WFS

Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

Aegirocassis benmoulae : A Giant paleo sea creature

March 13th, 2015

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Newly discovered fossils of a giant, extinct sea creature show it had modified legs, gills on its back, and a filter system for feeding — providing key evidence about the early evolution of arthropods.

The new animal, named Aegirocassis benmoulae in honor of its discoverer, Mohamed Ben Moula, attained a size of at least seven feet, ranking it among the biggest arthropods that ever lived. It was found in southeastern Morocco and dates back some 480 million years.

“Aegirocassis is a truly remarkable looking creature,” said Yale University paleontologist Derek Briggs, co-author of a Nature paper describing the animal. “We were excited to discover that it shows features that have not been observed in older Cambrian anomalocaridids — not one but two sets of swimming flaps along the trunk, representing a stage in the evolution of the two-branched limb, characteristic of modern arthropods such as shrimps.”

Briggs is the G. Evelyn Hutchinson Professor of Geology and Geophysics at Yale and curator of invertebrate paleontology at the Yale Peabody Museum of Natural History. First author Peter Van Roy, an associate research scientist at Yale, led the research; Allison Daley of the University of Oxford is co-author.

Since their first appearance in the fossil record 530 million years ago, arthropods have been the most species-rich and morphologically diverse animal group on Earth. They include such familiar creatures as horseshoe crabs, scorpions, spiders, lobsters, butterflies, ants, and beetles. Their success is due in large part to the way their bodies are constructed: They have a hard exoskeleton that is molted during growth, and their bodies and legs are made up of multiple segments. Each segment can be modified separately for different purposes, allowing arthropods to adapt to every environment and mode of life.

Artist’s rendering of Aegirocassis benmoulae. (Screenshot from video available at: https://www.youtube.com/watch?v=6KoqAA-RRnc)
Credit: Reconstruction by Marianne Collins, ArtofFact / Video from Yale Peabody Museum of Natural History

Modern arthropod legs, in their most basic form, have two branches. Each is highly modified to cater to a specific function on that leg, such as locomotion, sensing its surroundings, respiration, or copulation; or it has been lost altogether. Understanding how these double-branched limbs evolved has been a major question for scientists.

A long-extinct group of arthropods, the anomalocaridids, is considered central to the answer. The youngest known anomalocaridids are 480 million years old, and all of them looked quite alien: They had a head with a pair of grasping appendages and a circular mouth surrounded by toothed plates. Their elongate, segmented bodies carried lateral flaps that they used for swimming. Until now, it was believed that anomalocaridids had only one set of flaps per trunk segment, and that they may have lost their walking legs completely.

But the recent discovery of Aegirocassis benmoulae tells another story. The new animal shows that anomalocaridids in fact had two separate sets of flaps per segment. The upper flaps were equivalent to the upper limb branch of modern arthropods, while the lower flaps represent modified walking limbs, adapted for swimming. Furthermore, a re-examination of older anomalocaridids showed that these flaps also were present in other species, but had been overlooked. These findings show that anomalocaridids represent a stage before the fusion of the upper and lower branches into the double-branched limb of modern arthopods.

“It was while cleaning the fossil that I noticed the second, dorsal set of flaps,” said Van Roy, who spent hundreds of hours working on the specimens. “It’s fair to say I was in shock at the discovery, and its implications. It once and for all resolves the debate on where anomalocaridids belong in the arthropod tree, and clears up one of the most problematic aspects of their anatomy.”

Aegirocassis benmoulae is also remarkable from an ecological standpoint, note the researchers. While almost all other anomalocaridids were active predators that grabbed their prey with their spiny head limbs, the Moroccan fossil has head appendages that are modified into an intricate filter-feeding apparatus. This means that the animal could harvest plankton from the oceans.

“Giant filter-feeding sharks and whales arose at the time of a major plankton radiation, and Aegirocassis represents a much, much older example of this — apparently overarching — trend,” Van Roy said.

Reference:

Peter Van Roy, Allison C. Daley, Derek E. G. Briggs. Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps. Nature, 2015; DOI: 10.1038/nature14256 & Yale University. “Giant sea creature hints at early arthropod evolution.” ScienceDaily. ScienceDaily, 12 March 2015. <www.sciencedaily.com/releases/2015/03/150312083651.htm>.

Pockmarks :Linking Geology and Microbiology

March 8th, 2015

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Linking Geology and Microbiology: Inactive Pockmarks Affect Sediment Microbial Community Structure

Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor specialized microbial communities that proliferate on the seeping compounds. Such communities are not found in inactive pockmarks. Interestingly, inactive pockmarks are known to have different macrofaunal communities compared to the surrounding sediments. It is undetermined what the microbial composition of inactive pockmarks is and if it shows a similar pattern as the macrofauna. The Norwegian Oslofjord contains many inactive pockmarks and they are well suited to study the influence of these geological features on the microbial community in the sediment. Here we present a detailed analysis of the microbial communities found in three inactive pockmarks and two control samples at two core depth intervals. The communities were analyzed using high-throughput amplicon sequencing of the 16S rRNA V3 region. Microbial communities of surface pockmark sediments were indistinguishable from communities found in the surrounding seabed. In contrast, pockmark communities at 40 cm sediment depth had a significantly different community structure from normal sediments at the same depth. Statistical analysis of chemical variables indicated significant differences in the concentrations of total carbon and non-particulate organic carbon between 40 cm pockmarks and reference sample sediments. We discuss these results in comparison with the taxonomic classification of the OTUs identified in our samples. Our results indicate that microbial communities at the sediment surface are affected by the water column, while the deeper (40 cm) sediment communities are affected by local conditions within the sediment.

Bathymetric map of the sampling area in the Oslofjord.
The red crosses indicate the sampling sites and the sampling site designation is given. The map was generated with the www.mareano.no website.
doi:10.1371/journal.pone.0085990.g001

Citation: Haverkamp THA, Hammer Ø, Jakobsen KS (2014) Linking Geology and Microbiology: Inactive Pockmarks Affect Sediment Microbial Community Structure. PLoS ONE 9(1): e85990. doi:10.1371/journal.pone.0085990

Editor: Hauke Smidt, Wageningen University, Netherlands

Foraminifera reveal ancient temperatures

March 7th, 2015

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New research in Nature Communications showing how tiny creatures drifted across the ocean before falling to the seafloor and being fossilised has the potential to improve our understanding of past climates.

The research published in Nature Communications has identified which planktic foraminifera gathered up in core samples from the ocean floor, drifted thousands of kilometres and which species barely moved at all.The research will help scientists to more accurate distinguish which fossils most accurately reflect ocean and temperature states in the location where they were found.

This is a microscopic photo of the foraminifer Globigerinoides ruber, which is used in this study.
Credit: Frank J.C. Peeters, VU University Amsterdam

“This research will help scientists improve the study of past climates because they will be able to look at a species of foraminifera and the core location to very quickly get a sense of how site-specific that particular proxy measure is,” said Dr Van Sebille, lead-author of the study and a climate scientist at the ARC Centre of Excellence for Climate System Science at UNSW Australia.

“In a way it will give us a good indication of whether the creature we are looking at to get our past-temperature estimates was a bit of a globetrotter or a stay at home type.”

For many decades, deriving past temperatures from the shells of creatures living tens of thousands of years ago has been key to understanding climates of the past.However, interpreting the records has never been easy. This is the reason that many studies have very large margins of error when they use ocean sediments as a way of establishing past temperatures. It also explains why there is a greater focus on the trend of these results over the actual temperature.

“The older the proxy, the wider the margin of error. This is because ocean currents can change, tectonic plates move and there is even variation in which level of the ocean various plankton can be found,” said Dr Scussolini, a contributing author and climate scientist at VU University, Amsterdam.

“This research allows us for the first time to grasp the margins of error caused by drift and also opens an entirely new dimension for the interpretation of the deep-sea climate data.”

The international team used state-of-the-art computer models and analysis on fossil shells to investigate the impact of oceanic drift. In extreme cases the variation in temperature between where the fossilised shell was found and where it came from could be up to 3°C.In other cases for specific plankton and in areas of the ocean where currents were particularly slow, the variation in temperature was negligible.

As a result, the team is now working on creating a tool, so fellow researchers can easily estimate how large the impact of drift for the location is likely to be. This tool will also be extended to other species of plankton.

“Our results highlight the importance of the ocean currents in transporting anything that floats,” said Dr Van Sebille.

“By picking apart this variation we can add another level of certainty to estimates of past temperatures, opening a door that may help us discover what future climate change may bring to our planet.”

Plants survive better through mass extinctions than animals

March 5th, 2015

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At least 5 mass extinction events have profoundly changed the history of life on Earth. But a new study led by researchers at the University of Gothenburg shows that plants have been very resilient to those events.

For over 400 million years, plants have played an essential role in almost all terrestrial environments and covered most of the world’s surface. During this long history, many smaller and a few major periods of extinction severely affected Earth’s ecosystems and its biodiversity.

In the upcoming issue of the journal New Phytologist, the team reports their results based on more than 20,000 plant fossils with the aim to understand the effects of such dramatic events on plant diversity. Their findings show that mass extinction events had very different impacts among plant groups. Negative rates of diversification in plants (meaning that more species died out than new species were formed) were never sustained through long time periods. This indicates that, in general, plants have been particularly good at surviving and recovering through tough periods.

“In the plant kingdom, mass extinction events can be seen as opportunities for turnover leading to renewed biodiversity,” says leading author Daniele Silvestro.

Most striking were the results for the Cretaceous-Paleogene mass extinction, caused by the impact of an asteroid off the Mexican coast some 66 million years ago. This event had a great impact on the configuration of terrestrial habitats and led to the extinction of all dinosaurs except birds, but surprisingly it had only limited effects on plant diversity.

history of forests

Some important plant groups, such as the gymnosperms (including pines, spruce and firs) lost a great deal of their diversity through extinction. On the other hand, flowering plants (angiosperms) did not suffer from increased extinction, and shortly after the impact they underwent a new rapid increase in their diversity. These evolutionary dynamics contributed to make flowering plants dominate today’s global diversity above all other plant groups.

“Mass extinctions are often thought as a bad thing, but they have been crucial in changing the world into how we know it today,” says senior author Alexandre Antonelli.

If that asteroid had not struck the Earth, chances are that large dinosaurs would still be hunting around, mammals would be small and hiding in caves, and humans might never have evolved.

“By studying such extreme events we are trying to learn which groups of organisms and features are more sensitive to changes, so that we can apply this knowledge to protect biodiversity in the face of on-going climate change and human deterioration of natural ecosystems,” concludes Antonelli.

Courtesy: University of Gothenburg. “Plants survive better through mass extinctions than animals.” ScienceDaily. ScienceDaily, 17 February 2015. <www.sciencedaily.com/releases/2015/02/150217083934.htm>.

Penn-Dixie events in March 2015

March 4th, 2015

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March 14, 2015 –8:30 AM,

Penn Dixie Volunteer Training Program

in the auditorium of the GatewayExecutive office, 3556 Lake Shore Road, Blasdell. Call (716) 627-4560 to make reservation.

$30/person, Penn Dixie members are FREE.

March 14, 2015 9 AM-2PM,

Penn Dixie presentations at 10thAnniversary of Tech Savvy girls STEM Program

March 18, 2015–7 PM,

“Four Worlds, One Country: A Look into the Diverse Treasures of Ecuador,” by Abby LaPlaca, University of Buffalo, an illustrated presentation in the auditorium of the Gateway Executive Office 3556 Lake Shore Rd., Blasdell, NY.

$5/person, Penn Dixie members FREE. No pre-registrations required.

March 21-22, 2015

Penn Dixie exhibit at the Buffalo Geological Society’s Annual Gem-Mineral-Fossil Show in the Grange and Market Building at the Erie County Fair Grounds.

March 27, 2015–1-8 PM,

Penn Dixie exhibit at Hamburg Chamber of Commerce Trade Fair in the Grange Building at Erie County Fairgrounds.

March 27, 2015–6-8 PM,

Penn Dixie exhibit with fossil dig, program info, and telescopes at Union Pleasant Elementary School, Hamburg, NY.

March 28, 2015–9 AM-2 PM,

Penn Dixie exhibit at Town of Evans Environmental Day at Evans FireDept.

March 28-April 4 & April 6-12, 2015–

Penn Dixie Open during Spring Break,

Mon-Sat, 9 AM–5 PM & Sunday, 10 AM–5 PM,

Adults $9 and children 12 & under $7, children 2 and under & Penn Dixie members FREE.

March 28, 2015–7:30 PM,

Astronomy Night at Penn Dixie Site. Telescopes will be available to viewplanets and constellations. Dress for the weather. No pre

-registrations required.

$4/person, Penn Dixie Members FREE.

March 30,2015–1 PM,

Spring into Nature Program “Become a Wetland Detective” for children and adults.

Pre-registration required. $10/person, $8 per Penn Dixie member, Special Family discount $25

for families of 4. Visitwww.penndixie.org

for information or call (716) 627-4560 for information and/or to register.

March 31,2015–1 PM,

Spring Into Nature Program “Who Pooped at Penn Dixie ?,”for children and adults. Pre-registration required. $10/person, $8 per Penn Dixie member, Special Family discount $25 for families of 4. Visit www.penndixie.org for information or call (716) 627-4560 for information and/or to register.

How were fossil tracks so well preserved?

March 1st, 2015

Riffin

A type of vertebrate trace fossil gaining recognition in the field of paleontology is that made by various tetrapods (four-footed land-living vertebrates) as they traveled through water under buoyant or semibuoyant conditions.

Called fossil “swim tracks,” they occur in high numbers in deposits from the Early Triassic, the Triassic being a geologic period (250 to 200 million years ago) that lies between the Permian and Jurassic. Major extinction events mark the start and end of the Triassic.

While it is known that tetrapods made the tracks, what is less clear is just why the tracks are so abundant and well preserved. Paleontologists at the University of California, Riverside have now determined that a unique combination of factors in Early Triassic delta systems resulted in the production and unusually widespread preservation of the swim tracks: delayed ecologic recovery, depositional environments, and tetrapod swimming behavior.

“Given their great abundance in Lower Triassic strata, swim tracks have the potential to provide a wealth of information regarding environmental exploitation by reptiles during this critical time in their evolution following the end-Permian mass extinction,” said Mary L. Droser, a professor of paleontology in the Department of Earth Sciences, who led the research. “They also provide important data for our interpretation of Early Triassic sedimentological and stratigraphic processes. The Early Triassic period follows the largest mass extinction event in Earth’s history. The fossil record shows that a prolonged period of delayed ecologic recovery persisted throughout the Early Triassic.”

She explained that the fossil swim tracks are important and unique records of the aquatic behaviors and locomotion mechanics of tetrapods, and reveal a hidden biodiversity. They also constitute an excellent natural laboratory for investigating the paleoenvironmental and paleoecological conditions associated with their production and preservation.

Droser and Tracy J. Thomson, her former graduate student, surveyed the temporal distribution of the swim tracks seen in fossils in Utah, and report online this month, ahead of print, in the journal Geology that it is not the tetrapod swimming behavior alone, but the prevalence of unbioturbated substrates resulting from the unique combination of ecological and environmental conditions during the Early Triassic that led to the abundant production and preservation of swim tracks.They identify three interacting factors that composed a “Goldilocks” effect in promoting the production and preservation of Lower Triassic swim tracks. These factors were (1) ecological, i.e., delayed ecologic recovery resulting in the lack of well-mixed sediment, (2) paleoenvironmental, i.e., depositional environments that promoted the production of firmground substrates, and (3) behavioral, i.e., the presence of tetrapods capable of aquatic locomotion such as swimming or bottom walking.

Tracy J. Thomson stands next to a block with numerous swim tracks in Capitol Reef National Park, Utah.
Credit: Tracy Thomson.

“During the Early Triassic, sediment mixing by animals living within the substrate was minimal,” said Thomson, the first author of the research paper who is now pursuing a doctoral degree at UC Davis. “This strongly contributed to the widespread production of firm-ground substrates that are ideal for recording and preserving trace fossils like swim tracks.”

Thomson explained that the end-Permian mass extinction event resulted in ecologic restructuring of both the marine and terrestrial realms. Bioturbation was suppressed, resulting in no extensively mixed sediment layer, thereby allowing fine-grained, low-water-content firmgrounds to develop near the sediment-water interface.

“Early Triassic deltas and their paleoenvironments were favorable habitats for functionally amphibious reptiles,” Droser said. “There were few animals living in the sediment mixing it up after the extinction, and so the muds became firm and cohesive providing ideal conditions for preservation. Periodic flooding supplied coarser grained material, enhancing swim track preservation.”

Citation: University of California – Riverside. “How were fossil tracks made by Early Triassic swimming reptiles so well preserved?.” ScienceDaily. ScienceDaily, 27 February 2015. <www.sciencedaily.com/releases/2015/02/150227131008.htm>.

Kenyan fossils show evolution of hippos

February 26th, 2015

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A French-Kenyan research team has just described a new fossil ancestor of today’s hippo family. This discovery bridges a gap in the fossil record separating these animals from their closest modern-day cousins, the cetaceans. It also shows that some 35 million years ago, the ancestors of hippos were among the first large mammals to colonize the African continent, long before those of any of the large carnivores, giraffes or bovines. This work, co-signed by researchers of the Institut des sciences de l’évolution de Montpellier (CNRS/Université de Montpellier/IRD/EPHE) and Institut de paléoprimatologie et paléontologie humaine : évolution et paléo-environnements (CNRS/Université de Poitiers) is published in the journal Nature Communications.

The ancestry of hippopotamuses is somewhat of an enigma. For a long time, paleontologists thought these semi-aquatic animals, with their unusual morphology (canines and incisors with continual growth, primitive skull and trifoliate tooth-wear pattern), to be related to the Suidae family, which includes pigs and peccaries. But in the 1990s and 2000s, DNA comparisons showed that the hippo’s closest living relatives were the cetaceans (whales, dolphins, etc.), which disagreed with most paleontological interpretations. Moreover, the lack of fossils significantly hindered attempts to uncover the truth about hippo evolution.

Right, a hemi mandible of Epirigenys lokonensis with premolars 3 and 4 and molars 1 and 2. Compared with, to the left, a hemi mandible from a hippopotamid fossil.
Credit: © LPRP/J.-R. Boisserie

New paleontological work by a group of French and Kenyan researchers has now revealed that hippos are not related to suoids but instead descend from another, now extinct, group. The new fossils studied have made it possible to build the first evolutionary scenario that is compatible with both genetic and paleontological data. By analyzing a half-jaw and several teeth discovered at Lokone (in the Lake Turkana basin, Kenya), the French-Kenyan team described a new fossil species (belonging to a new genus (2)), dating back to about 28 million years. They named it Epirigenys lokonensis, from the word “Epiri” which means hippo in the Turkana language and the site of discovery, Lokone.

By comparing the characteristics of fossil teeth with those of ruminants, suoids, hippos and fossil anthracotheres (an extinct family of ungulates), the scientists reconstructed the relationships between these groups. The results show that Epirigenys forms a kind of evolutionary transition between the oldest known hippo in the fossil record (about 20 million years ago) and an anthracothere lineage. This position in the tree of life is compatible with the genetic data, confirming that the cetaceans are the hippos’ closest living cousins.

This kind of discovery may one day enable scientists to draw a picture of the common ancestor of cetaceans and hippos. Indeed, analysis of Epirigenys (28 million years old) has linked today’s hippos to a lineage of anthracotheres, the oldest of which date back about 40 million years. However, until now, the earliest known ancestor of the hippos was about 20 million years old, while the first fossils of cetaceans are 53 million years old. The time gap between today’s hippos and the oldest cetaceans is thereby filled by nearly 75% according to the present scenario.

Furthermore, this discovery shows the whole history of the African fauna in a new light. Africa was an isolated continent from about 110 to 18 million years ago. Most of the iconic African fauna (lions, leopards, rhinos, buffaloes, giraffes, zebras, etc.) are relatively recent arrivals on the continent (they have been there less than 20 million years). Until now, the same was believed to be true of hippos, but the discovery of Epirigenys demonstrates that their anthracothere ancestors migrated from Asia to Africa some 35 million years ago.

Source: Fabrice Lihoreau, Jean-Renaud Boisserie, Fredrick Kyalo Manthi, Stéphane Ducrocq. Hippos stem from the longest sequence of terrestrial cetartiodactyl evolution in Africa. Nature Communications, 2015; 6: 6264 DOI: 10.1038/ncomms7264

Were dinosaurs destined to be big? Testing Cope’s rule

February 24th, 2015

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In the evolutionary long run, small critters tend to evolve into bigger beasts — at least according to the idea attributed to paleontologist Edward Cope, now known as Cope’s Rule. Using the latest advanced statistical modeling methods, a new test of this rule as it applies dinosaurs shows that Cope was right — sometimes.

“For a long time, dinosaurs were thought to be the example of Cope’s Rule,” says Gene Hunt, curator in the Department of Paleobiology at the National Museum of Natural History (NMNH) in Washington, D.C. Other groups, particularly mammals, also provide plenty of classic examples of the rule, Hunt says.

To see if Cope’s rule really applies to dinosaurs, Hunt and colleagues Richard FitzJohn of the University of British Columbia and Matthew Carrano of the NMNH used dinosaur thigh bones (aka femurs) as proxies for animal size. They then used that femur data in their statistical model to look for two things: directional trends in size over time and whether there were any detectable upper limits for body size.

In the evolutionary long run, small critters tend to evolve into bigger beasts — at least according to the idea attributed to paleontologist Edward Cope, now known as Cope’s Rule. Using the latest advanced statistical modeling methods, a new test of this rule as it applies dinosaurs shows that Cope was right — sometimes.
Credit: © Derrick Neill / Fotolia

“What we did then was explore how constant a rule is this Cope’s Rule trend within dinosaurs,” said Hunt. They looked across the “family tree” of dinosaurs and found that some groups, or clades, of dinosaurs do indeed trend larger over time, following Cope’s Rule. Ceratopsids and hadrosaurs, for instance, show more increases in size than decreases over time, according to Hunt. Although birds evolved from theropod dinosaurs, the team excluded them from the study because of the evolutionary pressure birds faced to lighten up and get smaller so they could fly better.

As for the upper limits to size, the results were sometimes yes, sometimes no. The four-legged sauropods (i.e., long-necked, small-headed herbivores) and ornithopod (i.e., iguanodons, ceratopsids) clades showed no indication of upper limits to how large they could evolve. And indeed, these groups contain the largest land animals that ever lived.

Theropods, which include the famous Tyrannosaurus rex, on the other hand, did show what appears to be an upper limit on body size. This may not be particularly surprising, says Hunt, because theropods were bipedal, and there are physical limits to how massive you can get while still being able to move around on two legs.

Hunt, FitzJohn, and Carrano will be presenting the results of their study on Nov. 4, at the annual meeting of The Geological Society of America in Charlotte, North Carolina, USA.

As for why Cope’s Rule works at all, that is not very well understood, says Hunt. “It does happen sometimes, but not always,” he added. The traditional idea that somehow “bigger is better” because a bigger animal is less likely to be preyed upon is naïve, Hunt says. After all, even the biggest animals start out small enough to be preyed upon and spend a long, vulnerable, time getting gigantic.

Abstract: https://gsa.confex.com/gsa/2012AM/webprogram/Paper211594.html

Source: Geological Society of America. “Were dinosaurs destined to be big? Testing Cope’s rule.” ScienceDaily. ScienceDaily, 2 November 2012. <www.sciencedaily.com/releases/2012/11/121102151954.htm>.

Eonatator coellensis: New marine fossil from Columbia

February 20th, 2015

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A nearly complete fossil of a prehistoric marine reptile with preserved soft tissue has been found in central-western Colombia, at a spot several hundred miles from the Caribbean coast, a university in this capital said.

Experts have given the reptile the name “Eonatator coellensis” because the find was made in a dry stream bed in Coello, a town in Tolima province, the National University of Colombia’s news agency said Tuesday.Professor Luis Enrique Calderon and his son Ricardo discovered the fossil in rocks dating back 80 million years, during the Cretaceous period (145-66 million years ago), and informed the Colombian Geological Service.

Eonatator coellensis

The animal was a mosasaurus with a full body length of 2.8 meters (9.1 feet) and a head length of 41.5 centimeters (16 inches), according to experts from that institution, which said it was a member of the genus Eonatator.

Colombian paleontologist Maria Paramo, a National University professor who is heading up the investigation, discovered that the remains have a cream-pink coloration and have been almost entirely preserved with the exception of the tail.Her findings include 15 of the reptile’s teeth, its thoracic wall and part of its vertebral column.Based on the quantity, morphology and length of the preserved vertebrae, she estimates that the length of the animal’s tail was similar to that of the rest of its body.The soft tissue remains are located in the lungs and the pancreas, as well as the muscle fibers that extend to the ribs.

“One thing that troubled us was why the skin wasn’t preserved if what was inside was preserved,” the researcher said.

“From the geological characteristics, it’s apparent that it didn’t go frequently into the open sea, but rather stayed closer to the coast,” Paramo said.

“The anatomical shape of its front and hind limbs indicate it could have gone a little away from the mainland,” the paleontologist added.

Courtesy: Fox News

Life Possible On Earth 3.2 Billion Years Ago

February 17th, 2015

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A spark from a lightning bolt, interstellar dust, or a subsea volcano could have triggered the very first life on Earth. But what happened next? Life can exist without oxygen, but without plentiful nitrogen to build genes — essential to viruses, bacteria and all other organisms — life on the early Earth would have been scarce.

The ability to use atmospheric nitrogen to support more widespread life was thought to have appeared roughly 2 billion years ago. Now research from the University of Washington looking at some of the planet’s oldest rocks finds evidence that 3.2 billion years ago, life was already pulling nitrogen out of the air and converting it into a form that could support larger communities.

“People always had the idea that the really ancient biosphere was just tenuously clinging on to this inhospitable planet, and it wasn’t until the emergence of nitrogen fixation that suddenly the biosphere become large and robust and diverse,” said co-author Roger Buick, a UW professor of Earth and space sciences. “Our work shows that there was no nitrogen crisis on the early Earth, and therefore it could have supported a fairly large and diverse biosphere.”

The results were published Feb. 16 in Nature.

The authors analyzed 52 samples ranging in age from 2.75 to 3.2 billion years old, collected in South Africa and northwestern Australia. These are some of the oldest and best-preserved rocks on the planet. The rocks were formed from sediment deposited on continental margins, so are free of chemical irregularities that would occur near a subsea volcano. They also formed before the atmosphere gained oxygen, roughly 2.3 to 2.4 billion years ago, and so preserve chemical clues that have disappeared in modern rocks.

The oldest samples are sedimentary rocks that formed 3.2 billion years ago in northwestern Australia. They contain chemical evidence for nitrogen fixation by microbes.
Credit: R. Buick / UW

Even the oldest samples, 3.2 billion years old — three-quarters of the way back to the birth of the planet — showed chemical evidence that life was pulling nitrogen out of the air. The ratio of heavier to lighter nitrogen atoms fits the pattern of nitrogen-fixing enzymes contained in single-celled organisms, and does not match any chemical reactions that occur in the absence of life.

“Imagining that this really complicated process is so old, and has operated in the same way for 3.2 billion years, I think is fascinating,” said lead author Eva Stüeken, who did the work as part of her UW doctoral research. “It suggests that these really complicated enzymes apparently formed really early, so maybe it’s not so difficult for these enzymes to evolve.”

Genetic analysis of nitrogen-fixing enzymes have placed their origin at between 1.5 and 2.2 billion years ago.

“This is hard evidence that pushes it back a further billion years,” Buick said. Fixing nitrogen means breaking a tenacious triple bond that holds nitrogen atoms in pairs in the atmosphere and joining a single nitrogen to a molecule that is easier for living things to use. The chemical signature of the rocks suggests that nitrogen was being broken by an enzyme based on molybdenum, the most common of the three types of nitrogen-fixing enzymes that exist now. Molybdenum is now abundant because oxygen reacts with rocks to wash it into the ocean, but its source on the ancient Earth — before the atmosphere contained oxygen to weather rocks — is more mysterious.

The authors hypothesize that this may be further evidence that some early life may have existed in single-celled layers on land, exhaling small amounts of oxygen that reacted with the rock to release molybdenum to the water.

“We’ll never find any direct evidence of land scum one cell thick, but this might be giving us indirect evidence that the land was inhabited,” Buick said. “Microbes could have crawled out of the ocean and lived in a slime layer on the rocks on land, even before 3.2 billion years ago.”

Future work will look at what else could have limited the growth of life on the early Earth. Stüeken has begun a UW postdoctoral position funded by NASA to look at trace metals such as zinc, copper and cobalt to see if one of them controlled the growth of ancient life.

Source: Eva E. Stüeken, Roger Buick, Bradley M. Guy, Matthew C. Koehler. Isotopic evidence for biological nitrogen fixation by molybdenum-nitrogenase from 3.2 Gyr. Nature, 2015; DOI: 10.1038/nature14180