Latest news with #CretaceousPeriod
Straits Times
11-06-2025
- Science
- Straits Times
Mongolia's 'Dragon Prince' dinosaur was forerunner of T. rex
The newly identified dinosaur species Khankhuuluu mongoliensis is shown in the timeline of the dinosaur lineage called tyrannosaurs, which included Tyrannosaurus rex, in this illustration released on June 11, 2025. Jared Voris/Handout via REUTERS The newly identified dinosaur species Khankhuuluu mongoliensis is seen in front of three of its evolutionary descendants, including Tyrannosaurus rex (rear) in this handout illustration released on June 11, 2025. Masato Hattori/Handout via REUTERS A life reconstruction of the newly identified dinosaur species Khankhuuluu mongoliensis, which lived 86 million years ago in Mongolia, is seen in this handout illustration released on June 11, 2025. Julius Csotonyi/Handout via REUTERS A newly identified mid-sized dinosaur from Mongolia dubbed the "Dragon Prince" has been identified as a pivotal forerunner of Tyrannosaurus rex in an illuminating discovery that has helped clarify the famous predator's complicated family history. Named Khankhuuluu mongoliensis (pronounced khan-KOO-loo mon-gol-ee-EN-sis), it lived roughly 86 million years ago during the Cretaceous Period and was an immediate precursor to the dinosaur lineage called tyrannosaurs, which included some of the largest meat-eating land animals in Earth's history, among them T. rex. Khankhuuluu predated Tyrannosaurus by about 20 million years. It was about 13 feet (4 meters) long, weighed about 1,600 pounds (750 kg), walked on two legs and had a lengthy snout with a mouthful of sharp teeth. More lightly built than T. rex, its body proportions indicate Khankhuuluu was fleet-footed, likely chasing down smaller prey such as bird-like dinosaurs called oviraptorosaurs and ornithomimosaurs. The largest-known T. rex specimen is 40-1/2 feet long (12.3 meters). Khankhuuluu means "Dragon Prince" in the Mongolian language. Tyrannosaurus rex means "tyrant king of the lizards." "In the name, we wanted to capture that Khankhuuluu was a small, early form that had not evolved into a king. It was still a prince," said paleontologist Darla Zelenitsky of the University of Calgary in Canada, co-author of the study published on Wednesday in the journal Nature. Tyrannosaurs and all other meat-eating dinosaurs are part of a group called theropods. Tyrannosaurs appeared late in the age of dinosaurs, roaming Asia and North America. Khankhuuluu shared many anatomical traits with tyrannosaurs but lacked certain defining characteristics, showing it was a predecessor and not a true member of the lineage. "Khankhuuluu was almost a tyrannosaur, but not quite. For example, the bone along the top of the snout and the bones around the eye are somewhat different from what we see in tyrannosaurs. The snout bone was hollow and the bones around the eye didn't have all the horns and bumps seen in tyrannosaurs," Zelenitsky said. "Khankhuuluu had teeth like steak knives, with serrations along both the front and back edges. Large tyrannosaurs had conical teeth and massive jaws that allowed them to bite with extreme force then hold in order to subdue very large prey. Khankhuuluu's more slender teeth and jaws show this animal took slashing bites to take down smaller prey," Zelenitsky added. The researchers figured out its anatomy based on fossils of two Khankhuuluu individuals dug up in the 1970s but only now fully studied. These included parts of its skull, arms, legs, tail and back bones. The Khankhuuluu remains, more complete than fossils of other known tyrannosaur forerunners, helped the researchers untangle this lineage's evolutionary history. They concluded that Khankhuuluu was the link between smaller forerunners of tyrannosaurs and later true tyrannosaurs, a transitional animal that reveals how these meat-eaters evolved from speedy and modestly sized species into giant apex predators. "What started as the discovery of a new species ended up with us rewriting the family history of tyrannosaurs," said University of Calgary doctoral student and study lead author Jared Voris. "Before this, there was a lot of confusion about who was related to who when it came to tyrannosaur species." Some scientists had hypothesized that smaller tyrannosaurs like China's Qianzhousaurus - dubbed "Pinnochio-rexes" because of their characteristic long snouts - reflected the lineage's ancestral form. That notion was contradicted by the fact that tyrannosaur forerunner Khankhuuluu differed from them in important ways. "The tyrannosaur family didn't follow a straightforward path where they evolved from small size in early species to larger and larger sizes in later species," Zelenitsky said. Voris noted that Khankhuuluu demonstrates that the ancestors to the tyrannosaurs lived in Asia. "Around 85 million years ago, these tyrannosaur ancestors crossed a land bridge connecting Siberia and Alaska and evolved in North America into the apex predatory tyrannosaurs," Voris said. One line of North American tyrannosaurs later trekked back to Asia and split into two branches - the "Pinnochio-rexes" and massive forms like Tarbosaurus, the researchers said. These apex predators then spread back to North America, they said, paving the way for the appearance of T. rex. Tyrannosaurus ruled western North America at the end of the age of dinosaurs when an asteroid struck Earth 66 million years ago. "Khankhuuluu was where it all started but it was still only a distant ancestor of T. rex, at nearly 20 million years older," Zelenitsky said. "Over a dozen tyrannosaur species evolved in the time between them. It was a great-great-great uncle, sort of." REUTERS Join ST's Telegram channel and get the latest breaking news delivered to you.
Yahoo
10-06-2025
- Science
- Yahoo
Ancient fossils show how the last mass extinction forever scrambled the ocean's biodiversity
About 66 million years ago – perhaps on a downright unlucky day in May – an asteroid smashed into our planet. The fallout was immediate and severe. Evidence shows that about 70% of species went extinct in a geological instant, and not just those famous dinosaurs that once stalked the land. Masters of the Mesozoic oceans were also wiped out, from mosasaurs – a group of aquatic reptiles topping the food chain – to exquisitely shelled squid relatives known as ammonites. Even groups that weathered the catastrophe, such as mammals, fishes and flowering plants, suffered severe population declines and species loss. Invertebrate life in the oceans didn't fare much better. But bubbling away on the seafloor was a stolid group of animals that has left a fantastic fossil record and continues to thrive today: bivalves – clams, cockles, mussels, oysters and more. What happened to these creatures during the extinction event and how they rebounded tells an important story, both about the past and the future of biodiversity. Marine bivalves lost around three-quarters of their species during this mass extinction, which marked the end of the Cretaceous Period. My colleagues and I – each of us paleobiologists studying biodiversity – expected that losing so many species would have severely cut down the variety of roles that bivalves play within their environments, what we call their 'modes of life.' But, as we explain in a study published in the journal Sciences Advances, that wasn't the case. In assessing the fossils of thousands of bivalve species, we found that at least one species from nearly all their modes of life, no matter how rare or specialized, squeaked through the extinction event. Statistically, that shouldn't have happened. Kill 70% of bivalve species, even at random, and some modes of life should disappear. Most bivalves happily burrow into the sand and mud, feeding on phytoplankton they strain from the water. But others have adopted chemosymbionts and photosymbionts – bacteria and algae that produce nutrients for the bivalves from chemicals or sunlight in exchange for housing. A few have even become carnivorous. Some groups, including the oysters, can lay down a tough cement that hardens underwater, and mussels hold onto rocks by spinning silken threads. We thought surely these more specialized modes of life would have been snuffed out by the effects of the asteroid's impact, including dust and debris likely blocking sunlight and disrupting a huge part of the bivalves' food chain: photosynthetic algae and bacteria. Instead, most persisted, although biodiversity was forever scrambled as a new ecological landscape emerged. Species that were once dominant struggled, while evolutionary newcomers rose in their place. The reasons some species survived and others didn't leave many questions to explore. Those that filtered phytoplankton from the water column suffered some of the highest species losses, but so did species that fed on organic scraps and didn't rely as much on the Sun's energy. Narrow geographic distributions and different metabolisms may have contributed to these extinction patterns. Life rebounded from each of the Big Five mass extinctions throughout Earth's history, eventually punching through past diversity highs. The rich fossil record and spectacular ecological diversity of bivalves gives us a terrific opportunity to study these rebounds to understand how ecosystems and global biodiversity rebuild in the wake of extinctions. The extinction caused by the asteroid strike knocked down some thriving modes of life and opened the door for others to dominate the new landscape. While many people lament the loss of the dinosaurs, we malacologists miss the rudists. These bizarrely shaped bivalves resembled giant ice cream cones, sometimes reaching more than 3 feet (1 meter) in size, and they dominated the shallow, tropical Mesozoic seas as massive aggregations of contorted individuals, similar to today's coral reefs. At least a few harbored photosymbiotic algae, which provided them with nutrients and spurred their growth, much like modern corals. Today, giant clams (Tridacna) and their relatives fill parts of these unique photosymbiotic lifestyles once occupied by the rudists, but they lack the rudists' astonishing species diversity. Mass extinctions clearly upend the status quo. Now, our ocean floors are dominated by clams burrowed into sand and mud, the quahogs, cockles and their relatives – a scene far different from that of the seafloor 66 million years ago. Ecological traits alone didn't fully predict extinction patterns, nor do they entirely explain the rebound. We also see that simply surviving a mass extinction didn't necessarily provide a leg up as species diversified within their old and sometimes new modes of life – and few of those new modes dominate the ecological landscape today. Like the rudists, trigoniid bivalves had lots of different species prior to the extinction event. These highly ornamented clams built parts of their shells with a super strong biomaterial called nacre – think iridescent pearls – and had fractally interlocking hinges holding their two valves together. But despite surviving the extinction, which should have placed them in a prime position to accumulate species again, their diversification sputtered. Other types of bivalves that made a living in the same way proliferated instead, relegating this once mighty and global group to a handful of species now found only off the coast of Australia. These unexpected patterns of extinction and survival may offer lessons for the future. The fossil record shows us that biodiversity has definite breaking points, usually during a perfect storm of climatic and environmental upheaval. It's not just that species are lost, but the ecological landscape is overturned. Many scientists believe the current biodiversity crisis may cascade into a sixth mass extinction, this one driven by human activities that are changing ecosystems and the global climate. Corals, whose reefs are home to nearly a quarter of known marine species, have faced mass bleaching events as warming ocean water puts their future at risk. Acidification as the oceans absorb more carbon dioxide can also weaken the shells of organisms crucial to the ocean food web. Findings like ours suggest that, in the future, the rebound from extinction events will likely result in very different mixes of species and their modes of life in the oceans. And the result may not align with human needs if species providing the bulk of ecosystem services are driven genetically or functionally extinct. The global oceans and their inhabitants are complex, and, as our team's latest research shows, it is difficult to predict the trajectory of biodiversity as it rebounds – even when extinction pressures are reduced. Billions of people depend on the ocean for food. As the history recorded by the world's bivalves shows, the upending of the pecking order – the number of species in each mode of life – won't necessarily settle into an arrangement that can feed as many people the next time around. This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Stewart Edie, Smithsonian Institution Read more: Megalodon sharks ruled the oceans millions of years ago – new analyses of giant fossilized teeth are helping scientists unravel the mystery of their extinction As climate change and pollution imperil coral reefs, scientists are deep-freezing corals to repopulate future oceans Growing quickly helped the earliest dinosaurs and other ancient reptiles flourish in the aftermath of mass extinction Stewart Edie receives funding from the Smithsonian Institution.
Yomiuri Shimbun
16-05-2025
- Science
- Yomiuri Shimbun
Oldest-known Ant Fossil Found in Brazil Preserved in Limestone
Anderson Lepeco / Current Biology / Handout via Reuters A 113-million-year-old fossilized ant preserved in limestone unearthed in northeastern Brazil is seen in this photo released on April 24. Scientists have identified the fossilized remains of the oldest-known ant — a winged insect with fearsome scythe-like jaws that lived about 113 million years ago during the age of dinosaurs and was preserved in limestone unearthed in northeastern Brazil. The species, called Vulcanidris cratensis, is part of a lineage called hell ants — named for their demonic-looking jaws — that prospered in a wide geographical range during the Cretaceous Period but have no descendants alive today. A previously discovered Cretaceous hell ant was named Haidomyrmex in honor of Hades, the ancient Greek god of the underworld. A medium-sized ant about 1.35 centimeters long, Vulcanidris possessed highly specialized jaws that would have enabled it to pin down or impale prey. Like some ants alive today, it had wings and appears to have been a capable flier. It also had a well-developed stinger like a wasp. 'It would probably be confused with a wasp by an untrained eye,' said entomologist Anderson Lepeco of the Museum of Zoology of the University of Sao Paulo, lead author of the study published last month in the journal Current Biology. 'They probably used their mandibles (mouthparts) to handle their prey in a specific way,' Lepeco said. Its mandibles moved up and down and not side to side, as they do in today's ants. 'Currently, many odd mandible shapes can be found in ants, but they usually articulate horizontally,' Lepeco said. This ant is roughly 13 million years older than the previous oldest-known ants, specimens found in France and Myanmar that were preserved in amber, which is fossilized tree sap. The Vulcanidris anatomy is remarkably well preserved in the limestone, which was excavated decades ago in the Crato geological formation in the Brazilian state of Ceara, probably in the 1980s or 1990s, according to Lepeco. It was held in a private collection before being donated to the Sao Paulo museum about five years ago. 'I was looking for wasps among the fossils of the collection and was shocked when I recognized this one as a close relative of a hell ant previously described from Burmese amber,' Lepeco said, referring to the fossil from Myanmar. The specialized nature of the Vulcanidris anatomy and the fact that two hell ants lived so far from each other during this part of the Cretaceous suggest that ants as a group emerged many millions of years before this newly identified species existed. 'According to molecular estimates, ants originated between 168 million and 120 million years ago. This new finding supports an earlier age within these limits,' Lepeco said. Ants are believed to have evolved from a form of wasp. Their closest living relatives are wasps and bees. Vulcanidris inhabited an ecosystem teeming with life. Fossils from the region show that Vulcanidris lived alongside other insects, spiders, millipedes, centipedes, various crustaceans, turtles, crocodilians, flying reptiles called pterosaurs, birds and dinosaurs including the feathered meat-eater Ubirajara. The ant's predators may have included frogs, birds, spiders and larger insects. Ants have colonized almost everywhere on Earth, and research published in 2022 estimated that their total population is 20 quadrillion globally. That dwarfs the human population of about 8 billion. 'They are one of the most abundant groups in most environments on Earth,' Lepeco said. 'They play many roles where they occur, such as predation and herbivory, controlling populations of other organisms. They also have intrinsic relationships with specific plants and insects, protecting them from other animals. Subterranean and litter ants help in soil health, and they may also act as decomposers, feeding on dead organisms,' Lepeco said.
Observer
29-04-2025
- Science
- Observer
Oldest-known ant preserved in 113 million-year-old Brazilian fossil
Scientists have identified the fossilized remains of the oldest-known ant - a winged insect with fearsome scythe-like jaws that lived about 113 million years ago during the age of dinosaurs and was preserved in limestone unearthed in northeastern Brazil. The species, called Vulcanidris cratensis, is part of a lineage called hell ants - named for their demonic-looking jaws - that prospered in a wide geographical range during the Cretaceous Period but have no descendants alive today. A previously discovered Cretaceous hell ant was named Haidomyrmex in honor of Hades, the ancient Greek god of the underworld. A medium-sized ant about a half-inch (1.35 cm) long, Vulcanidris possessed highly specialized jaws that would have enabled it to pin down or impale prey. Like some ants alive today, it had wings and appears to have been a capable flier. It also had a well-developed stinger like a wasp. "It would probably be confused with a wasp by an untrained eye," said entomologist Anderson Lepeco of the Museum of Zoology of the University of São Paulo, lead author of the study published this week in the journal Current Biology. "They probably used their mandibles (mouthparts) to handle their prey in a specific way," Lepeco said. Its mandibles moved up and down and not side to side, as they do in today's ants. "Currently, many odd mandible shapes can be found in ants, but they usually articulate horizontally," Lepeco said. This ant is roughly 13 million years older than the previous oldest-known ants, specimens found in France and Myanmar that were preserved in amber, which is fossilized tree sap. The Vulcanidris anatomy is remarkably well preserved in the limestone, which was excavated decades ago in the Crato geological formation in the Brazilian state of Ceará, probably in the 1980s or 1990s, according to Lepeco. It was held in a private collection before being donated to the São Paulo museum about five years ago. "I was looking for wasps among the fossils of the collection and was shocked when I recognized this one as a close relative of a hell ant previously described from Burmese amber," Lepeco said, referring to the fossil from Myanmar. The specialized nature of the Vulcanidris anatomy and the fact that two hell ants lived so far from each other during this part of the Cretaceous suggest that ants as a group emerged many millions of years before this newly identified species existed. "According to molecular estimates, ants originated between 168 million and 120 million years ago. This new finding supports an earlier age within these limits," Lepeco said. Ants are believed to have evolved from a form of wasp. Their closest living relatives are wasps and bees. Vulcanidris inhabited an ecosystem teeming with life. Fossils from the region show that Vulcanidris lived alongside other insects, spiders, millipedes, centipedes, various crustaceans, turtles, crocodilians, flying reptiles called pterosaurs, birds and dinosaurs including the feathered meat-eater Ubirajara. The ant's predators may have included frogs, birds, spiders and larger insects. Ants have colonized almost everywhere on Earth, and research published in 2022 estimated that their total population is 20 quadrillion globally. That dwarfs the human population of about 8 billion. "They are one of the most abundant groups in most environments on Earth," Lepeco said. "They play many roles where they occur, such as predation and herbivory, controlling populations of other organisms. They also have intrinsic relationships with specific plants and insects, protecting them from other animals. Subterranean and litter ants help in soil health, and they may also act as decomposers, feeding on dead organisms," Lepeco said. —Reuters
Asharq Al-Awsat
27-04-2025
- Science
- Asharq Al-Awsat
Oldest-known Ant Preserved in 113 Million-year-old Brazilian Fossil
Scientists have identified the fossilized remains of the oldest-known ant - a winged insect with fearsome scythe-like jaws that lived about 113 million years ago during the age of dinosaurs and was preserved in limestone unearthed in northeastern Brazil. The species, called Vulcanidris cratensis, is part of a lineage called hell ants - named for their demonic-looking jaws - that prospered in a wide geographical range during the Cretaceous Period but have no descendants alive today, Reuters reported. A previously discovered Cretaceous hell ant was named Haidomyrmex in honor of Hades, the ancient Greek god of the underworld. A medium-sized ant about a half-inch (1.35 cm) long, Vulcanidris possessed highly specialized jaws that would have enabled it to pin down or impale prey. Like some ants alive today, it had wings and appears to have been a capable flier. It also had a well-developed stinger like a wasp. "It would probably be confused with a wasp by an untrained eye," said entomologist Anderson Lepeco of the Museum of Zoology of the University of São Paulo, lead author of the study published this week in the journal Current Biology. "They probably used their mandibles (mouthparts) to handle their prey in a specific way," Lepeco said. Its mandibles moved up and down and not side to side, as they do in today's ants. "Currently, many odd mandible shapes can be found in ants, but they usually articulate horizontally," Lepeco said. This ant is roughly 13 million years older than the previous oldest-known ants, specimens found in France and Myanmar that were preserved in amber, which is fossilized tree sap. The Vulcanidris anatomy is remarkably well preserved in the limestone, which was excavated decades ago in the Crato geological formation in the Brazilian state of Ceará, probably in the 1980s or 1990s, according to Lepeco. It was held in a private collection before being donated to the São Paulo museum about five years ago. "I was looking for wasps among the fossils of the collection and was shocked when I recognized this one as a close relative of a hell ant previously described from Burmese amber," Lepeco said, referring to the fossil from Myanmar. The specialized nature of the Vulcanidris anatomy and the fact that two hell ants lived so far from each other during this part of the Cretaceous suggest that ants as a group emerged many millions of years before this newly identified species existed. "According to molecular estimates, ants originated between 168 million and 120 million years ago. This new finding supports an earlier age within these limits," Lepeco said. Ants are believed to have evolved from a form of wasp. Their closest living relatives are wasps and bees. Vulcanidris inhabited an ecosystem teeming with life. Fossils from the region show that Vulcanidris lived alongside other insects, spiders, millipedes, centipedes, various crustaceans, turtles, crocodilians, flying reptiles called pterosaurs, birds and dinosaurs including the feathered meat-eater Ubirajara. The ant's predators may have included frogs, birds, spiders and larger insects. Ants have colonized almost everywhere on Earth, and research published in 2022 estimated that their total population is 20 quadrillion globally. That dwarfs the human population of about 8 billion. "They are one of the most abundant groups in most environments on Earth," Lepeco said. "They play many roles where they occur, such as predation and herbivory, controlling populations of other organisms. They also have intrinsic relationships with specific plants and insects, protecting them from other animals. Subterranean and litter ants help in soil health, and they may also act as decomposers, feeding on dead organisms," Lepeco said.
