A near-complete skeleton found on the UK’s Jurassic Coast has been identified as a new and rare species of ichthyosaur—a type of prehistoric marine reptile that once ruled the ancient oceans.

The dolphin-sized ichthyosaur called Xiphodracon goldencapensis, or the “Sword Dragon of Dorset,” is the only known example of its kind in existence and helps to fill an important gap in the evolutionary fossil record of ichthyosaurs.

Thousands of ichthyosaur fossils have been found along the UK’s Jurassic Coast since the discoveries of pioneering paleontologist Mary Anning. Yet the discovery of Xiphodracon is the first described genus of an Early Jurassic ichthyosaur described from the region in over 100 years.

Discovered near Golden Cap in 2001 by Dorset fossil collector Chris Moore, the fossil is almost perfectly preserved in three dimensions. The skeleton includes a skull with an enormous eye socket and a long sword-like snout. The scientists say the animal would have been about three meters long and would have dined on fish and squid.

The remains even show what may be traces of its last meal. It is probably the world’s most complete prehistoric reptile from the Pliensbachian period.

The finding has been described by a trio of international paleontologists, led by ichthyosaur expert Dr. Dean Lomax, an Honorary Research Fellow at the University of Manchester and an 1851 Research Fellow at the University of Bristol, in the journal Papers in Palaeontology.

Dr. Lomax said, “I remember seeing the skeleton for the first time in 2016. Back then, I knew it was unusual, but I did not expect it to play such a pivotal role in helping to fill a gap in our understanding of a complex faunal turnover during the Pliensbachian.

“This time is pretty crucial for ichthyosaurs as several families went extinct and new families emerged, yet Xiphodracon is something you might call a ‘missing piece of the ichthyosaur puzzle.” It is more closely related to species in the later Early Jurassic (in the Toarcian), and its discovery helps pinpoint when the faunal turnover occurred, being much earlier than expected.”

After its discovery in 2001, the skeleton was acquired by the Royal Ontario Museum, Canada, where it became part of their extensive collection of ichthyosaurs but had remained unstudied.

Ichthyosaurs from the Pliensbachian (193–184 million years ago) are incredibly rare and makes Xiphodracon a vital piece of evidence for scientists studying the critical but poorly understood time in ichthyosaurian evolution.

Ichthyosaur expert and co-author, Professor Judy Massare, from the State University of NY at Brockport, U.S., said, “Thousands of complete or nearly complete ichthyosaur skeletons are known from strata before and after the Pliensbachian. The two faunas are quite distinct, with no species in common, even though the overall ecology is similar.

“Clearly, a major change in species diversity occurred sometime in the Pliensbachian. Xiphodracon helps to determine when the change occurred, but we still don’t know why.”

Dr. Erin Maxwell, a co-author and ichthyosaur expert from the State Museum of Natural History Stuttgart, added, “This skeleton provides critical information for understanding ichthyosaur evolution, but also contributes to our understanding of what life must have been like in the Jurassic seas of Britain.

“The limb bones and teeth are malformed in such a way that points to serious injury or disease while the animal was still alive, and the skull appears to have been bitten by a large predator—likely another much larger species of ichthyosaur—giving us a cause of death for this individual. Life in the Mesozoic oceans was a dangerous prospect.”

Collectively, the trio have identified several features in Xiphodracon that have never been observed in any ichthyosaur. The most peculiar is a strange and unique bone around the nostril (called a lacrimal) that has prong-like bony structures.

Dr. Lomax, who is the author of the book, “The Secret Lives of Dinosaurs,” said, “One of the coolest things about identifying a new species is that you get to name it! We opted for Xiphodracon because of the long, sword-like snout (xipho from Greek xiphos for sword) and dracon (Greek and Latin for dragon) in reference to ichthyosaurs being referred to as ‘sea dragons’ for over 200 years.”

The skeleton will go on display at the Royal Ontario Museum, Toronto, Canada.

Reference:
A new long and narrow-snouted ichthyosaur illuminates a complex faunal turnover during an undersampled Early Jurassic (Pliensbachian) interval. Papers in Palaeontology. DOI: 10.1002/spp2.70038

Note: The above post is reprinted from materials provided by University of Manchester.

When saltwater fish long ago evolved to live in fresh water, many of them also evolved a more sophisticated hearing system, including middle ear bones similar to those in humans.

Two-thirds of all freshwater fish today—including more than 10,000 species, from catfish to popular aquarium fish like tetras and zebrafish—have this middle ear system, called the Weberian apparatus, which allows them to hear sounds at much higher frequencies than most ocean fish can, with a range close to that of humans.

University of California, Berkeley paleontologist Juan Liu has now used the structure of this Weberian apparatus in a newly discovered fossil fish to revise the origin story for the evolution of freshwater fish.

Fish with a Weberian ear system, referred to as otophysan fish, were thought to have moved into fresh water approximately 180 million years ago, before the supercontinent of Pangea had broken up into the continents we see today.

Based on Liu’s new timeline, they now appear to have arisen much later—about 154 million years ago, during the late Jurassic Period—after the beginning of Pangea’s breakup and coinciding with the appearance of today’s oceans.

Liu’s analysis of fossil and genomic data implies that the fish originally developed precursor bones of their superb hearing while still in the ocean.

Only later did they develop fully functional enhanced hearing, after the two separate lineages moved into fresh water: one evolving into today’s catfish, knife fish and African and South American tetras; the other evolving into the largest order of freshwater fish, the carp, suckers, minnows and zebrafish.

“The marine environment is the cradle of a lot of vertebrates,” said Liu, an assistant adjunct professor of integrative biology and an assistant curator in the UC Museum of Paleontology.

“A long time consensus was that these bony fish had a single freshwater origin in the large continent Pangea and then dispersed with the separation of different continents.

“My team’s analysis of some fantastic fossils that shed new light on the evolutionary history of freshwater fish and found completely different results: the most recent common ancestor of otophysan fish was a marine lineage and there were at least two freshwater incursions after that lineage split up.”

This finding reshapes our understanding of the evolutionary history and intricate biogeography of the world’s most successful group of freshwater fish, she added.

“These repeated incursions into freshwater at the early divergence stage likely accelerated speciation, and are key factors in explaining the extraordinary hyper-diversity of otophysans in modern freshwater faunas.”

Liu and her colleagues describe and name the 67 million-year-old fossil fish, Acronichthys maccagnoi, in a paper published in the journal Science. In that paper, the researchers analyze 3D scans of the fossil’s Weberian structure and the genomes and morphology of modern fish to revise the genealogy of freshwater fish, and also simulate the frequency response of the fossil fish’s middle ear structure.

A Rube Goldberg-like structure in the middle ear

Ears that work underwater require a different anatomy than ears that detect sound traveling through the air. Many land vertebrates evolved an eardrum-like structure that vibrates in response to sound waves. That eardrum moves a Rube Goldberg-like array of bones in the middle ear—in humans, the malleus, incus and stapes—that amplify the sound and poke the fluid-filled inner ear, which jiggles and eventually jostles hairs that send signals to the brain.

But sound waves in water go right through a fish, which has a similar density to the surrounding water. So fish developed a bladder filled with air—essentially a bubble—that vibrates in response to sounds passing through the fish. Those vibrations are transferred to the fish’s inner ear in a rudimentary way in most saltwater fish, which limits their hearing to bass notes below about 200 Hertz.

Otophysan fish, however, developed bony “ossicles” between the air bladder—often inaccurately referred to as the swim bladder—and the inner ear to amplify and extend the frequency range the ears can detect. Zebrafish, for example, can hear frequencies up to 15,000 Hz, not far from the 20,000 Hz limit of humans.

Why these fish need to hear high frequencies is a mystery, though it may be because they live in diverse and complicated environments, from rushing streams to static lakes.

Liu studies the Weberian apparatus in living and fossil fish, and last year published a computational simulation of how the apparatus works. That simulation allows her to predict the frequency response of the bony ossicles, and thus the hearing sensitivity of fish.

Numerous specimens of the newly named fossil fish, a mere 2 inches long, were excavated and collected in Alberta, Canada, over six field seasons starting in 2009 by ichthyologist and co-author Michael Newbrey of Columbus State University in Georgia.

The fossils are housed in the Royal Tyrrell Museum in Drumheller, Alberta. A couple of specimens were so well preserved that the bones in the middle ear were clearly Weberian. The fish is the oldest known North American fossil of an otophysan fish, or Otophysi, dating from the late Cretaceous Period, only a short time before the non-avian dinosaurs disappeared.

Older specimens have been found elsewhere in the world, but none had a well-preserved Weberian apparatus, Liu said.

Technicians with the Canadian Light Source at the University of Saskatchewan in Saskatoon and at McGill University in Montreal captured 3D X-ray scans of the fish, and Liu modeled the ossicles of the Weberian apparatus in her laboratory. The model suggests that, even 67 million years ago, otophysan fish had nearly as sensitive hearing as zebrafish do today.

“We weren’t sure if this was a fully functional Weberian apparatus, but it turns out the simulation worked,” Liu said. “The Weberian apparatus has just a little bit lower output power, which means lower sensitivity, compared to a zebrafish. But the peak, the most sensitive frequency, is not too much lower than zebrafish—between 500 and 1,000 Hertz—which is not too bad at all and which means the higher frequency hearing should have been achieved in this old otophysan fish.”

She noted that the findings highlight a general pattern in evolution: sudden increases in new species can arise from repeated incursions into new habitat rather than a single dispersal event, especially when coupled with new innovations, such as more sensitive hearing.

“For a long time, we presumed that the Otophysi probably had a freshwater origin because this group consisted almost exclusively of freshwater fishes,” Newbrey said. “The new species provides crucial information for a new interpretation of the evolutionary pathways of the Otophysi with a marine origin. It just makes so much more sense.”

Other co-authors of the paper are Donald Brinkman of the Royal Tyrrell Museum, Alison Murray of the University of Alberta, former UC Berkeley undergraduate Zehua Zhou, now a graduate student at Michigan State University, and Lisa Van Loon and Neil Banerjee of Western University in London, Ontario.

Reference:
Juan Liu et al, Marine origins and freshwater radiations of the otophysan fishes, Science (2025). DOI: 10.1126/science.adr4494.

Note: The above post is reprinted from materials provided by University of California – Berkeley.

New research has uncovered a species of hook-toothed lizard that lived about 167 million years ago and has a confusing set of features seen in snakes and geckos—two very distant relatives. One of the oldest relatively complete fossil lizards yet discovered, the Jurassic specimen is described in a study, published in the journal Nature, from a multinational collaboration between the American Museum of Natural History and scientists in the United Kingdom, including University College London and the National Museums Scotland, France, and South Africa.

The species was given the Gaelic name Breugnathair elgolensis meaning “false snake of Elgol,” referencing the area in Scotland’s Isle of Skye where it was discovered. Breugnathair had snake-like jaws and hook-like, curved teeth similar to those of modern-day pythons, paired with the short body and fully-formed limbs of a lizard.

“Snakes are remarkable animals that evolved long, limbless bodies from lizard-like ancestors,” said the study’s lead author Roger Benson, Macaulay Curator in the American Museum of Natural History’s Division of Paleontology.

“Breugnathair has snake-like features of the teeth and jaws, but in other ways, it is surprisingly primitive. This might be telling us that snake ancestors were very different to what we expected, or it could instead be evidence that snake-like predatory habits evolved separately in a primitive, extinct group.”

Lizards and snakes together form a group called squamates. Breugnathair has been placed in a new group of extinct, predatory squamates called Parviraptoridae, which was previously known only from more fragmentary fossils.

Earlier studies reported snake-like tooth-bearing bones that were found in close proximity with bones that had gecko-like features. But because these seemed so drastically different, some researchers believed they belonged to two different animals.

The new work on Breugnathair rejects those earlier findings, showing that both snake-like and gecko-like features exist together in a single animal.

Breugnathair was discovered in 2016 by Stig Walsh from the National Museums Scotland while on an expedition with Benson and others on the Isle of Skye. The researchers have spent almost 10 years since then preparing the specimen, imaging it with computed tomography as well as with high-powered X-rays at the European Synchrotron Radiation Facility in Grenoble, France, and analyzing the results.

“The Jurassic fossil deposits on the Isle of Skye are of world importance for our understanding of the early evolution of many living groups, including lizards, which were beginning their diversification at around this time,” said Susan Evans from University College London, who co-led the study.

“I first described parviraptorids some 30 years ago based on more fragmentary material, so it’s a bit like finding the top of the jigsaw box many years after you puzzled out the original picture from a handful of pieces. The mosaic of primitive and specialized features we find in parviraptorids, as demonstrated by this new specimen, is an important reminder that evolutionary paths can be unpredictable.”

Nearly 16 inches long from head to tail, Breugnathair was one of the largest lizards in its ecosystem, where it likely preyed on smaller lizards, early mammals, and other vertebrates, like young dinosaurs. But is it a lizard-like ancestor of snakes? Because it has such an unusual mixture of features, and because other fossils that shed light on early squamate evolution are rare, the researchers did not arrive at a conclusive answer.

Another possibility is that Breugnathair could be a stem-squamate, a predecessor of all lizards and snakes, that independently evolved snake-like teeth and jaws.

“This fossil gets us quite far, but it doesn’t get us all of the way,” Benson said. “However, it makes us even more excited about the possibility of figuring out where snakes come from.”

Reference:

• Roger Benson, Mosaic anatomy in an early fossil squamate, Nature (2025). DOI: 10.1038/s41586-025-09566-y.
• Hussam Zaher, Mix-and-match fossils tell the tale of snake and lizard evolution, Nature (2025). DOI: 10.1038/d41586-025-02972-2 

Note: The above post is reprinted from materials provided by American Museum of Natural History.

A newly described fossil reveals that leeches are at least 200 million years older than scientists previously thought, and that their earliest ancestors may have feasted not on blood, but on smaller marine creatures.

“This is the only body fossil we’ve ever found of this entire group,” said Karma Nanglu, a paleontologist with the University of California, Riverside. He collaborated with researchers from the University of Toronto, University of São Paulo, and Ohio State University on a paper describing the fossil, which is published in PeerJ.

Roughly 430 million years old, the fossil includes a large tail sucker—a feature still found in modern leeches—along with a segmented, teardrop-shaped body. But one important feature isn’t found in this fossil: the forward sucker that many of today’s leeches use to pierce skin and draw blood.

This absence, along with the fossil’s marine origin, suggests a very different early lifestyle for the group known as Hirudinida. Rather than sucking blood from mammals, reptiles, and other vertebrates, the earliest leeches may have roamed the oceans, consuming soft-bodied invertebrates whole or feeding on their internal fluids.

“Blood feeding takes a lot of specialized machinery,” Nanglu said. “Anticoagulants, mouthparts, and digestive enzymes are complex adaptations. It makes more sense that early leeches were swallowing prey whole or maybe drinking the internal fluids of small, soft-bodied marine animals.”

Previously, scientists believed leeches emerged about 150–200 million years ago. That timeline has now been pushed back by at least 200 million years, thanks to the fossil found in the Waukesha biota, a geological formation in Wisconsin known for preserving the bodies of soft tissue animals that usually decay before fossilization.

Preserving a leech fossil is no small feat. Leeches lack bones, shells, or exoskeletons that are most easily preserved over millions of years. Fossils like this require exceptional circumstances to preserve, often involving near-immediate burial, a low-oxygen environment, and unusual geochemical conditions.

“A rare animal and just the right environment to fossilize it—it’s like hitting the lottery twice,” Nanglu said.

The fossil came to light during a broader study of the Waukesha site by researchers at Ohio State University, who are co-authors on this paper. Though initially unrecognized for what it was, the specimen caught Nanglu’s eye during the early pandemic years.

He consulted with leech specialists, including lead author Danielle de Carle of the University of Toronto, and the group worked together to confirm its identity. They were ultimately convinced they’d found a leech because of the tail sucker and the clear body segmentation, which is a combination only found in leeches.

Today’s leeches are found in freshwater, saltwater, and even on land. Their feeding behaviors are equally diverse, from scavenging to predation to parasitic blood feeding. But understanding their origin has been difficult because soft-bodied animals rarely leave fossils.

Nanglu, who studies creatures rarely found in the fossil record, said the find is part of a larger effort to trace the early history of complex life, and to challenge assumptions about the past.

“We don’t know nearly as much as we think we do,” he said. “This paper is a reminder that the tree of life has deep roots, and we’re just beginning to map them.”

“It’s a beautiful specimen,” Nanglu added. “And it’s telling us something we didn’t expect.”

Reference:
de Carle D, et al. The first leech body fossil predates estimated hirudinidan origins by 200 million years, PeerJ (2025). doi.org/10.7717/peerj.19962

Note: The above post is reprinted from materials provided by University of California – Riverside.

A team of international scientists has discovered new fossils at a field site in Africa that indicate Australopithecus, and the oldest specimens of Homo, coexisted at the same place in Africa at the same time—between 2.6 and 2.8 million years ago. The paleoanthropologists discovered a new species of Australopithecus that has never been found anywhere.

The paper “New discoveries of Australopithecus and Homo from Ledi-Geraru, Ethiopia,” is published in the journal Nature.

The Ledi-Geraru Research Project is led by scientists at Arizona State University and the site has revealed the oldest member of the genus Homo and the earliest Oldowan stone tools on the planet.

The research team concluded that the Ledi-Geraru Australopithecus teeth are a new species, rather than belonging to Australopithecus afarensis (the famous “Lucy”), confirming that there is still no evidence of Lucy’s kind younger than 2.95 million years ago.

“This new research shows that the image many of us have in our minds of an ape to a Neanderthal to a modern human is not correct—evolution doesn’t work like that,” said ASU paleoecologist Kaye Reed. “Here we have two hominin species that are together. And human evolution is not linear, it’s a bushy tree, there are lifeforms that go extinct.”

Reed is a Research Scientist at the Institute of Human Origins and President’s Professor Emerita at the School of Human Evolution and Social Change at ASU. She has been co-director of the Ledi-Geraru Research Project since 2002.

Ledi-Geraru

What fossils did they find to help them tell this story? Teeth, 13 of them to be exact.

This field site has been famous before. In 2013, a team led by Reed discovered the jaw of the earliest Homo specimen ever found at 2.8 million years old. This new paper details new teeth found at the site that belong to both the genus Homo and a new species of the genus Australopithecus.

“The new finds of Homo teeth from 2.6–2.8 million-year-old sediments—reported in this paper—confirms the antiquity of our lineage,” said Brian Villmoare, lead author and ASU alumnus.

“We know what the teeth and mandible of the earliest Homo look like, but that’s it. This emphasizes the critical importance of finding additional fossils to understand the differences between Australopithecus and Homo, and potentially how they were able to overlap in the fossil record at the same location.”

The team cannot name the species yet based on the teeth alone; more fossils are needed before that can happen.

How old are the fossils? How do scientists know these fossil teeth are millions of years old?

Volcanoes.

The Afar region is still an active rifting environment. There were a lot of volcanoes and tectonic activity and when these volcanoes erupted ash, the ash contained crystals called feldspars that allow the scientists to date them, explained Christopher Campisano, a geologist at ASU.

“We can date the eruptions that were happening on the landscape when they’re deposited,” said Campisano, a Research Scientist at the Institute of Human Origins and Associate Professor at the School of Human Evolution and Social Change.

“And we know that these fossils are interbed between those eruptions, so we can date units above and below the fossils. We are dating the volcanic ash of the eruptions that were happening while they were on the landscape.”

Finding fossils and dating the landscape not only helps scientists understand the species—it helps them recreate the environment millions of years ago. The modern faulted badlands of Ledi-Geraru, where the fossils were found, are a stark contrast to the landscape these hominins traversed 2.6–2.8 million years ago. Back then, rivers migrated across a vegetated landscape into shallow lakes that expanded and contracted over time.

Ramon Arrowsmith, a geologist at ASU, has been working with the Ledi-Geraru Research Project since 2002. He explained the area has an interpretable geologic record with good age control for the geologic time range of 2.3 to 2.95 million years ago.

“It is a critical time period for human evolution as this new paper shows,” said Arrowsmith, professor at the School of Earth and Space Exploration. “The geology gives us the age and characteristics of the sedimentary deposits containing the fossils. It is essential for age control.”

Reed said the team is examining tooth enamel now to find out what they can about what these species were eating. There are still remaining questions the team will continue to work on.

Were the early Homo and this unidentified species of Australopithecus eating the same things? Were they fighting for or sharing resources? Did they pass each other daily? Who were the ancestors of these species?

No one knows—yet.

“Whenever you have an exciting discovery, if you’re a paleontologist, you always know that you need more information,” said Reed. “You need more fossils. That’s why it’s an important field to train people in and for people to go out and find their own sites and find places that we haven’t found fossils yet.”

“More fossils will help us tell the story of what happened to our ancestors a long time ago—but because we’re the survivors, we know that it happened to us.”

The team of scientists and field team working on this project is widespread and many work at Arizona State University, or are alumni of ASU.

Reference:
New discoveries of Australopithecus and Homo from Ledi-Geraru, Ethiopia, Nature (2025). DOI: 10.1038/s41586-025-09390-4.

Note: The above post is reprinted from materials provided by Arizona State University.

Researchers at the Gray Fossil Site and Museum have discovered something surprisingly familiar among the site’s exotic ancient tapirs and rhinos: the first fossil deer, representing one of the earliest records of the deer family in North America.

The newly described fossils of Eocoileus gentryorum, detailed in the journal Palaeontologia Electronica, offer a fascinating glimpse into the deep roots of America’s most recognizable wildlife.

These 5-million-year-old fossils reveal the likely ancestor of today’s white-tailed deer—animals that have a deep history in Appalachian forests and have great importance to the people living here.

“The Gray Fossil Site continues to yield extraordinary discoveries that reshape our understanding of ancient life,” said Dr. Blaine Schubert, executive director of the Gray Fossil Site and Museum. “Our team’s collaborative research is uncovering remarkable stories about how ecosystems have evolved over millions of years. From tapirs and mastodons to these early deer, we’re revealing the incredible diversity of life that once flourished in Tennessee and how some species, like deer, have shown amazing resilience through geological time.”

The research team, which was led by Head Curator Dr. Joshua Samuels and included recent graduate Olivia Williams and Assistant Collections Manager Shay Maden, collaborated to piece together the story from fragmentary remains. Those remains include part of a juvenile skull, an upper molar and various limb bones.

Previously, Eocoileus gentryorum was known only from Florida, making the Tennessee discovery significant for understanding how quickly these early deer spread across the continent.

Interestingly, these ancient deer were notably smaller than most modern species.

“These early deer are generally smaller than modern deer species in the New World,” Williams explained, highlighting how the animals have evolved over millions of years. “The only smaller species today are the Key deer of Florida and brocket deer of Central and South America.”

The discovery underscores the incredible versatility of deer as a species.

Fossil evidence from Washington and Florida shows these early deer dispersed rapidly coast-to-coast after their North American arrival, successfully adapting to diverse habitats from Pacific forests to Appalachian highlands.

“Deer have probably filled the same ecological role in Appalachian forests for nearly 5 million years,” Samuels said, “persisting and thriving through dramatic climate changes and habitat shifts that eliminated other large herbivores from the region.”

This fossil deer is the latest in a string of fascinating discoveries, including a strong-jawed salamander and a giant flying squirrel, at the site. It’s part of what makes ETSU the flagship institution of Appalachia.

“Discoveries like this connect Appalachia’s past to its present in powerful ways,” said Dr. Joe Bidwell, dean of the College of Arts and Sciences. “Our researchers are revealing not just the history of a species, but the evolutionary lineage of life in this region. It is work that exemplifies ETSU’s commitment to exploring and preserving the natural history of Appalachia.”

Reference:
Joshua X. Samuels et al, Early Pliocene Deer from the Gray Fossil Site, Appalachian Highlands, Tennessee, USA, Palaeontologia Electronica (2025). DOI: 10.26879/1560

Note: The above post is reprinted from materials provided by East Tennessee State University.

Scientists have discovered the fossil of a tiny mouse-sized mammal that lived in the time of the dinosaurs in Chilean Patagonia.

“Yeutherium pressor” weighed between 30 and 40 grams (about one ounce) and lived in the Upper Cretaceous period, about 74 million years ago.

It is the smallest mammal ever found in this region of South America, dating back to the era when it was part of a continental land mass known as Gondwana.

The fossil consists of “a small piece of jaw with a molar and the crown and roots of two other molars,” said Hans Puschel, who led the team of scientists from the University of Chile and Chile’s Millennium Nucleus research center on early mammals.

The discovery was published this month in the British scientific journal Proceedings of the Royal Society B.

Researchers found the fossil in the Rio de las Las Chinas Valley in Chile’s Magallanes region, about 3,000 kilometers (1,864 miles) south of Santiago.

Despite its similarity to a small rodent, “Yeutherium pressor” was a mammal that must have laid eggs, like the platypus, or carried its young in a pouch like kangaroos or opossums.

The shape of its teeth suggests that it probably had a diet of relatively hard vegetables.

Just like the dinosaurs with whom it coexisted, the tiny mammal abruptly went extinct at the end of the Cretaceous period, about 66 million years ago.

Reference:
Hans P. Püschel et al, A subantarctic reigitheriid and the evolution of crushing teeth in these enigmatic Mesozoic mammals, Proceedings of the Royal Society B: Biological Sciences (2025). DOI: 10.1098/rspb.2025.1056

Note: The above post is reprinted from materials provided by AFP.

Fossils are the backbone—oftentimes literally—of researching the far past. And because most of human evolution took place throughout Africa, the fossils the continent holds are vital to piecing together early human history. The fossils there also tell other stories of ancient ecological history, and how humans fit into the lives of the animals and plants around them.

But most of the known fossil record comes from just a handful of sites across Africa, said Tyler Faith, chief curator and curator of paleontology at the Natural History Museum of Utah. That’s one reason why he’s been squeezing his way through newly discovered caves in South Africa.

In 2022, Faith, a paleoecologist and University of Utah professor of anthropology, set out to find a series of caves mentioned in a report from the 1980s. They were somewhere near the tip of South Africa in the Cango Valley, a region streaked with outcrops of limestone, the kind of rock that is often riddled with caves. But when he arrived, there were so many caves he couldn’t narrow down which were described in the report. He came back several times over the years, documenting two dozen caves.

“We found all these caves, and there appears to be a really rich fossil record within them,” Faith said. “Fossils are everywhere.”

The caves formed as water worked its way through the limestone over millions of years, eventually carving out tunnels and chambers in the rock. Throughout the caves’ existence, bones found their way inside. Sometimes, this was because a predator took its meals within the cave. Other times, remains were swept in with debris and water. And occasionally, an unlucky animal might have fallen in if a cave entrance or roof collapsed. Layers of sediment slowly built up over the bones, fossilizing them.

In June of 2025, Faith returned to the caves with a crew of researchers, ready to excavate. The work began with a tromp around, looking for cave entrances. Those entrances are inconspicuous to the untrained eye, sheltered by trees and vegetation. But their leafy concealment is one major tell that there’s a cave nearby, Faith said. Because the caves need flowing water to form, trees and shrubs cluster around their opening to take advantage of the extra moisture.

The cave entrances are often just large enough for an adult to wriggle through. Once inside, the limestone gives way to a maze of tunnels that could require belly crawling through bat guano or descending tight, steep shafts to navigate. Cave ticks writhed among the piles of guano, waiting to sink their hooks into a passerby. And without marking which direction they came from, the spelunkers could easily get lost amidst the twists and turns.

“It’s oppressively quiet and dark,” Faith said. “You start hearing things that aren’t there.”

Faith and his crew visited four caves on their trip, with two main goals: find fossils and peg an age to the things they found. There were fossils galore, sticking out of sediments adhering to ceilings and walls and erupting out of the ground. To further explore the caves’ potential, the team dug multiple test pits to see what lies beneath the surface.

Ancient wildebeests, zebras and unknown carnivores were among the finds. A molar, conspicuously like that of a human, was found poking out of a ceiling—but it’s not yet confirmed if the tooth is indeed from a hominid. Further hominid-like fossils emerged from other caves as well.

One of the most abundant animals the team found was an extinct mountain goat relative, likely similar to an ibex. The animal was first discovered around 25 years ago, but the known fossils were too incomplete to give it a name or to understand how it is connected to related species.

But now, thanks to the Cango Valley caves, Faith has sufficiently complete fossils to properly document the species. The prize specimen will come from an individual lodged in sediments cemented to the side of a cave, which was painstakingly removed with a hammer and chisel over several days.

As for the second goal of dating the fossils, the Cango Valley research team won’t know any ages for sure until they can date samples of the caves’ flowstones, the sheet-like mineral deposits that form as water flows through. Dating the flowstones sandwiching a layer of sediment gives researchers the minimum and maximum age of the fossils trapped in between.

Faith’s hunch is that the fossils probably came from the Pleistocene Epoch, but that’s a wide window: a period of around 2.5 million to 11,700 years ago. “I strongly suspect they are more than 100,000 years old,” he said.

The caves’ age is great news for South Africa’s fossil record. Most fossils recovered in southern parts of the country are from the last 100,000 years, while older fossils—those from the last several million years or so—are mostly isolated in the north, near Johannesburg.

The Cango Valley cave project has the potential to bolster the older fossil record, Faith said. And, since the caves hold what seem to be hominid fossils, they could help fill gaps about early human evolution and humans’ place in the landscape.

For now, the caves Faith and his team explored are just the beginning. The sheer number of subterranean time capsules in the area means decades of discoveries lie ahead.

“There’s zillions of caves in this area that I think are waiting for someone to pop into them and start working,” Faith said. “There’s lifetimes of work to do in that valley.”

Note: The above post is reprinted from materials provided by Jude Coleman, University of Utah.

About 56 million years ago, when Earth experienced a dramatic rise in global temperatures, one meat-eating mammal responded in a surprising way: It started eating more bones.

That’s the conclusion reached by a Rutgers-led team of researchers, whose recent study of fossil teeth from the extinct predator Dissacus praenuntius reveals how animals adapted to a period of extreme climate change known as the Paleocene–Eocene Thermal Maximum (PETM). The findings, published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology, could help scientists predict how today’s wildlife might respond to modern global warming.

“What happened during the PETM very much mirrors what’s happening today and what will happen in the future,” said Andrew Schwartz, a doctoral student in the Department of Anthropology at the School of Arts and Sciences, who led the research. “We’re seeing the same patterns. Carbon dioxide levels are rising, temperatures are higher and ecosystems are being disrupted.”

Associate Professor Robert Scott of the Department of Anthropology is a co-author of the study. Schwartz, Scott and another colleague used a technique called dental microwear texture analysis to study the tiny pits and scratches left on fossilized teeth. These marks reveal what kinds of food the animal was chewing in the weeks before it died.

The ancient omnivore was about the size of a jackal or a coyote and likely consumed a mix of meat and other food sources like fruits and insects. “They looked superficially like wolves with oversized heads,” Schwartz said, describing them as “super weird mammals.” “Their teeth were kind of like hyenas. But they had little tiny hooves on each of their toes.”

Before this period of rising temperatures, Dissacus had a diet similar to modern cheetahs, eating mostly tough flesh. But during and after this ancient period, its teeth showed signs of crunching harder materials, such as bones.

“We found that their dental microwear looked more like that of lions and hyenas,” Schwartz said. “That suggests they were eating more brittle food, which were probably bones, because their usual prey was smaller or less available.”

This dietary shift happened alongside a modest reduction in body size, likely because of food scarcity. While earlier hypotheses blamed shrinking animals on hotter temperatures alone, this latest research suggests that limited food played a bigger role, Schwartz said.

This period of rapid global warming lasted about 200,000 years, but the changes it triggered were fast and dramatic. Schwartz said studies of the past like his can offer practical lessons for today and what comes next.

“One of the best ways to know what’s going to happen in the future is to look back at the past,” he said. “How did animals change? How did ecosystems respond?”

The findings also highlight the importance of dietary flexibility, he said. Animals that can eat a variety of foods are more likely to survive environmental stress.

“In the short term, it’s great to be the best at what you do,” Schwartz said. “But in the long term, it’s risky. Generalists, meaning animals that are good at a lot of things, are more likely to survive when the environment changes.”

Such an insight may be helpful for modern conservation biologists, allowing them to identify which species today may be most vulnerable, he said. Animals with narrow diets, such as pandas, may struggle as their habitats shrink. But adaptable species, including jackals or raccoons, might fare better.

“We already see this happening,” Schwartz said. “In my earlier research, jackals in Africa started eating more bones and insects over time, probably because of habitat loss and climate stress.”

The study also showed that rapid climate warming as seen during the ancient past can lead to major changes in ecosystems, including shifts in available prey and changes in predator behavior. This may suggest that modern climate change could similarly disrupt food webs and force animals to adapt, or risk extinction, he said.

Even though Dissacus was a successful and adaptable animal that lived for about 15 million years, it eventually went extinct. Scientists think this happened because of changes in the environment and competition from other animals, Schwartz said.

Schwartz conducted his research using a combination of fieldwork and lab analysis, focusing on fossil specimens from the Bighorn Basin in Wyoming, a site with a rich and continuous fossil record spanning millions of years. Schwartz chose the location because it preserves a detailed sequence of environmental and ecological changes during the ancient period of climate warming.

Schwartz has been interested in paleontology, specifically dinosaurs, since he was a boy, journeying with his father, an amateur fossil hunter, on treks through New Jersey’s rivers and streams. Now, as a late-stage doctoral student, he hopes to use ancient fossils to answer urgent questions about the future.

He also wants to inspire the next generation of researchers.

“I love sharing this work,” he said. “If I see a kid in a museum looking at a dinosaur, I say, ‘Hey, I’m a paleontologist. You can do this, too.'”

Reference:
Andrew Schwartz et al, Dietary change across the Paleocene-Eocene Thermal Maximum in the mesonychid Dissacus praenuntius, Palaeogeography, Palaeoclimatology, Palaeoecology (2025). DOI: 10.1016/j.palaeo.2025.113089

Note: The above post is reprinted from materials provided by Kitta MacPherson, Rutgers University.