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

Research: Ichthyosaur Survival across the Jurassic–Cretaceous Boundary

September 13th, 2012

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Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood.

icthyosaur

Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval.

skull of icthyosaur

The thunnosaurian ichthyosaur Ophthalmosaurus Seeley 1874 (family Ophthalmosauridae) is known from abundant material, most of it from the Oxford and Kimmeridge Clay formations of England and the Sundance Formation of the USA . The widely accepted stratigraphic range for this taxon is Callovian-Tithonian . However, the presence of Ophthalmosaurus in Lower Cretaceous sediments has been claimed twice in the modern literature: McGowan figured and discussed a humerus with three large distal facets from the Lower Cretaceous of Prince Patrick Island (Canada) that he referred toOphthalmosaurus sp. and McGowan & Motani mentioned the presence of isolated basioccipitals and humeri referable to Ophthalmosaurus in the early Cenomanian Cambridge Greensand Formation (which also includes a reworked late Albian fauna from the top of the Gault formation . These claims are, however, based on isolated material, and other ophthalmosaurid ichthyosaurs with three large distal humeral facets have been described from Cretaceous sediments since then, including Caypullisaurus and Maiaspondylus . Therefore, the presence of Ophthalmosaurus in the Cretaceous remains ambiguous at best. This has important consequences for the evolution and diversity of Early Cretaceous ophthalmosaurids. Indeed, until recently , all Middle and Late Jurassic ichthyosaurs were thought to have become extinct at the end of the Jurassic, at the Jurassic–Cretaceous boundary or during a more protracted extinction event that started during the Middle Jurassic . The JCB, which is associated with climate change , was therefore considered a major extinction event for ichthyosaurs, during which the successful “ophthalmosaurs” became extinct and replaced by what seemed to be less specialized forms. As summarized by Bakker

“The Jurassic-Cretaceous boundary extinction disrupted ichthyosaur history profoundly – the hyper-specialized ophthalmosaur clade disappears, and the only Early Cretaceous ichthyosaurs, the platypterygians, are much more generalized, with longer bodies, smaller eyes, larger teeth and heavier snouts.”

Basicranium, quadrate, and dentition of Acamptonectes densus

This contributed to the generally accepted idea that, despite their longevity (Olenekian, Early Triassic–Cenomanian, Late Cretaceous , ichthyosaurs underwent at least three major extinctions events throughout their history: during the Triassic–Jurassic boundary event , at the Jurassic–Cretaceous boundary (JCB), and during the Cenomanian–Turonian boundary event . However, the worldwide record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, making preservation biases an important parameter to consider when analyzing the Jurassic–Cretaceous extinction event . Yet, recent papers have highlighted the presence of some Late Jurassic ichthyosaurs in the Lower Cretaceous strata of South America, Europe, and Russia (Caypullisaurus , Aegirosaurus and the doubtful Yasykovia , respectively). The effect of the JCB extinction event on ichthyosaurs therefore remains poorly understood, whereas this extinction substantially affected several other groups related to the marine realm such as radiolarians, ammonites, marine crocodyliforms, pterosaurs, and plesiosaurs .

In order to examine the effect of the JCB extinction event on ichthyosaurs in detail and better understand the diversity and relationships of Early Cretaceous ophthalmosaurids, we:

Re-evaluate the presence of Ophthalmosaurus in the Cretaceous of Europe
Name a new Cretaceous ophthalmosaurid, Acamptonectes densus gen. et sp. nov., based on three well preserved specimens for a poorly sampled stage of the Early Cretaceous: the Hauterivian. This genus is also present in the Cambridge Greensand Formation (late Albian–early Cenomanian).
Propose a robust phylogenetic hypothesis for the evolution of ophthalmosaurids, which diverged early in its history into two clades: Ophthalmosaurinae and Platypterygiinae. Both clades crossed the JCB and persisted to the late Albian at least
Calculate cladogenesis, extinction, and survival rates for the Oxfordian–Aptian interval and show that the JCB event had a negligible impact on ichthyosaurs

Published in PLos One.

Valentin Fischer¹^,²^*, Michael W. Maisch^¤a, Darren Naish³^,⁴,Ralf Kosma⁵, Jeff Liston⁶^¤b, Ulrich Joger⁵, Fritz J. Krüger⁵,Judith Pardo Pérez⁷, Jessica Tainsh⁶, Robert M. Appleby^†

1 Geology department, University of Liège, Liège, Belgium, 2 Paleontology Department, Royal Belgian Institute of Natural Sciences, Brussels, Belgium,3 School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth, United Kingdom, 4 School of Ocean and Earth Sciences, University of Southampton, Southampton, United Kingdom, 5 Staatliches Naturhistorisches Museum, Braunschweig, Germany, 6 Division of Environmental and Evolutionary Biology, School of Life Sciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, 7 Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany

World’s Smallest Fossil Footprints: Small Amphibian Roamed Earth 315 Million Years Ago

September 12th, 2012

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A new set of fossil footprints discovered in Joggins, Nova Scotia, near Amherst, have been identified as the world’s smallest known fossil vertebrate footprints.

The footprints were found at the UNESCO World Heritage Site, the Joggins Fossil Cliffs. A fossil specimen of the ichnogenusBatrachichnus salamandroides was collected by local amateur paleontologist Gloria Melanson, daughter of Don Reid, the famed Keeper of the Joggins Cliffs, while walking the Joggins beach.

Smallest trackway.

“This was one of the most exciting finds I have ever made and I am very pleased that, along with my colleagues, we are able to share it with the world. Every big fossil find is by chance; it’s all about being lucky and recognizing what you’re looking at. When I saw the very small tail and toes I knew we had something special. I never thought it would be the world’s smallest,” said Melanson.

The footprints belonged to a small amphibian which would have roamed Earth 315 million years ago, a creature not unlike a salamander.

The fossil record at Joggins is most famous for its diverse skeletal record of small tetrapods, dominated by an array of small, primitive amphibians (temnospondyls and microsaurs), and the oldest known reptile, Hylonomus lyelli, entombed within once-hollow fossil tree stumps.

Small trackways of these animals at Joggins are common, but none so small as the one discovered recently. The 48-mm-long trackway preserves approximately 30 footprints with the front feet measuring 1.6 mm long and back feet measuring 2.4 mm long. Study of the footprints by paleontologists at Saint Mary’s University (student Matt Stimson) and the New Mexico Museum of Natural History (Dr. Spencer Lucas) has revealed the trace maker was a juvenile amphibian, similar to a salamander (temnospondyl or microsaur) with an estimated body length of only 8 mm from snout to tail.

Further examination shows the animal began in a walk and later changed direction as it began to run. Speculation could be made that these are some of the juvenile’s first footsteps on land after transforming from a tadpole stage that hatched in a local pond. The change in direction and speed may be interpreted as the animal either becoming startled by a larger predator, or perhaps while hunting some small insects, itself.

Melanson’s fossil is on display at the Joggins Fossil Centre at the UNESCO World Heritage site, the Joggins Fossil Cliffs. The fossil is described in a paper by Stimson, Lucas and Melanson in the international scientific journal Ichnos on Aug. 27, 2012. The scientific article documents the significance of Melanson’s fossil discovery and the secrets it reveals about ancient juvenile life in the Coal Age 315 million years ago in Nova Scotia.

‘Absolutely amazing’ fossil excavated near Richmond

September 11th, 2012

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Curator at Kronosaurus Korner museum at Richmond says the well-preserved fossil of a baby Ichthyosaur, being excavated and prepared this week, is “absolutely amazing”.

Paul Stumkat says the fossil, discovered last year, is a rare find, “what we’ve got here is probably the most complete baby Ichthyosaur ever found in Australia. This thing is absolutely amazing. It is not in utero, it probably would have been an infant. What is really fantastic, is this thing is almost 99 per cent intact.”

“There’s so much material that’s never been found, so we’ve never had a really good understanding of what’s happening with Ichthyosaurs, because quite often they’ve all broken up, eaten by other animals, and disintegrated when they’ve been preserved. So for a paleontologist to find any complete creature, especially a vertebrate creature, that is really special.”

“Ichthyosaur means ‘fish lizard’. It’s an amazing marine reptile from the early Cretaceous around the Richmond area.”

“What we’re beginning to understand about the inland ocean is the bottom of the ocean was anoxic, there was no oxygen down there in certain areas, and that’s why the animals stay complete, no predators lived down in that layer of the ocean, and that’s why we think we’ve got nice complete specimens in this particular layer.”

“It’s incredibly rare to find an intact articulated specimen, and that’s what’s so wonderful about this. It’s all laid out, basically, as it died.”

Paul Stumkat says the sounds of power tools echo through the dig site this week, “we’ve got these amazing little micro-jackhammer tools that we’re busily trying to discover where all the parts of the body are so when I cut it out I don’t accidently cut through anything important. They chip away at the surface of the limestone block. Pretty soon I’ll be getting my big circular saw out, and doing a number of cuts around the perimeter of the specimen, and then take it back to the museum.”

The remains of another Ichthyosaur lies close by, and Paul Stumkat says plans for a dig are set for next year, “I don’t know if that’s mum or dad over there, who knows!”

The Kronosaurus Korner museum expects the Ichthyosaur to be on public display in Richmond soon.

Strange predatory dinosaur from Europe’s Late Cretaceous

September 10th, 2012

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By describing a new double-clawed and highly-unusual relative of Velociraptor, paleontologists have answered a long-standing question: what did the Late Cretaceous predatory dinosaurs in Europe look like? Balaur bondoc, described this week in Proceedings of the National Academy of Sciences, is the first reasonably complete skeleton of a meat-eating dinosaur from the final 60 million years of the Age of Dinosaurs in Europe and provides insight into an ecosystem very different from that of today. Europe at the end of the Cretaceous was awash in higher seas and was an island archipelago dominated by animals smaller and more primitive than their relatives living on larger landmasses.

Strange Predator

“We’ve all been waiting for something like this, and the wait has yielded an interesting surprise,” says Mark Norell, chair of the Division of Paleontology at the American Museum of Natural History and one of the authors of the research paper describing the fossil. “B. bondoc is heavy, with unexpectedly stocky limbs and fused bones. It shows just how unusual the fauna of the area was during the waning years of the dinosaur era.”

“Balaur might be one of the largest predators in this ecosystem because not even a big tooth has been found in Romania after over a hundred years of research,” says co-author Zoltán Csiki of the University of Bucharest. “Fragmentary remains of Balaur were already known for more than 10 years, but the morphology is so weird we didn’t have any idea where to fit them.”

Balaur bondoc, which means “stocky dragon,” was unearthed in Romania by geologist and co-author Mátyás Vremir of the Transylvanian Museum Society. Higher sea levels at the end of the Cretaceous flooded much of present-day continental Europe, so Romania, which was an island, is now one of the best windows into Europe at the end of the Age of Dinosaurs. Other fossils discovered in these deposits include dwarf sauropods that were the size of cows and tiny duck-billed dinosaurs.

These herbivorous dinosaurs had features not unexpected in island inhabitants: the so-called “island effect” postulates that island dwellers tend to be stranger and smaller than close relatives on continental land masses. Also, animals endemic to islands are often more primitive than their mainland relatives.

The new theropod fossil, the type specimen, is a partial skeleton that includes leg, hip, backbone, arms, hand, rib, and tail bones. But B. bondoc has 20 unique features when compared to its nearest relatives, including a re-evolved functional big toe with a large claw that can be hyperextended, presumably used to slash prey. Because there is also a large claw on the second toe, as is typical of the group of dinosaurs to which B. bondoc belongs, the new species has unusual double-clawed feet. Unique features are also found in other parts of the foot, leg, and pelvis. The feet and legs are short and stocky, with bones fused together, and the pelvis has enormous muscle attachment areas, indicating that this species was adapted for strength over speed. Finally, the hand is atrophied and some of the bones are fused, features that would have made grasping difficult. This, in combination with the leg and foot traits, indicates that the lower limbs rather than hands were used to grasp and disembowel prey.

“Balaur is a new breed of predatory dinosaur, very different from anything we have ever known,” says Stephen Brusatte, a graduate student at Columbia University who is affiliated with the Museum. “Its anatomy shows that it probably hunted in a different way than its less stocky relatives. Compared to Velociraptor, Balaur was probably more of a kickboxer than a sprinter, and it might have been able to take down larger animals than itself, as many carnivores do today.”

“Nevertheless, Balaur is the size of an oversized turkey and unlike what we know of the large predators from other parts of the world at the same time period, like Tyrannosaurus or Carnotaurus,” says Csiki. “As European dinosaur faunas were known to be peculiar, we half-expected to find peculiar predators as well. But, as the first good record of these, Balaur surely exceeds our most daring expectations.”

But while B. bondoc has unique features expected from the “island effect,” its relationship with other dromaeosaurs shows that there was some faunal exchange between the Romanian island that the mainland-at least among the carnivorous dinosaurs.

“Because Balaur is related to dinosaurs like Velociraptor, it indicates that the European island archipelago had a faunal connection with other parts of Europe, Asia and North America where this group of dinosaurs has also been found in similarly aged rocks,” says Norell. “It also shows how pervasive island effects can be in producing truly unusual animals.”

The new fossil is described in the Proceedings of the National Academy of Sciences. The authors include Csiki, Vremir, Brusatte, and Norell. The research was funded in part by the American Museum of Natural History, the National Science Foundation, Columbia University Department of Earth and Environmental Sciences, the Romanian National University Research Council, Richard and Lynn Jaffe.

Note: This story has been adapted from a news release issued by the American Museum of Natural History

Scientists Obtain Rocks Moving Into Seismogenic Zone

September 9th, 2012

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An international group of scientists aboard the Deep-Sea Drilling Vessel CHIKYU, operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) for the Integrated Ocean Drilling Program (IODP), return from a 40-day scientific expedition off the shore of the Kii Peninsula, Japan on Oct. 10, 2009. Expedition 322, called “Subduction Inputs” in the multi-stage project, conducted drilling, logging and sampling beneath the ocean floor to investigate input material that will be transported to the seismogenic zone by the plate subduction system.

The drilling operations were carried out at two sites in the Shikoku Basin, the back-arc basin of the Izu-Bonin volcanic chain where the Philippine Sea Plate dives down into the Nankai Trough at a rate of about 4 cm per year. At the first site C0011, scientists began coring from a depth of 340 meters below the seafloor. The coring, however, had to be abandoned at a depth of 881 meters because of damage of the drill bit. At the second site C0012, coring was carried out from depths 60 meters to 576 meters below the seafloor, and successfully collected the targeted sedimentary and basement rock samples.

Dr. Michael Underwood, professor at University of Missouri, USA, and co-Chief Scientists of the expedition said, “We identified an interface of Miocene sediment and basement rock around 540 meters beneath the seafloor and successfully sampled basaltic pillow lava rocks that make up the basement.” He added “These sedimentary and volcanic rocks in the lower part of Shikoku Basin are key intervals for generating large earthquake slip after they are transported to the seismogenic zone. Studying their petrological, geotechnical, frictional and hydrogeological properties prior to subduction is expected to contribute significantly to the understanding of rupture dynamics in the seismogenic zone.”

The science party included 26 onboard research specialists from international member countries. “Scientists observed, measured and analyzed geological samples by day and night working shifts in the onboard laboratories,” said Dr. Saneatsu Saito from JAMSTEC who led research activities as another co-Chief Scientist. He explained the importance of the variety of data obtained, “The sand-rich volcanic sediments were confirmed in large quantity and may have been transported from the easterly located Izu-Bonin Arc about 5 to 11 million years ago. Other sandstones contain abundant minerals derived from land, implying the extensive supply of sand to the Shikoku Basin from the Japanese islands.” Prof. Underwood added, “Analysis of pore water and hydrocarbon gases retrieved from the sedimentary layers above the basement indicates multiple sources and migration paths of fluids. These results have important implications for understanding the properties of fluids within the seismogenic zone.”

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New World Drilling-Depth Record of Scientific Ocean Drilling

September 9th, 2012

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Scientific deep sea drilling vessel Chikyu sets a world new record by drilling down and obtains rock samples from deeper than 2,111 meters below the seafloor off Shimokita Peninsula of Japan in the northwest Pacific Ocean. The Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the implementing organization for scientific expedition aboard theChikyu, announced this achievement on 6th September, 2012.

deep sea drilling

Chikyu made this achievement during the Deep Coalbed Biosphere expedition, Expedition 337, conducted within the framework of an international marine research program, the Integrated Ocean Drilling Program (IODP). BeforeChikyu broke the record, the previous deepest hole in the history of scientific ocean drilling reached 2,111 meters into the seafloor, 504B at Costa Rica Rift.

“We have just opened a window to the new era of scientific ocean drilling,” Fumio Inagaki, Co-Chief scientist of Expedition 337, says. “The extended record is just a beginning for the Chikyu. This scientific vessel has tremendous potentials to explore very deep realms that humans have never studied before. The deep samples are precious, and I am confident that our challenges will extend our systematic understanding of nature of life and earth.”

His European colleague, Co-Chief scientist Kai-Uwe Hinrichs from the University of Bremen, Germany, adds, “I am very glad that I am here today and could witness this wonderful and important moment. Everybody on the ship worked really hard to make this happen. And, I am very pleased about the high quality of the core samples, which show only minimal drilling disturbance. This is very important for our research.”

Chikyu is the state-of-the-art scientific research vessel, capable of drilling as much as 10,000 m below sea level. It is designed to reach the deeper part of the Earth such as the mantle, the plate boundary seisomogenic zones and the deep biosphere.

Drilling down to 2,200 m below the seafloor and obtaining high-quality samples from the deeply buried coal formation is the main objective of the expedition. An international science party aboard Chikyu has already achieved this aim working jointly with CDEX and operational team.

Samples collected from the target coalbeds have been analyzed in the laboratory aboard Chikyu and will continue to be examined after the expedition. The research will provide new insights into the deep life associated with a hydrocarbon system in the deep marine subsurface.

The expedition that started in late July continues coring operations to obtain even deeper rock samples and formation fluids using a new borehole wire-line instrument in situ.

For another 3 weeks, the science party on Chikyu will continue to explore the deeply buried coal formation, in which microbes may be involved in the formation of natural gas, and to tackle fundamental scientific questions related to the co-evolution of Earth and life.

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Fossil records ‘crab’ death march

September 8th, 2012

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The behaviour of an ancient horseshoe crab in its final moments before death has been captured in the fossil record. A 9.7m-long trackway was created around 150 million years ago when a horseshoe crab fell into a lagoon. The find is of interest because the fossil of the animal itself is present at the end of the trackway, where the animal died.

The behaviour of an ancient horseshoe crab in its final moments before death has been captured in the fossil record.

The research appears in the journal Ichnos. Working out who made a trackway is normally like detective work. In this case, the suspect has been caught in the act” Dr Nic MinterUniversity of Saskatchewan

The fossil trackway of the animal’s last moments – known as a mortichnia, or death march – was discovered in the lithographic limestone of Bavaria in Germany in 2002, where spectacular fossils of the famous feathered dinosaur Archaeopteryx have also been found.

Since then, the fossil trackway had remained an exhibit in the Wyoming Dinosaur Center in the US until Dean Lomax of the Doncaster Museum and Art Gallery and Christopher Racay began working on a project to describe it

“It’s not particularly rare to find these horseshoe crabs at the end of short traces, but nothing quite as substantially large and scientifically important as this,” he said.

The fossil records an entire walk, and the researchers believe that the abrupt beginning of the trace can be explained by the animal being “flung” into the lagoon during a storm, although they cannot be certain of this interpretation.

However, the quality of preservation allowed the researchers to reconstruct very small details of the animal’s end

“The lagoon that the animal found itself in was anoxic, so at the bottom of these lagoons there was no oxygen and nothing was living,” Mr Lomax told the BBC.

“This horseshoe crab [Mesolimulus walchi] found itself on the lagoon floor and we can tell by looking at the trace that the animal righted itself, managed to get on to its feet and began to walk,” he explained.

However, the anoxic conditions of the lagoon floor quickly proved fatal to the arthropod and it soon began to struggle.

“We started to study the specimen closer and saw that the walking patterns and the animal’s behaviour started to change. The leg impressions became deeper and more erratic, the telson (the long spiny tail) started being lifted up and down, up and down, showing that the animal was really being affected by the conditions,” he said.

“To find a trackway and its track-maker preserved together in the fossil record is extremely rare. Working out who made a trackway is normally like detective work. In this case, the suspect has been caught in the act,” Dr Nic Minter, currently of the University of Saskatchewan, Canada, who was not involved in the study, told BBC News.

“Discoveries such as this provide unique insights into the behaviour of extinct species – in this example during the last throes of its life and the environmental conditions that led to its demise,” he said.

minutes.

Darwinopterus: New flying Reptile

September 8th, 2012

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Researchers in China and the UK say they have discovered the fossils of a new type of flying reptile that lived more than 160 million years ago.

The find is named Darwinopterus, after Charles Darwin.

Experts say it provides the first clear evidence of a controversial idea called modular evolution.

The 20 new fossils found in north-east China show similarities to both primitive and more advanced pterosaurs, or flying reptiles.

The research is published in the journal, Proceedings of the Royal Society B.

Missing link

Pterosaurs were flying reptiles that flourished between 65 and 220 million years ago.

Darwinopterus could offer evidence of modular evolution

Until now, scientists had known about two distinct groups of these creatures – primitive, long-tailed pterosaurs and more advanced short-tailed ones, separated by a gap in the fossil record.

But the discovery of more than 20 new fossil skeletons in north-east China sits in the gap in this evolutionary chain.

Darwinopterus is a hawk-like reptile with a head and neck just like advanced pterosaurs – but the rest of the skeleton is similar to more primitive forms.

Researchers say that this could be evidence of what they call modular evolution – where natural selection forces a whole series of traits to change rapidly rather than just one.

“Darwinopterus came as quite a shock to us” said Dr David Unwin, from the University of Leicester, UK.

“We had always expected a gap-filler with typically intermediate features such as a moderately elongate tail – neither long nor short.

“But the strange thing about Darwinopterus is that it has a head and neck just like that of advanced pterosaurs, while the rest of the skeleton, including a very long tail, is identical to that of primitive forms.”

With its long jaws and rows of sharp-pointed teeth, these creatures were very well suited to catching and killing other flying species.

The fossils were found in rocks that are 160 million years old, making them 10 million years older than the first bird, Archaeopteryx.

Dr Unwin collaborated on the study with researchers from the Geological Institute in Beijing, China.

Sinornithosaurus : Bird-like dinosaur was ‘venomous’

September 8th, 2012

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A bird-like dinosaur that prowled an ancient forest 125 million years ago used venom to subdue its prey, according to a new theory.

Sinornithosaurus‘s upper teeth resemble those of “rear-fanged” snakes which bite their prey and channel venom into the wound.The dinosaur probably fed on the abundant birds which inhabited what is now north-east China.The work appears in Proceedings of the National Academy of Sciences journal.

Rear-fanged snakes are considered less dangerous than other venomous snakes.The fangs in these snakes do not inject venom, but instead channel the poison along a groove on the outer surface of teeth that pierce their prey’s flesh.

Skull of Sinornithosaurus

Sinornithosaurus had upper teeth that were similarly long, grooved and fang-like.

David Burnham, from the University of Kansas, US, and colleagues, say the dinosaur’s upper jaw also contained a pocket that could have housed a venom gland. This is connected to the base of the teeth by a long groove.Like rear-fanged snakes, the venom Sinornithosaurus used was probably not lethal. The researchers suggest it instead caused rapid shock, allowing the dinosaur to subdue its prey.

The researchers propose that the length of the dinosaur’s fangs allowed it to penetrate the thick plumage of birds that populated the forests of north-east China during the early Cretaceous period.

Oxygen Theory Of Mass Extinction Questioned By New Research Findings

September 7th, 2012

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Several theories have been proposed by scientists to explain the two mass extinction events which took place on the earth 250 and 200 million years ago.

The Permian-Triassic catastrophe (250 million years ago) was the worst of all five of the mass extinction events to ever have befallen the earth. It eradicated almost 95% of all species, 53% of marine families, 84% of marine genera and an approximated 70% of all land species including plants, insects and vertebrate animals.

Many scientists suspect that the event was the result of a comet or an asteroid colliding with the earth. Others believe that flood volcanism from the Siberian Traps and the associated oxygen loss in the seas was the cause. While others continue to investigate the possibility that thinning levels of atmospheric oxygen caused the eradication of so many species at the time.

But new research findings by University College Dublin scientists published in Science question the theory of falling oxygen levels as a mechanism for causing the mass extinction events.

To assess the likely atmospheric oxygen levels at the time of the mass extinction events, using purposefully designed walk-in-plant-growth rooms equipped with thermal imaging system and full atmospheric, temperature and humidity control, Dr Claire Belcher and her University College Dublin colleagues spent several months measuring the lower limits of oxygen at which combustion can occur.

When the measurements were recorded, they compared their results with the charcoal in the fossil record from ancient times because the charcoal that remains in the fossil record reveals the presence of ancient wildfires which require a sufficient level of oxygen in the air for plants to burn.

“By performing experimental burns using pine wood, moss, matches, paper and a candle at 20°C in varying ranges of oxygen concentrations and comparing these results to the occurrences of fossil charcoal throughout the Mesozoic (250-65 million years ago), we were able to identify that prolonged periods of low oxygen are unlikely to have occurred,” says Dr Claire Belcher from the School of Biology and Environmental Science, University College Dublin, the lead author of the report.

“Low oxygen atmospheres, less than 12%, are considered to be the primary driver of at least two of the ‘big five’ mass-extinction events,” explains Dr Belcher. “But our research findings question that hypothesis and highlight the need for more detailed studies of fossil charcoal across these mass extinction events.”

This is the first time that research to identify the lower limit of atmospheric oxygen under which combustion can occur have been conducted within fully controlled and realistic environments. The six walk-in chambers at University College Dublin, funded by EU Marie Curie, enable the realistic reconstruction of environmental conditions from the past.