Tag Archives: dinosaurs

New Measurement of Crocodilian Nerves Could Lead to Better Understanding of Ancient Animals’ Behavior, MU Researcher Finds

COLUMBIA, Mo. ­— Crocodilians have nerves on their faces that are so sensitive, they can detect a change in a pond when a single drop hits the water surface several feet away. Alligators and crocodiles use these “invisible whiskers” to detect prey when hunting. Now, a new study from the University of Missouri has measured the nerves responsible for this function, which will help biologists understand how today’s animals, as well as dinosaurs and crocodiles that lived millions of years ago, interact with the environment around them. (more…)

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Asteroid that Killed the Dinosaurs also Wiped out the ‘Obamadon’

The asteroid collision widely thought to have killed the dinosaurs also led to extreme devastation among snake and lizard species, according to new research — including the extinction of a newly identified lizard Yale and Harvard scientists have named Obamadon gracilis.

“The asteroid event is typically thought of as affecting the dinosaurs primarily,” said Nicholas R. Longrich, a postdoctoral associate with Yale’s Department of Geology and Geophysics and lead author of the study. “But it basically cut this broad swath across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard.” (more…)

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Dinosaur Die Out Might Have Been Second of Two Closely Timed Extinctions

The most-studied mass extinction in Earth history happened 65 million years ago and is widely thought to have wiped out the dinosaurs. New University of Washington research indicates that a separate extinction came shortly before that, triggered by volcanic eruptions that warmed the planet and killed life on the ocean floor.

The well-known second event is believed to have been triggered by an asteroid at least 6 miles in diameter slamming into Mexico’s Yucatán Peninsula. But new evidence shows that by the time of the asteroid impact, life on the seafloor – mostly species of clams and snails – was already perishing because of the effects of huge volcanic eruptions on the Deccan Plateau in what is now India. (more…)

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Yale Study Reveals New Family Tree for Ray-Finned Fish

The most common lineages of fish found today in oceans, lakes, and rivers evolved about the same time as mammals and birds, a new Yale University-led study shows.

The comparative genetic analysis of more than 200 fish species, reported the week of Aug. 6 in the Proceedings of the National Academy of Sciences, gave an earlier than expected evolutionary birthday to well-known teleost — or ray-finned — fish such as salmon, bass, or tuna.

The analysis also shows that the very earliest lineages of living teleost fish were eels and bonefishes, not tropical freshwater bonytongue fish as some scientists had proposed. (more…)

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From a Few Bones, the Most Primitive Snake Emerges

Researchers at Yale have identified an ancient slithering creature from the time of T. rex as the most primitive known snake, a finding with implications for the debate over snake origins.

“It’s the missing-link snake,” said Nicholas Longrich, a postdoctoral fellow in Yale’s Department of Geology & Geophysics and the lead author of a paper about the lizard-like snake published July 25 online in the journal Nature. “It’s the ‘Lucy’ of snakes.”

The paper argues that snakes descend from terrestrial rather than marine ancestors, as recently proposed by others, and that snakes emerged once lizards developed long, limbless bodies for burrowing. (more…)

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Iconic New Zealand Reptile Shows Chewing is Not Just for Mammals

The tuatara, an iconic New Zealand reptile, chews its food in a way unlike any other animal on the planet –challenging the widespread perception that complex chewing ability is closely linked to high metabolism.

Using a sophisticated computer model, scientists from UCL and the University of Hull demonstrate how the tuatara is able to slice its food like a “steak knife”. The tuatara’s complex chewing technique raises doubts about the supposed link between chewing and high metabolism in mammals.

The New Zealand tuatara (Sphenodon) is a lizard-like reptile that is the only survivor of a group that was globally widespread at the time of the dinosaurs. It lives on 35 islands scattered around the coast of New Zealand and was recently reintroduced to the mainland. Its diet consists of beetles, spiders, crickets, small lizards and, occasionally, sea birds. (more…)

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Some Mammals Used Highly Complex Teeth to Compete With Dinosaurs

Conventional wisdom holds that during the Mesozoic Era, mammals were small creatures that held on at life’s edges. But at least one mammal group, rodent-like creatures called multituberculates, actually flourished during the last 20 million years of the dinosaurs’ reign and survived their extinction 66 million years ago.

New research led by a University of Washington paleontologist suggests that the multituberculates did so well in part because they developed numerous tubercles (bumps, or cusps) on their back teeth that allowed them to feed largely on angiosperms, flowering plants that were just becoming commonplace. (more…)

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Iridescent, Feathered Dinosaur Offers Fresh Evidence That Feathers Evolved to Attract Mates

AUSTIN, Texas — A team of American and Chinese researchers has revealed the detailed feather pattern and color of Microraptor, a pigeon-sized, four-winged dinosaur that lived about 120 million years ago. A new specimen shows the dinosaur had a glossy iridescent sheen and that its tail was narrow and adorned with a pair of streamer feathers, suggesting the importance of display in the early evolution of feathers, as presented in the March 9 edition of the journal Science.

The research was conducted by scientists at the Beijing Museum of Natural History, Peking University, The University of Texas at Austin, the University of Akron, and the American Museum of Natural History. (more…)

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