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Bird-sized dinosaurs evolved ability to glide, but time in the skies was short-lived

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Oct. 22 (UPI) — Often, evolutionary biologists focus on success. The planet’s tremendous biodiversity offers a treasure trove of success stories, but evolutionary history is also littered with short-lived experiments and forgotten failures.

Yi and Ambopteryx are two such failures. Roughly 160 million years ago, during the Late Jurassic, evolutionary tinkering allowed the pair of bird-like dinosaurs to take the skies across Asia — kind of. Their achievement was short-lived.

New research, published Thursday in the journal iScience, suggest Yi and Ambopteryx were unable to actually fly. Despite their bat-like wings, analysis of the duo’s skeletal and musculature makeup suggests the two dinosaurs species were only able to glide short distances — and clumsily.

To more precisely characterize the physiology of Yi and Ambopteryx, researchers relied on an imaging technology called laser-stimulated fluorescence.

“It allows you to see soft tissue structures, skin, feather impressions and the like, that are not visible under white light,” first author Alex Dececchi, an assistant professor of biology at Mount Marty University, told UPI in an email.

“It can help to bring out the fine details which are so important in reconstructing the life history of these creatures,” said Dececchi, an assistant professor of biology at Mounty Marty University.

Having gathered information about the arrangement and distribution of tissue and mass across the bodies and wings of Yi and Ambopteryx, Dececchi and his research partners turned to a series of math models designed to decipher the physics of flight.

First, scientists ran a simple model that showed flight was at least in the realm of possibility for the two bird-like dinosaurs. The pair didn’t have too much weight over their wings, for example.

“Then we used mathematical models, based on living flying organisms under the conditions that these dinosaurs would have experienced, to see things like: how fast they would need to go to generate enough lift to keep them in the air, how much power they would need fly by flapping, how big a turn radius they would need if they had to bank, etc.,” Dececchi said.

“We also compared these values to both modern gliding animals, other fossil gliders and to other dinosaurs and early birds who are thought to have some flight capabilities to see their relative flight worthiness,” he said.

The models showed that at high speeds, but not impossibly high speeds, the two dinosaurs could achieve a glide, which explains why the pair sported large membranous “wings.”

“But the models also showed that these guys could not take off from the ground by flapping,” Dececchi said. “As well, they could not generate enough power to sustain flapping flight if they did somehow take off. Thus, we can say that Yi and Ambopteryx could have used their wings to glide but not to flap fly.”

The fossil record suggests Yi and Ambopteryx went extinct not long after they developed their gliding abilities. Researchers suspect the arrival of real flying birds helped drive the duo’s decline.

“There were also pterosaurs flying at that time and some of them were hawk to eagle size, likely acting as a predator,” Dececchi said. “So with predators that were better at flying on one side and the rise of competitors for food and resources who were better from the other, these creatures had nowhere to hide and went extinct.”

Yi and Ambopteryx were effectively squeezed from the skies.

Of course, gliding itself is not an evolutionary dead end. To this day, a variety of species glide. But Dececchi suggests most successful gliders have been able to occupy small niches, and limit competition with birds or bats.

“Think of flying squirrels, colugos or sugar gliders and other gliding mammals, these animals are nocturnal to minimize the competition and predation from birds. These creatures are also simply better at it, which also helps,” Dececchi said. “I think this group [Yi and Ambopteryx] simply didn’t have the time to evolve a more efficient and effective gliding flight before birds came and pushed them out.”

Researchers suggest their work is a reminder of the value in studying evolutionary failure. By analyzing the different ways dinosaurs tried and failed to take to the skies, researchers can begin to pinpoint the evolutionary solutions that helped dinosaurs and birds get airborne — solutions that had long-term evolutionary impacts.

“I think this paper is a piece of the bigger puzzle of how over a 20 to 30 million year span the air space became a battlefield for which groups were going to seize what roles,” Dececchi said. “And the outcome of those battles has shaped how our modern ecosystems look and function.”



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NASA’s OSIRIS-REx touches down on asteroid Bennu to nab sample

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Oct. 20 (UPI) — NASA’s OSIRIS-REx touched down on asteroid Bennu on Tuesday evening in a mission to scoop a sample of rocks and dirt.

The spacecraft — the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer — made soft contact with the asteroid at 6:12 p.m. EDT.

The historic “touch and go” event featured animation displaying OSIRIS-REx’s sample collection activities in real time. It takes time for real images of the touchdown to travel back to the Earth, so they won’t be released to the public until Wednesday.

The craft executed a series of maneuvers over the course of several hours before making soft contact with the surface of the asteroid to collect regolith, or rocks and dirt.

“It will be four and a half hours of anxiousness,” Beth Buck, OSIRIS-REx mission operations manager at Lockheed Martin Space, said in a news conference ahead of the event.

Buck made a comparison to the descent of a spacecraft on Mars, when there is typically “seven minutes of terror.”

The goal is to learn more about the solar system’s history and help “planetary defense” engineers with missions to protect earth from rogue asteroids. Bennu is believed to be a window into the solar system’s past since it’s a pristine, carbon-rich body carrying building blocks of both planets and life.

At around 1:50 p.m. EDT, the spacecraft left orbit around the asteroid before executing a series of burns to position itself over a sampling area nicknamed Nightingale.

Once in position, the craft began its approach to the asteroid at 5:50 p.m. EDT. It then spent about 15 seconds attempting to collect the regolith sample before backing away again.

The area, which is 52 feet in diameter, will make for a more demanding landing than expected, Kenneth Getzandanner, OSIRIS-REx flight dynamics manager at the NASA Goddard Space Flight Center in Maryland, said in the news conference.

The original mission called for a landing “zone” about 150% larger than Nightingale, at 82 feet, but that changed because Bennu was more rocky than expected.

The goal was to collect at least 1.7 ounces of fine-grained material, but the spacecraft can carry up to 4.4 pounds, Heather Enos, OSIRIS-REx deputy principal investigator at the University of Arizona said.

“I would love for that capsule to be completely full,” Enos said.

Though early images from the asteroid should hint at whether the mission succeeded, it will take engineers roughly 10 days to compare and analyze the mass before and after the maneuver to actually know how much dirt is inside the OSIRIS-REx.

If it failed, the spacecraft has enough fuel to attempt two more touch downs to collect material.

The spacecraft is expected to return to Earth, with the regolith sample from Bennu, in 2023.



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SpaceX scrubs Starlink launch until Thursday, if weather cooperates

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Oct. 21 (UPI) — Just three days after sending 60 more Starlink satellites into orbit, SpaceX is aiming to launch another batch of broadband satellites into space from Florida.

If the weather cooperates, Thursday’s launch will be SpaceX’s 15th Starlink mission.

Liftoff had been scheduled for 12:29 p.m. EDT Wednesday aboard a Falcon 9 rocket at Launch Complex 40 at Cape Canaveral Air Force Station, but controllers scrubbed the launch due to weather and rescheduled for 12:14 p.m. on Thursday.

With a launch Sunday, SpaceX increased the size of their Starlink constellation to nearly 800 satellites. The 15th mission will see another 60-odd satellites join the network.

“The goal of Starlink is to create a network that will help provide Internet services to those who are not yet connected, and to provide reliable and affordable Internet across the globe,” according to the Kennedy Space Center.

Weather for Wednesday’s planned launch had looked so-so and the Space Force’s 45th Weather Squadron predicted a 60 percent chance of favorable conditions.

“A mid-level inverted trough and associated easterly wave currently across the Bahamas will meander into the state over the next few days, bringing enhanced moisture, cloud cover, and instability with a higher coverage of showers and storms,” Space Force forecasters wrote.

They said Thursday’s forecast looks quite similar to Wednesday’s.

Earlier this month, SpaceX founder and CEO Elon Musk tweeted that Starlink’s constellation was big enough to begin beta-testing the Internet service system in both the United States and southern Canada.

SpaceX has already offered Starlink Internet services to emergency responders in wildfire-stricken areas of Washington State.

Washington’s Hoh tribe is also using the Internet service to provide their members online education and telehealth services.



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Chernobyl-level radiation harms bumblebee reproduction

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Oct. 21 (UPI) — Bees are more sensitive to radiation than scientists thought. Scientists found the reproduction rates of bumblebees declined significantly when exposed to Chernobyl-level radiation.

The research, published Wednesday in the journal Proceedings of the Royal Society B: Biological Sciences, suggests radiation in Ukraine’s Chernobyl Exclusion Zone could impair pollination services, triggering wider ecological consequences than previously estimated.

Humans are not allowed to live in the Chernobyl Exclusion Zone, the disaster area more directly impacted by the 1986 nuclear accident, the worst in history. However, the destroyed nuclear reactors are surrounded by forests that are populated by robust populations of birds, bears, bison, lynx, moose, wolves and more.

Efforts to gauge the effects of radiation contamination on insects have yielded mixed results in the past. While some studies have suggested insects are relatively radiation-resistant, others have demonstrated significant impairment.

When researchers exposed bumblebees in the lab to radiation dose of 100 µGyh-1, an amount approximating exposure inside the Chernobyl Exclusion Zone, reproduction rates among the bees dropped between 30 and 45 percent.

Researchers found a direct correlation between the size of the radiation dose and reproduction rate declines. Lower levels of radiation had a smaller effect, while larger doses yielded greater declines.

Scientists were surprised to find they were able to detect reproductive rate declines at very small levels of radiation exposure.

“Our research provides much needed understanding as to the effects of radiation in highly contaminated areas and this is the first research to underpin the international recommendation for the effects of radiation on bees,” lead study author Katherine Raines, environmental scientist at the University of Stirling in Scotland, said in a news release.



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