The Great London:
Palaeontology

The diversity of mammals on Earth exploded straight after the dinosaur extinction event, according to UCL researchers. New analysis of the fossil record shows that placental mammals, the group that today includes nearly 5000 species including humans, became more varied in anatomy during the Paleocene epoch - the 10 million years immediately following the event.

Senior author, Dr Anjali Goswami (UCL Genetics, Evolution & Environment), said: "When dinosaurs went extinct, a lot of competitors and predators of mammals disappeared, meaning that a great deal of the pressure limiting what mammals could do ecologically was removed. They clearly took advantage of that opportunity, as we can see by their rapid increases in body size and ecological diversity. Mammals evolved a greater variety of forms in the first few million years after the dinosaurs went extinct than in the previous 160 million years of mammal evolution under the rule of dinosaurs."

The Natural Environment Research Council-funded research, published today in the Biological Journal of the Linnean Society, studied the early evolution of placental mammals, the group including elephants, sloths, cats, dolphins and humans. The scientists gained a deeper understanding of how the diversity of the mammals that roamed the Earth before and after the dinosaur extinction changed as a result of that event.

Placental mammal fossils from this period have been previously overlooked as they were hard to place in the mammal tree of life because they lack many features that help to classify the living groups of placental mammals. Through recent work by the same team at UCL, this issue was resolved by creating a new tree of life for placental mammals, including these early forms, which was described in a study published in Biological Reviews yesterday.

First author of both papers, Dr Thomas Halliday (UCL Earth Sciences and Genetics, Evolution & Environment), said: "The mass extinction that wiped out the dinosaurs 66 million years ago is traditionally acknowledged as the start of the 'Age of Mammals' because several types of mammal appear for the first time immediately afterwards.

"Many recent studies suggest that little changed in mammal evolution during the Paleocene but these analyses don't include fossils from that time. When we look at the mammals that were present, we find a burst of evolution into new forms, followed by specialisation that finally resulted in the groups of mammals we see today. The earliest placental mammal fossils appear only a few hundred thousand years after the mass extinction, suggesting the event played a key role in diversification of the mammal group to which we belong."

The team studied the bones and teeth of 904 placental fossils to measure the anatomical differences between species. This information was used to build an updated tree of life containing 177 species within Eutheria (the group of mammals including all species more closely related to us than to kangaroos) including 94 from the Paleocene - making it the tree with the largest representation from Paleocene mammals to date. The new tree was analysed in time sections from 140 million years ago to present day, revealing the change in the variety of species.

Three different methods were used by the team to investigate the range and variation of the mammals present and all showed an explosion in mammal diversity after the dinosaur extinction. This is consistent with theories that mammals flourished when dinosaurs were no longer hunting them or competing with them for resources.

Dr Anjali Goswami (UCL Genetics, Evolution & Environment), added: "Extinctions are obviously terrible for the groups that go extinct, non-avian dinosaurs in this case, but they can create great opportunities for the species that survive, such as placental mammals, and the descendants of dinosaurs: birds."

Professor Paul Upchurch (UCL Earth Sciences), co-author of the Biological Reviews study, added: "Several previous methodological studies have shown that it is important to include as many species in an evolutionary tree as possible: this generally improves the accuracy of the tree. By producing such a large data set, we hope that our evolutionary tree for Paleocene mammals is more robust and reliable than any of the previous ones. Moreover, such large trees are very useful for future studies of large-scale evolutionary patterns, such as how early placental mammals dispersed across the continents via land bridges that no longer exist today."

The team are now investigating rates of evolution in these mammals, as well as looking at body size more specifically. Further work will involve building data from DNA into these analyses, to extend these studies to modern mammals.

Source: University College London [December 21, 2015]

Scientists have found the oldest fossils of the familiar pine tree that dominates Northern Hemisphere forests today.

Scientists from the Department of Earth Sciences at Royal Holloway, University of London have found the oldest fossils of the familiar pine tree that dominates Northern Hemisphere forests today.

The 140-million-year-old fossils (dating from the Cretaceous 'Age of the Dinosaurs') are exquisitely preserved as charcoal, the result of burning in wildfires. The fossils suggest that pines co-evolved with fire at a time when oxygen levels in the atmosphere were much higher and forests were especially flammable.

Dr Howard Falcon-Lang from Royal Holloway, University of London) discovered the fossils in Nova Scotia, Canada. He said: "Pines are well adapted to fire today. The fossils show that wildfires raged through the earliest pine forests and probably shaped the evolution of this important tree." Modern pines store flammable resin-rich deadwood on the tree making them prone to lethal fires. However, they also produce huge numbers of cones that will only germinate after a fire, ensuring a new cohort of trees is seeded after the fire has passed by."

The research is published in the journal Geological Society of America.

Source: University of Royal Holloway London [March 10, 2016]

Scientists studying the Chicxulub crater have shown how large asteroid impacts deform rocks in a way that may produce habitats for early life.

Around 65 million years ago a massive asteroid crashed into the Gulf of Mexico causing an impact so huge that the blast and subsequent knock-on effects wiped out around 75 per cent of all life on Earth, including most of the dinosaurs. This is known as the Chicxulub impact.

In April and May 2016, an international team of scientists undertook an offshore expedition and drilled into part of the Chicxulub impact crater. Their mission was to retrieve samples from the rocky inner ridges of the crater -- known as the 'peak ring' -- drilling 506 to 1335 metres below the modern day sea floor to understand more about the ancient cataclysmic event.

Now, the researchers have carried out the first analysis of the core samples. They found that the impact millions of years ago deformed the peak ring rocks in such a way that it made them more porous, and less dense, than any models had previously predicted.

Porous rocks provide niches for simple organisms to take hold, and there would also be nutrients available in the pores, from circulating water that would have been heated inside the Earth's crust. Early Earth was constantly bombarded by asteroids, and the team have inferred that this bombardment must have also created other rocks with similar physical properties. This may partly explain how life took hold on Earth.

The study, which is published today in the >journal Science, also confirmed a model for how peak rings were formed in the Chicxulub crater, and how peak rings may be formed in craters on other planetary bodies.

The team's new work has confirmed that the asteroid, which created the Chicxulub crater, hit the Earth's surface with such a force that it pushed rocks, which at that time were ten kilometres beneath the surface, farther downwards and then outwards. These rocks then moved inwards again towards the impact zone and then up to the surface, before collapsing downwards and outwards again to form the peak ring. In total they moved an approximate total distance of 30 kilometres in a matter of a few minutes.

Professor Joanna Morgan, lead author of the study from the Department of Earth Science and Engineering, said: "It is hard to believe that the same forces that destroyed the dinosaurs may have also played a part, much earlier on in Earth's history, in providing the first refuges for early life on the planet. We are hoping that further analyses of the core samples will provide more insights into how life can exist in these subterranean environments."

The next steps will see the team acquiring a suite of detailed measurements from the recovered core samples to refine their numerical simulations. Ultimately, the team are looking for evidence of modern and ancient life in the peak-ring rocks. They also want to learn more about the first sediments that were deposited on top of the peak ring, which could tell the researchers if they were deposited by a giant tsunami, and provide them with insights into how life recovered, and when life actually returned to this sterilised zone after the impact.

Source: Imperial College London [November 17, 2016]

A multidisciplinary research team including University of Granada (UGR) researchers has analyzed two sea bed loggings retrieved from the Alboran Sea's basin at very high resolution and reconstructed climate and oceanographic conditions over the last millennium, including the anthropogenic influence in the westernmost region of the Mediterranean Sea.

Global warming, climate change and their effects on health and safety are probably the worst threats in mankind's history. Recent reports from the Intergovernmental Panel on Climate Change (IPCC 2007, 2014) have accumulated scientific evidence that the observed rise in mean ground temperature all over the world from the beginning of the 20th century is probably due to anthropogenic influence.

Moreover, global mean concentration of carbon dioxide in the atmosphere has risen since the industrial revolution due to human activities. This concentration has surpassed that found in ice cores over the last 800 000 years. In January 2016, NASA and the U.S. National Oceanic and Atmospheric Administration (NOAA) revealed that global mean temperature in 2015 was the highest since 1880, when records began.

Reconstructions of the global ground temperature in the Northern Hemisphere over the last millennium show hotter conditions during the so called Medieval Climatic Anomaly (800-1300 A.C.) and cooler temperatures during the Little Ice Age (1300-1850 A.C.).

Natural climate variability

Climate models give us a coherent explanation of the progressive cooling over the last millennium due to a natural climate variability (solar cycle changes and volcanic eruptions). However, we can see that this global tendency has reverted during the 20th century. Climate models are not capable of simulating the fast warming observed during the last century without including human impact along with natural mechanisms of climate forcing.

With this in mind, a multidisciplinary team of researchers has conducted a study reconstructing climate and oceanographic conditions in the westernmost region of the Mediterranean Sea. For that purpose, they have used marine sediments retrieved from the Alboran Sea's basin.

As a semi-closed basin located in a latitude affected by several climate types, it's especially sensitive and vulnerable to anthropogenic and climate forcing. Several organic and inorganic geochemical indicators have been integrated in the model for this research, thus deducing climate variables such as sea surface temperature, humidity, changes in vegetation cover, changes in sea currents, and human impact.

These indicators have shown consistent climate signals in the two sea bed loggings—essentially hot and dry climate conditions during the Medieval Climatic Anomaly, which switched to mostly cold and wet conditions during the Little Ice Age. The industrial period showed wetter conditions than during the Little Ice Age, and the second half of the 20th century has been characterized by an increasing aridity.

Climate variability in the Mediterranean region seems to be driven by variations in solar irradiation and changes in the North Atlantic Oscillation (NAO) during the last millennium. The NAO alternates a positive phase with a negative one. The positive phase is characterized by western winds, which are more intense and move storms towards northern Europe, which resulted in dry winters in the Mediterranean region and the north of Africa during the Medieval Climatic Anomaly and the second half of the 20th century.

In contrast, the negative phase is associated with opposite conditions during the Little Ice Age and the industrial period. Our records show that during NAO prolonged negative phases (1450 and 1950 A.C.), there occurred a weakening of the thermohaline circulation and a reduction of "upwelling" events (emergence of colder, more nutrient-rich waters). Anthropogenic influence shows up in the unprecedented increase of temperature, progressive aridification and soil erosion, and an increase of polluting elements since the industrial period. On a broad scale, atmospheric circulation patterns, oceanic circulation patterns (the NAO and the Atlantic meridional overturning circulation), and variations in solar irradiance seem to have played a key role during the last millennium.

Results show that recent climate records in the westernmost region of the Mediterranean Sea are caused by natural forcing and anthropogenic influence. The main conclusions derived from this research have been published in a special volume of the >Journal of the Geological Society of London about climate change during the Holocene.

Source: University of Granada [October 12, 2016]

Molecular-based moisture indicators, remains of midges and climate simulations have provided climate scientists with the final piece to one of the most enduring puzzles of the last Ice Age.

For years, researchers have struggled to reconcile climate models of the Earth, 13,000 years ago, with the prevailing theory that a catastrophic freshwater flood from the melting North American ice sheets plunged the planet into a sudden and final cold snap, just before entering the present warm interglacial.

Now, an international team of scientists, led by Swedish researchers from Stockholm University and in partnership with UK researchers from the Natural History Museum (NHM) London, and Plymouth University, has found evidence in the sediments of an ancient Swedish lake that it was the melting of the Scandinavian ice sheet that provides the missing link to what occurred at the end of the last Ice Age. The study, published in Nature Communications, today, examined moisture and temperature records for the region and compared these with climate model simulations.

Francesco Muschitiello, a PhD researcher at Stockholm University and lead author of the study, said: "Moisture-sensitive molecules extracted from the lake's sediments show that climate conditions in Northern Europe became much drier around 13,000 years ago."

Steve Brooks, Researcher at the NHM, added: "The remains of midges, contained in the lake sediments, reveal a great deal about the past climate. The assemblage of species, when compared with modern records, enable us to track how, after an initial warming of up to 4° Centigrade at the end of the last Ice Age, summer temperatures plummeted by 5°C over the next 400 years."

Dr Nicola Whitehouse, Associate Professor in Physical Geography at Plymouth University, explained: "The onset of much drier, cooler summer temperatures, was probably a consequence of drier air masses driven by more persistent summer sea-ice in the Nordic Seas."

According to Francesco Muschitiello the observed colder and drier climate conditions were likely driven by increasingly stronger melting of the Scandinavian ice sheet in response to warming at the end of the last Ice Age; this led to an expansion of summer sea ice and to changes in sea-ice distribution in the eastern region of the North Atlantic, causing abrupt climate change. Francesco Muschitiello added: "The melting of the Scandinavian ice sheet is the missing link to understanding current inconsistencies between climate models and reconstructions, and our understanding of the response of the North Atlantic system to climate change."

Dr Francesco Pausata, postdoctoral researcher at Stockholm University, explained: "When forcing climate models with freshwater from the Scandinavian Ice Sheet, the associated climate shifts are consistent with our climate reconstructions."

The project leader, Professor Barbara Wohlfarth from Stockholm University, concluded: "The Scandinavian ice sheet definitely played a much more significant role in the onset of this final cold period than previously thought. Our teamwork highlights the importance of paleoclimate studies, not least in respect to the ongoing global warming debate."

Source: University of Plymouth [November 17, 2015]

The Mesozoic played host to some of the most dangerous predators to ever swim the Earth's oceans. Among these, pliosaurs were lethal hunters, and some of the largest predators ever on this planet. They were the shorter-necked cousins of the plesiosaurs, which are often spoken of in reference to their superficial similarity to the Loch Ness Monster, which we're definitely not going to do here. Together, pliosaurs and plesiosaurs form a group known as Sauropterygia, which existed in the oceans from the Triassic right until the end of the Cretaceous, when they went extinct along with the non-avian dinosaurs and other vertebrate groups. This actually makes sauropterygians the longest living group of marine-adapted tetrapods (animals with four limbs), which is quite an impressive feat!

New discoveries show that perhaps this evolutionary success can be attributed to the ecological diversity that this group possessed, and in particular an ability to adapt to different feeding styles.

Valentin Fischer from the University of Oxford and an international team of researchers have discovered a new pliosaur from western Russia, named Makhaira rossica. The name dreives from the Latinized Ancient Greek word 'mákhaira', which describes a blade with a curved outline, as well as the Latin word 'rossica', which means Russian. The specimen comprises a fragmentary skeleton of a sub-adult animal, found within a series of limestone nodules along the banks of the Volga River.

Makhaira comes from a period in Earth's geological history, known as the earliest part of the Cretaceous, where our knowledge of vertebrate life is relatively poor due to the way in which fossils are differentially preserved through time. Sadly, this lack of knowledge means that our understanding of how faunas changed from the latest part of the Jurassic period into the first part of the Cretaceous is relatively poor compared to other important geological boundaries.

Analysis of the evolutionary placement of this new species places it as the most basal member of a group known as Brachaucheninae, which survived through the Cretaceous. However, the new species is different in being a little smaller than some of its more advanced relatives.

The weirdest feature of the new beasty has to be the teeth. The teeth occur in pairs, and have a trihedral form, meaning they had three peaks on each alveolus, and the edges of the teeth were adorned with wicked serrations. They were also very large, similar even to some teeth from theropod dinosaurs roaming the lands at the time!

The morphology of these teeth suggest that they were equipped just for one thing – devouring other large animals! This form of feeding is known as macrophagy, and was a common form of predation at the time for giant marine crocodyliforms (the ancestors of modern crocodiles) called metriorhynchids. Importantly, this feeding style previously seemed to have been lost in the early evolution of other brachauchenine pliosaurs, but now appears to have been present in at least one species from this group. This shows that Early Cretaceous pliosaurs were still well adapted to hypercarnivory, and retained a high feeding diversity at the beginning of the Cretaceous, and not lost from their Jurassic ancestors.

Recently, Alessandro Chiarenza, a colleague of mine at Imperial College London, reported on what appeared to be the oldest metriorhynchid remains currently known, from a fossil site in Sicily. Based on a single fossilised tooth from a period known as the Aptian, later on in the Cretaceous than when Makhaira was found, these remains extended the duration of metriorhynchids, and their eventual extinction, by several millions of years.

However, the morphology of the teeth of Makhaira wasn't known at the time of publishing the crocodyliform fossils, and it seems that it is actually impossible to distinguish between these and the teeth of some metriorhynchids. This means that the Sicilian tooth cannot be referred unequivocally to either a metriorhynchid or a pliosaur – the teeth of some species is just too similar to say for certain! What does this imply though? Well, it seems that the fate of metriorhynchids is still a mystery concealed by the fossil record, and is only something that future study of these fossils, their other monstrous counterparts, and discovery of new fossils can hope to solve!

The findings are published in the >Royal Society Open Science journal.

Author: Victoria Costello | Source: Public Library of Science [January 16, 2016]

Using the oldest fossil micrometeorites -- space dust -- ever found, Monash University-led research has made a surprising discovery about the chemistry of Earth's atmosphere 2.7 billion years ago.

The findings of a new study >published in the journal Nature -- led by Dr Andrew Tomkins and a team from the School of Earth, Atmosphere and Environment at Monash, along with scientists from the Australian Synchrotron and Imperial College, London -- challenge the accepted view that Earth's ancient atmosphere was oxygen-poor. The findings indicate instead that the ancient Earth's upper atmosphere contained about the same amount of oxygen as today, and that a methane haze layer separated this oxygen-rich upper layer from the oxygen-starved lower atmosphere.

Dr Tomkins explained how the team extracted micrometeorites from samples of ancient limestone collected in the Pilbara region in Western Australia and examined them at the Monash Centre for Electron Microscopy (MCEM) and the Australian Synchrotron.

"Using cutting-edge microscopes we found that most of the micrometeorites had once been particles of metallic iron -- common in meteorites -- that had been turned into iron oxide minerals in the upper atmosphere, indicating higher concentrations of oxygen than expected," Dr Tomkins said.

"This was an exciting result because it is the first time anyone has found a way to sample the chemistry of the ancient Earth's upper atmosphere," Dr Tomkins said.

Imperial College researcher Dr Matthew Genge -- an expert in modern cosmic dust -- performed calculations that showed oxygen concentrations in the upper atmosphere would need to be close to modern day levels to explain the observations.

"This was a surprise because it has been firmly established that the Earth's lower atmosphere was very poor in oxygen 2.7 billion years ago; how the upper atmosphere could contain so much oxygen before the appearance of photosynthetic organisms was a real puzzle," Dr Genge said.

Dr Tomkins explained that the new results suggest the Earth at this time may have had a layered atmosphere with little vertical mixing, and higher levels of oxygen in the upper atmosphere produced by the breakdown of CO 2 by ultraviolet light.

"A possible explanation for this layered atmosphere might have involved a methane haze layer at middle levels of the atmosphere. The methane in such a layer would absorb UV light, releasing heat and creating a warm zone in the atmosphere that would inhibit vertical mixing," Dr Tomkins said.

"It is incredible to think that by studying fossilised particles of space dust the width of a human hair, we can gain new insights into the chemical makeup of Earth's upper atmosphere, billions of years ago." Dr Tomkins said.

Dr Tomkins outlined next steps in the research.

"The next stage of our research will be to extract micrometeorites from a series of rocks covering over a billion years of Earth's history in order to learn more about changes in atmospheric chemistry and structure across geological time. We will focus particularly on the great oxidation event, which happened 2.4 billion years ago when there was a sudden jump in oxygen concentration in the lower atmosphere."

Source: Monash University [May 12, 2016]

The Australian Age of Dinosaurs Museum today announced the naming of Savannasaurus elliottorum, a new genus and species of dinosaur from western Queensland, Australia. The bones come from the Winton Formation, a geological deposit approximately 95 million years old.

Savannasaurus was discovered by David Elliott, co-founder of the Australian Age of Dinosaurs Museum, while mustering sheep in early 2005. As Elliott recalled yesterday, "I was nearly home with the mob -- only about a kilometre from the yards -- when I spotted a small pile of fossil bone fragments on the ground. I was particularly excited at the time as there were two pieces of a relatively small limb bone and I was hoping it might be a meat-eating theropod dinosaur." Mr Elliott returned to the site later that day to collect the bone fragments with his wife Judy, who 'clicked' two pieces together to reveal a complete toe bone from a plant-eating sauropod. The Elliotts marked the site and made arrangements to hold a dig later that year.

The site was excavated in September 2005 by a joint Australian Age of Dinosaurs (AAOD) Museum and Queensland Museum team and 17 pallets of bones encased in rock were recovered. After almost ten years of painstaking work by staff and volunteers at the AAOD Museum, the hard siltstone concretion around the bones was finally removed to reveal one of the most complete sauropod dinosaur skeletons ever found in Australia. More excitingly, it belonged to a completely new type of dinosaur.

The new discovery was nicknamed Wade in honour of prominent Australian palaeontologist Dr Mary Wade. "Mary was a very close friend of ours and she passed away while we were digging at the site," said Mr Elliott. "We couldn't think of a better way to honour her than to name the new dinosaur after her."

"Before today we have only been able to refer to this dinosaur by its nickname," said Dr Stephen Poropat, Research Associate at the AAOD Museum and lead author of the study. "Now that our study is published we can refer to Wade by its formal name, Savannasaurus elliottorum," Dr Poropat said. "The name references the savannah country of western Queensland in which it was found, and honours the Elliott family for their ongoing commitment to Australian palaeontology."

In the same publication, Dr Poropat and colleagues announced the first sauropod skull ever found in Australia. This skull, and the partial skeleton with which it was associated, has been assigned to Diamantinasaurus matildae -- a sauropod dinosaur named in 2009 on the basis of its nickname Matilda. "This new Diamantinasaurus specimen has helped to fill several gaps in our knowledge of this dinosaur's skeletal anatomy," said Poropat. "The braincase in particular has allowed us to refine Diamantinasaurus' position on the sauropod family tree."

Dr Poropat collaborated with British sauropod experts Dr Philip Mannion (Imperial College, London) and Professor Paul Upchurch (University College, London), among others, to work out the position of Savannasaurus (and refine that of Diamantinasaurus) on the sauropod family tree. "Both Savannasaurus and Diamantinasaurus belong to a group of sauropods called titanosaurs. This group of sauropods includes the largest land-living animals of all time," said Dr Mannion. "Savannasaurus and the new Diamantinasaurus specimen have helped us to demonstrate that titanosaurs were living worldwide by 100 million years ago."

Poropat and his colleagues suggest that the arrangement of the continents, and the global climate during the middle part of the Cretaceous Period, enabled titanosaurs to spread worldwide.

"Australia and South America were connected to Antarctica throughout much of the Cretaceous," said Professor Upchurch. "Ninety-five million years ago, at the time that Savannasaurus was alive, global average temperatures were warmer than they are today. However, it was quite cool at the poles at certain times, which seems to have restricted the movement of sauropods at polar latitudes. We suspect that the ancestor of Savannasaurus was from South America, but that it could not and did not enter Australia until approximately 105 million years ago. At this time global average temperatures increased allowing sauropods to traverse landmasses at polar latitudes."

Savannasaurus was a medium-sized titanosaur, approximately half the length of a basketball court, with a long neck and a relatively short tail. "With hips at least one metre wide and a huge barrel-like ribcage, Savannasaurus is the most rotund sauropod we have found so far -- even more so than the somewhat hippopotamus-like Diamantinasaurus," said Dr Poropat. "It lived alongside at least two other types of sauropod (Diamantinasaurus and Wintonotitan), as well as other dinosaurs including ornithopods, armoured ankylosaurs, and the carnivorous theropod Australovenator."

Mr Elliott is relieved that Wade can now join "Matilda" and the other new dinosaur species on display in the Museum's Holotype Room. "That this dinosaur specimen can now be displayed for our visitors is a testament to the efforts of numerous volunteers who have worked at the Museum on the fossils over the past decade," he said. Mr Elliott and Dr Poropat agree that the naming of Savannasaurus, the fourth new species published by the AAOD Museum, is just the tip of the iceberg with respect to the potential for new dinosaur species in western Queensland.

"The Australian Age of Dinosaurs Museum has a massive collection of dinosaur fossils awaiting preparation and the number of specimens collected is easily outpacing the number being prepared by volunteers and staff in our Laboratory," Mr Elliott said. "The Museum already has the world's largest collection of bones from Australia's biggest dinosaurs and there is enough new material to keep us working for several decades."

The paper naming the new dinosaur was published in >Scientific Reports.

Source: Australian Age of Dinosaurs Museum of Natural History [October 20, 2016]

A study, carried out by Professor Andrew C. Scott of the Department of Earth Sciences at Royal Holloway, University of London and Professor Sue Rimmer from Southern Illinois University, reveals widespread fire occurred on Earth more than 80 million years after plants first invaded the land.

The findings, published in the American Journal of Science, indicate that although plants were first detected on land more than 440 million years ago there is only scant evidence of fire at that time.

Professor Scott, said: "What surprised us was that many of these early extensive fires were surface fires burning the undergrowth, as we can see the anatomy of the plants being burned through scanning electron microscope studies of larger pieces of the fossil charcoal."

He added: "This may be because plants were small and were limited in their distribution but over the following 50 million years they diversified and spread across the globe and some of the plants were trees and could have provided a good fuel to burn. Extensive forest fires soon followed, however and we see widespread charcoal deposits throughout the Lower Carboniferous (Mississippian) Period 358-323 million years ago."

Professor Scott and Professor Rimmer made the discovery after analysing charcoal which was washed in to an ocean that lay across what is now part of present day North America.

The team believes that it was not fuel availability that prevented widespread fire, or climate, but that the atmospheric oxygen levels were too low. It had been suggested that only when oxygen levels rose to above 17% (it is 21% today) that widespread fires would be found. This new data suggests that it was at around 360 million years ago, in the latest Devonian Period, that this threshold was reached and probably never went below this level for the rest of geological history.

This time period defines a new phase of the evolution of Earth System and regular wildfire would have played an important role in the evolution of both animals and plants.

Source: University of Royal Holloway London [October 21, 2015]

New research suggests that the dodo, an extinct bird whose name has entered popular culture as a symbol of stupidity, was actually fairly smart. The work, published in the Zoological Journal of the Linnean Society, finds that the overall size of the dodo's brain in relation to its body size was on par with its closest living relatives: pigeons--birds whose ability to be trained implies a moderate level of intelligence. The researchers also discovered that the dodo had an enlarged olfactory bulb -- the part of the brain responsible for smelling -- an uncharacteristic trait for birds, which usually concentrate their brainpower into eyesight.

The dodo (Raphus cucullatus) was a large, flightless bird that lived on the island of Mauritius in the Indian Ocean. They were last seen in 1662.

"When the island was discovered in the late 1500s, the dodos living there had no fear of humans and they were herded onto boats and used as fresh meat for sailors," said Eugenia Gold, the lead author of the paper, a research associate and recent graduate of the American Museum of Natural History's Richard Gilder Graduate School, and an instructor in the Department of Anatomical Sciences at Stony Brook University. "Because of that behavior and invasive species that were introduced to the island, they disappeared in less than 100 years after humans arrived. Today, they are almost exclusively known for becoming extinct, and I think that's why we've given them this reputation of being dumb."

Even though the birds have become an example of oddity, obsolescence, stupidity, and extinction, and have been featured in popular stories ranging from Alice in Wonderland to Ice Age, most aspects of the dodo's biology are still unknown. This is partly because dodo specimens are extremely rare, having disappeared during the nascent stage of natural history collections.

To examine the brain of the dodo, Gold tracked down a well-preserved skull from the collections of the Natural History Museum, London, and imaged it there with high-resolution computed tomography (CT) scanning. In the American Museum of Natural History's Microscopy and Imaging Facility, she also CT-scanned the skulls of seven species of pigeons -- ranging from the common pigeon found on city streets, Columba livia, to more exotic varieties. Out of these scans, Gold built virtual brain endocasts to determine the overall brain size as well as the size of various structures. Gold's colleagues at the Natural History Museum of Denmark and National Museum of Scotland sent her the endocast for the dodo's closest relative, the extinct island-dwelling bird Rodrigues solitaire (Pezophaps solitaria).

When comparing the size of the birds' brains to their body sizes, Gold and collaborators found that the dodo was "right on the line."

"It's not impressively large or impressively small -- it's exactly the size you would predict it to be for its body size," Gold said. "So if you take brain size as a proxy for intelligence, dodos probably had a similar intelligence level to pigeons. Of course, there's more to intelligence than just overall brain size, but this gives us a basic measure."

The study also revealed that both the dodo and the Rodrigues solitaire, which recently was driven to extinction by human activity, had large and differentiated olfactory bulbs. In general, birds depend much more on sight rather than smell to navigate through their world, and as a result, they tend to have larger optic lobes than olfactory bulbs. The authors suggest that, because dodos and solitaires were ground-dwellers, they relied on smell to find food, which might have included fruit, small land vertebrates, and marine animals like shellfish.

"It is really amazing what new technologies can bring to old museum specimens," said co-author Mark Norell, Macaulay Curator of Paleontology and Chair of the Division of Paleontology at the American Museum of Natural History. "This really underscores the need for the maintenance and growth of natural history collections, because who knows what's next."

The researchers also discovered an unusual curvature of the dodo's semicircular canal -- the balance organs located in the ear. But as of yet, there's not a good hypothesis for this atypical feature.

Source: American Museum of Natural History [February 23, 2016]

Geologists have for the first time seen and documented the Banda Detachment fault in eastern Indonesia and worked out how it formed.

Lead researcher Dr Jonathan Pownall from The Australian National University (ANU) said the find will help researchers assess dangers of future tsunamis in the area, which is part of the Ring of Fire -- an area around the Pacific Ocean basin known for earthquakes and volcanic eruptions.

"The abyss has been known for 90 years but until now no one has been able to explain how it got so deep," Dr Pownall said.

"Our research found that a 7 km-deep abyss beneath the Banda Sea off eastern Indonesia was formed by extension along what might be Earth's largest-identified exposed fault plane."

By analysing high-resolution maps of the Banda Sea floor, geologists from ANU and Royal Holloway University of London found the rocks flooring the seas are cut by hundreds of straight parallel scars.

These wounds show that a piece of crust bigger than Belgium or Tasmania must have been ripped apart by 120 km of extension along a low-angle crack, or detachment fault, to form the present-day ocean-floor depression.

Dr Pownall said this fault, the Banda Detachment, represents a rip in the ocean floor exposed over 60,000 square kilometres.

"The discovery will help explain how one of Earth's deepest sea areas became so deep," he said.

Professor Gordon Lister also from the ANU Research School of Earth Sciences said this was the first time the fault has been seen and documented by researchers.

"We had made a good argument for the existence of this fault we named the Banda Detachment based on the bathymetry data and on knowledge of the regional geology," said Professor Lister.

Dr Pownall said he was on a boat journey in eastern Indonesia in July when he noticed the prominent landforms consistent with surface extensions of the fault line.

"I was stunned to see the hypothesised fault plane, this time not on a computer screen, but poking above the waves," said Dr Pownall.

He said rocks immediately below the fault include those brought up from the mantle.

"This demonstrates the extreme amount of extension that must have taken place as the oceanic crust was thinned, in some places to zero," he said.

Dr Pownall also said the discovery of the Banda Detachment fault would help assesses dangers of future tsunamis and earthquakes.

"In a region of extreme tsunami risk, knowledge of major faults such as the Banda Detachment, which could make big earthquakes when they slip, is fundamental to being able to properly assess tectonic hazards," he said.

The research has been published in the journal >Geology.

Source: Australian National University [November 28, 2016]

A new study published by PeerJ documents injuries inflicted in life and death to a large tyrannosaurine dinosaur. The paper shows that the skull of a genus of tyrannosaur called Daspletosaurus suffered numerous injuries during life, at least some of which were likely inflicted by another Daspletosaurus. It was also bitten after death in an apparent event of scavenging by another tyrannosaur. Thus there's evidence of combat between two large carnivores as well as one feeding on another after death.

Daspletosaurus was a large carnivore that lived in Canada and was only a little smaller than its more famous cousin Tyrannosaurus. Like other tyrannosaurs it was most likely both an active predator and scavenger. The individual in question, from Alberta Canada, was not fully grown and would be considered a 'sub-adult' in dinosaur terms (approximately equivalent to an older teenager in human terms). It would have been just under 6 m long and around 500 kg when it died.

Researchers found numerous injuries on the skull that occurred during life. Although not all of them can be attributed to bites, several are close in shape to the teeth of tyrannosaurs. In particular one bite to the back of the head had broken off part of the skull and left a circular tooth-shaped puncture though the bone. The fact that alterations to the bone's surface indicate healing means that these injuries were not fatal and the animal lived for some time after they were inflicted.

Lead author Dr David Hone from Queen Mary, University of London said "This animal clearly had a tough life suffering numerous injuries across the head including some that must have been quite nasty. The most likely candidate to have done this is another member of the same species, suggesting some serious fights between these animals during their lives."

There is no evidence that the animal died at the hands (or mouth) of another tyrannosaur. However, the preservation of the skull and other bones, and damage to the jaw bones show that after the specimen began to decay, a large tyrannosaur (possibly of the same species) bit into the animal and presumably ate at least part of it.

Combat between large carnivorous dinosaurs is already known and there is already evidence for cannibalism in various groups, including tyrannosaurs. This is however an apparently unique record with evidence of both pre- and post-mortem injuries to a single individual.

Source: PeerJ [April 09, 2015]

Medical scanners and the same software used to assess building strength after the Canterbury earthquakes, have revealed new information about the diet and dining preferences of New Zealand's extinct moa.

Researchers from Canterbury Museum, the University of Auckland, Finders University and the Universities of New England (Australia) and New South Wales have discovered that the nine species of moa were able to co-exist because differences in the structure and strength of each species' skull and bills were influenced by, or dictated by, diet.

The findings are published today in the journal >Proceedings of the Royal Society, in London.

Co-author, Dr Peter Johnston from the University of Auckland's Anatomy and Medical Imaging department, made MRI scans of the mummified moa remains to allow accurate models to be made for the research.

The moa, which roamed New Zealand until the 15th century, were herbivores and some of the largest birds to have ever existed. The largest species, the South Island Giant moa, weighed up to 240 kg whilst the smallest (the upland moa) was the size of a sheep.

Until now scientists had thought that the huge difference in size between the species determined their foraging behaviour as well as what, when and where they ate (ie their ecological niche).

Co-author Professor Paul Scofield from Canterbury Museum says that the team took the most complete skulls of each species of moa from the collections of Canterbury Museum and Te Papa Tongarewa and scanned those using medical CT (Computed Tomography) scanners.

"We then produced highly accurate 3D models of each. This wasn't a simple job as we didn't have a single skull that was perfect so we used sophisticated digital cloning techniques to digitally reconstruct accurate osteological models for each species," Professor Scofield said.

Using the medical MRI scans of the mummified remains, Dr Johnston digitally reconstructed the muscles of each species.

"Each moa species has a characteristic bill shape and the reasons for this have not previously been defined," says Dr Johnston. "Charles Darwin had an easier time investigating a similar situation in Galapagos finches, as the differences are more extreme and the diets are obvious in that group of birds."

Software used by civil engineers after the Canterbury Earthquakes to identify weak or unsound buildings, was used to test the strength and structure of each moa species' bill.

These were compared to each other and to two living relatives, the emu and cassowary. The models simulated the response of the skull to different biting and feeding behaviours including clipping twigs and pulling, twisting or bowing head motions to remove foliage.

The skull mechanics of moa were found to be surprisingly diverse. The little bush moa had a relatively short, sharp-edged bill and was superior among moa at cutting twigs and branches, supporting the proposition that they primarily fed on fibrous material from trees and shrubs.

At the opposite extreme, the coastal moa had a relatively weak skull compared to all other species which may have forced them to travel further than other moa in search of suitable food, such as soft fruit and leaves.

Dr Trevor Worthy (a New Zealander working at Flinders University in Australia) says "until now we have been limited in assessing anatomical function to examining the external aspect of bones. This new technology allows us to bring new life to old bones and to get one step closer to understanding the birds they came from."

"Little has been known about how New Zealand's ecosystem evolved, largely because we know so little about how moa lived and co-existed," says Associate Professor Stephen Wroe, leader of the Function, Evolution and Anatomy Research (FEAR) laboratory at the University of New England (Australia).

"This new research advances our understanding about the feeding behaviours of the moa species and their impact on New Zealand's unique and distinctive flora."

Source: University of Auckland [January 14, 2016]

Scientists have discovered an ancient animal that carried its young in capsules tethered to the parent's body like tiny, swirling kites. They're naming it after "The Kite Runner," the 2003 bestselling novel.

The miniscule creature, Aquilonifer spinosus, was an arthropod that lived about 430 million years ago. It grew to less than half an inch long, and there is only one known fossil of the animal, found in Herefordshire, England. Its name comes from "aquila," which means eagle or kite, and the suffix "fer," which means carry.

Researchers from Yale, Oxford, the University of Leicester, and Imperial College London described the new species in a paper published in the journal Proceedings of the National Academy of Sciences.

"Modern crustaceans employ a variety of strategies to protect their eggs and embryos from predators -- attaching them to the limbs, holding them under the carapace, or enclosing them within a special pouch until they are old enough to be released -- but this example is unique," said lead author Derek Briggs, Yale's G. Evelyn Hutchinson Professor of Geology and Geophysics and curator of invertebrate paleontology at the Yale Peabody Museum of Natural History. "Nothing is known today that attaches the young by threads to its upper surface."

The Kite Runner fossil shows 10 juveniles, at different stages of development, connected to the adult. The researchers interpret this to mean that the adult postponed molting until the juveniles were old enough to hatch; otherwise, the juveniles would have been cast aside with the shed exoskeleton.

The adult specimen's head is eyeless and covered by a shield-like structure, according to the researchers. It lived on the sea floor during the Silurian period with a variety of other animals including sponges, brachiopods, worms, snails and other mollusks, a sea spider, a horseshoe crab, various shrimp-like creatures, and a sea star. The juvenile pouches, attached to the adult by slender, flexible threads, look like flattened lemons.

Briggs said he and his colleagues considered the possibility that the juveniles were parasites feeding off a host, but decided it was unlikely because the attachment position would not be favorable for accessing nutrients.

"We have named it after the novel by Khalid Hosseini due to the fancied resemblance of the juveniles to kites," Briggs said. "As the parent moved around, the juveniles would have looked like decorations or kites attached to it. It shows that arthropods evolved a variety of brooding strategies beyond those around today -- perhaps this strategy was less successful and became extinct."

The researchers were able to describe Aquilonifer spinosus in detail thanks to a virtual reconstruction. They reconstructed the animal and the attached juveniles by stacking digital images of fossil surfaces revealed by grinding away the fossil in tiny increments.

Author: Jim Shelton | Source: Yale University [April 04, 2016]

An international research team is formalizing plans to drill nearly 5,000 feet below the seabed to take core samples from the crater of the asteroid that wiped out the dinosaurs.

The group met last week in Merida, Mexico, a city within the nearly 125-mile-wide impact site, to explain the research plans and put out a call for scientists to join the expedition planned for spring 2016. The roughly $10 million in funding for the expedition has been approved and scheduled by the European Consortium for Ocean Research Drilling (ECORD) — part of the International Ocean Discovery Program (IODP) — and the International Continental Scientific Drilling Program (ICDP).

Dinosaurs and other reptiles ruled the planet for 135 million years. That all changed 65.5 million years ago when a 9-mile-wide asteroid slammed into the Earth, triggering a series of apocalyptic events that killed most large animals and plants, and wiped out the dinosaurs and large marine reptiles. The event set the stage for mammals — and eventually humans — to take over. Yet, we have few geologic samples of the now buried impact crater.

Sean Gulick, a researcher at The University of Texas at Austin Institute for Geophysics (UTIG), and a team of scientists from the U.K. and Mexico are working to change that. The team is planning to take the first offshore core samples from near the center of the impact crater, which is called Chicxulub after the seaside village on the Yucatán Peninsula near the crater’s center.

The team, led by Gulick and Joanna Morgan of Imperial College London, will be sampling the crater’s “peak ring” — an enigmatic ring of topographically elevated rocks that surrounds the crater’s center, rises above its floor and has been buried during the past 65.5 million years by sediments.

A peak ring is a feature that is present in all craters caused by large impacts on rocky planetoids. By sampling the Chicxulub peak ring and analyzing its key features, researchers hope to uncover the impact details that set in motion one of the planet’s most profound extinctions, while also shedding light on the mechanisms of large impacts on Earth and on other rocky planets.

“What are the peaks made of? And what can they tell us about the fundamental processes of impacts, which is this dominant planetary resurfacing phenomena?” said Gulick, who is also a research associate professor at the UT Jackson School of Geosciences. UTIG is a research unit of the Jackson School.

The researchers are also interested in examining traces of life that may have lived inside the peak ring’s rocks. Density readings of the rocks indicate that they probably are heavily broken and porous — features that may have served as protected microenvironments for exotic life that could have thrived in the hot, chemically enriched environment of the crater site after impact. Additionally, the earliest recovery of marine life should be recorded within the sediments that filled in the crater in the millions of years after the impact.

“The sediments that filled in the [crater] should have the record for organisms living on the sea floor and in the water that were there for the first recovery after the mass extinction event,” Gulick said. “The hope is we can watch life come back.”

The expedition will last for two months and involve penetrating nearly 5,000 feet beneath the seabed from an offshore platform. The core will be the first complete sample of the rock layers from near the crater’s center.

Once extracted, the core will be shipped to Germany and split in two. Half will be immediately analyzed by an international team of scientists from the U.S., U.K., Mexico and other nations, and half will be saved at a core repository at Texas A&M University for future research needs by the international community.

The team also includes researchers from the National Autonomous University of Mexico (UNAM) and Centro de Investigación Científica de Yucatán (CICY). Scientists interested in joining the mission must apply by May 8, 2015. For more information on the mission and the application process, see the European Consortium for Ocean Research Drilling’s call for applications.

Source: University of Texas at Austin [April 06, 2015]

It took 100 million years for oxygen levels in the oceans and atmosphere to increase to the level that allowed the explosion of animal life on Earth about 600 million years ago, according to a UCL-led study funded by the Natural Environment Research Council.

Before now it was not known how quickly Earth's oceans and atmosphere became oxygenated and if animal life expanded before or after oxygen levels rose. The new study, published today in Nature Communications, shows the increase began significantly earlier than previously thought and occurred in fits and starts spread over a vast period. It is therefore likely that early animal evolution was kick-started by increased amounts of oxygen, rather than a change in animal behaviour leading to oxygenation.

Lead researcher, Dr Philip Pogge von Strandmann (UCL Earth Sciences), said: "We want to find out how the evolution of life links to the evolution of our climate. The question on how strongly life has actively modified Earth's climate, and why the Earth has been habitable for so long is extremely important for understanding both the climate system, and why life is on Earth in the first place."

Researchers from UCL, Birkbeck, Bristol University, University of Washington, University of Leeds, Utah State University and University of Southern Denmark tracked what was happening with oxygen levels globally 770 - 520 million years ago (Ma) using new tracers in rocks across the US, Canada and China.

Samples of rocks that were laid down under the sea at different times were taken from different locations to piece together the global picture of the oxygen levels of Earth's oceans and atmosphere. By measuring selenium isotopes in the rocks, the team revealed that it took 100 million years for the amount of oxygen in the atmosphere to climb from less than 1% to over 10% of today's current level. This was arguably the most significant oxygenation event in Earth history because it ushered in an age of animal life that continues to this day.

Dr Pogge von Strandmann, said: "We took a new approach by using selenium isotope tracers to analyse marine shales which gave us more information about the gradual changes in oxygen levels than is possible using the more conventional techniques used previously. We were surprised to see how long it took Earth to produce oxygen and our findings dispel theories that it was a quick process caused by a change in animal behaviour."

During the period studied, three big 'snowball Earth' glaciations - Sturtian (~716Ma), Marinoan (~635Ma) and Gaskiers (~580Ma) - occurred whereby the Earth's land was covered in ice and most of the oceans were frozen from the poles to the tropics. During these periods, temperatures plummeted and rose again, causing glacial melting and an influx of nutrients into the ocean, which researchers think caused oxygen levels to rise deep in the oceans.

Increased nutrients means more ocean plankton, which will bury organic carbon in seafloor sediments when they die. Burying carbon results in oxygen increasing, dramatically changing conditions on Earth. Until now, oxygenation was thought to have occurred after the relatively small Gaskiers glaciation melted. The findings from this study pushes it much earlier, to the Marinoan glaciation, after which animals began to flourish in the improved conditions, leading to the first big expansion of animal life.

Co-author Prof. David Catling (University of Washington Earth and Space Sciences), added: "Oxygen was like a slow fuse to the explosion of animal life. Around 635 Ma, enough oxygen probably existed to support tiny sponges. Then, after 580 Ma, strange creatures shaped like pizzas lived on a lightly oxygenated seafloor. Fifty million years later, vertebrate ancestors were gliding through oxygen-rich seawater. Tracking how oxygen increased is the first step towards understanding why it took so long. Ultimately, a grasp of geologic controls on oxygen levels can help us understand whether animal-like life might exist or not on Earth-like planets elsewhere."

Source: University College London [December 17, 2015]

An ancient relative of the giraffe was a huge, heavy animal with thick legs, a flat face and massive, curly horns flaring out from its skull, said a study Wednesday.

Dubbed Sivatherium giganteum, the impressive creature would have been shorter than today's giraffe, with a less elongated neck, a trio of British scientists wrote in the Royal Society journal >Biology Letters.

Using bones dug up in India in the 1830s and now in London's Natural History Museum, the team built a computerised 3D reconstruction of an animal they said would have stood about 1.8 metres (5.9 feet) tall at the shoulder and weighed about 1.2 tonnes.

"This was a heavy animal with thick legs," co-author Christopher Basu told AFP.

Added to the large, flattened horns or "ossicones" on the top of the skull, each about 70 centimetres (28 inches) long, it also had two smaller, pointy horns just over the eyes.m

"It would have been an impressive and strong animal," said Basu. "It's face would have looked very different from a giraffe. Giraffe's have very long, pointed skulls. Sivatherium had a very short, flattened skull."

It lived somewhere between the last five million and 12,000 years ago in Africa and Asia.

Related to the giraffe and its cousin the okapi, Sivatherium was possibly the largest ruminant animal—those with multi-compartmented stomachs—to ever have lived.

The first scientists to study Sivatherium bones misclassified the animal as an archaic link between modern ruminants and a long-extinct relative of elephants and rhinoceroses.

For the new study, the skeleton was reconstructed using 26 fossil bones from three individual animals. The ribs, back and pelvis are missing.

"We estimated what these might look like from giraffe and okapi anatomy—the two living relatives," said Basu.

Source: AFP [January 13, 2016]

The discovery of a tiny, 170-million-year-old fossil on the Isle of Skye, off the north-west coast of the UK, has led Oxford University researchers to conclude that three previously recognised species are in fact just one.

During a fossil-hunting expedition in Scotland last year, a team of researchers from the University's Department of Earth Sciences discovered the fossilised remains of a mouse-sized mammal dating back around 170 million years to the Middle Jurassic period. The new find -- a tiny lower jaw bearing 11 teeth -- shows that that three species previously described on the basis of individual fossilised teeth actually belong to just one species.

The United Kingdom has yielded many important mammalian fossils from the Middle Jurassic, a period dating between 176 and 161 million years ago, with most being found in the Scottish Isles and around Oxfordshire. Indeed, specimens obtained from Kirtlington Quarry -- just 10 miles north of Oxford -- have provided some of the richest Middle Jurassic mammal records to date. Included among those are a large number of teeth, each found in isolation, that had been thought to include at least three distinct species of what are known as 'stem therians' -- ancient relatives of many modern mammals, including rodents and marsupials.

Now, though, the team from Oxford has discovered a fossil which refutes those claims. The team found the 10 millimetre-long fossilised jaw at a site on the west coast of the Isle of Skye. 'We spent five days exploring the locality, finding nothing especially exciting, and were walking back along the beach to the house where we were staying,' recalls Dr Roger Close, the lead author of the study. 'Then, by chance, we spotted this specimen on the surface of a boulder.'

After carefully removing the specimen -- a complete left lower jaw of a small mammal -- the team carried out a series of analyses to determine its origins. First, they performed a high-resolution x-ray CT scan at the Natural History Museum in London, providing an incredibly detailed 3D model of the fossil that allowed the researchers to glean much more information about its anatomy than could ever be possible by visual inspection. 'Over half of the fossil is still buried in the rock,' explains Dr Close. 'The CT scan allows us to virtually remove this, and explore the whole specimen in exquisite detail.'

From there, they systematically compared the shape of each and every tooth present in the jaw to those found in all similar specimens discovered in the past. They were surprised to find that the new jaw resembled not one species, but three: Palaeoxonodon ooliticus, Palaeoxonodon freemani and Kennetheridium leesi, all known from isolated teeth preserved in rocks of the same age from Oxfordshire.

Differences in tooth shape that had been thought to distinguish three different species were in fact all present in the single lower jaw found on the Isle of Skye. 'In effect, we've "undiscovered" two species,' explains Dr Close. 'The new find shows that we should be cautious about naming new types of animals on the basis of individual teeth.' In a paper published in Palaeontology, the team identifies their find as Palaeoxonodon ooliticus -- the name given to the first of the three species to be described back in the late 1970s.

Palaeoxonodon has long been recognised as an important species for understanding the evolution of molar teeth in modern mammals, and this latest discovery sheds more light on the subject. The species appears to show an intermediate step in the evolution of what are known as 'tribosphenic' molars -- a kind of pestle-and-mortar geometry that is particularly well suited to processing food.

'Towards the front, three sharp cusps allow the animal to slice up the food, while at the back a flatter, grinding surface crushes it,' explains Dr Close. 'It's an evolutionary innovation that allowed much more versatile ways of feeding to evolve, and it may well have contributed to the long-term success of this group of mammals.'

Source: University of Oxford [November 13, 2015]

Large ornamental structures in dinosaurs, such as horns and head crests are likely to have been used in sexual displays and to assert social dominance, according to a new analysis of Protoceratops carried out by scientists at Queen Mary University of London (QMUL). This is the first time scientists have linked the function of anatomy to sexual selection in dinosaurs.

Protoceratops had a large bony frill that extended from the back of the head over the neck. Study of fossils aged from babies to adults revealed the adults to have disproportionately larger frills in relation to their size. The research, published in the journal >Palaeontologia Electronica, shows that the frill was absent in juveniles and suddenly increased in size as the animals reached maturity suggesting that its function is linked to sexual selection.

This suggests the frill might have been used to attract suitable mates by showing off their best attributes or helping them assert the most dominant position in social interactions.

Dr David Hone, lecturer in Zoology from QMUL's School of Biological and Chemical Sciences, said: "Palaeontologists have long suspected that many of the strange features we see in dinosaurs were linked to sexual display and social dominance but this is very hard to show. The growth pattern we see in Protoceratops matches that seen for signalling structures in numerous different living species and forms a coherent pattern from very young animals right through to large adults."

The researchers assessed the change in length and width of the frill over four life stages: hatchling babies, young animals, near-adults, and adults. Not only did the frill change in size but it also changed in shape, becoming proportionally wider as the dinosaur became older.

Dr Rob Knell, Reader in Evolutionary Ecology, also from QMUL's School of Biological and Chemical Sciences, said: "Biologists are increasingly realising that sexual selection is a massively important force in shaping biodiversity both now and in the past. Not only does sexual selection account for most of the stranger, prettier and more impressive features that we see in the animal kingdom, it also seems to play a part in determining how new species arise, and there is increasing evidence that it also has effects on extinction rates and on the ways by which animals are able to adapt to changing environments."

The research formed part of current postgraduate student and QMUL graduate Dylan Wood's undergraduate thesis, which looked at sexual selection in extinct species.

There are numerous, well-preserved specimens of ceratopisian dinosaurs of various sizes and ages making them a good groups to analyse. The researchers analysed 37 specimens of Protoceratops from fossils found in the Djadochta Formation in the Gobi desert and from previous published research. Protoceratops was a small-horned dinosaur that was similar in size to a sheep and was around 2m in total length from snout to tail tip.

Source: Queen Mary, University of London [January 13, 2016]

Researchers have identified the first known example of fossilised brain tissue in a dinosaur from Sussex. The tissues resemble those seen in modern crocodiles and birds.

An unassuming brown pebble, found more than a decade ago by a fossil hunter in Sussex, has been confirmed as the first example of fossilised brain tissue from a dinosaur.

The fossil, most likely from a species closely related to Iguanodon, displays distinct similarities to the brains of modern-day crocodiles and birds. Meninges -- the tough tissues surrounding the actual brain -- as well as tiny capillaries and portions of adjacent cortical tissues have been preserved as mineralised 'ghosts'.

The results are reported in a >Special Publication of the Geological Society of London, published in tribute to Professor Martin Brasier of the University of Oxford, who died in 2014. Brasier and Dr David Norman from the University of Cambridge co-ordinated the research into this particular fossil during the years prior to Brasier's untimely death in a road traffic accident.

The fossilised brain, found by fossil hunter Jamie Hiscocks near Bexhill in Sussex in 2004, is most likely from a species similar to Iguanodon: a large herbivorous dinosaur that lived during the Early Cretaceous Period, about 133 million years ago.

Finding fossilised soft tissue, especially brain tissue, is very rare, which makes understanding the evolutionary history of such tissue difficult. "The chances of preserving brain tissue are incredibly small, so the discovery of this specimen is astonishing," said co-author Dr Alex Liu of Cambridge's Department of Earth Sciences, who was one of Brasier's PhD students in Oxford at the time that studies of the fossil began.

According to the researchers, the reason this particular piece of brain tissue has been so well-preserved is that the dinosaur's brain was essentially 'pickled' in a highly acidic and low-oxygen body of water -- similar to a bog or swamp -- shortly after its death. This allowed the soft tissues to become mineralised before they decayed away completely, so that they could be preserved.

"What we think happened is that this particular dinosaur died in or near a body of water, and its head ended up partially buried in the sediment at the bottom," said Norman. "Since the water had little oxygen and was very acidic, the soft tissues of the brain were likely preserved and cast before the rest of its body was buried in the sediment."

Working with colleagues from the University of Western Australia, the researchers used scanning electron microscope (SEM) techniques in order to identify the tough membranes, or meninges, that surrounded the brain itself, as well as strands of collagen and blood vessels. Structures that could represent tissues from the brain cortex (its outer layer of neural tissue), interwoven with delicate capillaries, also appear to be present. The structure of the fossilised brain, and in particular that of the meninges, shows similarities with the brains of modern-day descendants of dinosaurs, namely birds and crocodiles.

In typical reptiles, the brain has the shape of a sausage, surrounded by a dense region of blood vessels and thin-walled vascular chambers (sinuses) that serve as a blood drainage system. The brain itself only takes up about half of the space within the cranial cavity.

In contrast, the tissue in the fossilised brain appears to have been pressed directly against the skull, raising the possibility that some dinosaurs had large brains which filled much more of the cranial cavity. However, the researchers caution against drawing any conclusions about the intelligence of dinosaurs from this particular fossil, and say that it is most likely that during death and burial the head of this dinosaur became overturned, so that as the brain decayed, gravity caused it to collapse and become pressed against the bony roof of the cavity.

"As we can't see the lobes of the brain itself, we can't say for sure how big this dinosaur's brain was," said Norman. "Of course, it's entirely possible that dinosaurs had bigger brains than we give them credit for, but we can't tell from this specimen alone. What's truly remarkable is that conditions were just right in order to allow preservation of the brain tissue -- hopefully this is the first of many such discoveries."

"I have always believed I had something special. I noticed there was something odd about the preservation, and soft tissue preservation did go through my mind. Martin realised its potential significance right at the beginning, but it wasn't until years later that its true significance came to be realised," said paper co-author Jamie Hiscocks, the man who discovered the specimen. "In his initial email to me, Martin asked if I'd ever heard of dinosaur brain cells being preserved in the fossil record. I knew exactly what he was getting at. I was amazed to hear this coming from a world renowned expert like him."

Source: University of Cambridge [October 27, 2016]