Wednesday , January 20 2021

The penis of this dinosaur is an evolutionary mystery

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Illustration of the red Anchiornis, Matt Martineck / CC BY 3.0

Meeting Anchiornis, A one-dimensional, four-pointed, 160-million-red-haired man from today's China, this dinosaur was a close precursor to modern birds, even to their chicken legs. Like many other dinosaurs found in China, she also had "feather boats," said Mary Schweitzer, a paleontologist at the North Carolina State University. The first bird, archeopteryx, appeared almost 10 million years later, but AnchiornisThe wealth of feathers made the researchers wonder if they could still fly. (Pterosaurs, what they were worth, they were not actually dinosaurs.)

Flight is an "expensive" opportunity, says Schweitzer. There must be a lot of "evolutionary reason" to justify it, so the discovery of feathered dinosaurs does not automatically indicate that these species can fly. New research published in Notifications of the National Academy of Sciences determine whether Anchiornis could. The answer is complicated.

High resolution fossil electron microscopy Anchiornis the pen indicates the presence of beta-keratin (β-keratin) and alpha-keratin (ker-keratin) in the feces of these dinosaurs. This co-expression shows what a 10 million-year difference can make: Modern bird feathers contain only small amounts of ker-keratin, and there is good reason to do so. Its fibers are about 10 nanometers in diameter, says Schweitzer, co-author of the new study, while beta-keratin fibers are only about three nanometers. It's not hard to understand why birds, as they flock to flight, carried proteins one-third larger than those that make up our hair, skin and nails.

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Mostly, Anchiornis a sample evaluated in the new study. Courtesy WANG Xiaoli

But it's not that simple. The particular type of β-keratin is found in AnchiornisSheiker is compatible with modern flying feathers. One beta-keratin is not necessarily the other: at one point, she says, there is an "eradication event" in which the protein has a piece cut off it, losing amino acids that make it more fragile. Keratin becomes more flexible and thus more favorable to the flight. Somehow, Anchiornis sports as post-deletion of the beta-keratins of its flying descendants as well as the keratines reserved for those of us seized on land and in the water.

It can happen this way Anchiornis fly? Not quite clear, and if so, it is not quite clear what it would look like. What the study tells us, the press release says, is that the beta-keratin flight eradication event happened earlier than previous estimates. "Molecular minerals," says Schweitzer in the report, can help "root molecular clocks and improve their accuracy" and can help us acquire a fuller, if more complex, sense of how the feathers have evolved.

From healthy hair, to glorious flight to protective mud, it's really all in keratin.

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