The world’s most famous dinosaur, Tyrannosaurus rex, was probably warm-blooded like birds and mammals, new evidence, obtained from 66-million-year-old tooth enamel, suggests, adding weight to previous findings.

at South Carolina State Museum, who wasn’t involved in the new study, says the research means “the opening to the last Jurassic World flick was one big pile of Hollywood bunk”.

“That film premised that dinosaurs could not survive in the modern world, except near the equator,” says Persons. “Not so. The evidence indicates that a Tyrannosaurus would be comfortable in subtropical and even mild climates.”

at the University of California, Los Angeles, and his colleagues analysed the chemistry in the enamel of three T. rex teeth and compared them with five similarly aged fossilised crocodile teeth.

The researchers also compared their results with data from mammals such as elephants and mammoths to try to determine whether T. rex was also an endotherm – an animal that can regulate its body heat through its metabolism. Ectothermic, or so-called cold-blooded animals like crocodiles, often warm up by basking in the sun instead.

Endothermy is common in large animals and even some fish, says Eagle, allowing them to move around and exhibit more sustained activity to find food and migrate, and to live in colder environments. It has long been thought that many dinosaurs, including T. rex, were also warm-blooded.

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“It comes at a cost though – higher metabolic rates mean higher food requirements and potentially more active hunting to acquire it,” he says.

Within the enamel chemistry, the researchers focused on the abundance of bonds between rare heavy isotopes of carbon and oxygen, known as carbon-13-oxygen-18 bonds. These bonds are more abundant in minerals that form at cold temperatures than minerals that form at warm temperatures.

“Therefore, in a very old tooth we can measure carbon-13-oxygen-18 bond abundance and figure out whether it formed in a hot or cold body.”

He says T. rex had a body temperature of around 36°C, similar to large modern mammals but below many modern birds.

“We also found that the reconstructed temperature of T. rex was significantly elevated compared to temperatures derived from crocodile teeth from the same geological formation – Hell Creek in Montana,” Eagle says.

The researchers also say that T. rex body temperatures were higher than the ambient temperatures in prehistoric Montana, reconstructed both from isotopic estimates and climate models.

“Using thermal performance curves and climate modelling based on these results, we found that the entire North American continent would have been habitable for T. rex in the Cretaceous Period,” he says.

The shocking fossils that show T. rex wasn’t the king of the dinosaurs

We’ve always thought that Tyrannosaurus rex was an unchallenged apex predator during the dying days of the dinosaurs. But a fresh look at controversial fossils has prompted palaeontology’s biggest-ever U-turn

Persons says there was already extensive evidence that T. rex was warm-blooded, including bone growth rates and predator-prey ratios – with energy-hungry endotherms than ectotherms – and a “slew of anatomical traits consistent with high-performance athleticism”.

at Carthage College in Wisconsin says the new work is an “example of science in action, converging upon a single, robust hypothesis, which in this case reveals T. rex as an active top predator”.

The researchers “make the case for a wide geographic distribution for T. rex, showing that it could tolerate cool temperatures in the north of its range and tolerate the tropical temperatures in the south”, says Carr. “And in both cases, T. rex‘s body temperature is higher than the average air temperature. That result is consistent with the hypothesis that T. rex might have migrated from Asia into North America at high latitudes.”

A humpback whale has been observed for the first time shortly after birthing a stillborn calf, showing apparent signs of grief similar to those seen in other large mammals such as elephants.

The encounter began at around 8am on 17 July 2025, when Andrew Mulville at the Sea World Foundation, an Australian charity, was aboard a boat a kilometre offshore from the Gold Coast in Queensland.

He noticed two adult whales milling in the same location, occasionally diving, vocalising and rolling on the surface. By 8.30am, Mulville saw and recorded an amniotic membrane floating on the surface, indicating a birth had occurred but, concerningly, no blood or placenta was visible.

He then placed a camera underwater and saw a stillborn calf, less than 4 metres long, that had sunk to the sandy seabed. The mother repeatedly approached the calf, looked at it eye to eye, and touched it with her head and pectoral fin.

While such behaviour has been recorded in toothed whales with dead calves, it is extremely rare in baleen whales such as humpbacks (Megaptera novaeangliae).

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With a live newborn, humpback mothers typically try to push the calf to the surface to help it breathe, but in this case she didn’t, perhaps suggesting she knew it wasn’t alive.

Meanwhile, the second adult stayed nearby, apparently supporting both the mother and dead calf.

Although stillbirth in mammals is common, it is extremely rare to observe the event in whales, says at Griffith University in Australia, who co-wrote a paper with Mulville on the observation. To his knowledge, it has never before been witnessed in humpback whales.

“It’s really important to not humanise an encounter like this,” says Meynecke. “But then also to understand that it’s a mammal, and we have evidence of, not necessarily grief, but the really dramatic change of behaviour that we see in other mammals such as elephants when they lose a member of their group or when they lose their calves.”

Mulville observed the whales for the next 2 hours, staying in the immediate vicinity of the dead calf and continuously diving down to it. On the next two days, members of the public on shore reported seeing the two adult whales in the same location.

The incident has raised concerns about why the calf was stillborn, especially because seven deceased humpback whale neonates and one deceased young whale of unconfirmed age were also observed in July 2025 in the same region. None of these appeared to be the stillborn whale observed by the scientists.

Also, while it has become increasingly common for humpbacks to calve in southern Queensland as their population has grown, no one is sure why so many female whales are now giving birth hundreds of kilometres south of their traditional breeding grounds in the Great Barrier Reef.

It was also extremely unusual that the mother didn’t deliver her placenta, and this may have also placed her at risk, says Meynecke.

Photos of her distinctive fluke have been uploaded to a database of 16,000 individuals, so the researchers hope she will be recognised if she re-appears in coming seasons.

at the University of Queensland says descriptive case study reports such as this one “run the risk of anthropomorphising observed behaviours”.

“However, the study does present a balanced argument of how the observed behaviour could be interpreted and notes that the terms ‘grief’, ‘emotion’ and ‘distress’ must be used with caution since we cannot definitively assign these terms to the observed behaviour,” says Dunlop.

She says only with “more data and more occurrences” would it be possible to test the hypothesis that what was observed was emotional or grieving behaviour.  

Wild adult chimpanzees have been seen passing tools to youngsters to help them learn and then coaching them, supporting the idea that teaching helps immature chimps acquire technological skills.

“To actually catch it on film is important and was very surprising for us,” says at the University of Barcelona, Spain.

Chimpanzees are known to make and use a variety of tools, from leaf or moss sponges that soak up water to sticks used to fish for or , and even crafting simple spears for hunting. But how chimpanzees learn such skills is debated.

It is clear that the knowledge does get passed on. For example, one study showed an increase in the number of chimps in Uganda using moss as a sponge to soak up water from a pond. Work with captive chimps has also shown that the animals can pass on knowledge to others. The big question is whether individuals copy behaviour after observation, actively teach each other or independently come up with the same solutions to a task.

To see if they could answer that, Hernandez-Aguilar and her colleagues analysed 15 hours of footage from camera traps at the ’s biological station in Dindefelo, Senegal, taken between 2017 and 2025. The cameras were placed near 14 sites in the area where wild western chimpanzees (Pan troglodytes verus) had previously been recorded using tools, including fishing for algae, army ants and termites.

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In total, the camera traps recorded 33 instances of tool transfer from one chimp to another: 19 when they were dipping for ants to eat, 10 during fishing for algae and four when fishing for termites. Generally, a chimp handed the key object to a close relative, and in 30 per cent of cases, this was from a mother to her offspring.

In one video, a mother, Soukki, inserted a dipping stick into an ant nest, then grabbed her baby daughter, Saïsaï, and led her to the tool. Saïsaï pulled the stick out and ate the ants clinging to it.

“We found support for the idea that tool transfers are a form of teaching that experienced chimpanzees may use to facilitate the learning of young individuals,” says team member , also at the University of Barcelona.

The team also gathered 30 minutes of footage from cameras at 11 sites where chimpanzees to crack them open. This is considered proto-tool use rather than tool use, because the stones are being used as an anvil rather than being directly held and manipulated.

In an example of this, a mother called Féré collected three baobab fruits and placed them near her infant son Fotti. A juvenile male – probably an older sibling – picked up a fruit and pounded it against some rocks while Fotti watched, then guided Fotti’s hand to a fruit. Fotti had a go himself, eventually managing to open up a fruit.  

The videos support the idea that other social mechanisms such as observation and supervised practice help youngsters learn to use tools, says Sánchez-Megías.

“Teaching events are quite rare and difficult to study because only so many learning attempts are needed until an individual learns a behaviour,” says at the Max Planck Institute of Animal Behavior in Germany. “Showing across many forms of tool use that these tool transfers are indicative of a very simple form of teaching is very cool and nice.”

During the observed interactions, the researchers noted that the teacher was forgoing food for the learning youngster’s benefit.

“This is an important observation because it fits the criteria for teaching used in animal behaviour research – that the behaviour benefits the pupil’s opportunities to learn, and is done despite having a cost to the teacher,” says at the University of St Andrews, UK.

A bird that was eaten and partially excreted by a dinosaur 66 million years ago has left behind the best-preserved feathers ever recovered by scientists from dinosaur-age rock. This pushes the evolution of feathers, like the ones on modern birds, back by 10 million years and may tell us more about why most birds didn’t survive the post-asteroid mass extinction.

“This is the best feather we’ve ever seen in a Mesozoic [252 million to 66 million years ago] deposit,” says at the Field Museum in Chicago. “[It’s] like a feather you could pick up off the ground.”

Birds were the only dinosaurs to survive the mass extinction triggered by an asteroid strike 66 million years ago. But, puzzlingly, only one branch made it through: neornithes, the ancestors of every bird alive today.

In 2016, at the University of Washington in Seattle was collecting fish fossils in north-eastern Montana’s Hell Creek Formation when he discovered a broken coprolite, a fossilised dropping, with a feather clearly visible along its fractured surface. “I couldn’t believe what I was seeing,” he says.

A few years later, he invited O’Connor to team up with him and his colleagues to analyse the coprolite using micro-CT scans and 3D surface scanning. Two leg-bone fragments, 18 and 12 millimetres long, resembled some previously found at Hell Creek and attributed to hesperornithiformes. These were flightless, short-winged diving birds, similar to modern loons (Gaviiformes) or grebes (Podicipediformes), and were related to Neornithes.

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Further analyses showed that the 9.3-millimetre-long primary feather had a water-repellent structure, similar to that of modern pelicans, says O’Connor. Both this and a second, smaller wing feather also had lightweight, spongy cores surrounded by a harder outer layer. This combination makes them both light and stiff, which is typical of modern feathers.

“What is exciting is to push the occurrence of modern feathers into non-modern birds,” says O’Connor. Differences in plumage are emerging as a major contributing factor as to why some birds survived while others didn’t, she says.

The team also found two fluffy body feathers with loosely arranged branches, echoing in a lineage that didn’t survive the extinction event.

Combined, this suggests that the bird the feather belonged to – and hesperornithiformes in general – had a “middle ground” of primitive and modern plumage, says O’Connor. While the wing and tail feathers might have allowed for successful diving, for example, the less advanced body feathers would have been relatively poor insulators, making the animals more vulnerable to the “winter” that occurred after the asteroid impact.

“These are the feathers that are responsible for keeping the body warm, right?” says O’Connor. “So maybe these primitive feathers were good enough to keep them warm during the greenhouse world of the Mesozoic, but not good enough to keep them warm during this environmental catastrophe that was triggered by this impact event.”

Dinosaur hunting in the Gobi desert: Mongolia

Embark on an exhilarating and one-of-a-kind expedition to uncover dinosaur remains in the vast wilderness of the Gobi desert, one of the world’s most famous palaeontological hotspots.

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The dropping – which probably came from a Nanotyrannus or a young Tyrannosaurus rex – also contained two rigid, diamond-shaped scales, 3 to 4 millimetres long. The researchers think this came from a gar (Lepisosteidae), a narrow-bodied fish that still exists today. This would have been too small for the dinosaur predator and thus was probably eaten by the bird.

“This discovery is really exciting,” says at the University of Connecticut. “It opens up so many questions about how feathers evolved, what they were originally used for, and how they came to perform so many different functions in modern birds.”

The links among the different animals involved are also fascinating, says Muzio. “Discoveries like this really make the imagination run wild,” he says. “From a single coprolite, we are learning about at least three individual species – morphologically, ecologically and evolutionarily. What more can you ask for?”

When it comes to gigantic predatory dinosaurs one animal reigns supreme: Tyrannosaurus rex, the tyrant lizard king, or T. rex for short. But what if T. rex never existed the way you might picture it? For almost 100 years, we’ve imagined T. rex as a lone king, an apex predator overseeing their world unchallenged. But that’s wrong. A new T. rex fossil has since changed everything we know about this iconic carnivore and revealed something astonishing: the T. rex isn’t just one species, but many. Meet Nanotyrannus.

The Dinosaur Extinction Was More Complicated Than You Think

The dinosaur-ending asteroid may have been especially devastating due to its angle

We cannot live without soil. It provides us with building materials, most of our antibiotics and 95 per cent of our food.

In, photographer and soil ecologist Frank Ashwood urges us to better appreciate and protect the soil we rely on. He does so with stunning images of the creatures that call soil home.

The adorable velvet worm in the main image was found under a log in a misty beech forest on the South Island of New Zealand. “They look like little worms rolled in sequins,” says Ashwood. But looks can be deceiving: “They crawl around and shoot glue out of special organs on their heads to immobilise their pray, which they’ll then go and eat while alive.”

A droplet of sperm deposited by a male springtail, a tiny insect-like creature, sits atop a delicate stem made of protein-rich secretions in the image below. “It’s like a lollipop, basically, with a bit of sperm-rich fluid on the top, which the males leave for the females to come and find,” says Ashwood.

But beware any marauding rivals. “If a male finds another springtail’s spermatophore, they will actually eat it to destroy it,” he says.

Below, a beautiful woodlouse spider stares straight down the lens of Ashwood’s camera. Its large fangs have evolved to better hunt woodlice. “They’ll come at a woodlouse from the top or the side, grasp it, then reach underneath with those sharp bits of the fangs and pierce into the soft underbelly,” he says.

A bright yellow slime mould stretches across a decaying log in the shot below. “It’s a big, sprawling mass of a single cell, essentially; they branch out looking for food,” says Ashwood. The mould’s efficient networks have been used to map road networks, the fastest way out of an IKEA showroom and dark matter throughout the universe, he says.

This gorgeous giant springtail, below, was found in a forest in New Zealand. Its orange spines help it camouflage against logs. “Because they’re rare, when you do see one, it’s a moment of pure exhilaration,” says Ashwood. “They’re an indicator of the forest being in really good condition.”

Ashwood, who is based at Lincoln University in New Zealand, snapped the silvery springtail below while in the UK. During the Victorian period in the 1800s, their iridescent scales were used to test microscopes. “They’ve got really ornate, tiny sculpturing on them, so the better detail you could see, the better your microscope,” he says.

Ashwood hopes his book will encourage people to protect soil, for instance by reducing deforestation and farming more sustainably. “Over half of the world’s biodiversity is in soil, and we’re losing it at a rate that is not sustainable,” he says.

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Young pygmy raccoons on a Mexican island have been seen teaching each other to make toy balls out of rubbish, in a rare example of animals crafting objects purely to play with.

“My first reaction was, oh my gosh, that’s absolutely adorable!” says at Miami University in Ohio, who is researching the impact of tourism on the critically endangered pygmy raccoons (Procyon pygmaeus) of Cozumel Island.

O’Neil filmed as one of the younger raccoons fished paper out of a rubbish bin, dipped it in a bowl of water and rolled it in sand, making a ball.

Over days of observation, she recorded the animals as they made more balls and used them to play “football” with other raccoons and dwarf coatis (Nasua narica nelsoni), another raccoon-like animal. Siblings taught each other the ball-making procedure, and even tried to get their mother involved, though she couldn’t quite figure it out – her coordination seemed to have been impaired after drinking a margarita she found at a beach bar earlier that day.

O’Neil’s colleague at Miami University, was impressed by the footage. While others have watched animals like chimps or tigers at play, researchers have seldom seen animals custom-making toys for later use. “It shouldn’t be surprising that raccoons are where we’re seeing this, just because they’re so tactile, they see with their hands,” says Szydlowski.

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“The observations show how complex animal play behaviour can be,” says at the Institute of Animal Science in the Czech Republic. “It will be intriguing to see whether the behaviour will get a hold in the population as a new cultural trait or will disappear.”

The observations may also help with conservation efforts. There are fewer than 200 pygmy raccoons on Cozumel, the only place the species is found. Understanding how they learn from each other might help conservationists discourage unhealthy behaviours like stealing margaritas and begging for snacks, and reacquaint them with foraging in the wild. And O’Neil hopes increased awareness of the animals will bring more support. “I really just want people to know that they are out there, and they need people to care,” she says. “And please don’t feed them!”