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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Dinosaurs—they grow up so fast, especially if they’re trying not to get eaten.
Hypacrosaurus, a duck-billed dinosaur that could reach more than 30 feet in length, was a preferred meal of the Tyrannosaurus Rex. But this prey dinosaur had a trick to keep the species alive—Hypacrosaurus grew to adulthood remarkably quickly, according to a new study in the Proceedings of the Royal Society B [pdf]. The research suggests that it took 10 to 12 years for Hypacrosaurus to become fully grown. Tyrannosaurs, however, reached adulthood after 20 to 30 years, said Drew Lee, a postdoctoral fellow in Ohio University’s College of Osteopathic Medicine who co-authored the paper [Science Daily].
The Hypacrosaurus’ accelerated growth rate allowed it to reach sexual maturity at only two or three years old, giving it the chance to reproduce before predators gobbled it up, according to study co-author Lisa Noelle Cooper. “That’s another added bonus when facing predators—if you can keep reproducing, you’re set, it’s the stuff of evolution,” said Cooper [AFP].
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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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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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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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