Latest news with #Miocene
Yahoo
18-07-2025
- Science
- Yahoo
Mammals Have Evolved Into Anteaters at Least 12 Times Since The Dinosaurs
If you want to get by in this world, you could do a lot worse than developing a predilection for ants. In fact, ant-eating may be a dramatically overlooked recipe for success. According to new research, relying on ants as a sole food source has evolved at least 12 times in mammals since the reign of the dinosaurs ended some 66 million years ago. But it's not the ant-exclusive diet itself that is the wonder: it's that it always follows a similar blueprint. "It's not necessarily surprising that mammals would specialize on ant-eating, as ecological niches almost inevitably get filled," biologist Thomas Vida of the University of Bonn in Germany told ScienceAlert, "but rather that we see the same, or at least very similar, morphological adaptations across so many unrelated groups." It's one of the most striking examples of convergent evolution, in which dramatically different organisms can come to evolve similar features to solve similar problems. Related: Evolution Keeps Making Crabs, And Nobody Knows Why There are a lot of ants on planet Earth. A recent study estimated the number of individual ants at around 20 quadrillion, for a combined biomass of 12 megatons of dry carbon. That's more than all the wild mammals and birds combined, and around 20 percent of the human biomass. It wasn't always this way; just after the dinosaurs went extinct, ants represented less than 1 percent of the insect population, exploding around 23 million years ago at the beginning of the Miocene. Many animals happily include insects as part of their diet, including mammals. It makes sense: insects are plentiful, and full of nutrition. However, a diet that revolves exclusively around ants – a strategy called obligate myrmecophagy – is a little more rare. "One of the things my lab focuses on is how social insects like ants and termites have reshaped the history of life on the planet," entomologist Phillip Barden of the New Jersey Institute of Technology told ScienceAlert. "Ants in particular have altered the trajectory of evolution in lots of insect and plant lineages, but a lingering question that I've had is just how much mammals have had to reckon with the rapid ascent of ants and termites over the last 100 million years. I also just love giant anteaters." To investigate, Vida, Barden, and their colleague Zachary Calamari of City University of New York undertook a painstaking review of more than 600 published scientific sources to compile a database of the dietary habits of 4,099 mammal species. The researchers divided these animals into five different categories based on their diets: insectivores, carnivores, omnivores, herbivores, and the obligate myrmecophages. These were then mapped onto an animal family tree to observe how these dietary adaptations emerged over tens of millions of years. Myrmecophagy, the researchers found, emerged at least 12 times, with 2 more tentative instances that could not be confirmed. This includes animals such as anteaters, pangolins, echidnas, numbats, and aardvarks – a diversity that the researchers did not expect – across all three major mammal groups: placental mammals, marsupials, and monotremes. These animals all developed similar traits to optimize eating ants. "There are a few obvious things: their skulls and tongues tend to elongate, their teeth often get reduced, and they usually have strong claws/forelimbs for tearing into insect nests," Vida explained. "There are also some less obvious things, like their low body temperatures/slow metabolisms and their enzymatic adaptations towards digesting chitin, both of which are adaptations for surviving off of abundant, but low-energy food." The finding is reminiscent of the famous phenomenon whereby crab body plans keep emerging, with at least five separate crab evolutions throughout evolutionary history. Well, crabs are cool and all, but apparently ants are where the real party is at. Related: "Ants really seem to be engineers of convergent evolution," Barden said. "There are twice as many origins of ant- and termite-eating in mammals as there are origins of crab body plans. And that's not even counting the over 10,000 species of arthropods that mimic ant and termite morphology, behavior, or chemical signaling to evade predation or get access to social insect resources." Their work, the researchers say, lays a solid foundation for future studies of mammalian dietary strategies. Vida notes that their database will allow further investigations of fascinating dietary specializations, and to drill down into the origins of individual myrmecophagous species. There may even be some interesting discoveries waiting in comparative studies of insectivorous birds, reptiles, and amphibians. "The history of life is full of crossovers. Even very distantly related lineages – social insects and mammals last shared a common ancestor more than 500 million years ago – interact in ways that can kick off striking specializations over tens of millions of years," Barden said. "As we rapidly reshape our planet, it's important to remember that the loss of any one species may have lots of unexpected consequences." The research has been published in Evolution. Related News A Gaping Hole Full of Milky Blue Water Has Appeared at Yellowstone Cuisine Fad Unleashes Invasive Threat Into The US Wilderness Fig Trees That Grow Rocks From Carbon Discovered in Africa Solve the daily Crossword
Otago Daily Times
11-07-2025
- Science
- Otago Daily Times
Study casts magpies in new light
A bird now seen as an unwelcome Australian import may have much deeper roots in New Zealand than previously thought. Magpies, often regarded in Central Otago and elsewhere as aggressive invaders introduced from Australia in the 1860s, have long divided public opinion. But new research reveals their ancestors once lived in New Zealand — millions of years before European settlers arrived. Researchers from Canterbury Museum, the University of Canterbury, and Australian institutions, including Flinders and New South Wales universities, have spent more than 20 years studying fossils from the St Bathans area of Central Otago. Their work has now uncovered enough evidence to describe a new species of currawong — an ancient relative of the modern magpie. The newly identified species, named the St Bathans currawong, lived between 19 and 16 million years ago, during the Miocene era, in what was then a lush, forested landscape surrounding a large prehistoric lake. The bird, likely similar in size to today's Australian magpie but probably all black, appears to have gone extinct before the end of the Miocene period. Dr Paul Scofield, senior curator of natural history at Canterbury Museum and a co-author of the study, said the findings challenged the widespread belief magpies were foreign intruders with no historical place in New Zealand's environment. "We persecute the magpie as an Australian that has no place in the New Zealand ecosystem, but its close relatives lived here in the past," he said. "We've probably been without a member of the magpie's extended family for only five million years." Co-author Associate Prof Trevor Worthy of Flinders University said New Zealand's ecosystems had been constantly evolving for millions of years, waves of extinctions and new arrivals shaping biodiversity long before human settlement. "There's an idea that we should return New Zealand to a pre-European ecological state," he said. "But that ignores the fact that Aotearoa's ecosystems were already dramatically different by the time humans arrived." The fossil record shows species such as currawong and native pigeons disappeared as the country's floral diversity declined. Other groups of animals and plants have arrived during the past few thousand years, both naturally and through human influence. Dr Scofield said during the Miocene period, New Zealand forests would have looked more like Australian bushland, eucalypts, laurels and she-oaks ( Casuarina ) being common. A major climate cooling event around 13 million years ago led to the extinction of many warm-climate species, reshaping the ecosystem into the one seen today. Fossil evidence from St Bathans suggests a greater diversity of songbirds once filled the bush with birdsong. Together the findings suggest New Zealand's natural history is far more complex and dynamic than the idea of a static, untouched ecosystem. So instead of striving to recreate a specific past state, these scientists are saying we should embrace and protect the biodiversity we have. — APL
Otago Daily Times
10-07-2025
- Science
- Otago Daily Times
Magpie roots found in St Bathans
Magpies may be regarded in Central Otago as annoying Australian imports or unwelcome newcomers from Canterbury but decades of research has revealed their ancestors lived in St Bathans 19 million years ago. Magpies were introduced from Australia in the 1860s and since then New Zealanders have developed a love-hate relationship with the sometimes aggressive bird. Researchers from Canterbury Museum and University of Canterbury along with those from Flinders and New South Wales Universities in Australia have spent more than two decades unearthing and analysing fossils discovered near St Bathans . The St Bathans fossil site, which has been studied since 2001, was once at the bottom of a large prehistoric lake. It offered the only significant insight into New Zealand's terrestrial wildlife from 16 to 19 million years ago. Researchers have now found enough fragments to describe a new species of currawong, which was an ancestor of the bird that menaces New Zealand today. The newly discovered bird, which the researchers have named the St Bathans Currawong, lived in New Zealand around 19 million to 16 million years ago. It probably went extinct near the end of the Miocene, an era that ran from 20 million years ago to 5 million years ago. The ancient bird would have been about the same size as the Australian magpie found in New Zealand today but was probably all black. Co-author and Canterbury Museum senior curator natural history Dr Paul Scofield said the research challenged New Zealand views on the much-maligned magpie. "We persecute the magpie as an Australian that has no place in the New Zealand ecosystem but its close relatives lived here in the past." "We've probably been without a member of the magpie's extended family for only 5 million years.' Co-author and Flinders University Associate Prof Trevor Worthy said New Zealand's ecosystem had changed dramatically over millions of years and harboured diverse species across different eras. "There's an idea that we should aim to return New Zealand to a pre-European ecological state. But at that point in time, New Zealand's ecosystems had been changing continuously for millions of years. Aotearoa had lost much of the floral diversity formerly present by the time humans arrived. There were few fruiting tree species left and the loss of currawongs and other pigeons reflects this. "Other groups of plants and animals arrived from 2.6 million to 11,700 years ago. Many more have arrived since humans occupied the land. The pre-European ecological state of New Zealand is not necessarily any better or worse than any other time in the past. Instead, the fossil record suggests there was no utopian state and that we should celebrate the diversity we currently have.' Dr Scofield said the work revealed New Zealand's bird population in the Miocene era had surprisingly strong similarities to that of Australia today. "During the Miocene, 20 to 5 million years ago, New Zealand was much different. Walking through a New Zealand forest from that era, you would have seen numerous eucalypts, laurels and Casuarina, much like you would in an Australian forest today.' "The major thing that shaped the New Zealand we see today was the extinction of many plants and animals that thrived in warm climates after a period of rapid cooling that began about 13 million years ago.' Separate research led by Dr Vanesa De Pietri, of University of Canterbury, found the early Miocene New Zealand bush was alive with more birdsong than today. Analysis of songbird fossils found at St Bathans indicates there were probably many more different species of songbirds living in New Zealand 20 million years ago than just before humans arrived. — APL
Yahoo
10-07-2025
- Science
- Yahoo
Scientists Found a Place Where the Earth's Layers Are Upside Down
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Here's what you'll learn when you read this story: Usually, geologic layers build on one another, with younger rocks piling on top of older ones. A new study, however, shows that this process is inverted in large, several-kilometer-wide mounds known as 'sinkites' found throughout the North Sea. This is the largest known example of a phenomenon known as 'stratigraphic inversion,' and could have implications for future carbon capture and storage plans. It may not look like much from its watery surface, but the North Sea is one of the most fascinating places on Earth, both in terms of its distant geologic past and its green-energy future. More than 8,000 years ago, this stretch of land—known today as Doggerland and located between what is now Great Britain and the rest of northern Europe—was filled with rolling hills and swampy lagoons, and traversed by mesolithic tribes. However, it's the North Sea's role as an important area for oil and gas extraction (as well as its potential as a platform for massive wind farms) that have brought more scientific data to light as energy companies probe its watery depths. In 2023, for example, environmental surveys provided a treasure trove of data that scientists used to investigate human habitation of the area, and two years later, a team of researchers—led by Mads Huuse from the University of Manchester—have now analyzed licensed data from oil company Aker BP to understand the geology of the region even further. And what they found was completely unexpected. In a study published in the journal Communications Earth & Environment, scientists found what's known as a stratigraphic inversion, which is a reversal of the typical process of geologic layers forming one on top of another over time. Simply put, younger rocks generally form above older rocks, which explains why you'll never find dinosaur fossils above the K-T boundary, for example. However, in the North Sea, huge mounds—some of which are several kilometers wide—known as 'sinkites' reverse this process. In studying these formations, scientists found Late Miocene and Early Pliocene deposits beneath ooze rafts that formed millions of years earlier, in the Early Miocene. 'This discovery reveals a geological process we haven't seen before on this scale,' Huuse said in a press statement. 'What we've found are structures where dense sand has sunk into lighter sediments that floated to the top of the sand, effectively flipping the conventional layers we'd expect to see and creating huge mounds beneath the sea.' So, what exactly caused this geologic inversion? The researchers' best guess is that millions of years ago, earthquakes caused shifts underground that messed with the local pressure, liquefying sand and sending it downward through seabed fractures. This displaced the older geologic layers and lifted them upwards—a geologic feature the authors call 'floatites.' This impressively large exception to a typical geologic rule is important to understand, because it could impact how companies search for underground reservoirs of oil and natural gas. But as demand for fossil fuels declines (and will likely continue to do so in the coming years), this understanding will be equally important for implementing effective carbon capture and storage technologies. 'Understanding how these sinkites formed could significantly change how we assess underground reservoirs, sealing, and fluid migration—all of which are vital for carbon capture and storage,' Huuse said in a press statement. With plans for 120 gigawatts worth of renewable energy to be generated by wind coming from the area by 2030, the North Sea is set to become northern Europe's green energy engine. Understanding the foundation of the engine—both its historical significance and its geologic oddities—will be vital in the coming years. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Forbes
11-06-2025
- Science
- Forbes
What Did Megalodon Really Eat? Probably Everything.
Lead study author Jeremy McCormack of Goethe University in Frankfurt, Germany, holds up a fossilized ... More megalodon tooth. For decades, the giant prehistoric shark known ominously as 'The Meg" has been portrayed as a massive apex predator that hunted the only formidable opponent in the oceans at the time: whales. But new research suggests the reality was more nuanced — and a lot more interesting. In a study published in Earth and Planetary Science Letters, scientists used advanced geochemical techniques to analyze fossilized tooth enamel and found evidence that indicate this now-extinct behemoth likely had a more varied and opportunistic diet, feeding on whatever was available in its environment to satisfy its immense appetite The key to figuring out this mystery lay in the isotopes of zinc preserved in its teeth, which serve as chemical fingerprints of what an animal ate during its life. Researchers led by Dr. Jeremy McCormack at Goethe University in Germany analyzed 209 fossil teeth from 21 different species (both marine and terrestrial) dating back to the early Miocene period, roughly 20 to 16 million years ago. The fossils were collected from sites in what is now southern Germany, specifically a shallow seaway that once connected the ancient seas known as the Upper Marine Molasse. By focusing on a specific time and place, the team were able to compare Megalodon's diet with that of other sharks, dolphins and marine animals living at the same time. What makes this research stand out is its use of zinc isotope ratios (specifically δ⁶⁶Zn) as a tool for estimating an animal's trophic position, or its level in the food web. While nitrogen isotopes (δ¹⁵N) have traditionally been used to track trophic levels, they can degrade over time, especially in fossils millions of years old. Zinc isotopes, on the other hand, are much more stable and are now emerging as a reliable alternative. The higher an animal is in the food chain, the lower its δ⁶⁶Zn values tend to be, because heavier zinc isotopes are preferentially retained in tissues lower down the food chain, while top predators, which eat those animals, end up with lighter zinc signatures. In this study, Megalodon teeth consistently showed some of the lowest δ⁶⁶Zn values across the entire fossil dataset, placing them at the very top of the marine food web. The researchers also looked at the extinct Carcharodon hastalis, which is a possible ancestor of the modern great white shark, and found its δ⁶⁶Zn values were slightly higher. This suggests it fed at a slightly lower trophic level or had a different diet, supporting what many paleontologists have long suspected — that Megalodon was a top predator, likely preying on large marine mammals such as whales and dolphins. Finally, the scientists analyzed modern marine species, including sharks and dolphins, to create a baseline for comparison. They found that even today, top predators like killer whales have similarly low δ⁶⁶Zn values, further supporting the idea that zinc isotopes accurately reflect trophic level. McCormack works at the mass spectrometer, which is used to determine the zinc isotope ratio. This ... More ratio provides information about the diet of Otodus megalodon. Paleontologists have long suspected that Megalodon was a top predator based on its massive size, tooth morphology, and fossil evidence showing bite marks on whale bones. What this study does is go a step further by providing chemical evidence that directly links Megalodon to a high trophic level, rather than relying only on anatomical or circumstantial evidence. See, scientists face major challenges when trying to reconstruct what a creature like Megalodon actually ate. Sharks have skeletons made mostly of cartilage, which doesn't fossilize well, so researchers often rely on teeth. While bite marks on fossilized whale bones have been strong evidence of marine mammal being part of the Meg's meals, bites on other sharks leave less obvious traces, making dietary conclusions based only on physical bite evidence tricky and potentially misleading. This new chemical analysis helps fill in those gaps. By creating a kind of prehistoric food web, the researchers placed animals like sea bream (which eat mussels and crustaceans) at the bottom, followed by smaller sharks and extinct toothed whales the size of modern dolphins. Megalodon still sat near the top, as expected, but its zinc isotope levels weren't wildly different from those just below it in the chain, suggesting that those species may have ended up on the menu too. While the conclusion itself (big shark ate big animals) isn't groundbreaking on its own, the method is what's novel and important. This is the first time zinc isotopes have been used in this way for extinct marine predators, and the fact that the values line up with what we see in modern apex predators opens the door to re-examining other ancient species' diets and food web roles with greater precision. Still, it seems that ancient ecosystems are not so different from today's. Apex predators existed, food webs were complex, and adaptability was key to survival. Megalodon may have ruled the oceans, but not alone… and not without competition.
