WFS News: Birgeria americana,Large-mouthed fish was top predator after mass extinction

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The 26 cm long fossil preserving the right side of the skull of Birgeria americana. Credit: UZH

The 26 cm long fossil preserving the right side of the skull of Birgeria americana.Credit: UZH

The most catastrophic mass extinction on Earth took place about 252 million years ago — at the boundary between the Permian and Triassic geological periods. Up to 90 percent of the marine species of that time were annihilated. Worldwide biodiversity then recovered in several phases throughout a period of about five million years. Until now, paleontologists have assumed that the first predators at the top of the food chain did not appear until the Middle Triassic epoch about 247 to 235 million years ago.

Unexpected find of a large predatory fish

Swiss and U.S. American researchers led by the Paleontological Institute and Museum of the University of Zurich have discovered the fossil remains of one of the earliest large-sized predatory fishes of the Triassic period: an approximately 1.8-meter-long primitive bony fish with long jaws and sharp teeth. This fish belongs to a previously unknown species called Birgeria americana. This predator occupied the sea that once covered present-day Nevada and the surrounding states already one million years after the mass extinction.

Triassic “Jaws”

In the United States, almost no vertebrate fossils from the Early Triassic epoch (252 to 247 million years ago) have been scientifically described until now. “The surprising find from Elko County in northeastern Nevada is one of the most completely preserved vertebrate remains from this time period ever discovered in the United States,” emphasizes Carlo Romano, lead author of the study. The fossil in question is a 26-centimeter-long partial skull of a fierce predator, as evidenced by three parallel rows of sharp teeth up to 2 centimeters long along the jaw margins, as well as several smaller teeth inside the mouth.

Birgeria hunted similarly to the extant great white shark: the prey fish were pursued and bitten, then swallowed whole. Species of Birgeria existed worldwide. The most recent discovery is the earliest example of a large-sized Birgeria species, about one and a half times longer than geologically older relatives.

Predators appeared earlier than assumed

According to earlier studies, marine food chains were shortened after the mass extinction event and recovered only slowly and stepwise. In addition, researchers assumed that the ancient equatorial regions were too hot for vertebrates to live during the Early Triassic. Finds such as the newly discovered Birgeria species and the fossils of other vertebrates now show that so-called apex predators (animals at the very top of the food chain) already lived early after the mass extinction. The existence of bony fish close to the equator — where Nevada was located during the Early Triassic — indicates that the temperature of the sea was a maximum of 36°C. The eggs of today’s bony fish can no longer develop normally at constant temperatures above 36°C.

“The vertebrates from Nevada show that previous interpretations of past biotic crises and associated global changes were too simplistic,” Carlo Romano says. Despite the severity of the extinctions of that time and intense climatic changes, the food webs were able to redevelop faster than previously assumed.

Citation: Carlo Romano, James F. Jenks, Romain Jattiot, Torsten M. Scheyer, Kevin G. Bylund, Hugo Bucher. Marine Early Triassic Actinopterygii from Elko County (Nevada, USA): implications for the Smithian equatorial vertebrate eclipse. Journal of Paleontology, 2017; 1 DOI: 10.1017/jpa.2017.36

University of Zurich. “Large-mouthed fish was top predator after mass extinction.” ScienceDaily. ScienceDaily, 26 July 2017. <www.sciencedaily.com/releases/2017/07/170726102929.htm>.

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WFS News: Ponomarenkia belmonthensis,300 MYO beetle

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He’s Australian, around half a centimetre long, fairly nondescript, 300 million years old, and he’s currently causing astonishment among both entomologists and palaeontologists. The discovery of a beetle from the late Permian period, when even the dinosaurs had not yet appeared on the scene, is throwing a completely new light on the earliest developments in this group of insects. The reconstruction and interpretation of the characteristics of Ponomarenkia belmonthensis was achieved by Prof. Dr Rolf Beutel and Dr Evgeny V. Yan of Friedrich Schiller University Jena (Germany). They have published this discovery together with beetle researcher Dr John Lawrence and Australian geologist Dr Robert Beattie in the current issue of the Journal of Systematic Palaeontology. It was Beattie who discovered the only two known fossilised specimens of the beetle in former marshland in Belmont, Australia.

Habitus photos of †Ponomarenkia belmonthensis sp. nov. A, B, holotype 40278; C, paratype 41618. Scale bars = 1 mm.

Habitus photos of †Ponomarenkia belmonthensis sp. nov. A, B, holotype 40278; C, paratype 41618. Scale bars = 1 mm.

“Beetles, which with nearly 400,000 described species today make up almost one-third of all known organisms, still lived a rather shadowy and cryptic existence in the Permian period,” explains Jena zoologist Beutel. “The fossils known to date have all belonged to an ancestral beetle lineage, with species preferring narrow spaces under bark of coniferous trees. They exhibit a whole series of primitive characteristics, such as wing cases (elytra) that had not yet become completely hardened or a body surface densely covered with small tubercles.”

Line drawings of †Ponomarenkia belmonthensis sp. nov. A, B, holotype; C, D, paratype. Scale bars = 1 mm.

Line drawings of †Ponomarenkia belmonthensis sp. nov. A, B, holotype; C, D, paratype. Scale bars = 1 mm.

Earliest form of the modern beetle

In contrast, the species that has now been discovered, assigned to the newly introduced family Ponomarenkiidae, can be identified as a modern beetle, in spite of its remarkable age. Modern characteristics are the antennae resembling a string of beads, antennal grooves, and the unusually narrow abdomen, tapering to a point. What is more, unlike previously known Permian beetles, the wing cases are completely hardened, the body’s surface is largely smooth, and the thoracic segments responsible for locomotion show modern features, notes insect palaeontologist Yan. In addition, it appears that this little beetle had stopped living under tree bark, the habitat favoured by its contemporaries, and had adopted a much more exposed lifestyle on plants. A significant fact is that, due to its unorthodox combination of ancestral and modern characteristics, this genus does not fit in any of the four suborders of beetles that still exist, which is why Yan and Beutel have given it the nickname Bad Boy. “Ponomarenkia belmonthensis shows above all that the first major events of radiation in the evolution of beetles took place before the Permian-Triassic mass extinction,” says Rolf Beutel. Beetles as a whole survived this dramatic event, which saw the acidification of the seas and major volcanic eruptions, considerably better than most other groups of organisms, presumably because of their terrestrial life style and hardened exoskeleton. However, the Bad Boy ran out of luck, as there are no more traces of its existence in the Mesozoic era.

Name honours eminent palaeontologist

The Jena researchers dedicated the genus and family to Moscow palaeontologist Prof. Alexander G. Ponomarenko. He has had a strong influence on beetle palaeontology for decades and supervised Dr Evgeny V. Yan’s doctorate. Yan obtained his doctorate from the Russian Academy of Sciences, spent five years as a postdoc at the Chinese Academy of Sciences in Nanjing, and since June 2016 he has done research at the Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum of the University of Jena as a guest researcher funded by the Alexander von Humboldt Foundation. It is Yan’s elaborate reconstructions on the computer that have provided the precise insights into Ponomarenkia belmonthensis.

In the first stage, some 40 photographs were taken of the two specimens, which were available as impressions on stone. “With this series of photographs an accurate 2D reconstruction was possible, with which we were able to correct for deformations in the original fossil. This allowed us to get closer to the actual beetle,” explains Dr Yan. Based on precise drawings and with the help of a special computer program that is also used for animation and computer games, a very informative 3D model was created. “The 3D reconstruction also enables us to draw conclusions about the way the beetle moved and lived,” the palaeontologist adds. He has developed this method of visualisation, as well as the analytical process in which he also includes hypothetical ancestors of the beetle, since his arrival in Jena. “We have already been able to apply this process to three newly discovered ancient beetle species,” Prof. Beutel is happy to report. “In this way, we have made significant steps towards deciphering the earliest stages in the evolution of an extremely successful genus of animals.”

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Citation:Friedrich-Schiller-Universitaet Jena. “300 million-year-old ‘modern’ beetle from Australia reconstructed.” ScienceDaily. ScienceDaily, 24 July 2017. <www.sciencedaily.com/releases/2017/07/170724105041.htm>

WFS News: Boy trips, falls and discovers million-year-old Ice Age fossil

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Researchers have their hands on a rare fossil from the Pleistocene era thanks to a 10-year-old’s clumsiness.Jude Sparks said he literally fell on the 1.2-million-year-old skull of a stegomastodon — a massive prehistoric creature with tusks like an elephant — while on a hike with his parents on the desert outskirts of his neighborhood in Las Cruces, New Mexico.

“I was running farther up and I tripped on part of the tusk,” Sparks said in a statement from New Mexico State University, where researchers are studying the find. “My face landed next to the bottom jaw. I looked farther up and there was another tusk.”

Jude Sparks, 10, said he literally fell on this 1.2-million-year-old stegomastodon skull on the outskirts of his neighborhood in Las Cruces, New Mexico. NEW MEXICO STATE UNIVERSITY

Jude Sparks, 10, said he literally fell on this 1.2-million-year-old stegomastodon skull on the outskirts of his neighborhood in Las Cruces, New Mexico. NEW MEXICO STATE UNIVERSITY

The stegomastodon is one of three species of proboscideans that inhabited the ancient Rio Grande Valley, and is believed to be an ancestor to modern-day elephants.Sparks’ parents contacted biologist Peter Houde, a professor at New Mexico State University, after hearing he had discovered a similar fossil in a quarry south of campus, the university said.

The fossil was found on private land, and it took several months to get permission to excavate from the property owner. In New Mexico, the law stipulates that vertebrate fossils found on private land belong to the landowner. Here, the property owner asked that the precise site remain confidential, according to the university.

The Sparks family eventually joined with Houde and his students to excavate the skull, a process that took one week.The large skull is deceptively delicate, and the only thing holding it together was the sediment around it, Houde said.

“When the sediments are removed from the sides of [the bones], they start to fall apart immediately and literally fall into tiny, tiny bits. It has to be done carefully by somebody who knows how to go about doing it. It is a very deliberate process that takes a little bit of time,” he said.

The team applied chemical hardeners to the fossil, mimicking the bone strength provided by protein, to keep it intact. Once dug from the ground, the fossil was coated in plaster and supported by wood braces for transport to New Mexico State University’s Vertebrate Museum, where it now lives.

Peter Houde of New Mexico State University poses with the tusk and mandible of a stegomastodon in the university's Vertebrate Museum. NMSU/ANDRES LEIGHTON

Peter Houde of New Mexico State University poses with the tusk and mandible of a stegomastodon in the university’s Vertebrate Museum. NMSU/ANDRES LEIGHTON

“We have the unique opportunity to really compare what the animal looks like [on] a much larger complete scale and compare it with others,” Houde told CBS Albuquerque affiliate KRQE, adding that it’s extremely rare to find a nearly intact skull of a mammal dating back to the Ice Age.

The process to reconstruct the skull, jaw and tusks is likely to take years to complete, Houde said.

“I have every hope and expectation that this specimen will ultimately end up on exhibit and this little boy will be able to show his friends and even his own children, look what I found right here in Las Cruces,” he said.

Source: Article by SHANIKA GUNARATNA CBS NEWS July 19, 2017

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WFS News: Albertavenator curriei named in honor of renowned paleontologist

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Scientists from the Royal Ontario Museum (ROM) and the Philip J Currie Dinosaur Museum have identified and named a new species of dinosaur in honour of renowned Canadian palaeontologist Dr. Philip J. Currie. Albertavenator curriei, meaning “Currie’s Alberta hunter.” It stalked Alberta, Canada, about 71 million years ago in what is now the famous Red Deer River Valley. The find recognizes Currie for his decades of work on predatory dinosaurs of Alberta. Research on the new species is published July 17 in the Canadian Journal of Earth Sciences.

Palaeontologists initially thought that the bones of Albertavenator belonged to its close relative Troodon, which lived around 76 million years ago — five million years before Albertavenator. Both dinosaurs walked on two legs, were covered in feathers, and were about the size of a person. New comparisons of bones forming the top of the head reveal that Albertavenator had a distinctively shorter and more robust skull than Troodon, its famously brainy relative.

This is a life recreation of Albertavenator curriei. Credit: Illustrated by Oliver Demuth. © Oliver Demuth

This is a life recreation of Albertavenator curriei. Credit: Illustrated by Oliver Demuth. © Oliver Demuth

“The delicate bones of these small feathered dinosaurs are very rare. We were lucky to have a critical piece of the skull that allowed us to distinguish Albertaventaor as a new species.” said Dr. David Evans, Temerty Chair and Senior Curator of Vertebrate Palaeontology at the Royal Ontario Museum, and leader of the project. “We hope to find a more complete skeleton of Albertavenator in the future, as this would tell us so much more about this fascinating animal.”

Identifying new species from fragmentary fossils is a challenge. Complicating matters of this new find are the hundreds of isolated teeth that have been found in Alberta and previously attributed to Troodon. Teeth from a jaw that likely pertains to Albertavenator appears very similar to the teeth of Troodon, making them unusable for distinguishing between the two species.

“This discovery really highlights the importance of finding and examining skeletal material from these rare dinosaurs,” concluded Derek Larson, co-author on the study and Assistant Curator of the Philip J. Currie Dinosaur Museum.”

The identification of a new species of troodontid in the Late Cretaceous of North America indicates that small dinosaur diversity in the latest Cretaceous of North America is likely underestimated due to the difficulty of identifying species from fragmentary fossils.

“It was only through our detailed anatomical and statistical comparisons of the skull bones that we were able to distinguish between Albertavenator and Troodon,” said Thomas Cullen, a Ph.D. student of Evans at the University of Toronto and co-author of the study.

The bones of Albertavenator were found in the badlands surrounding the Royal Tyrrell Museum, which Dr. Currie played a key role in establishing in the early 1980s. The rocks around the museum are the same age as some of the most fossiliferous rocks in the area of the newly erected Philip J. Currie Museum, also named in Dr. Currie’s honour. Although Dr. Currie has also had a several dinosaurs named after him, this is only the second one from Alberta, where he has made his biggest impact.

The fossils of Albertavenator studied by Evans and his team are housed in the collections of the Royal Tyrrell Museum. This is another example of a new species of dinosaur being discovered by re-examining museum research collections, which continually add to our understanding of the evolution of life on Earth. This study suggests that more detailed studies of fragmentary fossils may reveal additional, currently unrecognized, species.

 Journal Reference:David C. Evans, Thomas M. Cullen, Derek W. Larson, Adam Rego. A new species of troodontid theropod (Dinosauria: Maniraptora) from the Horseshoe Canyon Formation (Maastrichtian) of Alberta, Canada. Canadian Journal of Earth Sciences, 2017; 813 DOI: 10.1139/cjes-2017-0034  & Royal Ontario Museum. “New species of dinosaur named after Canadian icon: Dinosaur species from Alberta.” ScienceDaily. ScienceDaily, 17 July 2017. 

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WFS News: Can satellites be used as an early warning system for landslides?

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Researchers are using satellite data to accurately map the movement of the earth before a landslide in a bid to develop a life-saving early warning system.

The team from Newcastle University (UK), Chengdu University of Technology, Tongji University, China Academy of Space Technology and Wuhan University (China) have been tracking the devastating events of last week when a massive landslide struck Xinmo Village, Maoxian County, Sichuan Province in China.

Triggered by heavy rain, the Maoxian landslide swept away homes in Xinmo village, blocking a 2km section of river and burying 1,600 meters of road. The collapsed rubble was estimated to be about eight million cubic meters.

Three days later, a second landslide hit Xinmo Village and almost at the same time, a third landslide occurred in Shidaguan Town, 20km away from Xinmo Village.

Using ESA’s Sentinel-1 satellite radar mission — which comprises a constellation of two polar-orbiting satellites, operating day and night in all-weather conditions — the research team were able to capture before and after images of the landslides.

This provides vital information about the extent of the disaster which can be used to assess the damage and future risk in the area.

Professor Zhenhong Li, Professor of Imaging Geodesy at Newcastle University, explains:

“It is still hard, if not impossible, to detect a landslide using traditional techniques, especially in mountain areas. Using the satellite radar data, we were able to efficiently detect and map the active landslide over a wide region, identifying the source of the landslide and also its boundaries.

“Going forward, we can use this information to set up real-time monitoring systems — such as GPS, Beidou and Galileo — for those sites and whenever we detect abnormal behaviour, the system can send out an early warning message.

“In fact, while we were monitoring the Maoxian landslides we managed to identify over 10 other active landslides in the same region and forwarded this information to the relevant agencies.”

Living with the constant threat of a landslide

Sichuan province is prone to earthquakes, including the devastating Great Wenchuan Earthquake of 2008 when a 7.9 magnitude quake hit the area, killing over 70,000 people.

Professor Li says their data suggests the Maoxian (Shidaguan) landslide had been sliding for at least six months before it failed.

“When you consider this sort of timescale it suggests that a landslide Early Warning System is not only possible but would also be extremely effective,” says Professor Li.

“If we can detect movement at a very early stage then in many cases it is likely we would have time put systems in place to save lives.”

Professor Li and the team have been working on active faults and landslides in Southwest China for over ten years and have identified several active landslides in the area south to Maoxian County but this is the first time they have studied the Maoxian region.

Ultimately, the team hope to use the technology to detect and map active landslides in the whole region of SW China, and then build a landslide database.

The research findings were presented at the Dragon-4 symposium in Copenhagen on 27 June 2017.

Source: Newcastle University. “Can satellites be used as an early warning system for landslides?.” ScienceDaily. ScienceDaily, 5 July 2017. <www.sciencedaily.com/releases/2017/07/170705095421.htm>.

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WFS News: Fossil site shows impact of early Jurassic’s low oxygen oceans

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Using a combination of fossils and chemical markers, scientists have tracked how a period of globally low ocean-oxygen turned an Early Jurassic marine ecosystem into a stressed community inhabited by only a few species.

The research was led by Rowan Martindale, an assistant professor at The University of Texas at Austin Jackson School of Geosciences, and published in print in Palaeogeography, Palaeoclimatology, Palaeoeconology on July 15. The study was co-authored by Martin Aberhan, a curator at the Institute for Evolution and Biodiversity Science at the Natural History Museum in Berlin, Germany.

The study zeroes in on a recently discovered fossil site in Canada located at Ya Ha Tinda Ranch near Banff National Park in southwest Alberta. The site records fossils of organisms that lived about 183 million years ago during the Early Jurassic in a shallow sea that once covered the region.

Before the low oxygen period, bivalves were larger and more numerous. Credit: The University of Texas at Austin/Rowan Martindale Read more at: https://phys.org/news/2017-07-fossil-site-impact-early-jurassic.html#jCp

Before the low oxygen period, bivalves were larger and more numerous.                                                            Credit: The University of Texas at Austin/Rowan Martindale

The fossil site broadens the scientific record of the Toarcian Oceanic Anoxic Event, a period of low oxygen in shallow ocean waters which is hypothesized to be triggered by massive volcanic eruptions. The Oceanic Anoxic Event was identified at this site by the geochemical record preserved in the rocks. These geochemical data were collected in a previous research project led by Benjamin Gill and Theodore Them of Virginia Tech. The oxygen level of the surrounding environment during the Early Jurassic influences the type and amount of carbon preserved in rocks, making the geochemical record an important method for tracking an anoxic event.

“We have this beautiful geochemical record that gives us a backbone for the timing of the Oceanic Anoxic Event,” said Martindale, a researcher in the Jackson School’s Department of Geological Sciences. “So with that framework we can look at the benthic community, the organisms that are living on the bottom of the ocean, and ask ‘how did this community respond to the anoxic event?”

The low oxygen environment affected the growth and number of bivalves, reducing their number and population. Credit: The University of Texas at Austin/Rowan Martindale Read more at: https://phys.org/news/2017-07-fossil-site-impact-early-jurassic.html#jCp

The low oxygen environment affected the growth and number of bivalves, reducing their number and population.   Credit: The University of Texas at Austin/Rowan Martindale

The fossils show that before the anoxic event, the Ya Ha Tinda marine community was diverse, and included fish, ichthyosaurs (extinct marine reptiles that looked like dolphins), sea lilies, lobsters, clams and oysters, ammonites, and coleoids (squid-like octopods). During the anoxic event the community collapsed, restructured, and the organisms living in it shrunk. The clams that were most abundant in the community before the anoxic event were completely wiped out and replaced by different species.

The clams that survived during and after the event were much smaller than the clams from before the event, suggesting that low oxygen levels limited their growth.

The sea life recorded at Ya Ha Tinda before and during the anoxic event is similar to fossils found at European sites. Crispin Little, a senior lecturer in paleontology at The University of Leeds who was not involved with the research, said that the similarity between the sites underscores the widespread nature of the anoxic event.

“This confirms previous work suggesting that the T-OAE (anoxic event) was genuinely a global event,” Little said.

However, while other sites were recovering from the anoxic event, the environment at Ya Ha Tinda continued to face stress. Even for small, hardy bivalves, life was tough.

“One of the interesting things about the recovery [at Ya Ha Tinda] is that we actually see fewer individuals at a time when we’re supposed to be seeing community recovery,” Martindale said.

Fieldwork at Ya Ha Tinda Ranch, where the fossils were found. Credit: The University of Texas at Austin/Rowan Martindale Read more at: https://phys.org/news/2017-07-fossil-site-impact-early-jurassic.html#jCp

Fieldwork at Ya Ha Tinda Ranch, where the fossils were found.                                                                      Credit: The University of Texas at Austin/Rowan Martindale

The fossils suggest that the environment was undergoing local stresses that kept oxygen low, Martindale said. More research is needed to untangle why life at Ya Ha Tinda didn’t recover at the same rate as other places.

Since the oceanic anoxic event was a side-effect of climate change, looking back at ancient marine communities could be a window into the potential impacts of ongoing and future climate change, said co-author Martin Aberhan.

“One lesson we can learn from this study is that, on a human time scale, climate-related stresses can have very long-lasting effects, with no signs of recovery for hundred thousands of years, and that the communities before and after a climatic crises can look quite different in composition and ecological functioning,” Aberhan said.

Source :phys.org/news

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WFS Facts : The Pleistocene Epoch,Last Ice Age

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The Pleistocene Epoch is typically defined as the time period that began about 1.8 million years ago and lasted until about 11,700 years ago. The most recent Ice Age occurred then, as glaciers covered huge parts of the planet Earth.

There have been at least five documented major ice ages during the 4.6 billion years since the Earth was formed — and most likely many more before humans came on the scene about 2.3 million years ago.

Ice age

The Pleistocene Epoch is the first in which Homo sapiens evolved, and by the end of the epoch humans could be found in nearly every part of the planet. The Pleistocene Epoch was the first epoch in the Quaternary Period and the sixth in the Cenozoic Era. It was followed by the current stage, called the Holocene Epoch.

At the time of the Pleistocene, the continents had moved to their current positions. At one point during the Ice Age, sheets of ice covered all of Antarctica, large parts of Europe, North America, and South America, and small areas in Asia. In North America they stretched over Greenland and Canada and parts of the northern United States. The remains of glaciers of the Ice Age can still be seen in parts of the world, including Greenland and Antarctica.

But the glaciers did not just sit there. There was a lot of movement over time, and there were about 20 cycles when the glaciers would advance and retreat as they thawed and refroze. Scientists identified the Pleistocene Epoch’s four key stages, or ages — Gelasian, Calabrian, Ionian and Tarantian.

The name Pleistocene is the combination of two Greek words: pleistos (meaning “most”) and kainos (meaning “new” or “recent”). It was first used in 1839 by Sir Charles Lyell, a British geologist and lawyer.

As a result of Lyell’s work, the glacial theory gained acceptance between 1839 and 1846, and scientists came to recognize the existence of ice ages. During this period, British geologist Edward Forbes aligned the period with other known ice ages. In 2009, the International Union of Geological Sciences established the start of the Pleistocene Epoch at 1.806 million years before the present.

While scientists haven’t been able to determine the exact causes of an epoch, changes in ocean current, composition of the atmosphere, changes in the position of the Earth in relation to the sun are believed to be key contributors.

Overall, the climate was much colder and drier than it is today. Since most of the water on Earth’s surface was ice, there was little precipitation and rainfall was about half of what it is today. During peak periods with most of the water frozen, global average temperatures were 5 to 10 degrees C (9 to 18 degrees F) below today’s temperature norms.

There were winters and summers during that period. The variation in temperatures produced glacial advances, because the cooler summers didn’t completely melt the snow.

While Homo sapiens evolved, many vertebrates, especially large mammals, succumbed to the harsh climate conditions of this period.

One of the richest sources of information about life in the Pleistocene Epoch can be found in the La Brea Tar Pits in Los Angeles, where remains of everything from insects to plant life to animals were preserved, including a partial skeleton of a female human and a nearly complete woolly mammoth.

In addition to the woolly mammoth, mammals such as saber-toothed cats (Smilodon), giant ground sloths (Megatherium) and mastodons roamed the Earth during this period. Other mammals that thrived during this period include moonrats, tenrecs (hedgehog-like creatures) and macrauchenia (similar to a llamas and camels).

Although many vertebrates became extinct during this period, mammals that are familiar to us today — including apes, cattle, deer, rabbits, kangaroos, wallabies, bears, and members of the canine and feline families — could be found during this time.

Other than a few birds that were classified as dinosaurs, most notably the Titanis, there were no dinosaurs during the Pleistocene Epoch. They had become extinct at the end of the Cretaceous Period, more than 60 million years before the Pleistocene Epoch began.

Birds flourished during this period, including members of the duck, geese, hawk and eagle families. There were also some flightless birds such as ostriches, rheas and moas. The flightless birds did not fare as well, as they had to compete with mammals and other creatures for limited supplies of food and water, as a good portion of the water was frozen.

Crocodiles, lizards, turtles, pythons and other reptiles also thrived during this period.

As for vegetation, it was fairly limited in many areas. There were some scattered conifers, including pines, cypress and yews, along with some broadleaf trees such as beeches and oaks. On the ground, there were prairie grasses as well as members of the lilly, orchid and rose families.

About 13,000 years ago, more than three-fourths of the large Ice Age animals, including woolly mammoths, mastodons, saber-toothed tigers and giant bears, died out.  Scientists have debated for years over the cause of the extinction, with both of the major hypotheses — human overhunting and climate change — insufficient to account for the mega die-off.

Recent research suggests that an extraterrestrial object, possibly a comet, about 3 miles wide, may have exploded over southern Canada, nearly wiping out an ancient Stone Age culture as well as megafauna like mastodons and mammoths.

Source: Livescience

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WFS News:Falling sea level caused volcanoes to overflow

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Climate evolution shows some regularities, which can be traced throughout long periods of earth’s history. One of them is that the global average temperature and the carbon dioxide concentration in the atmosphere usually go hand-in-hand. To put it simple: If the temperatures decline, the CO2values also decrease and vice versa.

(a) Earth’s axial tilt (obliquity)66. (b) Calculated temperatures from the NGRIP ice core in Greenland on modelled chronology ‘ss09sea09bm’ with 10 years time steps67. (c) ΔT of EPICA Dome C in Antarctica68 on AICC2012 chronology69 (black line) and a recent stack of global sea surface temperature (SST) changes70 (orange line). (d) Atmospheric CO2 from the most recent CO2 stack on individual age models39. (e) Dust fluxes to EPICA Dome C37 on AICC2012 chronology. (f) Estimates of sea level changes. Solid black line with grey band is a Red Sea data-based 95% probability envelope15. Dashed blue line with cyan band: ice sheet-based deconvolution of a deep ocean benthic δ18O stack with 2 sigma uncertainty range16. Light red band: Monte-Carlo-based 95% probability to meet a compilation of U/Th-dated corals17 with own calculated mean (dark red broken line). Vertical dashed lines mark the decreasing phase in obliquity around the MIS 5/4 boundary, and coloured arrows highlight where atmospheric CO2 is apparently decoupled from long-term trends in temperatures. Antarctic ice core time series are interpolated to time steps of 100 years. The thick coloured lines in all subplots show 7 kyr running means to highlight the long-term orbitally driven changes. The time series based on global stacks of δ18O (ΔSST) and ice sheet simulation-based sea level (cyan band in f) contain only the orbital-driven signals and are therefore shown as published (without filtering).

(a) Earth’s axial tilt (obliquity)66. (b) Calculated temperatures from the NGRIP ice core in Greenland on modelled chronology ‘ss09sea09bm’ with 10 years time steps67. (c) ΔT of EPICA Dome C in Antarctica68 on AICC2012 chronology69 (black line) and a recent stack of global sea surface temperature (SST) changes70 (orange line). (d) Atmospheric CO2 from the most recent CO2 stack on individual age models39. (e) Dust fluxes to EPICA Dome C37 on AICC2012 chronology. (f) Estimates of sea level changes. Solid black line with grey band is a Red Sea data-based 95% probability envelope15. Dashed blue line with cyan band: ice sheet-based deconvolution of a deep ocean benthic δ18O stack with 2 sigma uncertainty range16. Light red band: Monte-Carlo-based 95% probability to meet a compilation of U/Th-dated corals17 with own calculated mean (dark red broken line). Vertical dashed lines mark the decreasing phase in obliquity around the MIS 5/4 boundary, and coloured arrows highlight where atmospheric CO2 is apparently decoupled from long-term trends in temperatures. Antarctic ice core time series are interpolated to time steps of 100 years. The thick coloured lines in all subplots show 7 kyr running means to highlight the long-term orbitally driven changes. The time series based on global stacks of δ18O (ΔSST) and ice sheet simulation-based sea level (cyan band in f) contain only the orbital-driven signals and are therefore shown as published (without filtering).

However, there are exceptions. An international team of scientists led by the GEOMAR Helmholtz Centre for Ocean Research Kiel and the Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research has now discovered a possible cause for such irregularities. An example is the last transition to glacial conditions. At approximately 80,000 years ago the temperatures declined, but the amount of carbon dioxide in the atmosphere remained relatively stable for several thousand years. The reason for this could be enhanced volcanic activity in the oceans induced by a falling sea level. The study is being published today in the journal Nature Communications.

During the development of glacial conditions temperatures decrease and ice sheets form, resulting in the redistribution of water from the ocean to continental regions. Thus, the sea level falls and the pressure on the on the seabed and thereby in the earth’s crust decreases, which enhances magma production.

In (a) an example simulation for the Hawaiian plume (isosurface at T=1,420 °C) is shown. The magmatic system at depth extends beyond the plume stem and is susceptible to sea level changes. Size and shape of the melting region not only depend on the plume’s strength and composition but also on speed and age of the overlying lithosphere. The effect of a 60 m sea level drop over 15 kyr on magma flux (b) and CO2 release (c) is shown for the 43 oceanic hotspots investigated. Steady background values are shown in red, the increases during the MIS 5/4 sea level change in blue. Note that the melt and CO2 fluxes from the Iceland hotspot are only considered in the baseline but not in the calculation of the increase in response to a falling sea level. This has to been done to honour the observation that Iceland was glaciated during the last interglacial-glacial transition.

In (a) an example simulation for the Hawaiian plume (isosurface at T=1,420 °C) is shown. The magmatic system at depth extends beyond the plume stem and is susceptible to sea level changes. Size and shape of the melting region not only depend on the plume’s strength and composition but also on speed and age of the overlying lithosphere. The effect of a 60 m sea level drop over 15 kyr on magma flux (b) and CO2 release (c) is shown for the 43 oceanic hotspots investigated. Steady background values are shown in red, the increases during the MIS 5/4 sea level change in blue. Note that the melt and CO2 fluxes from the Iceland hotspot are only considered in the baseline but not in the calculation of the increase in response to a falling sea level. This has to been done to honour the observation that Iceland was glaciated during the last interglacial-glacial transition.

“To better understand and quantify these processes, we developed a comprehensive computer model that we integrated with geodynamic data. In addition to this we analyzed paleo-climate data and carried out simulations with a model of the global carbon cycle,” Dr. Jörg Hasenclever, the lead author of the study explains the approach of the team. The study investigated the response of mid-ocean ridges and of 43 ocean island volcanoes to glacial sea level changes.

“Our approach has shown that the decreasing pressure at the seafloor could have induced increased lava- and carbon dioxide emissions. The enhanced volcanic carbon dioxide flux may have stabilized the atmospheric carbon dioxide concentrations during the climate system’s descent into the last ice age,” adds Prof. Dr. Lars Rüpke of GEOMAR.

The upper panel show the different geometries of volcanic edifices supported by a viscoelastic lithosphere; the lower panel plots show the percentage of the pressure signal, induced by sea level change, that is present at 60 km depth in the asthenospheric mantle. A maximum damping of ∼25% is found for the largest island sizes. All considered hotspots were catagorized into small, medium and large island depending on their subaerial area (see Supplementary Table 2). (a) shows the results for a cone-shaped island with a maximum topography of 700 m, (b) for a medium island with 2,800 m topographic elevation, and (c) for a large island with 4,800 m elevation.

The upper panel show the different geometries of volcanic edifices supported by a viscoelastic lithosphere; the lower panel plots show the percentage of the pressure signal, induced by sea level change, that is present at 60 km depth in the asthenospheric mantle. A maximum damping of ∼25% is found for the largest island sizes. All considered hotspots were catagorized into small, medium and large island depending on their subaerial area (see Supplementary Table 2). (a) shows the results for a cone-shaped island with a maximum topography of 700 m, (b) for a medium island with 2,800 m topographic elevation, and (c) for a large island with 4,800 m elevation.

The investigations suggest that close interactions between the solid earth and the climate system exist also on geologically relatively short time scales of about 5,000 to 15,000 years. Co-author Dr. Gregor Knorr of the Alfred-Wegener-Institute further explains: “Such interactions could provide a novel component for earth system research to better understand the climate evolution at times of glacial sea level changes.”

Journal Reference:Jörg Hasenclever, Gregor Knorr, Lars H. Rüpke, Peter Köhler, Jason Morgan, Kristin Garofalo, Stephen Barker, Gerrit Lohmann, Ian R. Hall. Sea level fall during glaciation stabilized atmospheric CO2 by enhanced volcanic degassing. Nature Communications, 2017; 8: 15867 DOI: 10.1038/NCOMMS15867

Helmholtz Centre for Ocean Research Kiel (GEOMAR). “Falling sea level caused volcanoes to overflow: New connections between the solid earth and the climate system.” ScienceDaily. ScienceDaily, 6 July 2017. <www.sciencedaily.com/releases/2017/07/170706113244.htm>.

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WFS News:Razanandrongobe sakalavae, the oldest known notosuchian

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

Little is known about the origin and early evolution of the Notosuchia, hitherto unknown in the Jurassic period. New research on fossils from Madagascar, published in the peer-reviewed journal PeerJ by Italian and French paleontologists, begin to fill the gap in a million-year-long ghost lineage.

Two bones, one individual. Identical counterlateral copies, 3-D printed from CT data, of the left dentary (MHNT.PAL.2012.6.1) and right premaxilla (MHNT.PAL.2012.6.2) herein described, rearticulated with the original specimens. The perfect occlusion of the two bones, in medial (A) as well as in ventral (B) views, unequivocally demonstrates that MHNT.PAL.2012.6.1 and MHNT.PAL.2012.6.2 pertain to the same individual. Scale bar = 5 cm.

Two bones, one individual.Identical counterlateral copies, 3-D printed from CT data, of the left dentary (MHNT.PAL.2012.6.1) and right premaxilla (MHNT.PAL.2012.6.2) herein described, rearticulated with the original specimens. The perfect occlusion of the two bones, in medial (A) as well as in ventral (B) views, unequivocally demonstrates that MHNT.PAL.2012.6.1 and MHNT.PAL.2012.6.2 pertain to the same individual. Scale bar = 5 cm.

Deep and massive jaw bones armed with enormous serrated teeth that are similar in size and shape to those of a T-rex strongly suggest that these animals fed also on hard tissue such as bone and tendon. The full name of the predatory crocodyliform (nicknamed ‘Razana’) is Razanandrongobe sakalavae, which means “giant lizard ancestor from Sakalava region.”

A combination of anatomical features clearly identify this taxon as a Jurassic notosuchian, close to the South American baurusuchids and sebecids, that were highly specialized predators of terrestrial habits, different from present-day crocodilians in having a deep skull and powerful erect limbs. “Like these and other gigantic crocs from the Cretaceous, ‘Razana’ could outcompete even theropod dinosaurs, at the top of the food chain,” says Cristiano Dal Sasso, of the Natural History Museum of Milan.

Right premaxilla of Razanandrongobe sakalavae. Specimen MHNT.PAL.2012.6.2 in rostral (R), caudal (C), lateral (L), dorsal (D), ventral (V), and medial (M) views. Scale bar = 5 cm.

Right premaxilla of Razanandrongobe sakalavae.Specimen MHNT.PAL.2012.6.2 in rostral (R), caudal (C), lateral (L), dorsal (D), ventral (V), and medial (M) views. Scale bar = 5 cm.

Razanandrongobe sakalavae is by far the oldest — and possibly the largest — representative of the Notosuchia, documenting one of the earliest events of exacerbated increase in body size along the evolutionary history of the group.

“Its geographic position during the period when Madagascar was separating from other landmasses is strongly suggestive of an endemic lineage. At the same time, it represents a further signal that the Notosuchia originated in southern Gondwana,” remarks co-author Simone Maganuco.

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Citation:Dal Sasso C, Pasini G, Fleury G, Maganuco S. (2017) Razanandrongobe sakalavae, a gigantic mesoeucrocodylian from the Middle Jurassic of Madagascar, is the oldest known notosuchian. PeerJ 5:e3481 https://doi.org/10.7717/peerj.3481

WFS News:Through fossil leaves, a step towards Jurassic Park

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

For the first time, researchers have succeeded in establishing the relationships between 200-million-year-old plants based on chemical fingerprints. Using infrared spectroscopy and statistical analysis of organic molecules in fossil leaves, they are opening up new perspectives on the dinosaur era.

The unique results stem from a collaboration between researchers at Lund University, the Swedish Museum of Natural History in Stockholm, and Vilnius University.

“We have solved many questions regarding these extinct plants’ relationships. These are questions that science has long been seeking answers to”, says Vivi Vajda, a professor at the Department of Geology at Lund University and active at the Swedish Museum of Natural History.

Remains of a ginkgo leaf preserved in fossil from the Jurassic era (Photo: Vivi Vajda)

Remains of a ginkgo leaf preserved in fossil from the Jurassic era (Photo: Vivi Vajda)

The researchers have collected fossil leaves from rocks in Sweden, Australia, New Zealand and Greenland. Using molecular spectroscopy and chemical analysis, the fossil leaves were then compared with the chemical signatures from molecules in plant leaves picked at the Botanical Garden in Lund.

The use of genetic DNA analysis in modern research to determine relationships is not possible on fossil plants. The oldest DNA fragments ever found are scarcely one million-years-old. Therefore, the scientists searched for organic molecules to see what these could reveal about the plants’ evolution and relationships.

The molecules were found in the waxy membrane, which covers the leaves and these showed to differ between various species. The membrane has been preserved in the fossil leaves, some of which are 200 million-years-old.

Using infrared spectroscopy, the researchers carried out analyses in several stages. Firstly, they examined leaves from living plants that have relatives preserved in the fossil archive. The analysis showed that the biomolecular signatures were similar among plant groups, much in the same way as shown by modern genetic DNA analysis.

When the method was shown to work on modern plants, the researchers went on to analyse their extinct fossil relatives. Among others, they examined fossil leaves from conifers and several species of Ginkgo. The only living species of Ginkgo alive today is Ginkgo biloba, but this genus was far more diverse during the Jurassic.

Fossil Ginkgo (Photo: Stephen McLoughlin)

                                             Fossil Ginkgo (Photo: Stephen McLoughlin)

“The results from the fossil leaves far exceeded our expectations, not only were they full of organic molecules, they also grouped according to well-established botanical relationships, based on DNA analysis of living plants i.e. Ginkgoes in one group, conifers in another,” says Vivi Vajda.

Finally, when the researchers had shown that the method gave consistent results, they analysed fossils of enigmatic extinct plants that have no living relatives to compare them with Among others, they examined Bennettites and Nilssonia, plants that were common in the area that is now Sweden during the Triassic and Jurassic around 250–150 million years ago. The analysis showed that Bennettites and Nilssonia are closely related. On the other hand, they are not closely related to cycads, which many researchers had thought until now.

Per Uvdal, Professor of Chemical Physics at Lund University and one of the researchers who conducted the study, considers that the overall results are astounding.

“The great thing about the biomolecules in the leaves’ waxy membranes is that they are so much more stable than DNA. As they reflect, in an indirect way, a plants DNA they can preserve information about the DNA. Therefore, the biomolecules can tell us how one plant is related in evolutionary terms to other plants”, he says.

The researchers are now going to extend their studies to more plant groups.

Source: Lund University News and Press releases

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