An ancient Maya astronomer-mathematician has been identified for the first time along with his complex calculations made around 1200 years ago, predicting the orbital cycles of Mars and Venus.

“This is the first direct mention of an ancestral Maya astronomer-mathematician by personal name,” says at the Massachusetts Institute of Technology.

It is also the oldest recorded name of an astronomer-mathematician ever known from anywhere in the Americas, he says.

The Maya civilisation flourished in Central America between roughly 2000 BC and AD 1697. They had advanced knowledge of mathematics and astronomy, but much of it was lost after the mass burning of their books by Spanish missionaries.

Since 2010, excavations at the site of Xultun, Guatemala, have revealed astronomical and mathematical inscriptions inside a small masonry building.

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On the east and north-east wall of the building are around 50 texts that scientists believe are “rough drafts” made by Maya mathematicians as they charted and predicted the cycles of celestial objects relative to Earth and to one another.

Rossi and his colleagues have painstakingly deciphered one of these murals, named Text 19. At the bottom of the mural is the name of Sak Tahn Waax, which translates to White-chested Fox, who is believed the be the author of the formula.

Text 19 consists of 11 hieroglyphs, which had to be scanned, photographed and magnified under different illumination angles, and compared to other, later, astronomical-mathematical writings, before their meaning could be deduced.

While similar mathematical and astronomical expertise is found across Maya cities, the mention of Sak Tahn Waax, who the researchers believe was probably male, is unique.

“Whether this is an instance of the scribe himself signing his own calculation or attributing the intellectual work to another, we have a formula and the name of its creator, which serves to demonstrate the importance of this kind of intellectual contribution for Classic Maya people,” says Rossi.

The calendar system on display in Text 19 uses maths in relation to time periods, he says. These time periods were drawn from a 260-day calendar, a 365-day solar calendar, a 584-day approximation of Venus’s synodic cycle (when the planet returns to the same position relative to both Earth and the sun) and a 780-day approximation of Mars’s synodic cycle. The total length of the formula is five Venus synodic cycles or 2920 days, and the date that Text 19 most likely refers to is 7 November of AD 781 in the Julian calendar.

Exactly how this formula would have been applied is unknown, says Rossi, as it “isn’t incorporated into any larger body of work”.

“We think it is meant to concisely and meaningfully show the relationship between these two planets and human counts of time in ways that could then be applied to political ceremony, predictive astronomy and understandings of seasonality,” he says.

Such meticulous mathematical legwork would have been critical to structuring life in a world before computers, smartphones and weather apps, says Rossi.

A 555-million-year-old worm had a predilection for turning right, possibly indicating the oldest known example of handedness.

Although these worms lacked limbs and so couldn’t be considered left- or right-handed in the way that we understand, the development of a tendency to favour one side over another is evidence of an advanced nervous system.

It remains a feature of free-living mobile life today, but until this discovery, it wasn’t thought to have emerged until the Cambrian Period, which began around 541 million years ago.

at the American Museum of Natural History in New York and his colleagues analysed 100 fossil specimens of a small flatworm-like creature, Spriggina floundersi, collected in South Australia over recent decades.

These animals lived during the Ediacaran Period, when multicellular life first became widespread. It preceded the Cambrian explosion, when animal life diversified dramatically and many groups of animals first appeared.

Spriggina lived in what was, half a billion years ago, a shallow ocean and is thought to have foraged on or close to the seafloor, moving by wriggling to the left or right.

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“We have around 50 specimens of Spriggina that are clearly bent,” says Evans. Twice as many of the fossilised worms are bent to the left than to the right, he says. This means the creature itself bent to the right, as the specimens are mirror-image impressions of the animals, made when storms buried them in sand.

“This appears to be statistically significant and matches what biologists find when they study handedness in different animals today,” says Evans. “Some specimens have multiple bends to both the right and left, suggesting that they all could bend both ways, which makes sense if you don’t want to be stuck moving in a circle.”

While the majority seem to demonstrate right-handedness, it is hard to tell if any were left-handed, he says. “I imagine it’s like taking a picture of 100 people waving with one hand today. You would likely be able to count that more people are waving with their right hand, but you wouldn’t be able to tell who is right- or left-handed.”

Discoveries like this demonstrate that many foundational characteristics that are common to a variety of animals today, such as the ability to move around, bilateral symmetry and handedness, evolved in the Ediacaran, says Evans.

In the Cambrian, organisms built on that foundation to become more complex, for example adding legs to move more efficiently, becoming “less alien and more like the major groups of animals we know today”, says Evans. “This is cool because it suggests that, while the Cambrian was an amazing time in animal evolution, those organisms didn’t just come out of nowhere: they built on the foundations established in the Ediacaran.”

“The presence of handedness in any kind of functional asymmetry, really deep into the fossil record, gives us important and interesting information about how these behaviours have evolved and how deeply in time they emerged,” says at Flinders University in Adelaide, Australia.

A huntsman spider found in Queensland, Australia, has been crowned the fastest spider in the world with a top speed of nearly 3.6 metres per second, according to a global study of arachnid sprinting prowess.

Currently, is held by the Moroccan flic-flac spider (Cebrennus rechenbergi) which can hit speeds of 1.7 metres per second when it is startled, using a rolling-tumbling motion. But some experts regard this as incorrect.

“The flic-flac is a special type of locomotion,” says at University of Greifswald, Germany. “It is not running and it only works downhill on sand dunes.”

To get a comprehensive picture of running speed in spiders, Shreyas Kuchibhotla at Imperial College London and his colleagues, including Wolff, collected 162 live spider species during fieldwork throughout the UK, North America, southern Europe and Australia, along with dozens of specimens sourced from pet shops.

Each of these was carefully weighed then tested for their speed on A4 or A3 grid paper, in an attempt to understand the biomechanics across as many species as possible.

Most species were coaxed into running by gently touching them with a paintbrush, but others weren’t so cooperative, says Kuchibhotla. “This project would have been over in a month if spiders could understand English,” he says. “Tarantulas aren’t built for running; they’d much rather stand their ground, so they had to be blown at with puffs of compressed air.”

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Kuchibhotla and his colleagues also collected speed recordings of a further 96 species made by other research teams. The 3-gram jungle huntsman spider (Heteropoda jugulans) was by and his colleagues at the University of the Sunshine Coast in Australia.

These spiders can achieve such high speeds because they are “relatively large as far as spiders go, but not large enough that their legs get over- burdened by a heavy abdomen,” says Clemente.

In general, bigger spiders tended to be faster, but some are much faster than expected for their size. The biggest surprise was the orange goblin spider (Oonops pulcher), which weighs a mere 0.1 milligrams but moved at over 20 centimetres per second. “Nothing could have prepared me for how it practically teleported across the arena,” says Kuchibhotla.

, a team member at Imperial, says speed is, in principle, entirely determined by physics. But it is lifestyles such as hunting strategies that drive the evolution of extreme anatomical and physiological adaptations, he says.

“A cheetah, say, comfortably outruns most similarly sized dogs. This is, of course, because its lifestyle has made this speed beneficial, but it is still dictated by physics,” says Labonte.

After accounting for both body size and shared ancestry, the team’s conclusion is that fast running is associated with relatively longer legs but not with leg slenderness or, surprisingly, whether a spider lives its life upside down or not.

at Edith Cowan University in Perth, Australia, says long legs appear to be a spider’s “speed gear”. “The huntsman supplies the record-book hook, but the deeper discovery is that spider speed is shaped by leg architecture and evolutionary history, not simply by size or whether a spider spins a web,” says Mason.

A huge crater in Western Australia was created by an asteroid strike 3 billion years ago, according to a mineral-dating technique. This would make it the oldest impact crater on Earth – but other researchers have questioned its proposed age.

The North Pole Dome crater, also known as the Miralga impact structure, was first described by at Curtin University in Perth, Australia, and his colleagues in 2025. They estimated that it could be up to 100 kilometres wide.

Kirkland and his team found a layer of rock containing cone-shaped features called shatter cones, which form only after a high-impact event, such as an asteroid strike. Their original study didn’t directly date this rock, but based on correlations with dated rocks in the layers above and below, they proposed that the impact .

This would make it more than 1.2 billion years older than the Yarrabubba crater in the south of the state, which is regarded as the oldest reliably dated asteroid-strike crater on Earth.

It would also make it the only known impact from the Archaean aeon, a time when the entire planet was a giant but inhospitable water world.

However, another team, including , also at Curtin University, strongly contested the 3.47-billion-year date. Based on their own analysis of rocks in the area, the team members argue that the impact took place no earlier than .

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Now, Kirkland and his colleagues say they have successfully dated recrystallised minerals at the crater site, which contain shatter cones. “We have now actually looked inside the rocks and tried to find minerals that directly responded to impact in the rock itself, rather than making correlations,” says Kirkland.

Using the rate of the decay of uranium into lead, the team dated zircons within the shatter cones, which recrystallised as a result of the force of the asteroid strike.

They also dated the mineral apatite, which would have formed in the hydrothermal system created by the heat of the impact.

Both the apatite and the zircons returned dates of around 3.02 billion years old, says Kirkland. “So now we’ve got evidence for very hot water percolating through the rocks 3 billion years ago and also evidence for this really unusual heating and recrystallisation process,” he says.

Kirkland says no other known process, such as mountain building or regional metamorphism, easily explains the mineral changes inside the shocked rocks, because there is no evidence that the area was heated or deformed by those processes at about 3.02 billion years ago.

“The only process really that we can link to these mineralogical changes is an impact,” he says. “So that means the best evidence now is a 3-billion-year-old impact, and that by far is the oldest impact crater on the planet.”

Cavosie welcomes the fact that the age of the crater has been revised significantly, but he thinks Kirkland’s team is still overestimating the crater’s age.

“While I’m relieved these authors have backed off their 2025 ‘3.5-billion-year impact’ hypothesis, I don’t think they’ve presented a compelling case for a [3.02-billion-year] impact either,” says Cavosie. “The slow march of science towards the truth thus continues.”

Cavosie says there are clearly shatter cones in younger rocks that are only 2.77 billion years old, which means the impact must have happened after this date.

at Yale University, who was also part of the group that critiqued the original study, agrees with Cavosie that the rocks must be younger than 2.77 billion years.

“While the new study dismisses this observation because these rocks ‘have not been dated’, they are straightforwardly correlated to nearby rocks that have been dated,” says Brenner.

Kirkland says the key difference is that his team has now directly dated minerals inside the shocked rocks. “The younger age argument still depends on long-distance correlation of undated rocks, largely from satellite-based mapping rather than direct geochemistry or geochronology,” he says. “We now have two mineral clocks from the impact rocks themselves giving the same age. That is why direct dating matters.”

A set of exquisitely preserved 300-million-year-old fossils suggests that early four-limbed vertebrates did not undergo a metamorphosis between their juvenile and adult stages, challenging conventional ideas about the evolution of life on land.

“We have for a very long time assumed that these animals were broadly amphibian-like, and that this life cycle would have bridged the gap between life in the water and life on land,” says at the Field Museum of Natural History in Chicago.

Today’s reptiles, birds, mammals and amphibians belong to a group called tetrapods, which evolved from lobe-finned fish around 390 million years ago. But almost nothing was known about the early developmental stages of these ancestral lobe-finned fish, says at Flinders University in Adelaide, Australia.

Pardo and his colleague , also at the Field Museum, examined a collection of fossils that were unearthed between the 1960s and 1990s at the Mazon Creek fossil site, south-west of Chicago. The preserved animals lived 307 million to 309 million years ago, during the Carboniferous Period.

Embolomeres, which had a body around 2 metres long in adulthood, were the largest tetrapods in the Carboniferous and one of the top predators. They spent most of their time in water, but had small legs with which they could have clambered onto the land.

The fossils included two 2-centimetre-long baby embolomeres, which were so well preserved that the scientists could see soft tissues and even egg yolk.

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In tadpoles, the yolk sac remains inside the body for a few days after hatching as a store of energy. But the young embolomeres had a yolk sac outside the body, similar to the case for some young fish such as lungfish.

Amphibian larvae, such as tadpoles, have external gills that enable them to breathe underwater, but the young embolomeres did not. “The absence of external gills across early development in these animals is the smoking gun,” says Pardo.

The skull and skeleton have “all the important parts seen in an adult embolomere”, says Pardo. The fossils show that embolomeres remained more or less the same from the time they hatched from their eggs until they reached adulthood.

“Human bodies basically work the same way from birth through adulthood, but we get bigger and our proportions change, but we don’t undergo the sort of fast, rapid change you see in a frog or salamander,” says Pardo. “Our fossils show that this sort of life cycle was the norm for our earliest terrestrial ancestors, too.”

Although embolomeres were aquatic, Pardo argues that the evidence available suggests our earliest terrestrial ancestors did not have a tadpole-like stage either. The team also studied the fossil remains of two other early tetrapod species that were alive at the same time and in the same place as the embolomeres.

“None of these show any evidence of a tadpole-like stage,” says Pardo. “Neither do other fishy tetrapod relatives such as early lungfishes and coelacanths. So is it impossible that a tadpole stage showed up somewhere and was subsequently lost? Maybe, but it seems vanishingly unlikely with the data we have.”

This study fills in a much-needed knowledge gap, says Long. “It shows how early tetrapod-like fishes living about 308 million years ago did not need to develop a tadpole phase in order to invade land, as was previously thought by some scientists.”

Fossil hunting in the Australian outback

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