Legend once had it that the huge, three-toed footprints scattered across the central highlands of Bolivia came from supernaturally strong monsters—capable of sinking their claws even into solid stone.

Then scientists came here in the 1960s and dispelled children’s fears, determining that the strange footprints in fact belonged to gigantic, two-legged dinosaurs that stomped and splashed over 60 million years ago, in the ancient waterways of what is now Toro Toro, a village and popular national park in the Bolivian Andes.

Now, a team of paleontologists, mostly from California’s Loma Linda University, have discovered and meticulously documented 16,600 such footprints left by theropods, the dinosaur group that includes the Tyrannosaurus rex. Their study, based on six years of regular field visits and published in the peer-reviewed journal PLOS One, reports that this finding represents the highest number of theropod footprints recorded anywhere in the world.

“There’s no place in the world where you have such a big abundance of (theropod) footprints,” said Roberto Biaggi, a co-author of the study led by Spanish paleontologist Raúl Esperante. “We have all these world records at this particular site.”

Prints record dinosaur behavior—including attempts to swim

The dinosaurs that ruled the earth and roamed this region also made awkward attempts to swim here, according to the study, scratching at what was squishy lake-bottom sediment to leave another 1,378 traces.

They pressed their claws into the mud just before water levels rose and sealed their tracks, protecting them from centuries of erosion, scientists said.

“The preservation of many of the tracks is excellent,” said Richard Butler, a paleontologist at the University of Birmingham who was not involved in the research. He said that, to his knowledge, the number of footprints and trackways found in Toro Toro had no precedent.

“This is a remarkable window into the lives and behaviors of dinosaurs at the end of the Cretaceous,” Butler added, referring to the period around 66 million years ago at the end of which an asteroid impact abruptly extinguished all dinosaurs and 75% of living species along with them, according to scientists.

Footprints face preservation threats

Although they’ve survived for millions of years, human life has threatened these traces. For decades, farmers threshed corn and wheat on the footprint-covered plateaus. Nearby quarry workers didn’t think much of the formations as they blasted rock layers for limestone. And just two years ago, researchers said, highway crews tunneling through hillsides nearly wiped out a major site of dinosaur tracks before the national park intervened.

Such disturbances may have something to do with the area’s striking absence of dinosaur bones, teeth and eggs, experts say. For all of the footprints and swim traces found across Bolivia’s Toro Toro, there are virtually no skeletal remains of the sort that litter the peaks and valleys of Argentine Patagonia and Campanha in Brazil.

But the lack of bones could have natural causes, too. The team said the quantity and pattern of tracks—and the fact they were all found in the same sediment layer—suggest that dinosaurs didn’t settle in what is now Bolivia as much as trudge along an ancient coastal superhighway stretching from southern Peru into northwest Argentina.

The range in footprint sizes indicated that giant creatures roughly 10 meters (33 feet) tall moved in a herd with tiny theropods the size of a chicken, 32 centimeters (1 foot) tall at the hip.

In presenting a snapshot of everyday behavior footprints “reveal what skeletons cannot,” said Anthony Romilio, a paleontologist at the University of Queensland in Australia who also did not participate in the study. Just from footprints, researchers can tell when dinosaurs strolled or sped up, stopped or turned around.

It’s not clear why so many dinosaurs roamed the site

But the reason they flocked in droves to this wind-swept plateau remains a mystery.

“It may have been that they were all regular visitors to a large, ancient, freshwater lake, frequenting its expansive muddy shoreline,” offered Romilio.

Biaggi suggested that they were “running away from something or searching for somewhere to settle.”

What’s certain is that research into this treasure trove of a dinosaur tracksite will continue.

“I suspect that this will keep going over the years and many more footprints will be found right there at the edges of what’s already uncovered,” Biaggi said.

Reference:
Morphotypes, preservation, and taphonomy of dinosaur footprints, tail traces, and swim tracks in the largest tracksite in the world: Carreras Pampa (Upper Cretaceous), Torotoro National Park, Bolivia, PLOS One (2025). DOI: 10.1371/journal.pone.0335973

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

An international team, involving researchers from the University of Seville, the Andalusian Institute of Earth Sciences in Granada and the University of Huelva, has identified the first fossilized vertebrate footprints from the Quaternary period in fossil dune deposits in Murcia, attributed to the elephant Palaeoloxodon antiquus, known as the straight-tusked elephant.

The study “New vertebrate footprint sites in the latest interglacial dune deposits on the coast of Murcia (southeast Spain). Ecological corridors for elephants in Iberia?” published in the journal Quaternary Science Reviews, reconstructs the movement routes of megafauna during the Last Interglacial, some 125,000 years ago. This record of footprints in coastal landscapes provides remarkable information about Iberian paleoecology.

The research was based on prospecting campaigns on the Murcian coast, in the areas of Calblanque and Torre de Cope, coordinated by Carlos Neto de Carvalho, from the Geology Office of the Municipality of Idanha-a-Nova and the University of Lisbon. The researchers Fernando Muñiz Guinea and Miguel Cortés-Sánchez, from the University of Seville, Francisco J. Jiménez Espejo and Jon Camuera, from IACT-CSIC (Granada), and Luis M. Cáceres, from the University of Huelva, participated in these campaigns. The team was completed by experts from Portugal, such as Noel Moreira (University of Évora) and João Belo (University of Coimbra).

Not only elephants, but also wolves and deer

Thanks to this work, the study has confirmed the existence of four areas with fossil footprints that evidence the presence of a very diverse community of mammals in a coastal forest ecosystem during the marine isotopic stage (MIS 5e) of Earth.

The main finding comes from Torre de Cope, where a 2.75-meter-long proboscidean trackway has been preserved, consisting of four rounded footprints 40–50 cm in diameter. The arrangement, typical of the quadrupedal gait of elephants, has made it possible to estimate that the trackway belonged to an adult Palaeoloxodon antiquus about 2.3 meters tall at the hip, over 30 years old and weighing approximately 2.6 tonnes.

Moreover, traces of a medium-sized mustelid have been found in Calblanque. The trail, one and a half meters long and consisting of ten almost circular footprints arranged in pairs, suggests slow movements near water sources. An isolated footprint of a canid, measuring 10 × 8 cm, with claw marks, has also been found in this area, pointing to the presence of predators such as wolves (Canis lupus) in wooded habitats.

In addition, bifid footprints up to 10 cm in size have been identified as compatible with red deer (Cervus elaphus). Their westward orientation indicates movement through dunes and scrubland. Meanwhile, the trail of a young equid (Equus ferus), with footprints measuring approximately 10 × 12 cm, represents the most recent record of this species in the south-east of the peninsula.

Taken together, these data support the hypothesis of coastal ecological corridors for seasonal migrations, connecting Mediterranean forests with beaches in a more humid landscape.

Coastal corridors and Neanderthal life in the Iberian Pleistocene

The possible megafaunal corridors located on the coast of Murcia open up a broader reflection on the role played by the Iberian Peninsula during the Pleistocene. This territory would have acted as a climate refuge for fauna and flora, as well as serving as a route for large mammals, including elephants.

In this study, the authors establish a connection between these coastal ecological corridors and paleoanthropology, showing a geographical coincidence between the routes followed by elephants in south-eastern Iberia and the sites with Neanderthal presence. These coastal areas would therefore have been rich in resources and key areas for hunting and subsistence for Neanderthal populations.

Reference:
Carlos Neto de Carvalho et al, New vertebrate tracksites from the Last Interglacial dune deposits of coastal Murcia (southeastern Spain): ecological corridors for elephants in Iberia?, Quaternary Science Reviews (2025). DOI: 10.1016/j.quascirev.2025.109631

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

For the first time, scientists have analyzed metabolism-related molecules from the fossilized bones of animals that lived 1.3 to 3 million years ago, revealing insights about both the animals and their environments.

The metabolic clues about the animals’ health and diets enabled researchers to paint a picture of their living conditions, including the temperature, soil, rainfall, and vegetation.

Their findings, published in Nature, reveal warmer and wetter conditions across these environments compared to today.

Studying metabolites—the molecules produced and used in digestion and other chemical processes in the body—can provide information about health and disease, as well as external factors like diet and environmental exposures.

While metabolomic research is increasingly used in studying human diseases and drugs, few scientists have explored its use in understanding the prehistoric world. Instead, they largely focus on DNA in fossils, which is primarily used for establishing genetic relationships.

“I’ve always had an interest in metabolism, including the metabolic rate of bone, and wanted to know if it would be possible to apply metabolomics to fossils to study early life. It turns out that bone, including fossilized bone, is filled with metabolites,” said Timothy Bromage, professor of molecular pathobiology at NYU College of Dentistry and affiliated professor in NYU’s Department of Anthropology, who led this study with an international team of researchers.

Measuring metabolites

In recent years, paleontologists learned that collagen—the protein that provides structure to bones, skin, and connective tissues—can be preserved in ancient bones, including those of dinosaurs.

“I thought, if collagen is preserved in a fossil bone, then maybe other biomolecules are protected in the bone microenvironment as well,” said Bromage, who directs the Hard Tissue Research Unit at NYU College of Dentistry.

The surfaces of bones are spongy and surrounded by capillary networks, exchanging oxygen and nutrients between the bloodstream and bones. Bromage suspected that, during the process of bone formation, metabolites carried in the bloodstream enter and become trapped in tiny niches in bone.

To test this idea, the researchers employed mass spectrometry, an analytical technique that converts molecules into ions, to see if they could extract metabolites from bone. Using present-day mouse bones, they identified nearly 2,200 metabolites for analysis. The technology also analyzed proteins to detect collagen in some bone samples.

The researchers then turned to animal fossils from 1.3 million to 3 million years ago, collected for prior paleontological research at sites in Tanzania, Malawi, and South Africa where early humans lived.

Focusing on species with living counterparts near these sites today, they used the same analytical methods on fossilized bone fragments from rodents (mouse, ground squirrel, gerbil), as well as an antelope, pig, and elephant.

The analyses yielded thousands of metabolites, many of which were shared with modern-day animals.

The stories fossils tell

Many of the metabolites the researchers found in the fossilized bones represent normal biological functions, including the metabolism of amino acids, carbohydrates, and vitamins and minerals. Several pointed to genes associated with estrogen, suggesting that some of the animals were female.

Other metabolites revealed the animals’ response to disease. Notably, in the bone of a 1.8-million-year-old ground squirrel from the Olduvai Gorge in Tanzania, the researchers found evidence that the squirrel was infected with a parasitic disease known as sleeping sickness in humans, caused by the Trypanosoma brucei parasite and transmitted by the tsetse fly.

“What we discovered in the bone of the squirrel is a metabolite that is unique to the biology of that parasite, which releases the metabolite into the bloodstream of its host. We also saw the squirrel’s metabolomic anti-inflammatory response, presumably due to the parasite,” said Bromage.

The researchers could also deduce what plants the animals ate. While data on plant metabolites are much more limited than those documented in human and animal health, they identified the metabolites of several regionally specific plants, including forms of aloe and asparagus.

“What that means is that, in the case of the squirrel, it nibbled on aloe and took those metabolites into its own bloodstream,” explained Bromage.

“Because the environmental conditions of aloe are very specific, we now know more about the temperature, rainfall, soil conditions, and tree canopy, essentially reconstructing the squirrel’s environment. We can build a story around each of the animals.”

The reconstructed environments corroborate what other research has found about these settings millions of years ago—for instance, that the Olduvai Gorge Bed in Tanzania was freshwater woodland and grassland, while the Olduvai Gorge Upper Bed was dry woodland and marsh. Across all of the sites studied, the conditions in which the animals lived were wetter and warmer than the regions are today.

“Using metabolic analyses to study fossils may enable us to reconstruct the environment of the prehistoric world with a new level of detail, as though we were field ecologists in a natural environment today,” said Bromage.

Reference:
Timothy Bromage, Palaeometabolomes yield biologic and ecologic profiles at early human sites, Nature (2025). DOI: 10.1038/s41586-025-09843-w.

Note: The above post is reprinted from materials provided by New York University.

A wildlife photographer stumbled upon one of the oldest and largest known collections of dinosaur footprints, dating back about 210 million years to the Triassic Period, high in an Italian national park near the 2026 Milan Cortina Winter Olympic venue of Bormio, officials announced Tuesday.

The discovery in the Stelvio National Park was striking for the sheer number of footprints, estimated at as many as 20,000 over some five kilometers (three miles), and the location near the Swiss border, once a prehistoric coastal area, that has never previously yielded dinosaur tracks, experts said.

“This time reality really surpasses fantasy,” said Cristiano Dal Sasso, a paleontologist at Milan’s Natural History Museum, who received the first call from wildlife photographer Elio Della Ferrera after making the discovery.

The dinosaur prints are believed to have been made by long-necked bipedal herbivores that were up to 10 meters (33 feet) long, weighing up to four tons, similar to a Plateosaurus, Dal Sasso said. Some of the tracks were 40 centimeters wide, with visible claws.

The footprints indicated that the dinosaurs traveled in packs and they sometimes stopped in circular formations, possibly as a protective measure.

“There are very obvious traces of individuals that have walked at a slow, calm, quiet rhythmic pace, without running,” Dal Sasso told a press conference.

The tracks were discovered by Della Ferrera, who set out to photograph deer and vultures in September when his camera was trained on a vertical wall about 600 meters (nearly 2,000 feet) above the nearest road.

The location, some 2,400 to 2,800 meters (7,900-9,200 feet) above sea level on a north-facing wall that is mostly in the shade, made the footprints, though in plain sight, particularly hard to spot without a very strong lens, Dal Sasso said.

Della Ferra said something strange caught his eye, and he scaled a vertical rock wall with some difficulty to get a closer look.

“The huge surprise was not so much in discovering the footprints, but in discovering such a huge quantity,” Della Ferrara said. “There are really tens of thousands of prints up there, more or less well-preserved.”

The entrance of the park, where the prints were discovered, is located just two kilometers (a mile) from the mountain town of Bormio, where Men’s Alpine skiing will be held during the Feb. 6-22 Games.

Lombardy regional governor, Attilio Fontana, hailed the discovery as a “gift for the Olympics,” even if the site is too remote to access in the winter, and plans for eventual public access have not been made.

Note: The above post is reprinted from materials provided by The Associated Press. All rights reserved.

A research group led by an evolutionary biologist at Johns Hopkins Medicine reports that giant reptiles living as far back as 220 million years ago may have developed the ability to fly at the very start of their evolutionary history. This contrasts with the ancestors of modern birds, which are thought to have reached powered flight more slowly and with larger, more complex brains.

Details of the investigation, which relied on advanced imaging methods to examine the internal brain cavities of pterosaur fossils and received partial support from the National Science Foundation, appeared Nov. 26 in Current Biology.

According to Matteo Fabbri, Ph.D., assistant professor of functional anatomy and evolution at the Johns Hopkins University School of Medicine, the results strengthen the idea that the enlarged brains seen in birds and likely in their ancestors were not responsible for allowing pterosaurs to take to the air.

“Our study shows that pterosaurs evolved flight early on in their existence and that they did so with a smaller brain similar to true non-flying dinosaurs,” Fabbri says.

Giant Fliers With Surprising Brain Structure

Fabbri describes pterosaurs as powerful airborne predators of the dinosaur era, capable of reaching 500 pounds in some species and stretching up to 30 feet across the wings. Pterosaurs are recognized as the earliest of the three major vertebrate lineages (in addition to birds and bats) that eventually achieved powered flight on their own.

To investigate how pterosaurs gained this ability and whether their path differed from that of birds and bats, the team examined the reptile’s evolutionary history. They looked closely at shifts in the shape and size of the brain over time and focused on the optic lobe, the region involved in vision that has been linked to flight capabilities.

CT Scans Reveal Clues From Early Relatives

Using CT imaging and specialized software that allowed them to digitally model fossilized nervous system structures, the researchers concentrated on the closest known relative of the pterosaur. This animal, the flightless and tree-climbing lagerpetid, was first identified by scientists in 2016 and lived during the Triassic period between 242 and 212 million years ago. In 2020, another team confirmed the lagerpetid’s close evolutionary connection to pterosaurs.

“The lagerpetid’s brain already showed features linked to improved vision, including an enlarged optic lobe, an adaptation that may have later helped their pterosaur relatives take to the skies,” says corresponding author Mario Bronzati, a researcher at University of Tübingen, Germany.

Fabbri notes that pterosaurs also had enlarged optic lobes. Outside of this trait, however, he explains that their brain shape and size differed considerably from those of the lagerpetid.

“The few similarities suggest that flying pterosaurs, which appeared very soon after the lagerpetid, likely acquired flight in a burst at their origin,” Fabbri says. “Essentially, pterosaur brains quickly transformed acquiring all they needed to take flight from the beginning.”

Comparing Pterosaur and Bird Flight

In contrast, modern birds are thought to have evolved flight through a more gradual process. They appear to have inherited several key traits, including expansion of the cerebrum, cerebellum and optic lobes, from earlier relatives before further adapting these regions for flight, Fabbri says. Support for this gradual model comes from 2024 research from the laboratory of Amy Balanoff, Ph.D., assistant professor of functional anatomy and evolution at Johns Hopkins Medicine, which highlights the importance of cerebellum expansion in the origins of bird flight. The cerebellum is located at the back of the brain and helps regulate muscle coordination and other functions.

“Any information that can fill in the gaps of what we don’t know about dinosaur and bird brains is important in understanding flight and neurosensory evolution within pterosaur and bird lineages,” Balanoff says.

Insights From Fossilized Brains Across Species

The team also examined brain cavities from crococdylians (crocodile ancestors) and early, extinct birds, comparing these structures with those of pterosaurs.

Their analysis showed that pterosaurs had moderately enlarged brain hemispheres, a feature comparable to other dinosaur groups. These include two-legged, bird-like troodontids that lived between the Late Jurassic and Late Cretaceous periods from 163 to 66 million years ago, as well as Archaeopteryx lithographica, the oldest-known bird that lived between 150.8 and 125.45 million years ago. These prehistoric species differ strongly from modern birds, which have significantly larger brain cavities.

Looking Ahead to Future Research

Fabbri says that future progress will depend on understanding how the brain’s internal structure, not just its size and shape, enabled pterosaurs to achieve flight. He explains that this will be essential for uncovering the broader biological principles that govern the evolution of flight.

Funding support for this research was provided by the Alexander von Humboldt Foundation, Brazilian Federal Government, The Paleontological Society, Agencia Nacional de Promoción Científica y Técnica, Conselho Nacional de Desenvolvimento Científico e Tecnológico, the European Union NextGeneration EU/PRTR, the National Science Foundation ( NSF DEB 1754596, NSF IOB-0517257, IOS-1050154, IOS-1456503), and the Swedish Research Council

In addition to Fabbri and Bronzati, other scientists who contributed to this research are Akinobu Watanabe from New York Institute of Technology, Roger Benson from the American Museum of Natural History, Rodrigo Müller from Federal University of Santa Maria, Brazil, Lawrence Witmer from the University of Ohio, Martín Ezcurra and M. Belén von Baczko from Bernardino Rivadavia Museum of Natural Science, Felipe Montefeltro from São Paulo State University; Bhart-Anjan Bhullar from Yale University; Julia Desojo from Universidad Nacional de La Plata, Argentina; Fabien Knoll from Museo Nacional de Ciencias Naturales, Spain; Max Langer from Universidade de São Paulo, Brazil; Stephan Lautenschlager from University of Birmingham; Michelle Stocker and Sterling Nesbitt from from Virginia Tech; Alan Turner from Stony Brook University; and Ingmar Werneburg from Eberhard Karls University of Tübingen.

Reference:
Mario Bronzati, Akinobu Watanabe, Roger B.J. Benson, Rodrigo T. Müller, Lawrence M. Witmer, Martín D. Ezcurra, Felipe C. Montefeltro, M. Belén von Baczko, Bhart-Anjan S. Bhullar, Julia B. Desojo, Fabien Knoll, Max C. Langer, Stephan Lautenschlager, Michelle R. Stocker, Alan H. Turner, Ingmar Werneburg, Sterling J. Nesbitt, Matteo Fabbri. Neuroanatomical convergence between pterosaurs and non-avian paravians in the evolution of flight. Current Biology, 2025; DOI: 10.1016/j.cub.2025.10.086

Note: The above post is reprinted from materials provided by Johns Hopkins Medicine.

Around 130 million years ago, the ocean’s most dominant hunters held far more power than any marine predator alive today. Recent research from McGill University reveals that during the Cretaceous period, some sea creatures sat at the very top of an extraordinarily complex food chain, surpassing modern standards of ecological dominance.

The findings come from a study published in the Zoological Journal of the Linnean Society, which reconstructs the ancient marine ecosystem preserved in Colombia’s Paja Formation. According to the research, this prehistoric sea was filled with enormous marine reptiles, some growing longer than 10 meters, that occupied a previously unseen seventh level of the food chain.

What Trophic Levels Reveal About Food Chains

Trophic levels describe an organism’s position in a food chain based on how it gets energy and nutrients. Put simply, they explain who eats whom within an ecosystem. In today’s oceans, food chains typically reach only six levels, with animals such as killer whales and great white sharks sitting at the top.

The discovery of predators operating at a seventh trophic level highlights just how rich and complex the Paja ecosystem once was. It also offers rare insight into a deep evolutionary struggle, where predators and prey continuously adapted in response to one another.

Reconstructing a Lost Marine Ecosystem

To uncover this ancient food web, McGill researchers analyzed all known animal fossils from a single geological formation in central Colombia. They built a detailed ecological network using fossil body sizes, feeding traits, and comparisons with modern animals that fill similar roles today.

To ensure accuracy, the team compared their reconstructed network with one of the most comprehensive modern marine ecosystem models available, based on living Caribbean environments. This allowed them to test whether their ancient model behaved realistically when measured against present-day ocean systems.

A Time of Explosive Marine Diversity

The Paja Formation dates back to the Mesozoic era, a time that included the Cretaceous period and was shaped by rising sea levels and warmer global temperatures. These conditions fueled a surge in marine biodiversity. The region supported plesiosaurs, ichthyosaurs, and large numbers of invertebrates, creating one of the most intricate marine food webs ever identified.

“Our study is the first to examine these possible ecological interactions,” said Dirley Cortés, lead author and doctoral student in the Department of Biology. “Understanding this complexity helps us trace how ecosystems evolve over time, shedding light on the structures that support today’s biodiversity.”

“These findings illuminate how marine ecosystems developed through intense trophic competition and shaped the diversity we see today,” added Hans Larsson, co-author of the study and Professor in the Department of Biology.

Why This Discovery Matters

The researchers note that this work marks only an early step in understanding ancient marine ecosystems. Very few fossil sites have been studied in enough detail to rebuild entire food webs. As more discoveries emerge, scientists will be able to compare ecosystems across different regions and time periods, deepening knowledge of how ancient oceans influenced the modern seas we depend on today.

“Top of the food chains: an ecological network of the marine Paja Formation biota from the Early Cretaceous of Colombia reveals the highest trophic levels ever estimated” by Dirley Cortés and Hans Larsson, was published in the Zoological Journal of the Linnean Society.

The research was supported by funding from the McGill-STRI Neotropical Environment Option (NEO) and the Natural Sciences and Engineering Research Council of Canada (NSERC).

Reference:
Dirley Cortés, Hans C E Larsson. Top of the food chains: an ecological network of the marine Paja Formation biota from the Early Cretaceous of Colombia reveals the highest trophic levels ever estimated. Zoological Journal of the Linnean Society, 2024; 202 (1) DOI: 10.1093/zoolinnean/zlad092

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