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Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

WFS News: Microbes were living on land as early as 3.22 billion years ago?

March 22nd, 2020

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The earliest signs of life on a young Earth, around 3.5 billion years ago, have generally come from the ocean in the form of fossilized microbes within ancient rock. Now, scientists working in the Barberton Greenstone Belt in South Africa—where some of the oldest rocks on Earth are preserved—find evidence of terrestrial microbial life that they estimate is about 3.22 billion years old. The results, published today (July 23) in Nature Geosciences, represent the oldest signs of land-based life on our planet yet discovered

“This work represents the oldest and least ambiguous work that we have so far that life existed on land already 3.2 billion years ago,” Kurt Konhauser, a professor of earth and atmospheric sciences at the University of Alberta in Canada who was also not involved in the work, writes in an email to The Scientist.

Researchers have found more fossil evidence of the earliest microbial life in shallow, marine deposits, which supports the dominant theory that before 3 billion years ago, most of the Earth consisted of oceans interspersed with volcanic islands. Evidence for life on land has so far been harder to come by. Part of the reason is that ancient marine rocks appear to be better preserved than terrestrial sediments. Another issue, according to Martin Homann, a postdoc at the European Institute for Marine Studies (IUEM) in Brest, France, is that very old terrestrial sediments are also difficult to distinguish from marine sediments because so-called index fossils—which help to determine the environment and to date rocks—do not exist from this early period of Earth’s history.

According to the study authors, the previously oldest visible fossilized remains of microbes on land were about 2.7 billion years old, found in a different location from the Barberton Greenstone Belt in South Africa and also in Australia. In a study published last year, researchers analyzed rocks from what they interpreted as hot springs in the Pilbara region of Western Australia. Although that paper, according to Konhauser, suggests that some 3.5-billion-year-old volcanoes may have been on land, the current study is definitive in showing there was extensive exposure of continental crust on the Earth’s surface 3.2 billion years ago.

Christoph Heubeck of the Freie Universität in Berlin, Germany, (left) and Martin Homann (right) in an abandoned gold mine near Sheba Mine sampling the lava at the Barberton Greenstone Belt
NADJA DRABON, STANFORD UNIVERSITY

For the current study, Homann and his colleagues focused on ancient sedimentary rocks, known as the Moodies Group, in the Barberton Greenstone Belt that were shown by geologists earlier to be approximately 3.22 billion years old. There, the team uncovered what are known as fossilized microbial mats—composed mainly of the imprints of bacteria and archaea and are among the earliest preserved forms of life. While living on the early Earth, these microbial community mats became interlayered and packed together with sedimentary rock made of rounded stones of different sizes that geologists call a conglomerate.

The team first analyzed and described the rocks’ positions in detail and compared these to current rock formations to understand how they moved, formed, and were preserved. The investigators concluded that the mat-forming microbes were indigenous to the host rock and part of what was once an ancient river delta.

“These are good data that show indeed that these fossilized, microbial mats [in Barberton Greenstone Belt] come from a terrestrial environment,” says Dominic Papineau, who studies the origin and evolution of life at the London Centre for Nanotechnology at University College London and who was not involved in the study.

The researchers then analyzed both the organic carbon and nitrogen isotopes within these fossilized terrestrial microbial mats and compared the profiles to isotopes extracted from nearby fossilized marine microbial mats. Both the carbon and nitrogen isotope values from the terrestrial and marine samples were unique from one another, suggesting that there were differences in the metabolism of microbes in the ocean compared to those on land.

“Already at 3.2 billion years ago, we see evidence of differences in mat-forming microbial communities suggesting that some were likely better adapted for life in the ocean versus on land,” says Homann.

A 15-centimenter-thick interval of fossilized microbial mats (arrow) embedded with sedimentary rock and sandstones in the Barberton Greenstone Belt, South Africa

MARTIN HOMANN, EUROPEAN INSTITUTE FOR MARINE STUDIES, FRANCE

A major question for scientists is whether the early Earth might have already had localized pockets of free oxygen in an atmosphere generally lacking it. Most modern microbial mats are composed of cyanobacteria, which create oxygen as a byproduct of their metabolism (oxygenic photosynthesis), and are thought to have been responsible for the accumulation of oxygen in Earth’s atmosphere. “The data here cannot distinguish whether these microorganisms produced oxygen through their photosynthesis or did anoxygenic photosynthesis,” says Papineau.

The nitrogen isotope values, which reflect the ratio of the most abundant nitrogen-14 and the more rare and heavier nitrogen-15, of the land microbial mats were more positive compared to the marine samples. This suggested to Homann and his colleagues that the land 3.2 billion years ago contained atmospheric nitrate. Another way that these positive nitrogen values could have come about would be if there were atmospheric oxygen 3.22 billion years ago, which is less likely, according to the study authors, as it would imply that there already existed oxygen-producing cyanobacteria, for which there is currently not enough evidence.

For Konhauser, it would be interesting to dig deeper into the source of the nitrate in the samples and whether it might have indeed come from the atmosphere or via generation of oxygen from the ancient photosynthetic bacteria. “The structures and isotopic composition of the microbial mats certainly seem to suggest the presence of photosynthetic microbes already existing on land,” writes Konhauser. If the nitrate were indeed formed by the microbes in the mats, he adds, then perhaps oxygen-producing cyanobacteria were around at this early stage of the Earth’s history.

M. Homann et al., “Microbial life and biogeochemical cycling on land 3,220 million years ago,” Nature Geosciences, doi.org/10.1038/s41561-018-0190-9, 2018.

Source: Article by Anna Azvolinsky,The Scientist.com

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WFS News: A newly discovered fossil bird could be the earliest known ancestor of every chicken on the planet.

March 19th, 2020

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A newly discovered fossil bird could be the earliest known ancestor of every chicken on the planet.

The bird may have lived on the shoreline

Living just before the asteroid strike that wiped out giant dinosaurs, the unique fossil, from about 67 million years ago, gives a glimpse into the dawn of modern birds.

Birds are descended from dinosaurs, but precisely when they evolved into birds like the ones alive today has been difficult to answer.

This is due to a lack of fossil data.

The newly discovered – and well-preserved – fossil skull should help fill in some of the gaps.

“This is a unique specimen: we’ve been calling it the ‘wonderchicken’,” said Dr Daniel Field of the University of Cambridge.

“It’s the only nearly complete skull of a modern bird that we have, so far, from the age of dinosaurs and it’s able to tell us quite a lot about the early evolutionary history of birds.”

The fossil bird has been named Asteriornis maastrichtensis, after Asteria, a Greek goddess of falling stars who turns into a quail. It was found in a quarry on the Netherlands-Belgium border.

The bird weighed in at just under 400g and was an early member of the group that gave rise to modern-day chickens, ducks and other poultry.

At the time, the region was covered by a shallow sea, and conditions were similar to modern tropical beaches. With its long, slender legs, the bird may have been a shore dweller.

“Birds are such a conspicuous and important group of living animals, being able to say something new about how modern birds actually arose is really a significant thing for palaeontologists and evolutionary biologists,” said Dr Field.

“The wonderchicken is going to rank as a truly important fossil for helping clarify the factors that actually gave rise to modern birds.”

DANIEL J FIELD Image caption Scan of the bird's skull

DANIEL J FIELD, Scan of the bird’s skull

The research is published in the journal Nature.

Source.BBC.com. Article By Helen Briggs

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WFS News:Novel track morphotypes from new tracksites indicate increased Middle Jurassic dinosaur diversity on the Isle of Skye, Scotland

March 12th, 2020

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Novel track morphotypes from new tracksites indicate increased Middle Jurassic dinosaur diversity on the Isle of Skye, Scotland

Citation: dePolo PE, Brusatte SL, Challands TJ, Foffa D, Wilkinson M, Clark NDL, et al. (2020) Novel track morphotypes from new tracksites indicate increased Middle Jurassic dinosaur diversity on the Isle of Skye, Scotland. PLoS ONE 15(3): e0229640. https://doi.org/10.1371/journal.pone.0229640

(a) The orthophoto for Brother’s Point Site 1 (BP1) strikingly demonstrates the high contrast between the dark gray, track-bearing shale and the overlying and in-filling light tan limestone in the Lonfearn Member of the Lealt Shale Formation. (b) The site map highlights the track distribution spatially and denotes the orientation and length of the trackways relative to one another. Each individual track is labeled with its field number (1–35). P1 and P2 denote ‘possible’ tracks 1 and 2 while PG denotes a ‘possible group’ of shallow impressions. Thick black lines denote the track outlines while lighter lines highlight the contrast between the lithologies and fractures on the outcrop. Dark gray lines delineate the extent of the limestone while lighter gray lines show the platform edges of the shale and some fractures within it. One quadrupedal trackway (Trackway 1; BP1_Twy_01), two bipedal trackways (Trackway 2–3; BP1_Twy_02 –BP1_Twy_03), and one set of associated tracks (TA_1) are present at the site.

Dinosaur fossils from the Middle Jurassic are rare globally, but the Isle of Skye (Scotland, UK) preserves a varied dinosaur record of abundant trace fossils and rare body fossils from this time. Here we describe two new tracksites from Rubha nam Brathairean (Brothers’ Point) near where the first dinosaur footprint in Scotland was found in the 1980s. These sites were formed in subaerially exposed mudstones of the Lealt Shale Formation of the Great Estuarine Group and record a dynamic, subtropical, coastal margin. These tracksites preserve a wide variety of dinosaur track types, including a novel morphotype for Skye: Deltapodus which has a probable stegosaur trackmaker. Additionally, a wide variety of tridactyl tracks shows evidence of multiple theropods of different sizes and possibly hints at the presence of large-bodied ornithopods. Overall, the new tracksites show the dinosaur fauna of Skye is more diverse than previously recognized and give insight into the early evolution of major dinosaur groups whose Middle Jurassic body fossil records are currently sparse.

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WFS News: Debate on shelf life of DNA vs presence of DNA in fossils

March 8th, 2020

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Reconstruction of the nesting ground of Hypacrosaurus stebingeri from the Two Medicine formation of Montana. In the center can be seen a deceased Hypacrosaurus nestling with the back of its skull embedded in shallow waters. A mourning adult is portrayed on the right. (©Science China Press, Art by Michael Rothman)

About 75 million years ago, a nest of plant-eating dinosaurs called Hypacrosaurus stebingeri died in what’s now Montana. Their fossils were found in the 1980s, and now an international team of scientists has presented evidence that the old bones contain traces of genetic material.

The paper published in National Science Review takes a close look at skull shards that would have been made of soft cartilage, instead of bone, in the young dinosaurs. The discovery is small in size, but hugely controversial among paleontologists: what appears to be microscopic cells, the building blocks of complex life, with dark clumps in the middle. A zoomed-in look at one possible cell’s dark spot reveals what the researchers suspect is genetic material.

Study author Alida Bailleul, a paleontologist at the Chinese Academy of Sciences in Beijing, first found the microscopic orbs in 2010 while a student at the Museum of the Rockies, and quickly recognized their resemblance to cells. “I freaked out a little bit—moving away from the microscope, thinking, moving back to the microscope,” she tells Michael Greshko at National Geographic. “I was like, Oh my god, that can’t be, there’s nothing else they can be!”

Photographs of the suspected cells in the nestling’s skull fragment. On the left, it appears that two cells are dividing, and the dark region resembles a cell nucleus, where DNA is stored. In the middle, what appears like strands of DNA. On the right, dye fluoresces red indicating chemicals like DNA. (©Science China Press, Photo by Alida Bailleul and Wenxia Zheng)

After getting a second opinion from Mary Schweitzer, a paleontologist at North Carolina State University and first author on the paper, the team moved forward analyzing their find. It was surprising because tiny structures like cells and DNA—the molecular twisted-ladder that carries a cell’s blueprint—are notoriously fragile. High heat or acidity can destroy them, and so they require a lot of upkeep while an animal is alive, and when it dies, the delicate bits are at the whims of the environment.

If the researchers have found fossilized cells and DNA, they would be several tens of times older than both any found before, and the theoretical preservation limits of the materials, paleontologist Evan Saitta, who works at the Integrative Research Center at the Field Museum of Natural History in Chicago, explains to George Dvorsky at Gizmodo.

Cartilage lacks pores, so Bailleul and her colleages suggest that it may have defended the microscopic structures from the outside environment, the researchers say.

“Fossilized, calcified cartilage may be an ideal place to search for exceptionally preserved biomolecules in other fossils, as this tissue may be less prone to contamination and internal decay than bone,” Royal Ontario Museum paleontologist David Evans, who wasn’t involved in the new study, tells National Geographic. “In calcified cartilage, the cells become trapped and isolated in their matrix and are more likely to be preserved in a sealed micro-environment.”

To check their find, the researchers applied a dye to the fossils that sticks to DNA and fluoresces red. Then, they dyed living emu cells and compared the two. Although it was much fainter than the dye in the emu’s cells, the fossil’s dye stuck to something.

“I’m not even willing to call it DNA because I’m cautious, and I don’t want to overstate the results,” Schweitzer tells National Geographic. “There is something in these cells that is chemically consistent with and responds like DNA.”

WFS News: The Earth was a “water world” of submerged continents

March 4th, 2020

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WFS News:

And that could have major implications on the origin of life.

“An early Earth without emergent continents may have resembled a ‘water world,’ providing an important environmental constraint on the origin and evolution of life on Earth as well as its possible existence elsewhere,” geologists Benjamin Johnson and Boswell Wing wrote in a paper just published online by the journal Nature Geoscience.

Johnson is an assistant professor of geological and atmospheric sciences at Iowa State University and a recent postdoctoral research associate at the University of Colorado Boulder. Wing is an associate professor of geological sciences at Colorado. Grants from the National Science Foundation supported their study and a Lewis and Clark Grant from the American Philosophical Society supported Johnson’s fieldwork in Australia.

Johnson said his work on the project started when he talked with Wing at conferences and learned about the well-preserved, 3.2-billion-year-old ocean crust from the Archaean eon (4 billion to 2.5 billion years ago) in a remote part of the state of Western Australia. Previous studies meant there was already a big library of geochemical data from the site.

Johnson joined Wing’s research group and went to see ocean crust for himself — a 2018 trip involving a flight to Perth and a 17-hour drive north to the coastal region near Port Hedland.

After taking his own rock samples and digging into the library of existing data, Johnson created a cross-section grid of the oxygen isotope and temperature values found in the rock.

(Isotopes are atoms of a chemical element with the same number of protons within the nucleus, but differing numbers of neutrons. In this case, differences in oxygen isotopes preserved with the ancient rock provide clues about the interaction of rock and water billions of years ago.)

Once he had two-dimensional grids based on whole-rock data, Johnson created an inverse model to come up with estimates of the oxygen isotopes within the ancient oceans. The result: Ancient seawater was enriched with about 4 parts per thousand more of a heavy isotope of oxygen (oxygen with eight protons and 10 neutrons, written as 18O) than an ice-free ocean of today.

How to explain that decrease in heavy isotopes over time?

Johnson and Wing suggest two possible ways: Water cycling through the ancient ocean crust was different than today’s seawater with a lot more high-temperature interactions that could have enriched the ocean with the heavy isotopes of oxygen. Or, water cycling from continental rock could have reduced the percentage of heavy isotopes in ocean water.

“Our preferred hypothesis — and in some ways the simplest — is that continental weathering from land began sometime after 3.2 billion years ago and began to draw down the amount of heavy isotopes in the ocean,” Johnson said.

The idea that water cycling through ocean crust in a way distinct from how it happens today, causing the difference in isotope composition “is not supported by the rocks,” Johnson said. “The 3.2-billion-year-old section of ocean crust we studied looks exactly like much, much younger ocean crust.”

Johnson said the study demonstrates that geologists can build models and find new, quantitative ways to solve a problem — even when that problem involves seawater from 3.2 billion years ago that they’ll never see or sample.

And, Johnson said these models inform us about the environment where life originated and evolved: “Without continents and land above sea level, the only place for the very first ecosystems to evolve would have been in the ocean.”

Source:Benjamin W. Johnson & Boswell A. Wing. Limited Archaean continental emergence reflected in an early Archaean 18O-enriched ocean. Nature Geoscience, 2020 DOI: 10.1038/s41561-020-0538-9 and .sciencedaily.com

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WFS News: P. antiquus,The oldest green seaweed

March 2nd, 2020

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An image of the green seaweed fossil discovered by Virginia Tech paleontologists in China. It may be be related to the ancestor of the earliest land plants and trees that first developed 450 million years ago.

A microscopic fossil discovered by Virginia Tech researchers may be key to understanding how modern plants evolved into their current form.

At around 1 billion years old, the seaweed microfossil — a type of algae known as Proterocladus antiquus — is the oldest green seaweed known to man. The findings were published Monday in Nature Ecology and Evolution.

The P. antiquus fossil, which is about the size of a flea, was discovered by Virginia Tech post-doctorate researcher Qing Tang on a rock in a dry area of northern China that was previously ocean.

He took the rock to his advisor, geosciences professor Shuhai Xiao. After inspecting their discovery, they found the microfossil on an electronic microscope and agreed that the finding was significant.

Prior to Xiao and Tang’s discovery, the oldest green seaweeds were found in a slab of rock estimated at around 800 million years old.

“These fossils are found in mudstones and fine-grained silty shales,” said Phoebe A. Cohen, an associate professor of geosciences at Williams College. “Think mud that has hardened and turned into rock.”

After the organism died, it descended onto the seafloor — where it was covered and pressed down by mud, she explained. It was especially well-preserved because the sediment it was covered in had little oxygen.

In the background of this digital recreation, ancient microscopic green seaweed is seen living in the ocean 1 billion years ago. In the foreground is the same seaweed in the process of being fossilized far later.

Many scientists theorize plants on land evolved from green seaweeds, which moved out of the ocean and into freshwater and then later adapted to the dry conditions on land. Xiao said the study’s findings strongly support this theory.

“These fossils are related to the ancestors of all the modern land plants we see today,” said Xiao in a statement. Land plants, he added, did not evolve until about 450 million years ago.

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Source: Article by Joshua Bote, @USA today

WFS News: Mesophthirus engeli,A newly discovered ancient insect species

February 21st, 2020

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A newly discovered ancient insect species, called Mesophthirus engeli, appears to have used strong mouthparts to chew on feathers. Claws and bristles on its legs would also have helped the insect climb or cling onto hosts’ feathers.T. GAO

Feathered dinosaurs, including early birds, may have dealt with pests similar to lice around 100 million years ago.

A newfound ancient insect species, dubbed Mesophthirus engeli, was found preserved with dinosaur feathers in two pieces of Myanmar amber dating to the mid-Cretaceous Period (SN: 7/24/14).

The fossils are the earliest evidence found of insects feeding on feathers, researchers report December 10 in Nature Communications. The previous record-holder was a fossilized louse from roughly 44 million years ago, says Taiping Gao, a paleoentomologist from Capital Normal University in Beijing.

M. engeli looks somewhat like modern lice, with teeth and a thick, wingless body. The insects also have anatomical traits seen in other ectoparasites — those that live outside of their host’s body. In one piece of amber that Gao and colleagues analyzed under a microscope, the team found nine insects on or near a feather. That feather had damage holes toward its end, but not near its base — a pattern that also occurs when lice chomp on modern birds’ feathers.

Modern birds replace old or damaged feathers through molting, says Luis Chiappe, a paleontologist at the Natural History Museum of Los Angeles County who specializes in birds. The new findings show that parasite–host relationships that could’ve damaged feathers began at least 100 million years ago, he says, and could be one reason why birds evolved to molt.

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Source: Article By Sofie Bates, Science news

WFS News: Paleoclimate Proxies

February 18th, 2020

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Every year, particles eroding from the continents are transported to the oceans by the wind as dust and by rivers as sands and gravels. Once they get to the ocean, they mix with billions of tons of dead plankton shells, sink, and settle on the seafloor. There, they accumulate vertically in layers on top of previous years’ material. Similarly, this year’s snow accumulates on top of the previous years’ snow at the polar regions in places like Greenland and Antarctica. Over time, this process forms new layers of ice. Trees, much the same way, add yearly layers of new cells in concentric circles just below their bark – called tree rings. And, in many caves around the world, the strength of the seasonal cycle of a wet monsoon followed by a dry season is recorded in the chemistry of stalagmites rising up from the cave floor, formed by drips of mineral-rich water from the roof of the cave.

Paleoclimatologists have learned that all of these yearly processes are sensitive to changes in regional climate, allowing them to be used like “natural thermometers,” or what scientists call “paleoclimate proxies.” For the last several decades, Paleoclimatologists have been collecting data from these natural archives of environmental change and using them to explore how climate change occurs naturally. Together with our observations of present climate, the data collected from these natural thermometers tells us that the climate changes we are observing today are unique with respect to much of Earth’s recent history.

For example, the bubbles filled with ancient atmosphere and trapped in the layers in ice cores show us that heat-trapping gases haven’t been at the levels they are today in nearly 800,000 years, and likely for millions of years. Similarly, tree rings show us that recent human-caused warming trends far outpace any natural warming the Earth did by itself over much of the last few thousands of years. These paleoclimate proxies can also tell us about nutrient cycling in the ancient ocean, the amount and pattern of past precipitation events throughout the tropics, the extent and magnitude of recent volcanic eruptions, and many other things – in fact, scientists are constantly discovering new and imaginative ways to leverage these natural archives of environmental change to help us understand present and future changes to our global climate.

The SOS NOAA Paleoclimatology dataset citation and access spreadsheet contains URLs that can be used to access citation information, and the actual data for the over 6,000 datasets represented in this presentation.

Notable Features

Locations of over 6,000 climate proxy datasets between 6 different data types are represented.
Near-global coverage of ocean sediment cores.
High density of North American tree ring climate reconstructions.
Highest concentration of coral-based climate reconstructions in tropical oceans. Speleothem climate reconstructions restricted to areas with limestone karst systems.

Source: NOAA

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WFS News: Thalattosaur. sea monster with needle-sharp snout

February 7th, 2020

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An articulated Late Triassic (Norian) thalattosauroid from Alaska and ecomorphology and extinction of Thalattosauria

This is an artist’s depiction of Gunakadeit joseeae, a species of the marine reptile thalattosaur previously unknown to science that roamed the coast of what is now Alaska 200 million years ago. (Ray Troll)

An iguana-like creature with a needle-sharp snout has been confirmed from a fossilized skeleton as a species of the marine reptile thalattosaur previously unknown to science that roamed the coast of what is now Alaska some 200 million years ago.

This fossil of Gunakadeit joseeae was found on an island in southeast Alaska. About two thirds of the tail had already eroded away when the fossil was discovered. (Alaska Museum of the North)

Dating from the Triassic period and identified from a lone fossil found in the Tongass National Forest in Alaska, the new creature has been named Gunakadeit joseeae, after a Tlingit name for a legendary sea monster, according to an article published on Tuesday in the journal Scientific Reports.

It is the only intact thalattosaur fossil ever found in North America, said paleontologist Pat Druckenmiller, director of the University of Alaska Museum of the North and lead author of the study.

“This animal is striking because it’s got this super-sharp pointed snout. Literally, it’s needle-like,” Druckenmiller said, describing the creature as “weird.”

The snout and the fine bones in its throat suggest a reptile that dug into cracks in submerged reefs to suck out food, mostly small crustaceans and squid.

Lucky low-tide find

The fossil was uncovered through a stroke of luck, when an extremely low tide in 2011 exposed the typically submerged rock where it was embedded on an island beach as scientists happened to be surveying the area.

Fully separating the fossil from rock took years, said U.S. Forest Service geologist Jim Baichtal, one of the scientists who found the specimen.

Positively identifying it as a new species included a trip by Druckenmiller to China, one of the few places where intact thalattosaurs have been discovered.

That work confirmed what was obvious to those who saw the fossil’s skull and snout in 2011, Druckenmiller said: “We knew right away that it was totally different.”

At the time Gunakadeit joseeae was living, what is now the rugged temperate rainforest of southeast Alaska was a much warmer place — a coastal region only about 10 to 20 degrees north of the equator, Druckenmiller said.

That territory migrated northward, pressing into North America and creating the paleontologically interesting terrain of Alaska’s southeast panhandle.

The newly identified thalattosaur is the latest among several important paleontological discoveries in the Tongass National Forest.

They include the 1996 discovery of a 10,300-year-old human skeleton in a cave in the southern part of the largest U.S. national forest. Those remains, of a young man with a fish-based diet, contributed to knowledge about people who migrated to North America by coastal routes rather than over the Bering Land Bridge.

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WFS News: Baby Pterosaurs Could Fly

February 3rd, 2020

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Baby pterosaurs — flying reptiles that lived alongside dinosaurs — were probably able to spread their leathery wings and fly shortly after emerging from their eggs, scientists reported in a new study.

Preserved eggs and embryos from Argentina and China suggested that pterosaur babies, or “flaplings,” according to the researchers, had skeletons and wing membranes that were already flight-capable when the flaplings were freshly hatched.

Previously, other researchers had suggested that hatchling pterosaurs’ bones and wings weren’t developed enough for the animals to take to the air. But this new analysis presents a greater range of developmental stages, delivering a more complete picture of the embryos as they grew. This suggests that embryos described in earlier studies were not yet fully developed; by the time the pterosaurs were ready to hatch, they would be ready to flap away on their own, the authors wrote in the new study.

Prior conclusions about flapling flight were also shaped by comparisons with modern animals that fly: birds and bats. Neither of those groups can fly as newborns, so it was thought that newly hatched pterosaurs probably couldn’t fly either, lead study author David Unwin, an associate professor with the School of Museum Studies at the University of Leicester in the United Kingdom, told Live Science in an email.

Unwin and co-author D. Charles Deeming, a principal lecturer with the School of Life Sciences at the University of Lincoln in the U.K., examined 19 embryos and 37 eggs from Hamipterus tianshanensis, which had been found in Argentina and China. Some embryos were in middle to late stages of development, while others were fully developed, the study authors reported.

To determine embryonic stages and calculate the pterosaurs’ potential wing power, the researchers looked at ossification in the embryos’ skeletons; this process shapes the skeletons as the embryos grow. They found that late-stage and near-term embryos had all the skeletal elements required for flight, while hatchlings showed fossilized evidence of wing membranes “with a complex internal structure related to how the membrane is used in flight,” Unwin said in the email.

The scientists also discovered that the shapes of the eggs could hold clues about developmental stages. Pterosaurs laid leathery, soft-shelled eggs, like those of modern reptiles. Lizard and snake eggs are known to change their shapes as they absorb water to nourish the embryo over time, increasing the egg’s mass, length and width.

According to the study, pterosaur eggs did the same; the shape and size of the eggs could therefore reveal how close they were to hatching.

“It matches what we know of soft-shelled eggs in living animals,” said Michael Habib, an assistant professor of clinical integrative anatomical sciences with the Keck Institute of Medicine at the University of Southern California. Habib, who studies pterosaurs, wasn’t involved in the new study.

Powering up

However, questions remain about whether skeletal ossification in the embryos’ limbs is a reliable indicator of flight ability, said Armita Manafzadeh, a doctoral candidate in the Department of Ecology and Evolutionary Biology at Brown University in Rhode Island.

“Living birds (and bats) whose limb bones are well-ossified in late embryonic and early post-hatching stages still cannot yet fly — largely invalidating a key premise of the authors’ argument,” Manafzadeh told Live Science in an email.

According to Manafzadeh, who also wasn’t part of this new study, recent research has shown that birds capable of early flight have bones that are well-ossified before and after hatching — yet flight muscles and joint surfaces in these birds’ forelimbs change dramatically after they hatch, suggesting that ossification alone is not enough to power their flight.

“It’s only after these additional musculoskeletal changes take place that juvenile birds are capable of generating the aerodynamic forces necessary for flight, which is the most power-demanding mode of locomotion, Manafzadeh said.

If flaplings were able to fly after hatching, that could mean that they were able to feed and take care of themselves, negating the need for extensive parental care, the researchers wrote in the study. In that scenario, baby pterosaurs would be active participants in their ecosystems and not helpless hatchlings wholly dependent on their parents. This new perspective has implications for scientists working to reconstruct the environments where pterosaurs lived, Habib said.

If the flaplings could fly right out of the gate, that brings up another challenge: How could they grow and fly at the same time? And how would they weather the metabolic and mechanical demands of flight on their small bodies, Habib asked.

“While our findings help solve one problem, they have also opened up many more interesting questions,” Unwin said. “We are only at the beginning of understanding these extraordinary creatures.”

The findings were published online June 12 in the journal Proceedings of the Royal Society B.

Source: Article By Mindy Weisberger, live science.com

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev