Latest news with #Cenozoic
Forbes
04-05-2025
- Science
- Forbes
The Tooth Of The Matter: How Sharks Lost Half Their Ecological Roles
Analyzing over 9,000 fossil shark teeth reveals that today's sharks occupy less ecological space ... More than their ancient counterparts. (Maggie Martorell/Miami Herald/Tribune News Service via Getty Images) Sharks are one of the ocean's oldest survivors, with a fossil record stretching back at least 250 million years. But their story isn't just merely about survival… it's about transformation. A global study by scientists Dr. Jack A. Cooper and Dr. Catalina Pimiento, analyzing more than 9,000 fossilized shark teeth from 537 species across the Cenozoic era (i.e. the last 66 million years), has shed light on how shark diversity, particularly in terms of function, has changed over time — and what that means for our oceans today. Instead of focusing on just species numbers, the duo turned to shark teeth to understand functional diversity, or the variety of ecological roles sharks have played, based on differences in size, feeding strategy and tooth shape. By examining six specific dental traits known to link closely with function, the two researchers mapped out how shark ecosystems evolved, and shrank, throughout deep time. The teeth came from museums around the world and all the scientific literature they could get their hands on, spanning a global range and capturing an evolutionary story told in enamel. For about 60 million years, from the Paleocene through the Miocene (roughly 66 to 10 million years ago), sharks thrived in a wide variety of ecological niches. During this time, 66% to 87% of the potential ecological 'functional space' was occupied. That means sharks weren't just numerous — they were doing lots of different things. Some were small suction feeders, others were massive predators, and many filled in-between roles that helped balance marine food webs. Notably, this period featured high levels of functional redundancy, where multiple species performed similar roles. That kind of overlap isn't wasteful. Think of it like a buffer against extinction: if one species disappears, another can step in to keep the ecosystem running. But this balance took a major hit about 30 million years ago during the Oligocene. Functional redundancy dropped by about 45%, making the ecosystem more fragile. The loss of overlap meant that each remaining species held a more unique, irreplaceable role. This left the whole system more vulnerable, and the trend didn't improve. From the late Miocene onward, about 10 million years ago, shark functional diversity began a steady decline. Today, sharks have lost 44% of the functional richness they once had. Many of the roles once filled by mid-sized suction feeders and large-bodied predators are simply… gone. What's striking is that extinct sharks were doing more than their modern relatives in terms of ecological variety. They spanned a broader range of functional roles than the sharks we see in today's oceans. The loss of those species — and their roles — means our current shark populations are not only smaller in number, but also less functionally diverse. This matters, Cooper and Pimiento explain, because functional diversity is closely tied to ecosystem health. The fewer roles sharks fill, the less resilient our oceans become. For about 60 million years, from the Paleocene through the Miocene (roughly 66 to 10 million years ... More ago), sharks thrived in a wide variety of ecological niches. During this time, 66% to 87% of the potential ecological 'functional space' was occupied. That means sharks weren't just numerous — they were doing lots of different things. Some, like Haimirichia amonensis, were small suction feeders likely adapted to snapping up soft-bodied prey like squid. Others, such as the massive Otodus megalodon, were apex predators capable of preying on large marine mammals. In between were species like Hemipristis serra, with serrated teeth suited for slicing through flesh, indicating a role as a powerful mid-sized predator. There were also bottom-dwellers like Galeorhinus cuvieri, which probably hunted crustaceans and small fish, and long-snouted filter-feeders like Pseudomegachasma, which may have filtered plankton from the water. Together, these species helped maintain a balance in the marine food web by occupying a broad spectrum of feeding strategies, sizes, and ecological roles. Importantly, this decline didn't happen overnight. It's (thankfully?) been unfolding for millions of years. But the pressure modern sharks face from overfishing, habitat destruction and climate change is piling on top of an already weakened system. It's like kicking a structure that's already crumbling at the foundation. What's left today is a thinner slice of the rich ecological tapestry that sharks once wove through the oceans. And if we continue to lose the few remaining threads, the consequences could ripple far beyond sharks themselves. Cooper and Pimiento hope their work acts as both a warning and a guide. By understanding how shark functional diversity has changed through time, scientists can better predict which roles are most at risk and which species are keystones worth prioritizing for conservation. Protecting the sharks of today isn't just about saving individual species, they argue, but about preserving the roles they play and the balance they bring to marine ecosystems. Sharks have weathered mass extinctions, sea-level shifts and global climate swings. But their long history on our blue marble planet also shows us that their current decline isn't part of a natural cycle, but a breaking point. The oceans of the past were richer, not just in life but in function. If we want to keep the ocean ecosystems we rely on, we'll need to make sure sharks can keep doing the jobs they've done for millions of years.
Forbes
22-04-2025
- Science
- Forbes
Meet Vasuki Indicus — A 45-Foot Prehistoric Serpent From India's Lost World Of Isolation And Collision
India was once a floating island of evolutionary experiments. Fifty million years ago, those ... More experiments were unleashed upon the world. Among them: a now-extinct family of giant snakes. Spin a globe, and it's easy to be lulled into a false sense of security. The landmasses stay put. But the story is very different on the planet globes were made to represent. Fifty million years ago, Earth was already ancient, but geologically restless. The continents were in flux. Africa hadn't yet collided with Europe. Australia was still drifting away from Antarctica. And India was a runaway. Having broken off from the southern supercontinent Gondwana roughly 120 million years ago, the Indian landmass drifted north, moving far faster than most tectonic plates do today. By 50 million years ago, it was on a direct collision course with Asia. On the Indian tectonic plate, however, life was evolving in isolation, utterly unaware of the looming collision. For tens of millions of years, India functioned like a biological island — cut off from the evolutionary arms race playing out across the rest of the world. Species that lived there were unique, shaped by the constraints and freedoms of geographic solitude. When India finally collided with Eurasia, it wasn't just rock against rock. It was biology breaching its borders. Species that had evolved in isolation suddenly found pathways into Eurasia — and vice versa. Among the evolutionary cast that spilled forth was a now-extinct family of giant snakes. Long before boas and pythons began their silent reign, the world belonged to another breed of constrictor. Called the madtsoiids, these large snakes emerged during the age of dinosaurs. Built for the long game, these serpents slithered their way from the Cretaceous right through to the Cenozoic — a stretch of over 80 million years. Most madtsoiids were giants by today's standards. Some stretched well over 30 feet, making them some of the largest snakes ever known. Like modern boas and pythons, they were powerful constrictors that relied on brute strength, not venom, to crush and subdue their prey. Their diet was anything they could overpower: mammals, reptiles, even small dinosaurs. Fossils of these predators have been unearthed on several continents, from South America and Africa to Australia and India. This wide distribution suggests that their roots were in the supercontinent Gondwana, before the landmasses split apart and carried madtsoiids to new evolutionary frontiers. The family tree itself is still being pieced together, with genera like Madtsoia, Wonambi, and Sanajeh adding to a tangled, global puzzle. But even the most enduring lineages fall, and madtsoiids were no exception. They were likely victims of shifting climates, disappearing habitats and competition from faster, more specialized predators. Yet, for millions of years, they were top-tier carnivores, with fossils suggesting a once-flourishing dynasty across much of the prehistoric world. And in India, their story reached a unique climax with the discovery of Vasuki indicus, a snake that could potentially rival the size of Titanoboa. Discovered in the lignite mines of Kutch, Western India, Vasuki is a prehistoric heavyweight — a snake estimated to stretch between 11 and 15 meters long, making it the largest madtsoiid ever found. Named after the serpent king from Hindu mythology who coils around Lord Shiva's neck, Vasuki indicus carries a name as rooted in India as the rocks it was pulled from. So far, its fossils have only been uncovered in India. But its story doesn't end there. Phylogenetic analysis links Vasuki to Madtsoia pisdurensis, another Indian madtsoiid from the Late Cretaceous, as well as Gigantophis garstini, a massive snake from Late Eocene North Africa. Taken together, the evidence suggests that Vasuki represents a lineage that evolved in isolation while India drifted northward — and may later have spread out, likely dispersing through southern Eurasia into North Africa following the India-Eurasia collision. In evolutionary terms, Vasuki is a relic from a vanished world — a creature forged in solitude and set loose by tectonic chaos. The answer lies in both its anatomy and the rocks it was found in. The structure of Vasuki's vertebrae suggests it wasn't built for swimming. And at its massive size, it probably wasn't climbing trees. Instead, it likely lived like today's large pythons and anacondas: slow-moving, ground-dwelling and built for ambush. Its bones bear a striking resemblance to those of modern Python and Malayopython, hinting at a similar lifestyle. The fossilized bones of Vasuki indicus bear a striking similarity to those of a modern python. The sediment in which Vasuki was discovered tells the rest of the story. It was buried in a back-swamp marsh. This is a humid, low-lying landscape not unlike the wetlands where today's large constrictors thrive. During the time Vasuki lived, average temperatures hovered around 82°F, making this region a tropical hothouse ideal for cold-blooded predators. It's in this hothouse that Vasuki would have waited: half-submerged, silent, and patient. And when the time came, it would strike — coiling around its prey and crushing it with sheer muscle, the way giant snakes have done for millions of years. Giant snakes are nightmare fuel for most people. Where do you think you stand on the science-backed Fear Of Animals Scale?
Miami Herald
17-03-2025
- Science
- Miami Herald
15 million-year-old creature — with its last meal inside — is new species in Australia
What can fossils tell us about prehistoric life? The length of a femur bone may help paleontologists determine how tall a dinosaur once was, or a curved tooth may help researchers identify an aquatic reptile as a carnivore or herbivore. In a few rare cases, something extra left behind in the fossil record leads to a groundbreaking discovery, or, at least, the identification of a new species. Researchers working in New South Wales, Australia, at a fossil site called the McGraths Flat discovered the bones of an ancient fish species, according to a study published March 17 in the peer-reviewed Journal of Vertebrate Paleontology. McGraths Flat was once a freshwater ecosystem during the Cenozoic period, ranging from 66 million years ago until recently, according to the study. When the fossil was examined, researchers saw the bones belonged to a fish, but not like one they had seen before. The fish was 'slender' and 'fusiform,' and it had an adipose fin, a fleshy dorsal fin without bony rays that is common in fish like salmon, according to the study. While the teeth and bones of the fossil were relatively 'poorly preserved,' outlines of multiple fins allowed researchers to identify the prehistoric fish as a species new to science. The new species was named Ferruaspis brocksi, or Brock's iron shield fish, according to the study, honoring Jochen Brocks, who discovered multiple specimens. The fossil was dated to the Miocene, between 11 million and 16 million years ago, and was found in iron-rich stone, researchers said. 'The discovery of the 15 million-year-old freshwater fish fossil offers us an unprecedented opportunity to understand Australia's ancient ecosystems and the evolution of its fish species, specifically the Osmeriformes group during the Miocene epoch,' study author Matthew McCurry said in a news release from the Australian Museum, shared with McClatchy News. 'Osmeriformes are a diverse group of fish within Australia which includes species like the Australian Grayling and the Australian Smelt. But, without fossils it has been hard for us to tell exactly when the group arrived in Australia and whether they changed at all through time.' However, the most exciting feature of the fossil may not be the bones of the fish at all. At the bottom edge of the fossilized fish is a grouping of fossilized material that was a little bit different than the rest, researchers said. The fish's stomach contents had also been preserved. 'Not only does this fossil provide a unique snapshot into the environment it lived, but also because its stomach contents are so well preserved it allows us a glimpse into the behavior of these ancient species,' McCurry said in the release. 'We now know that they fed on a range of invertebrates, but the most common prey was small phantom midge larvae.' Researchers also used a powerful microscope to look for features called melanosomes, part of the body of animals that creates color. In previous studies, melanosomes found in fossils were used to reconstruct the color of feathers for birds millions of years after they lived, study author Michael Frese said in the release. This is the first time the same process was used on a fish. 'The fish was darker on its dorsal surface, lighter in color on its belly and had two lateral stripes running along its side,' Frese said. Brock's iron shield fish adds to the rich prehistoric history of McGraths Flat, and contributes to its classification as a 'Lagerstätte,' or a 'site that contains fossils of exceptional quality with remarkable detail,' according to the museum. McGraths Flat is near Gulgong, New South Wales, in southeastern Australia, about a 180-mile drive northwest from Sydney. The research team includes McCurry, Frese, Anthony C. Gill, Viktor Baranov, Lachlan J. Hart and Cameron Slatyer.
