WFS News:New light shed on ‘world’s oldest animal fossils’

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A team of researchers, led by the University of Bristol, has uncovered that ancient fossils, thought to be some of the world’s earliest examples of animal remains, could in fact belong to other groups such as algae.

The Weng’an Biota is a fossil Konservat-Lagerstätte in South China that is around 600 million-years-old and provides an unparalleled snapshot of marine life during the interval in which molecular clocks estimate that animal groups had evolved.

However, all fossil evidence from this time has met with controversy.

Dr John Cunningham from the University of Bristol’s School of Earth Sciences, said: “Dated at around 600 million years old, these rocks preserve an assemblage of microscopic fossils, perfectly-aged to be candidates for the oldest evidence of animal life.

“These fossils aren’t recognisable as remains of fully grown animals, but some resemble embryos, ranging from single cells to clusters of thousands.

“The preservation is so exquisite, that even sub-cellular structures can be identified, including possible nuclei.

Dr Kelly Vargas, a postdoctoral researcher from the University of Bristol and one of the paper’s co-authors, said: “But with the lack of adult forms that could indicate their identity, paleontologists have to rely on information from cellular anatomy to determine whether these tiny fossils belong to animals or to a different group.”

This is a spiny acritarch from the Doushantuo biota imaged using synchrotron tomography. The affinities of these fossils are unknown. Credit: John Cunningham, University of Bristol

This is a spiny acritarch from the Doushantuo biota imaged using synchrotron tomography. The affinities of these fossils are unknown.   Credit: John Cunningham, University of Bristol

Now scientists have reviewed all the evidence pointing towards an animal identity of the Weng’an fossils.

Their findings have revealed that none of the characteristics previously used to define the fossils as animals are actually unique to animals alone, opening up the possibility for alternative identifications.

Professor Philip Donoghue, another Bristol co-author, added: “Many proponents of animal affinity have argued that the Y-shaped junctions between the cells in the fossils are an important animal character, but this a feature common to many multicellular groups, including algae, that are very distant relatives of animals.”

Dr Cunningham added: “It could be that the fossils belong to other groups, such as algae, and these possibilities need to be investigated carefully.”

Despite these results, paleontologists are continuing to make new discoveries from the Weng’an Biota, and these are helping to refine our knowledge of evolution during the Ediacaran.

Dr Cunningham concluded: “It might be possible that we’ll find definite animals in the Doushantuo Formation, but it’ll be like finding a needle in a haystack, or should we say an embryo in a really, really big quarry.”

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Citation:John A. Cunningham, Kelly Vargas, Zongjun Yin, Stefan Bengtson, Philip C. J. Donoghue. The Weng’an Biota (Doushantuo Formation): an Ediacaran window on soft-bodied and multicellular microorganisms. Journal of the Geological Society, 2017; jgs2016-142 DOI: 10.1144/jgs2016-142  & University of Bristol. “New light shed on ‘world’s oldest animal fossils’.” ScienceDaily. ScienceDaily, 3 May 2017. <www.sciencedaily.com/releases/2017/05/170503213547.htm

WFS News: Oldest orchid fossil on record identified.

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The orchid family has some 28,000 species — more than double the number of bird species and quadruple the mammal species. As it turns out, they’ve also been around for a while.

A newly published study documents evidence of an orchid fossil trapped in Baltic amber that dates back some 45 million years to 55 million years ago, shattering the previous record for an orchid fossil found in Dominican amber some 20-30 million years old.

Results of the discovery have just been published in the Botanical Journal of the Linnean Society.

“It wasn’t until a few years ago that we even had evidence of ancient orchids because there wasn’t anything preserved in the fossil record,” said George Poinar, Jr., a professor emeritus of entomology in the College of Science at Oregon State University and lead author on the study. “But now we’re beginning to locate pollen evidence associated with insects trapped in amber, opening the door to some new discoveries.”

Orchids have their pollen in small sac-like structures called pollinia, which are attached by supports to viscidia, or adhesive pads, that can stick to the various body parts of pollinating insects, including bees, beetles, flies and gnats. The entire pollination unit is known as a pollinarium.

In this study, a small female fungus gnat was carrying the pollinaria of an extinct species of orchid when it became trapped in amber more than 45 million years ago. The pollinaria was attached to the base of the gnat’s hind leg. Amber preserves fossils so well that the researchers could identify a droplet of congealed blood at the tip of the gnat’s leg, which had been broken off shortly before it was entombed in amber.

At the time, all of the continents hadn’t even yet drifted apart.

The fossil shows that orchids were well-established in the Eocene and it is likely that lineages extended back into the Cretaceous period. Until such forms are discovered, the present specimen provides a minimum date that can be used in future studies determining the evolutionary history and phylogeny of the orchids.

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A fungus gnat trapped in amber some 45-55 million years ago is carrying on the upper portion of its severed leg a pollen sac from an orchid -- the oldest evidence of the flower ever discovered. Credit: George Poinar, Oregon State University

A fungus gnat trapped in amber some 45-55 million years ago is carrying on the upper portion of its severed leg a pollen sac from an orchid — the oldest evidence of the flower ever discovered. Credit: George Poinar, Oregon State University

How the orchid pollen in this study ended up attached to the fungus gnat and eventually entombed in amber from near the Baltic Sea in northern Europe is a matter of speculation. But, Poinar says, orchids have evolved a surprisingly sophisticated system to draw in pollinating insects, which may have led to the gnat’s demise.

“We probably shouldn’t say this about a plant,” Poinar said with a laugh, “but orchids are very smart. They’ve developed ways to attract little flies and most of the rewards they offer are based on deception.”

Orchids use color, odor and the allure of nectar to draw in potential pollinating insects. Orchids will emit a scent that suggests to hungry insects the promise of food, but after entering the flower they will learn that the promise of nourishment was false.

Likewise, female gnats may pick up a mushroom-like odor from many orchids, which attracts them as a place to lay their eggs because the decaying fungal tissue is a source of future nutrition. Alas, again it is a ruse. In frustration, they may go ahead and lay their eggs, dooming their offspring to a likely death from a lack of food.

Finally, male insects are attracted by the ersatz scent of female flies and they actually will attempt to copulate with a part of the orchid they think is a potential mate.All three of these processes are based on deception, Poinar said, and they all have the same end result.

“Though the deception works in different ways, the bottom line is that the orchid is able to draw in pollinating insects, which unwittingly gather pollen that becomes attached to their legs and other body parts, and then pass it on to the next orchid flowers that lure them in,” he said.”Orchids are, indeed, pretty smart.”

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Citation:Oregon State University. “Oldest orchid fossil on record identified.” . ScienceDaily, 4 May 2017.

WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev: Chenanisaurus barbaricus,”Last dino in Africa” discovered in Moroccan mine

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One of the last dinosaurs living in Africa before their extinction 66 million years ago has been discovered in a phosphate mine in northern Morocco. A study of the fossil, led by the Milner Centre for Evolution at the University of Bath, suggests that following the breakup of the supercontinent Gondwana in the middle of the Cretaceous period, a distinct dinosaur fauna evolved in Africa.

  • The new species, Chenanisaurus barbaricus, was of one of the last dinosaurs on Earth and among those species wiped out when an asteroid hit 66 million years ago
  • It is the smaller African contemporary of the North American T. rex
  • Fossil is evidence of distinct fauna in southern hemisphere at this time

Almost nothing is known about the dinosaurs that lived in Africa at the end of the Cretaceous period 66 million years ago, just before they were wiped out by the impact of a giant asteroid. At this time sea levels were high, and so most of the fossils come from marine rocks.

Among these are the phosphate deposits of Morocco – remains of an ancient seabed, laid down 66 million years ago. The phosphate is harvested from vast strip mines and is used in everything from fertilizer to cola drinks.

Chenanisaurus barbaricus by lythronax-argestes Watch Digital Art / Vector / Animals

Chenanisaurus barbaricus by lythronax-argestes,Watch Digital Art / Vector / Animals

Last year, Dr Nick Longrich, from the Milner Centre for Evolution and the Department of Biology & Biochemistry at the University of Bath, studied a rare fragment of a jaw bone that was discovered in the mines at Sidi Chennane in the Oulad Abdoun Basin, Morocco. In collaboration with colleagues based in Morocco, France, and Spain, Longrich identified it as belonging to an abelisaur.

Rare fossil find

Abelisaurs were two-legged predators like T. rex and other tyrannosaurs, but with a shorter, blunter snout, and even tinier arms. While the tyrannosaurs dominated in North America and Asia, the abelisaurs were the top predators at the end of the Cretaceous in Africa, South America, India, and Europe.

Dr Longrich explained: “This find was unusual because it’s a dinosaur from marine rocks – it’s a bit like hunting for fossil whales, and finding a fossil lion. It’s an incredibly rare find – almost like winning the lottery. But the phosphate mines are so rich, it’s like buying a million lottery tickets, so we actually have a chance to find rare dinosaurs like this one.”

 

“We have virtually no dinosaur fossils from this time period in Morocco – it may even be the first dinosaur named from the end-Cretaceous in Africa. It’s also one of the last dinosaurs in Africa before the mass extinction that wiped out the dinosaurs.

“It’s an exciting find because it shows just how different the fauna was in the Southern hemisphere at this time.”

Distinct dinosaurs in Southern hemisphere

Named Chenanisaurus barbaricus, the newly discovered dinosaur stood on two legs and had stumpy arms. Dr Longrich added: “Abelisaurs had very short arms. The upper arm bone is short, the lower arm is shorter, and they have tiny little hands.”

The teeth from the fossil were worn as if from biting into bone, suggesting that like T. rex, Chenanisaurus was a predator. However, unlike the partially feathered T. rex, Chenanisaurus had only scales, its brain was smaller, and its face was shorter and deeper.

The research project was carried out as part of an international scientific collaboration that is helping create and study paleontology collections in Morocco with the aim of conserving the country’s rich fossil heritage. The specimens used for this study are conserved in the Office Chérifien de Phosphates paleontological collection in Morocco.

The team has published their results in the journal Cretaceous Research: Nicholas Longrich (University of Bath, UK), Xabier Pereda-Suberbiola (Universidad del País Vasco/EHU, Bilbao Spain), Nour-Eddine Jalil (UCA, Morocco – Muséum national d’Histoire naturelle, France), Fatima Khaldoune & Essaid Jourani (OCP S. A, Morocco) (2017) “An abelisaurid from the latest Cretaceous (late Maastrichtian) of Morocco, North Africa” http://doi.org/10.1016/j.cretres.2017.03.021

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WFS News:Fossil sheds light on ‘Jurassic Park’ dinosaurs

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Brachiosaurus, depicted in Jurassic Park, now has an early relative, providing clues to the evolution of some of the biggest creatures on Earth.Scientists say the plant-eating dinosaur was longer than a double-decker bus and weighed 15,000kg.Its remains were found in the 1930s in the Jura region of France.

Since then it has been somewhat over-looked, spending most of that time in storage crates in the National Museum of Natural History in Paris.Lead researcher Dr Philip Mannion of Imperial College London said the dinosaur would have eaten all kinds of vegetation, such as ferns and conifers, and lived at a time when Europe was a series of islands.

”We don’t know what this creature died from, but millions of years later it is providing important evidence to help us understand in more detail the evolution of brachiosaurid sauropods and a much bigger group of dinosaurs that they belonged to, called titanosauriforms,” he said.

Asteroid strike

Titanosauriforms were some of the largest creatures ever to have lived on land and were very diverse, surviving right up until the asteroid strike that wiped out most life on Earth.The new species, given the scientific name, Vouivria damparisensis, lived in the Late Jurassic, some 160 million years ago.

“It’s the earliest member of a group that includes Brachiosaurus – one of the most famous dinosaurs we know – one of the prominent animals in Jurassic Park,” Dr Mannion told BBC News

“And it gives us a much clearer idea of what’s going on in the early evolution of this really important radiation of dinosaurs.”

Sauropods

The dinosaur is a sauropod – a sub-group of titanosauriforms, which include well-known groups such as Brachiosaurus, Diplodocus and Brontosaurus.They had very long necks, long tails, and small heads with thick, pillar-like legs.

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Brachiosaurus dinosaurs at water, computer artwork                                            Image copyright SPL .     Brachiosaurus dinosaurs at water, computer artwork

The fossil predates the previously oldest-known member of this group by about five million years.

“It starts to give us an idea that these animals were evolving much earlier than the fossil record previously has indicated,” Dr Mannion added.

“This pushes back a lot of origin times for a range of sauropod dinosaurs based on our understanding of how these different species related to one another.”

The re-classification of Vouivria as an early member of the titanosauriforms will help in mapping their spread across the Earth, from Jurassic times to the extinction of all dinosaurs.It is thought that they were present across Europe, the US and Africa, but became extinct in Europe towards the end of their reign.

The fossil was discovered in the village of Damparis in the Jura region of eastern France in 1934.It was documented scientifically in the 1940s, but has not been studied in detail since then.Its scientific name, Vouivria damparisensis, relates to ‘La vouivre’, a local folklore legend about a winged serpent.

Dr Mannion examined the bones of the creature along with scientists at the National Museum of Natural History in Paris and the CNRS/Université Paris 1 Panthéon-Sorbonne.

Courtesy: Article By Helen Briggs,BBC News

Citation:Mannion PD, Allain R, Moine O. (2017) The earliest known titanosauriform sauropod dinosaur and the evolution of Brachiosauridae. PeerJ 5:e3217https://doi.org/10.7717/peerj.3217

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WFS News: Early organic carbon got deep burial in mantle

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Rice University petrologists who recreated hot, high-pressure conditions from 60 miles below Earth’s surface have found a new clue about a crucial event in the planet’s deep past.

Their study describes how fossilized carbon — the remains of Earth’s earliest single-celled creatures — could have been subsumed and locked deep in Earth’s interior starting around 2.4 billion years ago — a time when atmospheric oxygen rose dramatically. The paper appears online this week in the journal Nature Geoscience.

“It’s an interesting concept, but in order for complex life to evolve, the earliest form of life needed to be deeply buried in the planet’s mantle,” said Rajdeep Dasgupta, a professor of Earth science at Rice. “The mechanism for that burial comes in two parts. First, you need some form of plate tectonics, a mechanism to carry the carbon remains of early life-forms back into Earth. Second, you need the correct geochemistry so that organic carbon can be carried deeply into Earth’s interior and thereby removed from the surface environment for a long time.”

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This schematic depicts the efficient deep subduction of organic (reduced) carbon, a process that could have locked significant amounts of carbon in Earth's mantle and resulted in a higher percentage of atmospheric oxygen. Based on new high-pressure, high-temperature experiments, Rice University petrologists argue that the long-term sequestration of organic carbon from this process began as early as 2.5 billion years ago and helped bring about a well-known buildup of oxygen in Earth's atmosphere -- the "Great Oxidation Event" -- about 2.4 billion years ago. Credit: Image courtesy of R. Dasgupta/Rice University

This schematic depicts the efficient deep subduction of organic (reduced) carbon, a process that could have locked significant amounts of carbon in Earth’s mantle and resulted in a higher percentage of atmospheric oxygen. Based on new high-pressure, high-temperature experiments, Rice University petrologists argue that the long-term sequestration of organic carbon from this process began as early as 2.5 billion years ago and helped bring about a well-known buildup of oxygen in Earth’s atmosphere — the “Great Oxidation Event” — about 2.4 billion years ago.
Credit: Image courtesy of R. Dasgupta/Rice University

At issue is what caused the “great oxidation event,” a steep increase in atmospheric oxygen that is well-documented in countless ancient rocks. The event is so well-known to geologists that they often simply refer to it as the “GOE.” But despite this familiarity, there’s no scientific consensus about what caused the GOE. For example, scientists know Earth’s earliest known life, single-celled cyanobacteria, drew down carbon dioxide from the atmosphere and released oxygen. But the appearance of early life has been pushed further and further into the past with recent fossil discoveries, and scientists now know that cyanobacteria were prevalent at least 500 million years before the GOE.

“Cyanobacteria may have played a role, but the GOE was so dramatic — oxygen concentration increased as much as 10,000 times — that cyanobacteria by themselves could not account for it,” said lead co-author Megan Duncan, who conducted the research for her Ph.D. dissertation at Rice. “There also has to be a mechanism to remove a significant amount of reduced carbon from the biosphere, and thereby shift the relative concentration of oxygen within the system,” she said.

Removing carbon without removing oxygen requires special circumstances because the two elements are prone to bind with one another. They form one of the key components of the atmosphere — carbon dioxide — as well as all types of carbonate rocks.

Dasgupta and Duncan found that the chemical composition of the “silicate melt” — subducting crustal rock that melts and rises back to the surface through volcanic eruptions — plays a crucial role in determining whether fossilized organic carbon, or graphite, sinks into the mantle or rises back to the surface through volcanism.

Duncan, now a research scientist at the Carnegie Institution in Washington, D.C., said the study is the first to examine the graphite-carrying capacity of a type of melt known as rhyolite, which is commonly produced deep in the mantle and carries significant amounts of carbon to the volcanoes. She said the graphite-carrying capacity of rhyolitic rock is crucial because if graphite is prone to hitching a ride back to the surface via extraction of rhyolitic melt, it would not have been buried in sufficient quantities to account for the GOE.

“Silicate composition plays an important role,” she said. “Scientists have previously looked at carbon-carrying capacities in compositions that were much more magnesium-rich and silicon-poor. But the compositions of these rhyolitic melts are high in silicon and aluminum and have very little calcium, magnesium and iron. That matters because calcium and magnesium are cations, and they change the amount of carbon you can dissolve.”

Dasgupta and Duncan found that rhyolitic melts could dissolve very little graphite, even when very hot.

“That was one of our motivations,” said Dasgupta, professor of Earth science. “If subduction zones in the past were very hot and produced a substantial amount of melt, could they completely destabilize organic carbon and release it back to the surface?

“What we showed was that even at very, very high temperatures, not much of this graphitic carbon dissolves in the melt,” he said. “So even though the temperature is high and you produce a lot of melt, this organic carbon is not very soluble in that melt, and the carbon gets buried in the mantle as a result.

“What is neat is that with the onset and the expected tempo of crustal burial into the deep mantle starting just prior to the GOE, and with our experimental data on the efficiency of deep burial of reduced carbon, we could model the expected rise of atmospheric oxygen across the GOE,” Dasgupta said.

The research supports the findings of a 2016 paper by fellow Rice petrologist Cin-Ty Lee and colleagues that suggested that plate tectonics, continent formation and the appearance of early life were key factors in the development of an oxygen-rich atmosphere on Earth.

Duncan, who increasingly focuses on exoplanetary systems, said the research could provide important clues about what scientists should look for when evaluating which exoplanets could support life.

  1. Megan S. Duncan, Rajdeep Dasgupta. Rise of Earth’s atmospheric oxygen controlled by efficient subduction of organic carbon. Nature Geoscience, 2017; DOI: 10.1038/ngeo2939

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WFS News: long-held theory of Tsunami formation challenged

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A new NASA study is challenging a long-held theory that tsunamis form and acquire their energy mostly from vertical movement of the seafloor.

An undisputed fact was that most tsunamis result from a massive shifting of the seafloor — usually from the subduction, or sliding, of one tectonic plate under another during an earthquake. Experiments conducted in wave tanks in the 1970s demonstrated that vertical uplift of the tank bottom could generate tsunami-like waves. In the following decade, Japanese scientists simulated horizontal seafloor displacements in a wave tank and observed that the resulting energy was negligible. This led to the current widely held view that vertical movement of the seafloor is the primary factor in tsunami generation.

Tsunami formation

                                                                              Tsunami formation

In 2007, Tony Song, an oceanographer at NASA’s Jet Propulsion Laboratory in Pasadena, California, cast doubt on that theory after analyzing the powerful 2004 Sumatra earthquake in the Indian Ocean. Seismograph and GPS data showed that the vertical uplift of the seafloor did not produce enough energy to create a tsunami that powerful. But formulations by Song and his colleagues showed that once energy from the horizontal movement of the seafloor was factored in, all of the tsunami’s energy was accounted for. Those results matched tsunami data collected from a trio of satellites -the NASA/Centre National d’Etudes Spatiales (CNES) Jason, the U.S. Navy’s Geosat Follow-on and the European Space Agency’s Environmental Satellite.

Further research by Song on the 2004 Sumatra earthquake, using satellite data from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment (GRACE) mission, also backed up his claim that the amount of energy created by the vertical uplift of the seafloor alone was insufficient for a tsunami of that size.

“I had all this evidence that contradicted the conventional theory, but I needed more proof,” Song said.

His search for more proof rested on physics — namely, the fact that horizontal seafloor movement creates kinetic energy, which is proportional to the depth of the ocean and the speed of the seafloor’s movement. After critically evaluating the wave tank experiments of the 1980s, Song found that the tanks used did not accurately represent either of these two variables. They were too shallow to reproduce the actual ratio between ocean depth and seafloor movement that exists in a tsunami, and the wall in the tank that simulated the horizontal seafloor movement moved too slowly to replicate the actual speed at which a tectonic plate moves during an earthquake.

“I began to consider that those two misrepresentations were responsible for the long-accepted but misleading conclusion that horizontal movement produces only a small amount of kinetic energy,” Song said.

Building a Better Wave Tank

To put his theory to the test, Song and researchers from Oregon State University in Corvallis simulated the 2004 Sumatra and 2011 Tohoku earthquakes at the university’s Wave Research Laboratory by using both directly measured and satellite observations as reference. Like the experiments of the 1980s, they mimicked horizontal land displacement in two different tanks by moving a vertical wall in the tank against water, but they used a piston-powered wave maker capable of generating faster speeds. They also better accounted for the ratio of how deep the water is to the amount of horizontal displacement in actual tsunamis.

The new experiments illustrated that horizontal seafloor displacement contributed more than half the energy that generated the 2004 and 2011 tsunamis.

“From this study, we’ve demonstrated that we need to look at not only the vertical but also the horizontal movement of the seafloor to derive the total energy transferred to the ocean and predict a tsunami,” said Solomon Yim, a professor of civil and construction engineering at Oregon State University and a co-author on the study.

The finding further validates an approach developed by Song and his colleagues that uses GPS technology to detect a tsunami’s size and strength for early warnings.

The JPL-managed Global Differential Global Positioning System (GDGPS) is a very accurate real-time GPS processing system that can measure seafloor movement during an earthquake. As the land shifts, ground receiver stations nearer to the epicenter also shift. The stations can detect their movement every second through real-time communication with a constellation of satellites to estimate the amount and direction of horizontal and vertical land displacement that took place in the ocean. They developed computer models to incorporate that data with ocean floor topography and other information to calculate the size and direction of a tsunami.

“By identifying the important role of the horizontal motion of the seafloor, our GPS approach directly estimates the energy transferred by an earthquake to the ocean,” Song said. “Our goal is to detect a tsunami’s size before it even forms, for early warnings.”

The study is published in Journal of Geophysical Research — Oceans.

Citation:NASA/Jet Propulsion Laboratory. “Tsunami formation: Study challenges long-held theory.” ScienceDaily. ScienceDaily, 26 April 2017.

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WFS News: Tokummia Katalepsis, a Cambrian-era predator

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The newest creature discovered at the Burgess Shale fossil site in B.C. looks like it’s part centipede, part crab and part can-opener.

Meet the tokummia katalepsis, a Cambrian-era predator, found by paleontologists from the University of Toronto and the Royal Ontario Museum.The team released news of the tokummia and 21 other creatures found in the same fossil repository on Wednesday in the journal Nature.

A 3-D rendering of the tokummia katalepsis from the Royal Ontario Museum in Toronto shows its serrated pincers, which were too fragile to feed on shelled animals. (Royal Ontario Museum)

A 3-D rendering of the tokummia katalepsis from the Royal Ontario Museum in Toronto shows its serrated pincers, which were too fragile to feed on shelled animals.(Royal Ontario Museum)

 

 The discovery of can-opener-like pincers on the tokummia was among the most interesting findings, said Cédric Aria, lead author of the study and recent PhD graduate in ecology and evolutionary biology at U of T.Another major discovery was the mandibles – paired plate-like elements around the mouth – which have shed light on the origin of the species subgroup, mandibulates. These organisms are all defined by having mandibles they use to hold, bite and cut up food.

“It can be interesting in paleontology, how much can depend on one feature,” Dr. Aria said.

He said the discovery of the tokummia’s pincers is important because it gives

a timeline of the evolution of the larger animal group, anthropods. The fossils date back more than five hundred million years.

Jean-Bernard Caron, senior curator of invertebrate palaeontology at the Royal Ontario Museum and associate professor at U of T, said the tokummia, at more than 10-centimetres long, was one of the largest predators of its time and lived at the bottom of the sea.

“For today’s standards, they are very small, but you have to imagine they were very large at the time when the other animals were the size of my thumbnail,” Prof. Caron said.

According to Dr. Aria, the tokummia’s body was covered by a broad two-piece shell-like structure and it had numerous legs. The pincers were delicate, meaning they may have been too fragile to feed on shelled animals, therefore they adapted to capture soft prey and tear them apart before eating them.

The discovery of the mandibles wouldn’t have been possible if not for the quality of fossils.

“You need preservation that’s so exceptional that it gives you access to the tiniest of features,” Dr. Aria said.

Prof. Caron said the fossils were so well-preserved the researchers were able to dissect the findings.The researchers cut into the fossils with micro-jack hammers to uncover

smaller features. This allowed researchers to show the mandibles that were hidden behind the tokummia’s flattened shell.

“It’s really unusual to dissect fossils,” Prof. Caron says. “But without dissection, we would not have been able to find the smoking gun of the story – the mandibles.”

Robert Dalrymple, an active retired professor of paleobiology at Queen’s University, said the preservation is among the most impressive aspects of the study.

“To find such a beautiful, fully preserved specimen such as this is extremely rare,” Dr. Dalrymple said.

“[For the researchers to] work out all of the details of the organisms appearance in three dimensions from the squashed and flattened two-dimensional impression represents impressive work.”

Courtesy: Article By Luke Carroll,http://www.theglobeandmail.com

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WFS News: Moabosaurus discovered in Utah’s ‘gold mine’

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The Moabosaurus discovery was published this week by the University of Michigan’s Contributions from the Museum of Paleontology. The paper, authored by three Brigham Young University researchers and a BYU graduate at Auburn University, profiles Moabosaurus, a 125-million-year-old dinosaur whose skeleton was assembled using bones extracted from the Dalton Wells Quarry, near Arches National Park.

BYU geology professor and lead author Brooks Britt explained that in analyzing dinosaur bones, he and colleagues rely on constant comparisons with other related specimens. If there are enough distinguishing features to make it unique, it’s new.

“It’s like looking at a piece of a car,” Britt said. “You can look at it and say it belongs to a Ford sedan, but it’s not exactly a Focus or a Fusion or a Fiesta. We do the same with dinosaurs.”

BYU researcher Brooks Britt is with the newly discovered Moabosaurus, on display at BYU's Museum of Paleontology. Credit: Jaren Wilkey, BYU

BYU researcher Brooks Britt is with the newly discovered Moabosaurus, on display at BYU’s Museum of Paleontology.
Credit: Jaren Wilkey, BYU

Moabosaurus belongs to a group of herbivorous dinosaurs known as sauropods, which includes giants such as Brontosaurus and Brachiosaurus, who had long necks and pillar-like legs. Moabosaurus is most closely related to species found in Spain and Tanzania, which tells researchers that during its time, there were still intermittent physical connections between Europe, Africa and North America.

Moabosaurus lived in Utah before it resembled the desert we know — when it was filled with large trees, plentiful streams, lakes and dinosaurs. “We always think of Moab in terms of tourism and outdoor activities, but a paleontologist thinks of Moab as a gold mine for dinosaur bones,” Britt said.

In naming the species, Britt and his team, which included BYU Museum of Paleontology curator Rod Scheetz and biology professor Michael Whiting, decided to pay tribute to that gold mine. “We’re honoring the city of Moab and the State of Utah because they were so supportive of our excavation efforts over the decades it’s taken us to pull the animal out of the ground,” Britt said, referencing the digs that began when he was a BYU geology student in the late ’70s.

Credit: Brigham Young University

    Credit: Brigham Young University

A previous study indicates that a large number of Moabosaurus and other dinosaurs died in a severe drought. Survivors trampled their fallen companions’ bodies, crushing their bones. After the drought ended, streams eroded the land, and transported the bones a short distance, where they were again trampled. Meanwhile, insects in the soils fed on the bones, leaving behind tell-tale burrow marks.

“We’re lucky to get anything out of this site,” Britt said. “Most bones we find are fragmentary, so only a small percentage of them are usable. And that’s why it took so long to get this animal put together: we had to collect huge numbers of bones in order to get enough that were complete.”

BYU has a legacy of collecting dinosaurs that started in the early 1960s, and Britt and colleagues are continuing their excavation efforts in eastern Utah. Moabosaurus now joins a range of other findings currently on display at BYU’s Museum of Paleontology — though, until its placard is updated, it’s identified as “Not yet named” (pronunciation: NOT-yet-NAIM-ed).

“Sure, we could find bones at other places in the world, but we find so many right here in Utah,” Britt said. “You don’t have to travel the world to discover new animals.”

Journal Reference:Britt, Brooks B.; Scheets, Rodney D.; Whiting, Michael F.; Wilhite, D. Ray. MOABOSAURUS UTAHENSIS, N. Gen., N. SP., A New Sauropod From The Early Cretaceous (Aptian) of North America. Contributions from the Museum of Paleontology, 2017 [link] andBrigham Young University. “Moabosaurus discovered in Utah’s ‘gold mine’.” ScienceDaily. ScienceDaily, 13 April 2017. <www.sciencedaily.com

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WFS News: Evidence of Earthquakes recorded on fossils

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The Cascadia subduction zone (CSZ) has captured major attention from paleoseismologists due to evidence from several large (magnitude 8-9) earthquakes preserved in coastal salt marshes. Stratigraphic records are proving to be useful for learning about the CSZ’s past, and microfossils may provide more answers about large ancient earthquakes. They may also allow modelers to learn more about potential major hazards related to earthquakes in the area, which would contribute to public preparedness for such events.

Over the past three decades, researchers have found stratigraphic evidence of subsidence occurring during earthquakes beneath the salt marshes of Humboldt Bay, California, USA, at the southern end of the CSZ. J. Scott Padgett of the University of Rhode Island uses analysis of fossil foraminifera to estimate this subsidence at Arcata Bay, just north of Humboldt Bay. He will report on his research on 2 November at the Geological Society of America’s Annual Meeting in Baltimore, Maryland, USA.

mocrofossils

    microfossils

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Padgett notes, “Previous investigations were able to provide estimates of subsidence with large errors, which are only so helpful to the modelers.” More recently, researchers started using an improved analysis on the microfossil data in Oregon, and were able to generate subsidence estimates with smaller errors. Their refined results enabled modelers to produce earthquake models that are more consistent with observed subsidence measurements seen in today’s instrumented earthquakes.

Similar work is being done at Jacoby Creek, a small coastal drainage that flows into northern Arcata Bay. There, researchers have found three sharp contacts between salt marsh peat and intertidal mud dating back over the past 2,000 years. Radiocarbon ages of plant macrofossils at the top of the buried peats are 195, 1280, and 1710 years old. These new ages provide tighter constraints on the timing of past earthquakes and subsidence at the southern end of the CSZ.

Padgett says there are several lines of evidence that support their results and interpretation at Jacoby Creek. “These include the sharp mud-over-peat contacts that are laterally continuous over 5 kilometers, changes in fossil foraminifera assemblages across the buried peat contacts, long-lasting submergence also derived from fossil foraminifera records, and radiocarbon ages of plant macrofossils taken from buried peat deposits that are consistent with other southern Cascadia earthquake chronologies derived from buried peat and tsunami deposits.”

Citation:Geological Society of America. “Earthquakes recorded through fossils.”

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WFS News: How the darkness and the cold killed the dinosaurs

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Sixty six million years ago, the sudden extinction of the dinosaurs started the ascent of the mammals, ultimately resulting in humankind’s reign on Earth. Climate scientists now reconstructed how tiny droplets of sulfuric acid formed high up in the air after the well-known impact of a large asteroid and blocking the sunlight for several years, had a profound influence on life on Earth. Plants died, and death spread through the food web. Previous theories focused on the shorter-lived dust ejected by the impact. The new computer simulations show that the droplets resulted in long-lasting cooling, a likely contributor to the death of land-living dinosaurs. An additional kill mechanism might have been a vigorous mixing of the oceans, caused by the surface cooling, severely disturbing marine ecosystems.

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asteroid impact.

asteroid impact.

“The big chill following the impact of the asteroid that formed the Chicxulub crater in Mexico is a turning point in Earth history,” says Julia Brugger from the Potsdam Institute for Climate Impact Research (PIK), lead author of the study to be published in the Geophysical Research Letters. “We can now contribute new insights for understanding the much debated ultimate cause for the demise of the dinosaurs at the end of the Cretaceous era.” To investigate the phenomenon, the scientists for the first time used a specific kind of computer simulation normally applied in different contexts, a climate model coupling atmosphere, ocean and sea ice. They build on research showing that sulfur- bearing gases that evaporated from the violent asteroid impact on our planet’s surface were the main factor for blocking the sunlight and cooling down Earth.

In the tropics, annual mean temperature fell from 27 to 5 degrees Celsius

“It became cold, I mean, really cold,” says Brugger. Global annual mean surface air temperature dropped by at least 26 degrees Celsius. The dinosaurs were used to living in a lush climate. After the asteroid’s impact, the annual average temperature was below freezing point for about 3 years. Evidently, the ice caps expanded. Even in the tropics, annual mean temperatures went from 27 degrees to mere 5 degrees. “The long-term cooling caused by the sulfate aerosols was much more important for the mass extinction than the dust that stays in the atmosphere for only a relatively short time. It was also more important than local events like the extreme heat close to the impact, wildfires or tsunamis,” says co-author Georg Feulner who leads the research team at PIK. It took the climate about 30 years to recover, the scientists found.

In addition to this, ocean circulation became disturbed. Surface waters cooled down, thereby becoming denser and hence heavier. While these cooler water masses sank into the depths, warmer water from deeper ocean layers rose to the surface, carrying nutrients that likely led to massive blooms of algae, the scientists argue. It is conceivable that these algal blooms produced toxic substances, further affecting life at the coasts. Yet in any case, marine ecosystems were severely shaken up, and this likely contributed to the extinction of species in the oceans, like the ammonites.

“It illustrates how important the climate is for all lifeforms on our planet”

The dinosaurs, until then the masters of Earth, made space for the rise of the mammals, and eventually humankind. The study of Earth’s past also shows that efforts to study future threats by asteroids have more than just academic interest. “It is fascinating to see how evolution is partly driven by an accident like an asteroid’s impact — mass extinctions show that life on Earth is vulnerable,” says Feulner. “It also illustrates how important the climate is for all lifeforms on our planet. Ironically today, the most immediate threat is not from natural cooling but from human-made global warming.”

Citation:Potsdam Institute for Climate Impact Research (PIK). “How the darkness and the cold killed the dinosaurs.” ScienceDaily. ScienceDaily, 13 January 2017. www.sciencedaily.com/releases/2017/01/170113133043.htm.

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