About 240 million years ago, a 15-foot amphibian with a nasty bite ruled the Antarctic plains, say paleontologists who have described the creature for the first time. Fossils show that the predator, newly named Kryostega collinsoni, had an extra set of teeth protruding from the roof of its mouth, which helped it shred flesh and hold struggling prey still in its mouth.
The animal, which researchers called Antarctica’s top predator in the Triassic Period, resembled a modern crocodile but was actually a temnospondyl, a prehistoric amphibian that was an early relative of salamanders and frogs. Because of their odd mixture of characteristics, members of this group are sometimes nicknamed “crocamanders” or “frogodiles” [Discovery News]. The new species will be described in the forthcoming issue of the Journal of Vertebrate Paleontology.
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The dinosaurs that held dominion over the Earth in the Jurassic Period didn’t rule the lands because they out-competed every rival, a new study says. Researchers studied fossil evidence from an earlier epoch, the Triassic Period, and say that dinosaurs showed no evidence of being better adapted to their environment than their challengers. “For a long time it was thought that there was something special about the dinosaurs that helped them become more successful during the Triassic, the first 30 million years of their history, but this isn’t true,” said lead author of the study, Steve Brusatte [LiveScience].
Instead they may have just been lucky enough to survive a drastic climate shift when their rivals didn’t. Researchers compared fossils from the 30 million years in the Triassic when dinosaurs coexisted with crurotarsan archosaurs, a group whose only living relative is crocodiles. They found that not only did the groups evolve at the same rate, but the crurotarsans even developed a wider range of body types than dinosaurs, suggesting that the group as a whole was more successful at developing to live in different habitats and ecosystems [Telegraph].
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In a cluster of coal mines in eastern Illinois, researchers have discovered the fossilized remains of ancient rainforests that date from the Carboniferous era, including one forest that stretched for 39 square miles. Researchers say the forests date from both before and after an episode of intense global warming that occurred about 306 million years ago, and may shed light on the ecosystem‘s reaction to the drastic climate shift.
Researchers published a report on the first fossilized rainforest last year, but announced this week at the British Association’s Festival of Science that they have since come across five more patches of ancient woods. Says paleontologist Howard Falcon-Lang: “Three of the forests predate global warming and the rest follow it, so we can compare the ecology of those rain forests to see what the effect of global warming was.” During that period the Earth’s climate flipped from being covered with large polar icecaps to a greenhouse state that was completely ice-free, he added [National Geographic News].
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In an arid and lifeless stretch of the Sahara, archaeologists have discovered a massive graveyard and remnants of early settlements that hark back to Stone Age days when the desert was wet, green, and habitable. Researchers say the find is a striking reminder that climates and environments can shift drastically over the geologically short time period of 10,000 years.
In an area of Sahara that’s known to nomads as the “desert within a desert,” researchers found evidence of thriving prehistoric cultures and rich ecosystems on the edge of a lake. There were also hundreds of animal bones. In addition to antelope and giraffe, [lead researcher Paul] Sereno quickly recognized the remains of water-adapted creatures like crocodiles and hippos, then turtles, fish, and clams. “Everywhere you turned, there were bones belonging to animals that don’t live in the desert,” said Sereno. “I realized we were in the Green Sahara” [National Geographic].
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An extinct ancestor of the great white shark had a powerful bite that wouldn’t just put Jaws to shame, according to a new fossil analysis by Australian researchers. The colossal force of Carcharodon megalodon – also known as Big Tooth – made even Tyrannosaurus rex look puny [Telegraph].
In the study, to be published in an upcoming issue of the Journal of Zoology [subscription required], researchers took CT scans of both the skulls of great white sharks and those of the prehistoric megalodon, who swam the oceans about a million and a half years ago. They made computer models of the skulls, and then ran an analysis on the models that engineers use to determine how machinery holds up under stress.
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A new study may burst the bubble of dinosaur buffs by contradicting an exciting announcement of three years ago: what was earlier identified as soft tissue preserved in the thigh bone of a Tyrannosaurus fossil is actually just modern-day bacteria, researchers say.
The new study challenges the work done by paleontologist Mary Schweitzer, who garnered headlines in 2005 for reporting in the journal Science [that her team] had found the remains of blood vessels inside the fossils unearthed in the Hell Creek Formation in Montana. Finding tissue preserved at least 65 million years shocked paleontologists who believed any such traces were lost forever [USA Today].
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The Cretaceous period was such a good time for evolution that researchers talk about the “Cretaceous Terrestrial Revolution,” when as an explosion of new plant and animal species appeared. But researchers say that a detailed analysis of dinosaur diversity during this period debunks the prevailing theory that dinosaurs took part in this evolutionary spree; instead, their rapid evolution had taken place millions of years before.
The Cretaceous period, which lasted from 145 million years ago to 65 million years ago… saw the diversification of pollinating insects such as bees, butterflies, and moths. New forms of lizards, crocodiles, and snakes appeared, as did many of the ancestors of modern groups of birds and mammals. The Cretaceous also saw the explosion of angiosperms, or flowering plants [ScienceNOW Daily News]. Some researchers have previously suggested that the wide availability of those flowering plants sparked an evolutionary surge in dinosaurs who fed on the plants, and others who fed on the plant-eaters.
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In a cold, desert region of Antarctica, paleontologists have discovered the tiny fossils of shrimp-like creatures that lived in lakes during a more temperate era. The finding help refine the timing of the climate shift that gave rise to Antarctica’s remarkable Dry Valleys, a landscape akin to Mars [BBC News].
The well-preserved fossils of ostracods, a type of small crustaceans, came from… Antarctica’s Transantarctic Mountains and date from about 14 million years ago. The fossils were a rare find, showing all of the ostracods’ soft anatomy in 3-D [LiveScience]. The ostracods couldn’t survive in the Dry Valleys under current conditions, which include mean annual temperatures of minus 13 degrees Fahrenheit, indicating that the continent was a very different place 14 million years ago.
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In the primeval forests of Europe, scaly lizards leaped from the treetops and glided safely to the ground, according to a new study. Paleontologists investigated the fossilized remains of two kinds of kuehneosaurs, which were first found in the 1950s in an ancient cave system near Bristol [The Press Association]. They say that the prehistoric reptiles used extraordinary extensions of their ribs to form large gliding surfaces on the side of the body [LiveScience], which were surprisingly effective for the larger of the two species.
Researcher Koen Stein says: “We didn’t think kuehneosaurs would have been very efficient in the air, but all the work up to now had been speculation, so we decided to build models and test them in the wind tunnel in the Department of Aerospace Engineering at Bristol. Surprisingly, we found that Kuehneosuchus was aerodynamically very stable” [Telegraph]. Researchers said the Kuehneosuchus could have glided about 30 feet before touching down on the ground, while the Kuehneosaurus, with stubbier “wings,” was more of a parachutist.
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An evolutionary puzzle that Charles Darwin mulled over has finally been solved, thanks to a re-examination of some dusty fish fossils that had been lying neglected in a museum archive. Scientists had long wondered how flatfish evolved to their present form, with both eyes on the same side of their heads; now a report in the journal Nature [subscription required] reveals that the trait evolved gradually and in stages.
All living flatfishes, which include halibut, flounder and sole, have a bizarre adaptation: both eyes are on one side of their head [Telegraph]. This allows them to lie flat on the ocean floor while using both eyes to watch for passing prey. Scientists couldn’t figure out how this trait could evolve gradually over time, and wondered whether a fish in the intermediate evolutionary stage would garner any advantage from having one eyeball that was near the top of its head. This caused people to argue that flatfish might be the product of a large and sudden evolutionary leap, and the fish were used as an argument against natural selection. Googling “flatfish creationism” will also reveal that the arguments spilled out of scientific circles as well [Ars Technica].
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A new study of fossilized bird feathers from 100 million years ago has determined that the broad stripes visible on the feathers do indicate the color of that ancient bird’s plumage. Researchers say the discovery may allow them to reconstruct the colors of other prehistoric birds and even feathered dinosaurs.
The fossil feathers had an obvious striped pattern but its origin had long been debated, according to Professor [Mike] Benton. “The banding looks so life-like that it can’t be geological in origin – it has to be biological,” he said. “But then how do you square that with the well-known fact that the majority of organic molecules decay in thousands of years?” [BBC News].
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Around 365 million years ago, a fishy, finned creature that resembled a small alligator clambered up on a sandbank and earned its place in evolutionary history. Researchers who recently discovered fossils of the animal, named Ventastega curonica, say it’s the most primitive four-legged creature ever found. While it wasn’t the first “fishapod” to lurch out of the water (that honor goes to the Tiktaalik, which accomplished the feat about 375 million years ago), its more primitive evolutionary stage gives researchers new information about the earliest four-legged creatures, or tetrapods.
Ventastega was first described from a few bone fragments unearthed in Latvia in 1994, but it took additional years of excavation and the discovery of remains from many more individuals before scientists had a good idea of what the creature looked like. The latest portrait to emerge, from an especially well-preserved find, reveals an animal with a part-fish, part-tetrapod skull and a full-fledged tetrapod body. It would have spent the majority of its time on water and been clumsy on land [National Geographic News].
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The giant azhdarchid pterosaurs have fascinated paleontologists since their fossils were first discovered in the 1970s. The largest flying animals ever to grace the planet seemed ripped from science fiction: They were taller than giraffes and had wingspans of over 30 feet.
Researchers first believed that these pterosaurs, or “winged lizards,” were scavengers that picked apart carcasses. More recently, paleontologists marveled at the idea of the lizards swooping over coastal waters to hunt like enormous seabirds. Now, after a comprehensive study of the azhdarchids’ footprints and fossils, several researchers have announced their theory that the largest pterosaurs stalked their prey on land like storks, and fed on baby dinosaurs.
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