in caves. As a doctoral student, he devised a method for dating buried cave sediments that is now used by researchers all over the world. His previous work at Sterkfontein dated the Little Foot skeleton to about 3.7 million years old, but scientists are still debating the age of other fossils at the site.

Triassic revolution: animals grew back faster and smarter after mass extinction

The diversification of the saurichthyiform fishes (‘lizard fish’) in the Middle Triassic of South China (eastern paleo-Tethys), reflecting the establishment of a complexly tiered marine ecosystem (or marine fish communities) with intensive predator-prey interactions along the food chains.
Credit: Drawing by Feixiang Wu

Paleontologists in the UK and China have shown that the natural world bounced back vigorously following the End-Permian Extinction.

In a review, published today in the journal Frontiers in Earth Science, scientists reveal that predators became meaner and prey animals adapted rapidly to find new ways to survive. On land, the ancestors of mammals and birds became warm-blooded and could move around faster.

At the end of the Permian period, 252 million years ago, there was a devastating mass extinction, when nearly all of life died out, and this was followed by one of the most extraordinary times in the history of life. The Triassic period, from 252–201 million years ago, marks a dramatic re-birth of life on land and in the oceans, and was a time of massively rising energy levels.

“Everything was speeding up,” said Professor Michael Benton of the University of Bristol School of Earth Sciences, the lead author of the new study.

“Today, there is a huge difference between birds and mammals on the one hand, and reptiles on the other. Reptiles are cold-blooded, meaning they do not generate much body heat themselves and, although they can nip about quite quickly, they have no stamina, and they cannot live in the cold, said Prof Benton.

Researchers discover long-extinct giant dwarf crocodile species

Researchers led by the University of Iowa have discovered two new species of crocodiles that roamed parts of Africa between 18 million and 15 million years ago and preyed on human ancestors. The Kinyang giant dwarf crocodiles (in gold) were up to four times the length of their modern relatives, dwarf crocodiles (shown in green). The new species discovery comes after analysis of the skull of a Kinyang specimen.
Credit: Christopher Brochu, University of Iowa.

Millions of years ago, giant dwarf crocodiles roamed a part of Africa with a taste for our human ancestors.

In a new study, researchers led by the University of Iowa announced the discovery of two new species of crocodiles that roamed east Africa between 15 million and 18 million years ago before mysteriously disappearing. The species, called giant dwarf crocodiles, are related to dwarf crocodiles currently found in central and west Africa.

But the giant dwarf crocodiles were a lot bigger—hence, the name—than their modern relatives. Dwarf crocodiles rarely exceed 4 or 5 feet in length, but the ancient forms measured as long as 12 feet and likely were among the fiercest threats to any animal they encountered.

“These were the biggest predators our ancestors faced,” says Christopher Brochu, professor in the Department of Earth and Environmental Sciences at Iowa and the study’s corresponding author. “They were opportunistic predators, just as crocodiles are today. It would have been downright perilous for ancient humans to head down to the river for a drink.”

Pioneering study shows climate played crucial role in changing location of ancient coral reefs

Pre-historic coral reefs dating back up to 250 million years extended much further away from the Earth’s equator than today, new research has revealed.

The new study, published in Nature Communications, demonstrates how changes in temperature and plate tectonics, where the positions of Earth’s continents were in very different positions than today, have determined the distribution of corals through the ages.

Although climate has often been regarded as the main driver of the location of coral reefs, this has yet to be proven due to limited fossil records. Now, for the first time, a team of international scientists used habitat modelling and reconstructions of past climates to predict the distribution of suitable environments for coral reefs over the last 250 million years.

The researchers, from the University of Vigo, in Spain, the University of Bristol and University College London in the UK, then checked their predictions using fossil evidence of warm-water coral reefs. They showed that corals in the past, from 250 to about 35 million years ago, existed much further from the equator than today, due to warmer climatic conditions, and a more even distribution of shallow ocean floor.

“Our work demonstrates that warm-water coral reefs track tropical-to-subtropical climatic conditions over geological timescales. In warmer intervals, coral reefs expanded poleward. However, in colder intervals, they became constrained to tropical and subtropical latitudes,” said first author Dr Lewis Jones, a computational paleobiologist research fellow at the University of Vigo.

Mastodon tusk chemical analysis reveals first evidence of one extinct animal’s annual migration

A mounted skeleton of the Buesching mastodon, based on casts of individual bones produced in fiberglass, on public display at the University of Michigan Museum of Natural History in Ann Arbor. The Buesching mastodon is a nearly complete skeleton of an adult male recovered in 1998 from a peat farm near Fort Wayne, Indiana. A new study, led by Joshua Miller of the University of Cincinnati and Daniel Fisher of the University of Michigan, uses oxygen and strontium isotopes from the mastodon’s right tusk to reconstruct changing patterns of landscape use during its lifetime.
Image credit: Eric Bronson, Michigan Photography

Around 13,200 years ago, a roving male mastodon died in a bloody mating-season battle with a rival in what today is northeast Indiana, nearly 100 miles from his home territory, according to the first study to document the annual migration of an individual animal from an extinct species.

The 8-ton adult, known as the Buesching mastodon, was killed when an opponent punctured the right side of his skull with a tusk tip, a mortal wound that was revealed to researchers when the animal’s remains were recovered from a peat farm near Fort Wayne in 1998.

Northeast Indiana was likely a preferred summer mating ground for this solitary rambler, who made the trek annually during the last three years of his life, venturing north from his cold-season home, according to a paper scheduled for online publication June 13 in Proceedings of the National Academy of Sciences.

Europe’s Largest Land Predator Unearthed

Illustration of White Rock spinosaurid.
Credit: Anthony Hutchings 

Research involving paleontologists from the Universities of Portsmouth and Southampton has identified the remains of one of Europe’s largest ever land-based hunters: a dinosaur that measured over 10m long and lived around 125 million years ago.

Several prehistoric bones, uncovered on the Isle of Wight, on the south coast of England, and housed at Dinosaur Isle Museum in Sandown, belonged to a type of two-legged, crocodile-faced predatory dinosaur known as spinosaurids. Dubbed the ‘White Rock spinosaurid’ – after the geological layer in which it was found – it was a predator of impressive proportions.

“This was a huge animal, exceeding 10 m in length and probably several tons in weight. Judging from some of the dimensions, it appears to represent one of the largest predatory dinosaurs ever found in Europe – maybe even the biggest yet known”, said University of Southampton PhD student Chris Barker, who led the study. “It’s a shame it’s only known from a small amount of material, but these are enough to show it was an immense creature.”

The discovery follows previous work on spinosaurids by the University of Southampton team, which published a study on the discovery of two new species in 2021.

Paleontologists Discovered Teeth and Bones of Ancient Animals in the Urals

Credit: Ural Federal University

Paleontologists from the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences and Ural Federal University Dmitry Gimranov and Anton Kisagulov together with volunteers discovered teeth and bones of ancient Eocene animals in the Sverdlovsk Region (the Sugat River near the village of Talitsa). Most of the finds are 40 million years old. There are also later finds dating back to the Middle or Late Pleistocene (0.75-0.02 million years). The oldest finds were numerous and consisted mainly of shark and ray teeth and fish bones. The "mammoth time" finds were few and include bones of frogs, birds and mammals. Late finds will have to be dated by radiocarbon analysis.

Shark and ray teeth will be transferred for study to Tatyana Malyshkina, a Senior Researcher at the Laboratory of Stratigraphy and Paleontology at the Zavaritsky Institute of Geology and Geochemistry of the Ural Branch of the Russian Academy of Sciences. The finds will enrich her collection with new specimens and possibly serve as a basis for the description of new species. The mammal finds will be studied by Dmitry Gimranov, a Senior Researcher at the Paleoecology Laboratory of the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences and the Laboratory of Natural Science Methods in Humanities of the UrFU.

How plesiosaurs swam under water

Anna Krahl (front) and Ulrich Witzel used a model made of bone copies and material from the hardware store to reconstruct the muscles. This analog model consists of casts of the front and rear fin, wooden slats, chandelier clamps, eyelets and ropes.
Credit: Ruhr University Bochum

The plesiosaurs are characterized by four uniform fins. Whether they rowed or flew under water could be reconstructed thanks to the combination of paleontological and engineering methods.

Plesiosaurs, which lived around 210 million years ago, have adapted in a unique way to life under water: their front and rear legs have developed into four uniform, wing-like fins in the course of evolution. How they could get on with it in the water, Dr. Anna Krahl worked out in her dissertation supervised at the Ruhr University Bochum and the Rheinische Friedrich-Wilhelms-Universität Bonn. Among other things, by using the finite element method, which is widespread in engineering, it was able to show that the fins had to be twisted in order to advance. Using bones, models and muscle reconstructions, she was able to reconstruct the movement. She reports in the PeerJ journal from 3. June 2022.

Plesiosaurs belong to a group of dinosaurs, the Sauropterygia or paddle lizards, who have adapted to a life in the sea again. They developed in the late Triassic 210 million years ago, lived at the same time as the dinosaurs and died out at the end of the Cretaceous period. Plesiosaurs are characterized by an often extremely elongated neck with a small head - the Elas mosaic animals even have the longest neck of all vertebrates. But there were also large predatory shapes with a rather short neck and huge skulls. In all plesiosaurs, the neck sits on a teardrop-shaped, hydrodynamically well-adapted body with a very shortened tail.

Great white sharks may have contributed to megalodon extinction

Tooth size comparison between the extinct Early Pliocene Otodus megalodon tooth and a modern great white shark. 
Credit: MPI for Evolutionary Anthropology

The diet of fossil extinct animals can hold clues to their lifestyle, behavior, evolution and ultimately extinction. However, studying an animal’s diet after millions of years is difficult due to the poor preservation of chemical dietary indicators in organic material on these timescales. An international team of scientists led by the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, applied a new method to investigate the diet of the largest shark to have ever existed, the iconic Otodus megalodon. This new method investigates the zinc isotope composition of the highly mineralized part of teeth and proves to be particularly helpful to decipher the diet of these extinct animals.

Megatooth sharks like Otodus megalodon, more commonly known as megalodon, lived between 23 and 3.6 million years ago in oceans around the globe and possibly reached as large as 20 meters in length. For comparison, the largest great white sharks today reach a total length of only six meters. Many factors have been discussed to explain the gigantism and extinction of megalodon, with its diet and dietary competition often being thought of as key factors.

Palms at the Poles: Fossil Plants Reveal Lush Southern Hemisphere Forests in Ancient Hothouse Climate

For decades, paleobotanist David Greenwood has collected fossil plants from Australia – some so well preserved it’s hard to believe they’re millions of years old. These fossils hold details about the ancient world in which they thrived, and Greenwood and a team of researchers including climate modeler and research David Hutchinson, from the University of New South Wales, and UConn Department of Geosciences paleobotanist Tammo Reichgelt, have begun the process of piecing together the evidence to see what more they could learn from the collection. Their findings are published in Paleoceanography & Paleoclimatology.

The fossils date back 55 to 40 million years ago, during the Eocene epoch. At that time, the world was much warmer and wetter, and these hothouse conditions meant there were palms at the North and South Pole and predominantly arid landmasses like Australia were lush and green. Reichgelt and co-authors looked for evidence of differences in precipitation and plant productivity between then and now.

Since different plants thrive under specific conditions, plant fossils can indicate what kinds of environments those plants lived in.

By focusing on the morphology and taxonomic features of 12 different floras, the researchers developed a more detailed view of what the climate and productivity was like in the ancient hothouse world of the Eocene epoch.

Reichgelt explains the morphological method relies on the fact that the leaves of angiosperms — flowering plants — in general have a strategy for responding to climate.