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Stunningly well-preserved dinosaur embryo found inside fossilized egg – CNET

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This life reconstruction shows what the “Baby Yingliang” dinosaur embryo might’ve looked like inside its egg.


Lida Xing

An illustration shows a small animal in a tight tuck, legs pulled up, back curved and beaked head bent toward its tail. This is Baby Yingliang, a nickname given to a remarkable fossilized dinosaur embryo found inside an ancient egg and tucked into a position much like that of a modern bird just before it hatches.

The Baby Yingliang fossil dates to the late Cretaceous, putting it at between 72 million and 66 million years old. It was found in southern China and is the remains of a theropod dinosaur called a oviraptorosaur. The embryo’s state of preservation and its position inside the egg make the fossil a remarkable find. 

Previously unrecognized in dinosaurs, this posture is similar to that of modern bird embryos,” says a Tuesday statement from the University of Birmingham. Researchers from that institution and from Beijing’s China University of Geosciences led a study of the fossil, which was published in the journal iScience this week.

The fossilized theropod embryo shows a dinosaur in a curled posture prior to hatching. 


Xing et al./iScience

The scientists estimate the dinosaur would be about 10.6 inches (27 centimeters) long. The egg is 6.7 inches (17 centimeters) long, which gives you an idea of how much the creature was folded over.

“It is interesting to see this dinosaur embryo and a chicken embryo pose in a similar way inside the egg, which possibly indicates similar prehatching behaviors,” said joint first author Fion Waisum Ma, a paleontologist at the University of Birmingham. The researchers would like to study more well-preserved dinosaur embryos to test the idea that the tucking posture is something that first developed in theropods. The posture helps ensure modern birds hatch successfully. 

Study co-author Steve Brusatte of the University of Edinburgh described the find as “one of the most beautiful fossils I have ever seen,” saying it represents “yet more evidence that many features characteristic of today’s birds first evolved in their dinosaur ancestors.”

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NASA’s new space telescope reaches destination in solar orbit

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NASA‘s James Webb Space Telescope, designed to give the world an unprecedented glimpse of infant galaxies in the early stages of the universe, arrived at its gravitational parking spot in orbit around the sun on Monday, nearly a million miles from Earth.

With a final five-minute, course-correcting thrust of its onboard rocket, Webb reached its destination at a position of gravitational equilibrium known as the second Sun-Earth Lagrange point, or L2, arriving one month after launch, NASA officials said.

The thruster was activated by mission control engineers at the Space Telescope Science Institute in Baltimore, with radio signals confirming Webb was successfully “inserted” into its desired orbital loop around L2.

From there, Webb will follow a special “halo” path that keeps it in constant alignment with Earth but out of its shadow, as the planet and telescope circle the sun in tandem. The prescribed L2 orbit within the larger solar orbit thus enables uninterrupted radio contact, while bathing Webb’s solar-power array in non-stop sunlight.

By comparison, Webb’s 30-year-old predecessor, the Hubble Space Telescope, orbits the Earth from 340 miles (547 km) away, passing in and out of the planet’s shadow every 90 minutes.

The combined pull of the sun and Earth at L2 – a point of near gravitational stability first deduced by 18-century mathematician Joseph-Louis Legrange – will minimize the telescope’s drift in space.

But ground teams will need to fire Webb’s thruster briefly again about once every three weeks to keep it on track, Keith Parrish, the observatory’s commissioning manager from NASA’s Goddard Space Flight Center in Maryland, told reporters on Monday.

Mission engineers are preparing next to fine-tune the telescope’s primary mirror – an array of 18 hexagonal segments of gold-coated beryllium metal measuring 21 feet, 4 inches (6.5 meters) across, far larger than Hubble’s main mirror.

Its size and design – operating mainly in the infrared spectrum – will allow Webb to peer through clouds of gas and dust and observe objects at greater distances, thus farther back in time, than Hubble or any other telescope.

These features are expected to usher in a revolution in astronomy, giving a first view of infant galaxies dating to just 100 million years after the Big Bang, the theoretical flashpoint that set the expansion of the known universe in motion an estimated 13.8 billion years ago.

Webb’s instruments also make it ideal to search for signs of potentially life-supporting atmospheres around scores of newly documented exoplanets – celestial bodies orbiting distant stars – and to observe worlds much closer to home, such as Mars and Saturn’s icy moon Titan.

NEXT STEPS

It will take several more months of work to ready the telescope for its astronomical debut.

The 18 segments of its principal mirror, which had been folded together to fit inside the cargo bay of the rocket that carried the telescope to space, were unfurled with the rest of its structural components during a two-week period following Webb’s launch on Dec. 25.

Those segments were recently detached from fasteners and edged away from their original launch position. They now must be precisely aligned – to within one-ten-thousandth the thickness of a human hair – to form a single, unbroken light-collecting surface.

Ground teams will also start activating Webb’s various imaging and spectrographic instruments to be used in the three-month mirror alignment. This will be followed by two months spent calibrating the instruments themselves.

Mirror alignment will begin by aiming the telescope at a rather ordinary, isolated star, dubbed HD-84406, located in the Ursa Major, or “Big Dipper,” constellation but too faint to be seen from Earth with the naked eye.

Engineers will then gradually tune Webb’s mirror segments to “stack” 18 separate reflections of the star into a single, focused image, Lee Feinberg, Webb’s optical telescope element manager at Goddard, said during Monday’s NASA teleconference.

Alignment is expected to start next week when the telescope, whose infrared design makes it super-sensitive to heat, has cooled down enough in space to work properly – a temperature of about 400 degrees below zero Fahrenheit (-240 Celsius).

If all goes smoothly, Webb should be ready to begin making scientific observations by summer.

Sometime in June, NASA expects to make public its “early release observations,” a ‘greatest hits’ collection of initial images used to demonstrate proper functioning of Webb’s instruments during its commissioning phase.

Webb’s most ambitious work, including plans to train its mirror on objects farthest from Earth, will take a bit longer to conduct.

The telescope is an international collaboration led by NASA in partnership with the European and Canadian space agencies. Northrop Grumman Corp was the primary contractor.

(Reporting by Steve Gorman; Editing by Karishma Singh, Rosalba O’Brien and Kenneth Maxwell)

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Copy or innovate? Study sheds light on chimp culture – Geo News

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Research tells that Chimpanzees in one part of Guinea crack and eat nuts while others declined to do so even when offered tools. — AFP/File
  • Chimpanzees in one part of Guinea crack and eat nuts while others declined to do so even when offered tools, according to research. 
  • Professor Koops experiments to check if the chimps would develop the behaviour if tools are provided but not once did they attempt to crack a nut.
  • Findings so far suggest there may be “greater continuity between chimpanzee and human cultural evolution than is normally assumed.”

TOKYO: Chimpanzees in one part of Guinea crack and eat nuts while others declined to do so even when offered tools, research published on Monday found, and the difference could shed light on their culture.

As humans, we are said to have cumulative culture: skills and technologies are transmitted and refined from generation to generation, producing behaviours more sophisticated than a single person could dream up.

Some experts believe this is unique to humans, and that traits like tool use by chimps instead develops spontaneously in individuals.

Their theory argues animals can innovate certain behaviours without a model to copy.

Evidence for this comes in part from captive chimps, who have been seen apparently independently developing simple tool use like scooping with a stick and sponging with a leaf.

But those behaviours differ from comparatively more complex techniques, like cracking nuts, and captivity is vastly different to the wild.

So Kathelijne Koops, a professor in the University of Zurich’s anthropology department, designed a series of experiments involving wild chimpanzees in Guinea.

While one population of chimps in Guinea’s Bossou does crack nuts, another group just six kilometres away in Nimba does not.

Koops wanted to see whether the Nimba population would develop the behaviour if introduced to the tools to do so.

The researchers set up four different scenarios: in the first, the chimps encountered palm nuts in shells, and stones that could be used for cracking them open.

In the second, there were palm nuts in shells, stones, but also edible palm nut fruit. In the third, they found the stones, unshelled palm nuts and some cracked nut shells.

And the final experiment offered them stones and Coula nuts, which are more commonly and easily cracked by chimpanzee populations that use the technique.

Secret cameras 

Each experiment ran for several months at a time, mostly in 2008, though in some cases as late as 2011.

But while the experiment sites in Nimba were visited and explored by dozens of chimpanzees, who were filmed with cameras installed at the location, not once did they attempt to crack a nut.

“Having observed nut cracking by Bossou chimpanzees on many occasions, it was so interesting to watch the Nimba chimpanzees interact with the same materials without ever cracking a nut,” Koops told AFP.

The study, published Monday in the journal Nature Human Behaviour suggests that nut cracking may in fact be an outcome of cumulative culture, similar to that of humans.

The researchers acknowledged difficulties studying chimps in the wild, including the inability to control the numbers visiting their sites.

Between 16 and 53 chimps visited each site during the experiments and primate behaviour specialist Professor Gisela Kaplan, who was not involved with the research, questioned whether the numbers were sufficient to draw broad conclusions.

“As in human society: the number of innovators is relatively small in animals and the expression of innovation depends also on many social and ecological circumstances and pressures,” said Kaplan, professor emerita in animal behaviour at the University of New England, Australia.

The study’s authors acknowledge there are other possible explanations for the chimps’ reticence, including the possibility that they simply weren’t motivated to eat the nuts.

But as chimpanzees in neighbouring areas do crack nuts, they consider it unlikely the Nimba population was uninterested in a new food source.

Koops said the involvement of a “normal-sized wild community” of chimps and the length of the experiments allow insights.

“Of course it would be interesting to test additional communities,” she said.

But the findings so far suggest there may be “greater continuity between chimpanzee and human cultural evolution than is normally assumed.”

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Ancient DNA suggests woolly mammoths roamed Canada more recently than previously thought – National Post

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THE CONVERSATION

This article was originally published on The Conversation, an independent and nonprofit source of news, analysis and commentary from academic experts. Disclosure information is available on the original site.

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Author: Tyler J. Murchie, Postdoctoral fellow, Anthropology, McMaster University

In 2010, small cores of permafrost sediments were collected by a team at the University of Alberta from gold mines in the Klondike region of central Yukon. They had remained in cold storage until paleogeneticists at the McMaster Ancient DNA Centre applied new genomics techniques to better understand the global extinction of megafauna that had culminated in North America some 12,700 years ago.

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These tiny sediment samples contain an immense wealth of ancient environmental DNA from innumerable plants and animals that lived in those environments over millennia. These genetic microfossils originate from all components of an ecosystem — including bacteria, fungi, plants and animals — and serve as a time capsule of long-lost ecosystems, such as the mammoth-steppe, which disappeared around 13,000 years ago.

How exactly these ecosystems restructured so significantly, and why large animals seem to have been the most impacted by this shift has been an active area of scientific debate since the 18th century.

We can now use environmental DNA to help fill the gaps that have driven this debate.

Ancient DNA, cutting-edge technologies

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Bacterial, fungal and unidentifiable DNA make up over 99.99 per cent of an environmental sample. In our case, we wanted a way to selectively recover the much smaller fraction of ancient plant and animal DNA that would help us better understand the collapse of the mammoth-steppe ecosystem.

For my doctoral research, I was part of a team that developed a a new technique to extract, isolate, sequence and identify tiny fragments of ancient DNA from sediment.

We analyzed these DNA fragments to track the shifting cast of plants and animals that lived in central Yukon over the past 30,000 years. We found evidence for the late survival of woolly mammoths and horses in the Klondike region, some 3,000 years later than expected.

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We then expanded our analysis to include 21 previously collected permafrost cores from four sites in the Klondike region that date between 4,000 to 30,000 years ago.

With current technologies, we not only could identify which organisms a set of genetic microfossils came from. But we were also able to reassemble those fragments into genomes to study their evolutionary histories — solely from sediment.

Tremendous environmental change

The Pleistocene-Holocene transition, which occurred about 11,700 years ago, was a period of tremendous change across the globe. In eastern Beringia (the former Eurasian land bridge and unglaciated regions of Yukon and Alaska), this period saw the collapse of the mammoth-steppe biome and its gradual replacement with the boreal forest as we know it today.

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This brought about the loss of iconic ice age megaherbivores like the woolly mammoth, Yukon horse, and steppe bison, along with predators such as the American scimitar cat and Beringian lion, among many others.

We found ancient environmental DNA from a diverse spectrum of ancient fauna, including woolly mammoths, horses, steppe bison, caribou, rodents, birds and many other animals.

We were also able to observe how ecosystems shifted with the rise of woody shrubs around 13,500 years ago, and how that correlated with a decline of DNA from woolly mammoths, horses and steppe bison. With this remarkably rich dataset, we observed four main findings.

1. There was a surprising consistency in the signal between sites, suggesting our data was representative of ecological trends in the region.

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2 . Woolly mammoth DNA declines prior to the Bølling–Allerød warming, a warm period at the end of the last ice age, suggesting that megafaunal losses may have been staggered.

3. Forbs (herbaceous flowering plants) make up a substantial component of the mammoth-steppe ecosystem alongside grasses.

4. There is a consistent signal of woolly mammoth and Yukon horse persistence into the Holocene, as much as 7,000 years after their disappearance from fossil records.

When paired with other records, our genetic reconstructions suggest that the transition out of the last glacial period may have been more drawn out than dated bones alone would suggest.

Mammoths, for example, may have declined in local population abundance thousands of years earlier than other megafauna, which is potentially correlated with the first controversial evidence of humans in the area. Further, grassland grazing animals may have persisted for thousands of years in refugia (habitats that support the existence of an isolated population), despite the environmental shift.

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Woolly mammoths alongside humans

Our data suggest that horses and woolly mammoths may have persisted in the Klondike until approximately 9,000 years ago and perhaps as recently as 5,700 years ago, outliving their supposed disappearance from local fossil records by 7,000 years. However, it is possible for ancient environmental DNA to survive erosion and re-deposition, which could mix the genetic signals of different time periods, necessitating a degree of caution in our interpretations.

Until recently, there was no evidence of mammoth survival into the mid-Holocene. But studies have now shown that mammoths survived until 5,500 and 4,000 years ago on Arctic islands.

Researchers at the Centre for GeoGenetics in Copenhagen found evidence for the late survival of horses and mammoths in Alaska until as recently as as 7,900 years ago. They also found evidence of mammoths surviving as recently as 3,900 years ago in Siberia, alongside woolly rhinoceros to at least 9,800 years ago.

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Steppe bison, which were thought to have disappeared and been replaced by the American bison during the Pleistocene, have likewise been found to have survived even as recently as perhaps just 400 years ago. We were able to observe the presence of distinct genetic lineages of both woolly mammoths and steppe bison in the same sediment samples, which suggests that there were likely distinct populations of these animals living in the same area.

There is a growing body of evidence that many ice age megafauna probably survived well into recorded human history, roaming the north during the Bronze Age and while builders worked on the pyramids of Egypt.

Genetic archives of our ecological past

The growing sophistication of environmental DNA methods to study ancient genetic microfossils highlights just how much information is buried in sediments.

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Permafrost is ideal for preserving ancient DNA, but as this perennially frozen ground thaws and degrades with a warming Arctic, so too will the genetic material preserved within, and the evolutionary mysteries they once held.

Advances in paleogenetics continues to push the boundaries of what was once relegated to science fiction. Who knows what undiscovered evolutionary information remains frozen in ordinary sediments, hidden in microfossils of ancient DNA?

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Tyler J. Murchie currently receives funding from the CANA Foundation, a non-profit organization with horse rewilding initiatives.

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This article is republished from The Conversation under a Creative Commons license. Disclosure information is available on the original site. Read the original article: https://theconversation.com/ancient-dna-suggests-woolly-mammoths-roa https://theconversation.com/ancient-dna-suggests-woolly-ma

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