Ancient reptile tracks rewrite when animals conquered land
PARIS - After a brief rain in part of the ancient supercontinent of Gondwana 350 million years ago, a reptile pressed its small claws into the still-wet ground.
Its tracks, which have been discovered in Australia, mean it is the oldest-known vertebrate animal to have permanently abandoned the oceans for dry land, a study suggested on Wednesday.
It also significantly pushes back the date for when these four-limbed pioneers made this important evolutionary step that would eventually lead to humans conquering the globe.
The tracks were found by amateur archaeologists on a 30-centimetre-wide sandstone slab in a mountainous area of the southeastern Australian state of Victoria.
First there was a single footprint of an unknown animal which has "raindrop pockmarks all over it," Per Ahlberg, a palaeontologist at Sweden's Uppsala University, told AFP.
This suggests it was made before the brief shower, said the senior author of a new Nature study describing the discovery.
Then there were two sets of tracks from after the rain.
The second set of tracks suggests this reptile ancestor "was in more of a hurry", he added.
"You see the claws making long scratches on the ground."
- 'Keyholes' into 'lost world' -
The researchers cannot determine whether both sets of tracks were made by the same individual animal, but Ahlberg thinks this is unlikely.
The animal was 60-80 centimetres long and would have looked "quite lizard-like", he added.
That the animal had claws is a clear sign it was an amniote, a group of animals which today includes mammals, birds and reptiles.
Its ancestor tetrapods -- notable for their four limbs -- split into two groups, amniotes and amphibians.
While amphibians had to return to water to lay their eggs, amniotes evolved to have eggs strong enough to survive on land, shedding its last connection to water life.
The discovery indicates that amniotes existed 35 to 40 million years earlier than previously thought, during the turn of the Devonian and Carboniferous periods, the study said.
This suggests the "water-to-land-dwelling transition" may have taken place in just 50 million years, much quicker than had been believed, Stuart Sumida of California State University commented in Nature.
That would be just the latest twist in the tale of how animals rose from the ocean to dominate the land.
"The only way to ever understand it is to look through these tiny little keyholes that we find into this strange, dark, lost world," Ahlberg said.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Daily Maverick
3 days ago
- Daily Maverick
X-rays have revealed a mysterious cosmic object never before seen in our galaxy
After the initial discovery, we began follow-up observations using telescopes around the world, hoping to catch more pulses. With continued monitoring, we found the radio pulses from ASKAPJ1832 arrive regularly — every 44 minutes. This confirmed it as a new member of the rare long-period transient group. In a new study published today in Nature, we report the discovery of a new long-period transient — and, for the first time, one that also emits regular bursts of X-rays. Long-period transients are a recently identified class of cosmic objects that emit bright flashes of radio waves every few minutes to several hours. This is much longer than the rapid pulses we typically detect from dead stars such as pulsars. What these objects are, and how they generate their unusual signals, remains a mystery. Our discovery opens up a new window into the study of these puzzling sources. But it also deepens the mystery: the object we found doesn't resemble any known type of star or system in our galaxy – or beyond. Watching the radio sky for flickers There's much in the night sky that we can't see with human eyes but can detect when we look at other wavelengths, such as radio emissions. Our research team regularly scans the radio sky using the Australian SKA Pathfinder (ASKAP), operated by CSIRO on Wajarri Yamaji Country in Western Australia. Our goal is to find cosmic objects that appear and disappear (known as transients). Transients are often linked to some of the most powerful and dramatic events in the universe, such as the explosive deaths of stars. In late 2023, we spotted an extremely bright source, named ASKAP J1832-0911 (based on its position in the sky), in the direction of the galactic plane. This object is located about 15,000 light years away. This is far, but still within the Milky Way. A dramatic event After the initial discovery, we began follow-up observations using telescopes around the world, hoping to catch more pulses. With continued monitoring, we found the radio pulses from ASKAPJ1832 arrive regularly — every 44 minutes. This confirmed it as a new member of the rare long-period transient group. But we did not just look forward in time — we also looked back. We searched through older telescope data from the same part of the sky. We found no trace of the object before the discovery. This suggests something dramatic happened shortly before we first detected it — something powerful enough to suddenly switch the object 'on'. Then, in February 2024, ASKAPJ1832 became extremely active. After a quieter period in January, the source brightened dramatically. Fewer than 30 objects in the sky have ever reached such brightness in radio waves. For comparison, most stars we detect in radio are about 10,000 times fainter than ASKAPJ1832 during that flare-up. A lucky break X-rays are a form of light that we can't see with our eyes. They usually come from extremely hot and energetic environments. Although about 10 similar radio-emitting objects have been found so far, none had ever shown X-ray signals. In March, we tried to observe ASKAPJ1832 in X-rays. However, due to technical issues with the telescope, the observation could not go ahead. Then came a stroke of luck. In June, I reached out to my friend Tong Bao, a postdoctoral researcher at the Italian National Institute for Astrophysics, to check if any previous X-ray observations had captured the source. To our surprise, we found two past observations from NASA's Chandra X-ray Observatory, although the data were still under a proprietary period (not yet public). We contacted Kaya Mori, a research scientist at Columbia University and the principal investigator of those observations. He generously shared the data with us. To our amazement, we discovered clear X-ray signals coming from ASKAPJ1832. Even more remarkable: the X-rays followed the same 44-minute cycle as the radio pulses. It was a truly lucky break. Chandra had been pointed at a different target entirely, but by pure coincidence, it caught ASKAPJ1832 during its unusually bright and active phase. A chance alignment like that is incredibly rare — like finding a needle in a cosmic haystack. Still a mystery Having both radio and X-ray bursts is a common trait of dead stars with extremely strong magnetic fields, such as neutron stars (high-mass dead stars) and white dwarfs (low-mass dead stars). Our discovery suggests that at least some long-period transients may come from these kinds of stellar remnants. But ASKAPJ1832 does not quite fit into any known category of object in our galaxy. Its behaviour, while similar in some ways, still breaks the mould. We need more observations to truly understand what is going on. It is possible that ASKAPJ1832 is something entirely new, or it could be emitting radio waves in a way we have never seen before. DM
Eyewitness News
3 days ago
- Eyewitness News
The hunt for mysterious 'Planet Nine' offers up a surprise
PARIS - It's an evocative idea that has long bedevilled scientists: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all our efforts to spot it. Some astronomers say the strange, clustered orbits of icy rocks beyond Neptune indicate that something big is out there, which they have dubbed Planet Nine. Now, a US-based trio hunting this elusive world has instead stumbled on what appears to be a new dwarf planet in the solar system's outer reaches. And the existence of this new kid on the block could challenge the Planet Nine theory, the researchers have calculated. Named 2017 OF201, the new object is roughly 700 kilometres (430 miles) across according to a preprint study, which has not been peer-reviewed, published online last week. That makes it three times smaller than Pluto. But that is still big enough to be considered a dwarf planet, lead study author Sihao Cheng of New Jersey's Institute for Advanced Study told AFP. - Distant traveller - The object is currently three times farther away from Earth than Neptune. And its extremely elongated orbit swings out more than 1,600 times the distance between the Earth and the Sun, taking it into the ring of icy rocks around the solar system called the Oort cloud. It goes so far out, it could have passed by stars other than our Sun in the past, Cheng said. During its 25,000-year orbit, the object is only close enough to Earth to be observed around 0.5 percent of the time, which is roughly a century. "It's already getting fainter and fainter," Cheng said. The discovery suggests "there are many hundreds of similar things on similar orbits" in the Kuiper Belt beyond Neptune, Cheng said. After taking a risk spending more than half a year sorting through a difficult dataset in search of Planet Nine, Cheng said he was "lucky" to have found anything at all. The researchers are requesting time to point the James Webb, Hubble and ALMA telescopes at their discovery. But Sam Deen, a 23-year-old amateur astronomer from California, has already been able to track the dwarf planet candidate through old datasets. "OF201 is, in my opinion, probably one of the most interesting discoveries in the outer solar system in the last decade," Deen told AFP. - What about Planet Nine? - The icy rocks discovered in the Kuiper belt tend to have a clustered orbit going in a particular direction. Two decades ago, astronomers proposed this was due to the gravitational pull of a world up to 10 times larger than Earth, naming it Planet Nine and kicking off a debate that has rumbled since. It is also sometimes called Planet X, a name proposed for a hypothetical world beyond Neptune more than a century ago. Back in 1930, astronomers were searching for Planet X when they discovered Pluto, which became our solar system's ninth planet. But Pluto turned out to be too tiny -- it is smaller than the Moon -- and was demoted to dwarf planet status in 2006. There are now four other officially recognised dwarf planets, and Cheng believes 2017 OF201 could join their ranks. When the researchers modelled its orbit, they found it did not follow the clustered trend of similar objects. This could pose a problem for the Planet Nine theory, but Cheng emphasised more data is needed. Samantha Lawler of Canada's University of Regina told AFP that this "great discovery" and others like it mean that "the original argument for Planet Nine is getting weaker and weaker". The Vera Rubin Observatory, which is scheduled to go online in Chile this year, is expected to shed light on this mystery, one way or another. Deen said it was discouraging that no sign of Planet Nine has been found so far, but with Vera Rubin "on the horizon I don't think we'll have to wonder about its existence for much longer". For Cheng, he still hopes that this huge planet is out there somewhere. "We're in an era when big telescopes can see almost to the edge of the universe," he said. But what is in our "backyard" still largely remains unknown, he added.
eNCA
5 days ago
- eNCA
Ancient bread rises again as Turkey recreates 5,000-year-old loaf
ANKARA - In the early Bronze Age, a piece of bread was buried beneath the threshold of a newly built house in what is today central Turkey. Now, more than 5,000 years later, archaeologists have unearthed it, and helped a local bakery to recreate the recipe -- with customers lining up to buy it. Round and flat like a pancake, 12 centimetres in diameter, the bread was discovered during excavations at Kulluoba, a site near the central Anatolian city of Eskisehir. "This is the oldest baked bread to have come to light during an excavation, and it has largely been able to preserve its shape," said Murat Turkteki, archaeologist and director of the excavation. "Bread is a rare find during an excavation. Usually, you only find crumbs," he told AFP. "But here, it was preserved because it had been burnt and buried," he said. The bread was charred and buried under the entrance of a dwelling built around 3,300 BC. A piece had been torn off, before the bread was burnt, then buried when the house was built. "It makes us think of a ritual of abundance," Turkteki said. Unearthed in September 2024, the charred bread has been on display at the Eskisehir Archaeological Museum since Wednesday. AFP | Yasin AKGUL "We were very moved by this discovery. Talking to our excavation director, I wondered if we could reproduce this bread," said the city's mayor, Ayse Unluce. Analyses showed that the bread was made with coarsely ground emmer flour, an ancient variety of wheat, and lentil seeds, with the leaf of an as yet undetermined plant used as yeast. Ancient emmer seeds no longer exist in Turkey. To get as close as possible to the original recipe, the municipality, after analysing the ancient bread, decided to use Kavilca wheat, a variety that is close to ancient emmer, as well as bulgur and lentils. At the Halk Ekmek bakery (meaning "People's Bread" in Turkish), promoted by the municipality to offer low-cost bread, employees have been shaping 300 loaves of Kulluoba by hand every day. "The combination of ancestral wheat flour, lentils and bulgur results in a rich, satiating, low-gluten, preservative-free bread," said Serap Guler, the bakery's manager. The first Kulluoba loaves, marketed as 300g cakes that cost 50 Turkish lira (around $1.28), sold out within hours. "I rushed because I was afraid there wouldn't be any left. I'm curious about the taste of this ancient bread," said customer Suzan Kuru.
