Jackpot of fossilized pterosaur eggs unearthed in China

Hundreds of eggs belonging to a species of flying reptile that lived alongside dinosaurs are giving scientists a peek into the earliest development of the animals.

The find includes at least 16 partial embryos, several still preserved in 3-D. Those embryos suggest that the animals were able to walk, but not fly, soon after hatching, researchers report in the Dec. 1 Science.

Led by vertebrate paleontologist Xiaolin Wang of the Chinese Academy of Sciences in Beijing, the scientists uncovered at least 215 eggs in a block of sandstone about 3 meters square. All of the eggs belonged to one species of pterosaur, Hamipterus tianshanensis, which lived in the early Cretaceous Period about 120 million years ago in what is now northwestern China.
Previously, researchers have found only a handful of eggs belonging to the winged reptiles, including five eggs from the same site in China (SN: 7/12/14, p. 20) and two more found in Argentina. One of the Argentinian eggs also contained a flattened but well-preserved embryo.
One reason for the dearth of fossils may be that the eggs were rather soft with a thin outer shell, unlike the hard casings of eggs belonging to dinosaurs, birds and crocodiles but similar to those of modern-day lizards. Due to that soft shape, pterosaur eggs also tend to flatten during preservation. Finding fossilized eggs containing 3-D embryos opens a new window into pterosaur development, says coauthor Alexander Kellner, a vertebrate paleontologist at Museu Nacional/Universidade Federal do Rio de Janeiro.
The eggs weren’t found at an original nesting site but had been jumbled and deformed, probably transported by a flood during an intense storm, Kellner says. Sand and other sediments carried by the water would then have rapidly buried the soft eggs, which was necessary to preserve them, Kellner says. “Otherwise, they would have decomposed.”
Using computerized tomography, the researchers scanned the internal contents of the eggs. Two of the best-preserved embryos revealed a tantalizing clue to pterosaur development, Kellner says. A key part of a wing bone, called the deltopectoral crest, was not fully developed in the embryos, even in an embryo the researchers interpret as nearly at term. The femur, or leg bone, of the embryo, however, was well developed. This suggests that, when born, the hatchlings could walk but not yet fly and may have still required some parental care for feeding, the scientists propose.
Such an interpretation requires an abundance of caution, says D. Charles Deeming, a vertebrate paleontologist at the University of Lincoln in England not involved in the study. For example, he says, there isn’t enough evidence to say for certain that the embryo in question was nearly at term and, therefore, to say that it couldn’t fly when born, a point he also raises in a column published in the same issue of Science. “There’s a real danger of overinterpretation.” But with such a large group of eggs, he says, researchers can make quantitative measurements to better understand the range of egg sizes and shapes to get a sense of variation in animal size.

Kellner says this work is ongoing and agrees that there is still a significant amount of study to be done on these and other eggs more recently found at the site. And the hunt is on for more concentrations of eggs in the same site. “Now that we know what they look like, we can go back and find more. You just have to get your knees down and look.”

AI eavesdrops on dolphins and discovers six unknown click types

A new computer program has an ear for dolphin chatter.

The algorithm uncovered six previously unknown types of dolphin echolocation clicks in underwater recordings from the Gulf of Mexico, researchers report online December 7 in PLOS Computational Biology. Identifying which species produce the newly discovered click varieties could help scientists better keep tabs on wild dolphin populations and movements.

Dolphin tracking is traditionally done with boats or planes, but that’s expensive, says study coauthor Kaitlin Frasier, an oceanographer at the Scripps Institution of Oceanography in La Jolla, Calif. A cheaper alternative is to sift through seafloor recordings — which pick up the echolocation clicks that dolphins make to navigate, find food and socialize. By comparing different click types to recordings at the surface — where researchers can see which animals are making the noise — scientists can learn what different species sound like, and use those clicks to map the animals’ movements deep underwater.
But even experts have trouble sorting recorded clicks, because the distinguishing features of these signals are so subtle. “When you have analysts manually going through a dataset, then there’s a lot of bias introduced just from the human perception,” says Simone Baumann-Pickering, a biologist at the Scripps Institution of Oceanography not involved in the work. “Person A may see things differently than person B.” So far, scientists have only determined the distinct sounds of a few species.
To sort clicks faster and more precisely, Frasier and her colleagues outsourced the job to a computer. They fed an algorithm 52 million clicks recorded over two years by near-seafloor sound sensors across the Gulf of Mexico. The algorithm grouped echolocation clicks based on similarities in speed and pitch — the same criteria human experts use to classify clicks. “We don’t tell it how many click types to find,” Frasier says. “We just kind of say, ‘What’s in here?’”
The algorithm picked out seven major kinds of clicks, which the researchers think are made by different dolphin species. Frasier’s team recognized one class as being made by a species called Risso’s dolphin. The scientists suspect that another group of clicks, most common in recordings near the Green Canyon south of Louisiana, was produced by short-finned pilot whales that frequent this region. Another type resembles sounds from the eastern Pacific Ocean that a dolphin called the false killer whale makes.
To confirm the identifications, the researchers now need to compare their computer-generated categories against surface observations of these dolphins, Frasier says.

The algorithm’s click classes may not match up with dolphin species one-to-one, says Baumann-Pickering. If that were the case, “we would expect to see a heck of a lot more categories, really, based on the number of species that ought to be in that area,” she says. That absence suggests that some closely related species produce highly similar clicks the algorithm didn’t tease apart.

Still, “it would be great to be able to confidently assign certain species to each of the different click types, even if more than one species is assigned to a single click type,” says Lynne Hodge, a marine biologist at Duke University who wasn’t involved in the work. More precisely monitoring dolphins with seafloor recordings could provide new insight into how these animals respond to environmental problems such as oil spills and the long-term effects of climate change.

A quantum communications satellite proved its potential in 2017

During the world’s first telephone call in 1876, Alexander Graham Bell summoned his assistant from the other room, stating simply, “Mr. Watson, come here. I want to see you.” In 2017, scientists testing another newfangled type of communication were a bit more eloquent. “It is such a privilege and thrill to witness this historical moment with you all,” said Chunli Bai, president of the Chinese Academy of Sciences in Beijing, during the first intercontinental quantum-secured video call.

The more recent call, between researchers in Austria and China, capped a series of milestones reported in 2017 and made possible by the first quantum communications satellite, Micius, named after an ancient Chinese philosopher (SN: 10/28/17, p. 14).
Created by Chinese researchers and launched in 2016, the satellite is fueling scientists’ dreams of a future safe from hacking of sensitive communiqués. One day, impenetrable quantum cryptography could protect correspondences. A secret string of numbers known as a quantum key could encrypt a credit card number sent over the internet, or encode the data transmitted in a video call, for example. That quantum key would be derived by measuring the properties of quantum particles beamed down from such a satellite. Quantum math proves that any snoops trying to intercept the key would give themselves away.

“Quantum cryptography is a fundamentally new way to give us unconditional security ensured by the laws of quantum physics,” says Chao-Yang Lu, a physicist at the University of Science and Technology of China in Hefei, and a member of the team that developed the satellite.

But until this year, there’s been a sticking point in the technology’s development: Long-distance communication is extremely challenging, Lu says. That’s because quantum particles are delicate beings, easily jostled out of their fragile quantum states. In a typical quantum cryptography scheme, particles of light called photons are sent through the air, where the particles may be absorbed or their properties muddled. The longer the journey, the fewer photons make it through intact, eventually preventing accurate transmissions of quantum keys. So quantum cryptography was possible only across short distances, between nearby cities but not far-flung ones.

With Micius, however, scientists smashed that distance barrier. Long-distance quantum communication became possible because traveling through space, with no atmosphere to stand in the way, is much easier on particles.
In the spacecraft’s first record-breaking accomplishment, reported June 16 in Science, the satellite used onboard lasers to beam down pairs of entangled particles, which have eerily linked properties, to two cities in China, where the particles were captured by telescopes (SN: 8/5/17, p. 14). The quantum link remained intact over a separation of 1,200 kilometers between the two cities — about 10 times farther than ever before. The feat revealed that the strange laws of quantum mechanics, despite their small-scale foundations, still apply over incredibly large distances.

Next, scientists tackled quantum teleportation, a process that transmits the properties of one particle to another particle (SN Online: 7/7/17). Micius teleported photons’ quantum properties 1,400 kilometers from the ground to space — farther than ever before, scientists reported September 7 in Nature. Despite its sci-fi name, teleportation won’t be able to beam Captain Kirk up to the Enterprise. Instead, it might be useful for linking up future quantum computers, making the machines more powerful.

The final piece in Micius’ triumvirate of tricks is quantum key distribution — the technology that made the quantum-encrypted video chat possible. Scientists sent strings of photons from space down to Earth, using a method designed to reveal eavesdroppers, the team reported in the same issue of Nature. By performing this process with a ground station near Vienna, and again with one near Beijing, scientists were able to create keys to secure their quantum teleconference. In a paper published in the Nov. 17 Physical Review Letters, the researchers performed another type of quantum key distribution, using entangled particles to exchange keys between the ground and the satellite.

The satellite is “a major development,” says quantum physicist Thomas Jennewein of the University of Waterloo in Canada, who is not involved with Micius. Although quantum communication was already feasible in carefully controlled laboratory environments, the Chinese researchers had to upgrade the technology to function in space. Sensitive instruments were designed to survive fluctuating temperatures and vibrations on the satellite. Meanwhile, the scientists had to scale down their apparatus so it would fit on a satellite. “This has been a grand technical challenge,” Jennewein says.

Eventually, the Chinese team is planning to launch about 10 additional satellites, which would fly in formation to allow for coverage across more areas of the globe.

A new kind of spiral wave embraces disorder

A type of spiraling wave has been busted for disorderly conduct.

Spiral waves are waves that ripple outward in a swirl. Now scientists from Germany and the United States have created a new type of spiral wave in the lab. The unusual whorl has a jumbled, disordered center rather than an orderly swirl, making it the first “spiral wave chimera,” the researchers report online December 4 in Nature Physics.

Waves, which exhibit a variety of shapes, are common in nature. For example, they can be found in cells that undergo cyclical patterns, such as heart cells rhythmically contracting to produce heartbeats or nerve cells firing in the brain. In a normal heart, electrical signals propagate from one end to another, triggering waves of contractions in heart cells. But sometimes the wave can spiral out of control, creating swirls that can lead to a racing or irregular heartbeat. Such spiral waves emanate in an orderly fashion from a central point, reminiscent of the red and white swirls on a peppermint candy. But the newly observed spiral wave chimera is messy in the middle.
Harnessing an oscillating chemical process known as the Belousov–Zhabotinsky reaction, the researchers created the wave using an array of small beads, each containing a catalyst for the reaction. When placed in a chemical solution, the beads acted as individual pulsating oscillators — analogous to heart cells — in which the reaction took place.

The researchers monitored the brightness of each bead as it alternated between a fluorescent state that emits red light and a dim state. Because the reaction is light sensitive, illuminating individual beads allowed the researchers to induce nearby beads to sync up. Thanks to that syncing, a spiral wave took shape. But, unlike any seen before, it had a muddled center.
The wave is a new kind of “chimera,” a grouping of oscillators in which some sync up, but others march to their own drummer, despite being essentially identical to their neighbors. Although researchers have previously created other kinds of chimeras in the lab, “it’s a step further to show that you can have this in even more complex setups” such as spiral wave chimeras, says Erik Martens of the Technical University of Denmark in Kongens Lyngby, who was not involved with the research.

While spiral wave chimeras had been predicted theoretically, there were some surprises to the real-world curlicues. Single spirals, for example, sometimes broke up into several independent swirls, each with disordered centers. “That was quite unexpected,” says chemist Kenneth Showalter of West Virginia University in Morgantown, a coauthor of the study.

It’s still not known whether the chimera form of spiral waves can appear in biological systems like the heart or the brain — but the new whorl is one to watch out for.

Boy robot passes agility tests

Robots are on their way to passing gym class.

The design of a new life-size bot named Kengoro closely resembles the anatomy of a teenage boy in body proportion, skeletal and muscular structure, and joint flexibility, researchers report online December 20 in Science Robotics. Compared with previous humanoid robots with more rigid, bulky bodies, Kengoro’s anatomically inspired design gives the bot a wide range of motion to perform humanlike, full-body exercises.
Constructed by Masayuki Inaba, an engineer at the University of Tokyo, and colleagues, Kengoro has a multi-jointed spine that allows the robot to curl into a sit-up or do back extensions. The bot’s arms are limber enough to execute various stretches or swing a badminton racket. And its artificial muscles are strong enough that Kengoro can stand on tiptoe or do push-ups. Batteries in each leg power Kengoro through about 20 minutes of exercise at a time, and water seeping from inside Kengoro’s metal skeleton like sweat keeps the motors of the artificial muscles cool while the bot works out.

Such a nimble robot that so closely imitates human movement and anatomy is “very unique,” says Luis Sentis, an engineer at the University of Texas at Austin not involved in the work. Building more humanlike robots could lead to the development of more sophisticated prosthetics or more realistic crash-test dummies that make humanlike reflexive movements during an accident.

Jazz improvisers score high on creativity

Improvisation may give jazz artists a creative boost not seen among musicians more likely to stick to the score. Jazz musicians’ brains quickly embrace improvisational surprises, new research on the neural roots of creativity shows.

Neuroscientist Emily Przysinda and colleagues at Wesleyan University in Middletown, Conn., measured the creative aptitudes of 12 jazz improvisers, 12 classical musicians and 12 nonmusicians. The researchers first posed creativity challenges to the volunteers, such as listing every possible use for a paper clip. Volunteers then listened to three different kinds of chord progressions — common ones, some that were a bit off and some that went in wild directions — as the team recorded the subjects’ brain waves with an electroencephalogram. Afterward, volunteers rated how much they liked each progression.

Jazz musicians, more so than the other participants, preferred the unexpected riffs, brain waves confirmed. And the improvisers’ faster and stronger neural responses showed that they were more attuned to unusual music and quickly engaged with it. Classical musicians’ and nonmusicians’ brains hadn’t yet figured out the surprising music by the time the jazz musicians had moved on, the researchers report in the December Brain and Cognition.

The jazz musicians’ striking responses to unexpected chords mirrored their out-of-the-box thinking on the creativity challenges. Training to be receptive to the unexpected in a specific area of expertise can increase creativity in general, says Harvard University cognitive neuroscientist Roger Beaty, who was not involved in the study.

‘Laid-back’ bonobos take a shine to belligerents

Despite a reputation as mellow apes, bonobos have a thing for bad guys.

Rather than latching on to individuals with a track record of helpfulness, adult bonobos favor obstructionists who keep others from getting what they want. The result may help explain what differentiates humans’ cooperative skills from those of other apes, biological anthropologists Christopher Krupenye of the University of St. Andrews in Scotland and Brian Hare of Duke University report online January 4 in Current Biology.
Previous investigations indicate that, by 3 months old, humans do the opposite of bonobos, choosing to align more frequently with helpers than hinderers. Humans, unlike other apes, have evolved to seek cooperative partnerships that make large-scale collaborations possible (SN: 10/28/17, p. 7), Krupenye and Hare propose.

“Conducting similar experiments with chimpanzees and other apes is a key next step,” Krupenye says. If chimps view hinderers as kindly as bonobos do, that finding would support the duo’s proposal about human cooperation, he says.

Bonobos may view those who impede others’ actions as socially dominant and thus worth grooming as allies, Krupenye says. Although bonobos readily share food, social pecking orders still affect the animals’ behavior.

The researchers showed 24 bonobos four animated videos featuring pairs of colored shapes, most depicted with a pair of eyes. In one video, a circle tries and fails to climb a hill until a “helper” triangle arrives and pushes the circle to the top. In a second video, a circle tries and fails to climb a hill before a “hinderer” square arrives and pushes the circle farther down the hill. In the other two videos, other shapes with eyes push an eyeless, unmoving circle up or down a hill.
After watching the first two videos, bonobos chose between paper cutouts of helper and hinderer shapes placed on top of small apple pieces. The same choice was presented for cutouts of shapes from the last two videos.

Snacks covered by hinderer shapes were chosen about 70 percent of the time by the 14 adult animals, ages 9 and older. Younger bonobos displayed no strong preference either way. Apes of all ages showed no partiality to either shape that had pushed inanimate circles.

Adult bonobos also reached more often for an apple piece offered by a human they had observed snatch a toy dropped by another person, versus a human they had seen return the toy.

In a final experiment, eight of 24 bonobos usually selected apple pieces covered by cutouts of an animated shape that the apes had seen win a contest with another shape to occupy a location. This result suggests that some bonobos’ strong preference for dominant individuals partly accounts for the newly reported fondness for hinderers, Krupenye says.

“The notion that bonobos approach the bully because they view that individual as more dominant is a very plausible interpretation,” says psychologist Felix Warneken of the University of Michigan in Ann Arbor. Warneken, who did not participate in the new study, studies cooperative behavior in human children and nonhuman apes.

50 years ago, IUDs were deemed safe and effective

In 1929, the German scientist Ernst Grafenberg inserted silver rings into the uteri of 2,000 women, and reported a pregnancy rate of only 1.6 percent. Despite this history, the use of intrauterine devices, or IUDs, was not generally accepted.… A report made public last week by the FDA’s Advisory Committee on Obstetrics and Gynecology concludes that while it doesn’t know how they work, it finds IUDs to be safe and effective in blocking conception. — Science News, February 3, 1968.
Update
Early intrauterine devices came in myriad shapes, including a double-S, loops and spirals. One IUD, the spiked Dalkon Shield, was taken off the market in 1974 amid complaints of severe infections. Consumers quickly lost interest. But after companies redesigned the devices in the 1990s, use rose. From 1988 to 2002, just 1.5 percent of U.S. women ages 15 to 44 used an IUD; from 2011 to 2013, use was as high as 7.2 percent.

Scientists now know how IUDs prevent pregnancy. Hormonal IUDs thin the lining of the uterus and thicken the mucus on the cervix, preventing sperm from swimming. The devices can also reduce how frequently women ovulate. Copper IUDs and others without hormones prevent pregnancy by releasing ions that create a sperm- and egg-killing environment in women’s reproductive tracts. IUDs and other long-acting contraceptives are currently the most reliable reversible forms of birth control (SN: 6/30/12, p. 9).

Massive dust storms are robbing Mars of its water

Storms of powdery Martian soil are contributing to the loss of the planet’s remaining water.

This newly proposed mechanism for water loss, reported January 22 in Nature Astronomy, might also hint at how Mars originally became dehydrated. Researchers used over a decade of imaging data taken by NASA’s Mars Reconnaissance Orbiter to investigate the composition of the Red Planet’s frequent dust storms, some of which are vast enough to circle the planet for months.

During one massive dust storm in 2006 and 2007, signs of water vapor were found at unusually high altitudes in the atmosphere, nearly 80 kilometers up. That water vapor rose within “rocket dust storms” — storms with rapid vertical movement — on convection currents similar to those in some storm clouds on Earth, says study coauthor Nicholas Heavens, an astronomer at Hampton University in Virginia.
At altitudes above 50 kilometers, ultraviolet light from the sun easily penetrates the Red Planet’s thin atmosphere and breaks down water’s chemical bonds between hydrogen and oxygen. Left to its own devices, hydrogen slips free into space, leaving the planet with less of a vital ingredient for water.

“Because it’s so light, hydrogen is lost relatively easily on Mars,” Heavens says. “Hydrogen loss is measurable from Earth, too, but we have so much water that it’s not a big deal.”

Previous studies have indicated that Mars, which was once covered in an ocean about 100 meters deep, lost the bulk of its water through hydrogen escape (SN Online: 10/15/14). But this is the first study to identify dust storms as a mechanism for helping the gas break away. The total effect of all dust storms could account for about 10 percent of Mars’ current hydrogen loss, Heavens says.
Whether that was true in the past is up in the air. Extrapolating back billions of years ago, when Mars was warm and wet, isn’t so easy. Scientists don’t know how dust storms would have worked in a wetter climate or a thicker atmosphere.

“Variations over weeks or months don’t really tell you anything about the 1,000-year timescale that governs hydrogen,” notes Kevin Zahnle, an astronomer at NASA’s Ames Research Center in Moffett Field, Calif., who was not involved in the study.

But Zahnle, an expert on atmospheric escape of gases, agrees with the main thrust of the study: Right now, dust storms are helping to bleed Mars dry.

Life may have been possible in Earth’s earliest, most hellish eon

Maybe Earth’s early years weren’t so hellish after all.

Asteroid strikes repeatedly bombarded the planet during its first eon, but the heat released by those hits wasn’t as sterilizing as once thought, new research suggests. Simulations indicate that after the first few hundred million years of bombardment, the heat from the impacts had dissipated enough that 10 to 75 percent of the top kilometer of the subsurface was habitable for mesophiles — microbes that live in temperatures of 20° to 50° Celsius. If so, the planet may have been habitable much earlier than previously believed.
Earth’s earliest eon, the Hadean, spans the period from about 4.6 billion years ago, when the planet was born, to 4 billion years ago. The name, for the Greek god of the underworld, reflects the original conception of the age: dark and hellish and inhospitable to life. But little direct evidence of Hadean asteroid impacts still exists, limiting scientists’ understanding of how those collisions affected the planet’s habitability.

“There has been an assumption that the Hadean was mostly an uninteresting slag heap until the sky stopped falling and life could take hold,” says Stephen Mojzsis, a geologist at the University of Colorado Boulder. That’s not to say that all of the Hadean was pleasant; the first 150 million years of Earth’s history, which included the giant whack that formed the moon, were pretty dramatic. But after that, things settled down considerably, says Mojzsis, who was not an author of the new study.

For example, scientists have found signs of liquid water and even faint hints of possible life in zircon crystals dating back 4.1 billion years (SN: 11/28/15, p. 16). Other researchers have contested the idea that Earth was continually bombarded by asteroids through much of the Hadean, or that a last barrage of asteroids shelled the planet 3.9 billion years ago in what has been called the Late Heavy Bombardment, killing any incipient life (SN Online: 9/12/16).

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In the new study, geophysicist Robert Grimm and planetary scientist Simone Marchi, both of the Southwest Research Institute in Boulder, Colo., estimated how hot it would have been just a few kilometers beneath the planet’s surface during the Hadean. The scientists used an estimated rate of asteroid bombardment, as well as how much heat the projectiles would have added to the subsurface and how much that heat would have dissipated over time to simulate how hot it got — and whether microbial life could have withstood those conditions. The research built on earlier work, including Marchi’s 2014 finding that asteroid impacts became smaller and less frequent with time (SN: 8/23/14, p. 13).

Asteroid impacts did heat the subsurface, according to the simulations, but even the heaviest bombardment scenarios were not intense enough to sterilize the planet, the researchers report March 1 in Earth and Planetary Science Letters. And if the rate of bombardment did decrease as the eon progressed, the heat the asteroids delivered to Earth’s subsurface would also have had time to dissipate. As a result, that habitable zone would have increased over time.

A Late Heavy Bombardment, if it occurred, would have been tougher for the microbes, because the heat wouldn’t have had time to dissipate with such a rapid barrage. But that just would have meant the habitable zone didn’t increase, the team reports; mesophiles could still have inhabited at least 20 percent of the top kilometer of subsurface.

Mojzsis says he’s come to similar conclusions in his own work. “For a long time people said, with absolutely no data, that there could be no biosphere before 3.9 billion years ago,” he says. But “after the solar system settled down, the biosphere could have started on Earth 4.4 billion years ago.”

That’s not to say that there was definitely life, Grimm notes. Although the heat from impacts may not have been a limiting factor for life, asteroid bombardment introduced numerous other challenges, affecting the climate, surface or even convection of the mantle. Still, the picture of Earth’s earliest days is undergoing a sea change. As Grimm says, “An average day in the Hadean did not spell doom.”