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How Jurassic Park Ushered in a Golden Age of Dinosaurs

Monday, December 24, 2018

 Laura Dern and Sam Neill get tender with a Triceratops in Steven Spielberg’s 1993 blockbuster, Jurassic Park. The film has inspired a new golden age of discovery, having ‘de-nerded’ the study of dinosaurs. Photograph: MCA/Everett/Rex Features

A generation of scientists, inspired by Steven Spielberg’s 1993 blockbuster, are spearheading a revival in palaeontology.

Near crumbling cliffs outside Hastings in southern England, a herd of giant, plant-eating iguanodons gathered 130 million years ago and left their fossilised footprints embedded in the soil, Cambridge scientists revealed last week. Nearby, researchers also found the ancient tracks of a huge spike-covered dinosaur called an ankylosaurus. East Sussex was a busy place in Jurassic times, it seems.

In addition, Portsmouth University scientists last week outlined their discovery of a new species of flying reptile which once swooped above Britain. This giant raptor, Klobiodon rochei, had large fangs that would have meshed together to form a toothy cage, from which prey would have no escape once caught.

Nor have these newly discovered fossil wonders been confined to Britain. Scientists in South Africa recently announced they had found a new species of plant-eating dinosaur – Ledumahadi mafube – that was twice the size of an elephant while details of feathered dinosaurs, the predecessors of birds today, have been pouring out of China. Never has the probing of our prehistoric past been so productive.

It is a point stressed by Prof Paul Barrett of the Natural History Museum in London. “It would be wrong to say we are about to enter a new golden age of palaeontology. In fact, we have been in the middle of one for several years.”

This idea is backed by the fact there are now more palaeontologists working the field than ever before; more countries are being exploited for their dinosaur remains; more new species are being dug up and named; and more interesting work – using new technologies – is being done on fossilised bones once they have been disinterred.

In the process, scientists are learning how animals and plants responded to the very different and frequently much warmer climates that prevailed in those days. In turn, this information could have key importance in understanding how our world might respond to global heating later this century, researchers say.

Nor is there any dispute about one of the most important factors that triggered this rebirth of dinosaur studies. It was the film Jurassic Park, which was released 25 years ago. “Jurassic Park played a huge and under-appreciated role in the transformation of palaeontology that we are now witnessing,” said Dr Steve Brusatte, of Edinburgh University. “It used to be a rather dry academic topic carried out by old men at Oxbridge or Harvard. Today it is practised by a diverse group of scientists in many parts of the world, and it was Jurassic Park that provided the momentum for that change.”

Dr Susannah Maidment, a Natural History Museum palaeontologist agrees. “I was a teenager when Jurassic Park came out, and although I was already interested in dinosaurs by that time, its massive popularity meant I was no longer embarrassed about talking about such a career. I didn’t feel like a nerd.”

A ‘dinosaur’ promotes the 2015 film Jurassic World, at the Kings Cross station concourse, London. Fiction has fired the imagination, leading to a new wave of research.  Photograph: RZUK Images/Alamy Stock Photo

At Bristol University, Prof Mike Benton runs a masters course in palaeontology. “We have about 30 students a year, and we ask them what factor was the main influence in their decision to study dinosaurs. Jurassic Park gets the biggest show of hands.”

Other factors have played a role in the rebirth of dinosaur studies, however. “National pride is certainly involved,” said Barrett. “Dinosaur fossils are now being found all over the world. China and South Africa have provided key sites in recent years, for example, and that has had important consequences.”

Palaeontology is a cheap science that does not require huge telescopes or particle accelerators to proceed and can be used to kickstart scientific studies in a relatively poor nation. “You don’t have to put a lot of money into the subject but you can still boost national prestige and develop scientific expertise,” said Barrett.

Palaeontology has also benefited from technologies such as CAT scans, computer modelling, and high-powered microscopes which reveal tiny fragments of pigment and indicate how colourful some dinosaurs could be. Another example of this type of work was recently provided by Manchester University researchers who used computer simulations to show that the world’s most famous dinosaur, Tyrannosaurus rex, was not able to run at all and could only have lumbered towards its prey. Scavenging – not running after prey – was clearly a key part of its diet. “It is this ability to give dinosaurs colour and real lives that has also stimulated interest in them,” added Brusatte.

For good measure, there is the impact of dinosaur studies on the modern world. This has special relevance to research on the creatures and makes them important in resolving modern problems, said Maidment. One of the most important of these mysteries is known as the latitudinal biodiversity gradient.

“As you walk from the pole to the equator, you find the number of different species in a given area increases for each mile you travel towards the equator,” she said. “There are relatively few species at the poles and a lot at the equator. The trouble is that we don’t really know why species increase in that way because we have only one set of data – taken from the present day.

“If we can learn how things were in the past, when continents were in different positions or there was no ice at the poles, then we can gain an understanding of the phenomenon, and that will be crucial as global warming takes an effect on wildlife. How will diseases and their vectors behave and how will the growing of food be disrupted? Dinosaurs can teach us a lot.”

In the end, though, it is the simple sense of wonder that dinosaurs generate that has made them such a popular topic of investigation, said Benton. “Many of these creatures simply beggar belief. You have to ask: how the hell did that thing fly? How could something that vast even walk? You have to look at the physics of these creatures and realise they were doing something pretty wonderful.”

Source: www.theguardian.com

4 Cool Paleontological Discoveries In 2018

Saturday, December 22, 2018

Archaeopteryx fossils are rare and precious - GETTY

Fossils have taught us an enormous amount about the history of life on Earth, but there are always new things to find. Here is a highly subjective selection of the best discoveries of the year.

The ancestor of all life lived at least 3.9 billion years ago

All living organisms are related, which means they all descend from the Last Universal Common Ancestor: a mysterious organism that lived early in Earth's history. LUCA, as it's known, must have been a single-celled organism, somewhat like a bacterium.

A study published in August argued that LUCA lived at least 3.9 billion years ago, no more than 600 million years after the Earth formed.

Holly Betts at the University of Bristol and her colleagues compared the sequences of 29 genes across 102 species. They used that data to build a family tree, showing the order in which new groups split away from their relatives. Then they added dates from the geological record, which allowed them to estimate roughly when the various splits happened.

LUCA cannot be any younger than 3.9 billion years, the team reported. It could be considerably older, the maximum being about 4.5 billion years ago when the Earth formed and, soon after, a huge rock smacked into it and formed the Moon.

In this case, the genetics is revealing something the fossil record cannot. The oldest accepted fossils of living organisms are just 3.4 billion years old. Putative fossils from 3.7 billion years ago were reassessed this year, and it seems they were just peculiar folded rocks.

Animals with backbones emerged in shallow seas near the shore

Creatures with backbones are known as vertebrates. They include all fish, amphibians, reptiles, birds and mammals - including humans. So figuring out how and why the first vertebrates evolved is one of the biggest questions in paleontology.

In a study published in October, Lauren Sallan at the University of Pennsylvania and her colleagues compiled a database of nearly 3000 fish fossils from 480 to 360 million years ago. All the earliest vertebrate fossils were found in near-shore environments, such as tidal zones and lagoons. It was their descendants that moved out to colonise the wider, deeper ocean.

It's not clear why shallow seas acted as a cradle for the first vertebrates. It may be that the endless crashing waves near the shore acted as a selective pressure on animals to evolve tougher skeletons. A backbone stiffens an animal's entire body, which may have offered greater resilience.

The "first bird" Archaeopteryx really could fly, just not very well

Archaeopteryx is one of the most famous fossils ever discovered. The first specimens turned up just a few years after Darwin published Origin of Species, in which he set out his argument that new species evolve by natural selection. A fossilised "dino-bird" that had feathers and wings, but also had a toothed snout instead of a beak, and claws on its wings, was a perfect example of evolution in action. Later fossil discoveries, particularly from China, have revealed that Archaeopteryx was just one of a huge radiation of primitive birds, but it remains a crucial species.

Given its status as one of the first birds, it often surprises people to learn that paleontologists have long argued about whether or not it could actually fly. It had wings and feathers, but so do penguins and you don't see them taking to the skies. The question was whether it had gone far enough down the evolutionary road towards being a proper bird. Was its skeleton set up in such a way that it could flap its wings with enough force to take off?

According to a study published in March, the answer is: "kind of". Dennis Voeten of the ESRF, the European Synchrotron facility in Grenoble, France and his colleagues scanned an Archaeopteryx skeleton and found that its wing bones were set up for active flight. But it probably couldn't fly any great distance. Instead, it could take off for short bursts, perhaps to escape predators. Imagine a pheasant being flushed out by a fox, briefly hurtling up into the air to get to safety before returning to earth a short distance away, and you will have the idea.

An extinct bird from Madagascar was the largest bird ever to exist

Birds today can get pretty big. The ostrich is the heaviest living bird, regularly topping 100 kilograms, while the wandering albatross has the largest wingspan at over 3 metres.

However, in the past birds were bigger. The heaviest group seems to have been the elephant birds, which lived on Madagascar off Africa's east coast and resembled giant ostriches. They died out around 1000 years ago. It's not clear why, but humans were on Madagascar by then so we may have had something to do with it.

In a study published in September, James Hansford and Samuel Turvey of the Zoological Society of London, UK examined 346 specimens of elephant bird. As well as sorting out how the various groups were related, they identified a new species, which they dubbed Vorombe titan. Its average body mass was 650kg, far more than any ostrich and larger than any known extinct bird.

What's more, the pair examined a V. titan femur that was too incomplete to be included in their analyses. Based on its circumference, the animal it belonged to could have weighed 860kg, making it the largest individual bird ever found.

This doesn't change our understanding of the evolutionary story much; I just think giant birds are cool.

Source: www.forbes.com

Huge Global Tsunami Followed Dinosaur-Killing Asteroid Impact

Friday, December 21, 2018

Artist’s impression of an asteroid in the distance impacting shallow waters near the modern-day Yucatán Peninsula. Credit: Science Photo Library/Alamy Stock Photo

The cataclysmic Chicxulub impact roughly 66 million years ago spawned a tsunami that produced wave heights of several meters in distant waters, new simulations suggest.

The devastating tsunamis that struck the coastlines of Chile, Haiti, Indonesia, and Japan in recent decades produced waves tens of meters high, unimaginable to most people accustomed to gentle seas. But millions of years ago, a truly inconceivable set of waves—the tallest roughly 1,500 meters high—rammed through the Gulf of Mexico and spread throughout the ancient ocean, producing wave heights of several meters in distant waters, new simulations show.

The enormous waves were triggered by a large asteroid slamming into the shallow waters of the modern-day Yucatán Peninsula. That asteroid impact, which occurred about 66 million years ago and created the Chicxulub crater, contributed to the demise of the dinosaurs.

A Global Look

Molly Range, a paleoceanographer working at the University of Michigan when this research was conducted, and her colleagues have now modeled how the ensuing tsunami propagated in the Gulf of Mexico and beyond. “As far as we know, no one has done a global simulation of this impact,” said Range.

Range and her collaborators used two models: one simulating the initial impact of an asteroid 14 kilometers in diameter into shallow water and one modeling the ensuing propagation of displaced water throughout the ancient ocean. It was necessary to use the two models in tandem, explained Brian Arbic, a physical oceanographer at the University of Michigan who was involved in the study. “A typical ocean model just can’t handle an asteroid,” he noted.

The first effect of the asteroid impact, the researchers found, would have been a roughly 1,500-meter-high tsunami wave. This wave represented the “initial blast of water away from the impact,” said Range.

A simulation is shown in the video below. Crustal material is shown in brown, sediments are shown in yellow, and the ocean is shown in blue.

A few minutes later, the models show that water began refilling the gaping crater formed by the impact. “You have a steep wall of water that rushes back in,” said Arbic. This rapid inflow likely triggered yet another set of waves. Although the strongest effects from the tsunami were felt in the Gulf of Mexico, the waves would have propagated globally, Range and her team found. Thanks to the seaway that existed between North America and South America at the time of the dinosaurs, the tsunami waves would have rushed freely into the Pacific Ocean.

Range and her colleagues calculated that the tsunami wave heights in the Pacific and Atlantic basins would have been as large as 14 meters. As these waves approached land and slowed down, they would have gotten even larger. But because the researchers’ models didn’t include the topography of the continents 66 million years ago, it wasn’t possible to calculate actual wave run-up heights, Arbic said.

Displaced Sediments

The scientists also showed that the tsunami waves would have pushed water at the seafloor by more than 20 centimeters per second. Such strong water flows are sufficient to scour sediments from the bottom of the ocean, the researchers said. Scouring would have occurred in the South Pacific and the North Atlantic, the modeling revealed. Tantalizingly, in-progress research by the same team is showing that these very places are also where sediment coring experiments have found dislodged and displaced sediments.

These results were presented at AGU’s Fall Meeting 2018 in Washington, D. C.

The implications of this work are significant, said Timothy Bralower, an Earth scientist at Pennsylvania State University who was not involved in the research. “Geologists can now glean the sediments at sites far afield from the crater to detect the fingerprints of the tsunami.”

This modeling provides a glimpse into a cataclysmic part of Earth’s history that, thankfully, hasn’t been repeated. But more advanced simulations—incorporating, for example, higher spatial resolution or estimates of on-land topography so wave run-ups can be estimated—would improve our understanding of this tsunami, Arbic explained.

But one thing is very clear: The Chicxulub tsunami was clearly a force to be reckoned with. As Arbic said, “It must have been one of the biggest tsunami ever.”

Citation: Kornei, K. (2018), Huge global tsunami followed dinosaur-killing asteroid impact, Eos, 99, https://doi.org/10.1029/2018EO112419. Published on 20 December 2018.

Source: https://eos.org

Argentina Puts 65-Million-Year-Old Dinosaur Replica on Display

Friday, December 21, 2018

A reproduction of the skeleton of a 65-million-year-old plesiosaur marine reptile discovered in cretaceous rocks in Argentine Patagonia

Argentine paleontologists unveiled the replica of a 65-million-year-old skeleton of a plesiosaur marine reptile found in a Patagonian lake in 2009.

"We've been working since 2009 until now to liberate the fossil from the  surrounding it, making a reproduction and hanging it here in the museum hall," paleontologist Fernando Novas of the Bernardino Rivadavia Natural Science Museum in Buenos Aires told AFP.

The fossil is of a marine reptile found in Cretaceous period rocks close to the southern town of El Calafate, 2,800 kilometers (1,700 miles) from Buenos Aires.

The fossil was found in Cretaceous period rocks close to the southern town of El Calafate

The remains of this plesiosaur are the most complete found in Argentina and were discovered in rocks submerged in Lake Argentino at the foot of the Andes mountains.

"It was around 50 centimeters (1.64 feet) under the water and part of the lake had to be drained to take out the rocks," said scientist Marcelo Isasi.

Four tons of rocks had to be removed to unearth the fossil remains, found just 500 meters (1,640 feet) from an international airport.

Plesiosaurs were huge marine reptiles that lived in seas throughout the entire planet inhabited the entire planet, with long necks, tiny heads and sharp teeth.

Four tons of rocks had to be removed to unearth the fossil remains, found just 500 meters (1,640 feet) from an international airport

It was an era before the Andes existed and when Argentine Patagonia lay underwater.

The fossil is nine meters long with each fin measuring 1.3 meters.

Source: https://phys.org

Scientists Discover Over 450 Fossilized Millipedes in 100-Million-Year-Old Amber

Thursday, December 20, 2018

One of the newly discovered millipede fossilized in Cretaceous amber from Myanmar (Burma). Credit: Dr Thomas Wesener

Since the success of the Jurassic Park film series, it is widely known that insects from the Age of the Dinosaurs can be found exceptionally well preserved in amber, which is in fact fossilised tree resin.

Especially diverse is the animal fauna preserved in Cretaceous amber from Myanmar (Burma). Over the last few years, the almost 100-million-year-old amber has revealed some spectacular discoveries, including dinosaur feathers, a complete dinosaur tail, unknown groups of spiders and several long extinct groups of insects.

However, as few as three millipede species, preserved in Burmese amber, had been found prior to the study of Thomas Wesener and his Ph.D. student Leif Moritz at the Zoological Research Museum Alexander Koenig - Leibniz Institute for Animal Biodiversity (ZFMK). Their research was recently published in the open-access journal Check List.

Having identified over 450 millipedes preserved in the Burmese amber, the scientists confirmed species representing as many as 13 out of the 16 main orders walking the Earth today. The oldest known fossils for half of these orders were found within the studied amber.

The researchers conducted their analysis with the help of micro-computed tomography (micro-CT). This scanning technology uses omni-directional X-rays to create a 3-D image of the specimen, which can then be virtually removed from the amber and digitally examined.

One of the newly discovered fossilized millipede. Credit: Dr Thomas Wesener

The studied amber is mostly borrowed from private collections, including the largest European one, held by Patrick Müller from Käshofen. There are thought to be many additional, scientifically important specimens, perhaps even thousands of them, currently inaccessible in private collections in China.

Over the next few years, the newly discovered specimens will be carefully described and compared to extant species in order to identify what morphological changes have occurred in the last 100 million years and pinpoint the speciation events in the millipede Tree of Life. As a result, science will be finally looking at solving long-standing mysteries, such as whether the local millipede diversity in the southern Alps of Italy or on the island of Madagascar is the result of evolutionary processes which have taken place one, ten or more than 100-million years ago.

According to the scientists, most of the Cretaceous millipedes found in the amber do not differ significantly from the species found in Southeast Asia nowadays, which is an indication of the old age of the extant millipede lineages.

On the other hand, the diversity of the different orders seems to have changed drastically. For example, during the Age of the Dinosaurs, the group Colobognatha—millipedes characterised by their unusual elongated heads which have evolved to suck in liquid food—used to be very common. In contrast, with over 12,000 millipede species living today, there are only 500 colobognaths.

Another curious finding was the discovery of freshly hatched, eight-legged juveniles, which indicated that the animals lived and reproduced in the resin-producing trees.

"Even before the arachnids and insects, and far ahead of the first vertebrates, the -eating millipedes were the first animals to leave their mark on land more than 400-million-years ago," explain the scientists. "These early millipedes differed quite strongly from the ones living today—they would often be much larger and many had very large eyes."

The larger species in the genus Arthropleura, for example, would grow up to 2 m (6.5 ft) long and 50-80 cm (2-3 ft) wide—the largest arthropods to have ever crawled on Earth. Why these giants became extinct and those other orders survived remains unknown, partly because only a handful of usually badly preserved fossils from the whole Mesozoic era (252-66-million years ago) has been retrieved. Similarly, although it had long been suspected that the 16 modern millipede orders must be very old, a fossil record to support this assumption was missing.

More information: Thomas Wesener et al, Checklist of the Myriapoda in Cretaceous Burmese amber and a correction of the Myriapoda identified by Zhang (2017), Check List (2018). DOI: 10.15560/14.6.1131

Source: https://phys.org

Why Massive Dinosaurs Had Funky ‘Crazy Straw’ Noses?

Thursday, December 20, 2018

A model of the head of Euoplocephalus, showing its convoluted nasal passages (LAWRENCE WITMER)

The late Cretaceous period, which ended 66 million years ago, was a rough-and-tumble time. Dinosaurs like ankylosaurus left reminders of brutishness in their fossilized armor. Spikes sprouted from their shoulders. Row after row of bony plates covered their backs. With low and well-protected bulks, tipping the scales at a ton or more, they were built like battle tanks.

Their heads, in contrast to their backs, were simple. Other dinosaurs have ornate frills and crests or jaws full of banana-size teeth. But the armored dinosaurs had small, boxy heads. Even dinosaur fans “don’t usually think much about” these skulls, said Jason M. Bourke, a vertebrate paleontologist at the New York Institute of Technology.

At least they hadn’t until some of Bourke’s colleagues, led by Lawrence M. Witmer at Ohio University, digitally pried open an ankylosaur skull. What the paleontologists found, according to a study published in the journal PLOS One, can explain how these walking tanks avoided boiling their brains under the prehistoric sun.

Using a CT scanner, Witmer tracked long, twisty airways that curled like “crazy straws,” Bourke said. No one knew exactly what these nasal loops were for: Perhaps the convolutions aided vocalizations or gave the animals a superior sense of smell.

There was a third possible explanation, which biologists call thermoregulation. Most vertebrate animals must maintain their bodies within a narrow range of temperatures. For smaller animals, especially those in cold climates, thermoregulation is often viewed as a way of preventing heat loss. However, large animals, who hold in lots of heat, have the opposite problem.

The heat exchange of air passing through the nasal cavity of the Euoplocephalus, an ankylosaur. (Witmer Lab/Ohio University)

Delicate organs like brains must be kept cool. “Neural structures really don’t like undergoing rapid changes in temperature,” Bourke said. The armored dinosaurs must have been particularly vulnerable. Not only were they bulky, which means they accumulated lots of body heat, but their smallish brains had a high ratio of surface area to volume, which means the heads could gain or lose heat readily. It wouldn’t take much to fry an ankylosaur noggin.

Bourke and Witmer, along with Wm. Ruger Porter, a postdoctoral researcher in Witmer’s lab, recently created a detailed computer model to follow heat as it passes through the animals' noses. Bourke, who conducted this work as part of his graduate research at Ohio University, is the first person to use computational fluid dynamics to model dinosaur nose tissues.

Thanks to CT scans of fossilized skulls that retained soft tissue, the scientists reconstructed the passageways and blood vessels of two armored dinosaur species. When they unwound the nasal straws in digital space, the passages, stretched end to end, were 1.4 to two times as long as the dinosaurs' skulls.

They also estimated how much energy it would take for a dinosaur to warm a breath of Cretaceous air, estimated to be about 60 degrees, to a body temperature of around 95 degrees Fahrenheit. Those temperatures are rough estimates, but logical ones. “Estimates for things like body mass, lung volume and body temperature, which feed into the parameters of the model, are justified based on the supporting literature,” said Caleb M. Brown, a paleontologist at the Royal Tyrrell Museum in Alberta, Canada, who was not involved with this work. Anyway, he said, the exact numbers aren’t important. “It is these overall trends that are important.”

To heat a single breath to the body temperature of an Euoplocephalus, an ankylosaurian dinosaur, required more than 1.5 calories. (About three breaths would burn the calories in a cup of lettuce.) Put another way, the looping passages draw heat from blood vessels. This warmed the air headed to the lungs while cooling the blood near the airway. A network of vessels, the study authors said, shuttled that chilled blood back toward the brain, like coolant water piped through a power plant.

This model “shows quite convincingly that the convoluted nasal passages of both armored dinosaurs would have efficiently warmed and moistened air on inhalation, and cooled and dried air on exhalation,” Brown said.

Though this is strong support for the thermoregulation hypothesis, the scientists haven’t ruled out multiple uses. Perhaps the winding noses lowered the timbre of their calls, too, Bourke said.

Armored dinosaur respiration was different from that in the largest animals alive today. An ankylosaurus the size of a rhino probably breathed about a third as frequently. Breathing in air through these passages meant it took a while for air to get to lungs. Bursts of high activity would have been difficult.

“They probably didn’t have to do a lot of running,” Bourke said. When they did, it’s possible they became mouth-breathers.

Source: www.washingtonpost.com

Scientists Study Fossil Evidence of Shark Hunting Flying Reptile Mid-Air

Thursday, December 20, 2018

The red arrow points to where the prehistoric shark tooth got lodged in the pterosaur's neck. (David Hone)

A new study suggests that the winged reptile fell prey to a hungry predator lurking in the water.

In 1965, archaeologists working in the Smoky Hill Chalk region of Kansas discovered the fossil of a large Pteranodon, a pterosaur (or flying reptile) that soared through the air during the Late Cretaceous PeriodPteranodon remains are quite common in the fossil record; some 1,100 specimens have been found, more than any other prehistoric winged reptile. But there was something unusual about this particular specimen: it had a shark tooth lodged against its neck vertebrae.

Now, as Stephanie Pappas reports for Live Science, researchers have taken a closer look at the fossil to try and determine how the tooth came to be embedded in the Pteranodon remains. And the results of their inquiry, published in Peer J, suggest that this great predator of the sky may have fallen victim to a great predator of the sea.

The area where the Pteranodon fossil was discovered is a marine deposit created by the Western Interior Seaway, a huge waterway that once stretched from the Gulf of Mexico to Canada. After it was excavated, the Pteranodon was stored at the Los Angeles County Natural History Museum and eventually put on permanent display, shark tooth and all. It was a big creature, with a wingspan stretching more than 16 feet, and it weighed around 100 pounds. Like other members of its species, it had a crested skull and fed by catching fish in its pelican-like jaws.

The shark tooth, according to the study authors, belonged to the species Cretoxyrhina mantelli, a large and fearsome predator that stalked the Late Cretaceous seas. These sharks could grow as long as 23 feet, but the owner of the lost tooth was only around eight feet in length, based on the size of the tooth in question.

Two views of the Cretoxyrhina mantelli tooth with tracings. (David Hone)

When trying to figure out why the remains of two distinct animals were intertwined in the fossil record, the researchers had to consider the possibility that they were pulled together by the sea's currents. But Michael Habib, study co-author and a paleontologist at the University of Southern California, tells Pappas that sediment in the area suggests the waters were relatively calm millions of years ago. Additionally, the study authors write, “the spatial relationship between the tooth and the vertebra is complex and intimate, and unlike that expected to have occurred by chance association.” Other ancient shark species have also been known to feast on flying pteroaurs; earlier this year, a series of bite marks from the prehistoric Squalicorax shark were found on the wing bone of a Pteranodon.

The researchers thus suspected that the Cretoxyrhina mantelli shark had taken a hefty bite out of the pteranodon, losing its tooth in the process. It is possible, they study authors say, that the shark was simply scavenging on a pteranodon carcass. But it is also possible that the pteranodon was actively hunted.

Today’s sharks are known to dramatically breach the water while pursuing prey, but Habib tells Atlas Obscura’s Matthew Taub that the ancient Cretoxyrhina mantelli probably didn’t have to leap out of the sea to catch the pteranodon mid-flight. Pteranodons are thought to have hunted by diving after fish or scooping them up from an alighted position on the water. The winged reptile’s feeding habits, in other words, brought it within range of hungry sharks lurking below the surface.

According to the study authors, an unsuspecting pteranodon would have been no match for even a mid-sized Cretoxyrhina mantelli. “[W]e have little doubt that such predators could subdue these pterosaurs if they caught them,” they write.

Though it is impossible for the researchers to come up with a definitive story of how the pteranodon met its end, the implications of their hypothesis are important to the study of the species. It is rare to find signs of predation on Pteranodon skeletons; only seven of the more than 1,000 known specimens show evidence of predator-prey interaction. The new study also suggests that there may be parallels between the hunting behaviors of today’s sharks, which are known to prey on sea birds, and those that swam through ancient waters.

“Understanding the ecology of these animals is important to understanding life on Earth through time,” Habib says. “We now know sharks were hunting flying animals as long ago as 80 million years.”

Source: www.smithsonianmag.com

Saltriovenator zanellai: New Carnivorous Dinosaur Unveiled

Friday, December 21, 2018

Life reconstruction of Saltriovenator zanellai. Image credit: Davide Bonadonna.

A partial skeleton of a ceratosaurian theropod dinosaur unearthed over two decades ago in Italy has been recognized as belonging to a new genus and species.

The newly-identified dinosaur belongs to Ceratosauria (ceratosaurs), a group of large-bodied theropod dinosaurs.

Named Saltriovenator zanellai, it lived approximately 198 million years ago (Early Jurassic epoch).

With an estimated body length of 25 feet (7.5 m), it is the largest and most robust theropod from the Early Jurassic, pre-dating the occurrence in theropods of a body mass approaching 1,000 kg by over 25 million years.

The ancient creature is also the oldest known ceratosaur and is the first Jurassic dinosaur known from Italy.

Selected elements used in the diagnosis of Saltriovenator zanellai: right humerus in medial (A), frontal (B) and distal (C) views; (D) left scapula, medial view; (E) right scapular glenoid and coracoid, lateral view; (F) furcula, ventral view; tooth, labial (G) and apical (H) views; (I) left humerus, medial view; right second metacarpal in dorsal (J), lateral (L) and distal (N) views; first phalanx of the right second digit in dorsal (K), lateral (M) and proximal (O) views; (P–T) right third digit in proximal, dorsal and lateral views; (U) right distal tarsal IV, proximal view; third right metatarsal in proximal (V) and frontal (X) views; second right metatarsal, proximal (W) and frontal (Y) views; (Z) reconstructed skeleton showing identified elements (red). Abbreviations as in text, asterisks mark autapomorphic traits. Scale bars – 10 cm in (A)–(E), (I), and (U)–(Y); two cm in (F), and (J)–(T); one cm in (G). Image credit: G. Bindellini / C. Dal Sasso / M. Zilioli / M. Auditore.

The partial skeleton of Saltriovenator zanellai was accidentally discovered in 1996 by Angelo Zanella, fossil amateur and collaborator of the Museo di Storia Naturale di Milano, in a huge quarry located in the Alpine foothills, at the Swiss-Italian border near Saltrio, less than 50 miles (80 km) north of Milan, Varese Province, Lombardy.

Many bones of the dinosaur bear feeding marks by marine invertebrates, which represent the first case on its remains and indicate that its carcass floated in a marine basin and then sunk, remaining on the sea bottom for quite a long time before burial.

“Although fragmentary, Saltriovenator zanellai shows a mosaic of ancestral and advanced anatomical features, respectively seen in the four-fingered dilophosaurids and ceratosaurs, and the three-fingered tetanuran theropods, such as allosaurids,” said Dr. Cristiano Dal Sasso, a paleontologist at the Museo di Storia Naturale di Milano.

“Paleohistological analysis indicates that Saltriovenator zanellai was a still growing subadult individual, therefore its estimated size is all the more remarkable, in the context of the Early Jurassic epoch,” added Dr. Simone Maganuco, also from the Museo di Storia Naturale di Milano.

“The evolutionary ‘arms race’ between stockier predatory and giant herbivorous dinosaurs, involving progressively larger species, had already begun 200 million of years ago.”

“The grasping hand of Saltriovenator zanellai fills a key gap in the theropod evolutionary tree: predatory dinosaurs progressively lost the pinky and ring fingers, and acquired the three-fingered hand which is the precursor of the avian wing,” said Dr. Andrea Cau, a researcher at the Museo Geologico ‘Giovanni Capellini.’

The discovery of Saltriovenator zanellai is reported in the journal PeerJ.

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C. Dal Sasso et al. 2018. The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds. PeerJ 6: e5976; doi: 10.7717/peerj.5976

Source: www.sci-news.com

Sue the T. rex — Now With More Bones! — Goes Back on Display

Wednesday, December 19, 2018

Sue has new digs, more bones and a new pose in its new exhibit opening Friday at the Field Museum. | Field Museum/Martin

The largest and most complete Tyrannosaurus rex skeleton ever found is making its debut (again) at the Field Museum — and it’s now even more complete than before.

Sue the T. rex back on display to the public. The T. rex had been living in Stanley Hall on the main floor for nearly two decades, but the fossil is taking up permanent residence upstairs in the Griffin Halls of Evolving Planet exhibit. Her new digs — and new look — were unveiled to the media.

The Field Museum began the de-installation of SUE the Tyrannosaurus rex from Stanley Field Hall earlier this year. | Sun-Times file photo

Officials at the Field Museum say it took years of planning to get Sue’s new exhibit just right. The T. rex gets its name from Sue Hendrickson, who is credited with the dinosaur’s discovery in South Dakota in 1990. Sue has no known gender, but in the years since the Field Museum acquired the fossil for a record-breaking $8.4 million in 1997, experts have learned a lot about T. rex dinosaurs, the museum said in a press release. The new 5,100-square-foot suite incorporates that research and better introduces visitors in the daily life of a 40-foot dinosaur, officials said.

Some of that research includes the addition of a missing puzzle piece: gastralia, a set of bones previously left off Sue  because scientists weren’t sure how to mount them. Scientists believe the bones, which resemble a rib cage, helped the dinosaur breathe. Sue has a new walking pose and its wishbone was adjusted.

“When SUE was discovered, scientists didn’t know exactly how the gastralia fit onto the skeleton, so they were left off,” says Pete Makovicky, the museum’s curator of dinosaurs. “Thanks to the research we’ve been doing on Sue for the last 20 years, we now know what they were for and where they should go.”

In the new exhibit, visitors will be immersed in Sue’s surroundings from the Cretaceous period 67 million years ago, including other life forms from the time. The exhibit offers multimedia presentations on everything from how Sue hunted and interacted with other dinosaurs — to how Sue pooped. Her mounted pose has also been changed.

Sue before (left) and after. Changes include an added set of belly ribs and updates in posture. JOHN WEINSTEIN/FIELD MUSEUM

Sue had been on display in Stanley Hall since May 2000. In early February 2018, scientists began to disassemble the mammoth fossil to make way for a model of a 122-foot titanosaur the museum acquired last year and put on display the summer of that year.

Sue’s comings and goings have been featured on its Twitter account, @SUEtheTrex, which has gained nearly 50,000 followers since the fossil started tweeting in 2009. Sue tweeted: “I’m back on display this week and everything else pales in comparison right now.”

Sue’s colorful new digs feature renderings of environments they once roamed. MARTIN BAUMGAERTNER/FIELD MUSEUM

Source: https://chicago.suntimes.com

After 80 Million Years, Oregon's First Dinosaurs 'Discovered' Within Weeks of Each Other

Wednesday, December 19, 2018

John Griffith/Special to The Oregonian

In November 2018, we reported that a researcher from the University of Oregon made the first discovery of a dinosaur fossil in Oregon, a monumental find for a state that was covered by an ocean when the prehistoric creatures roamed the earth.

The fossil in question was discovered in central Oregon, near the town of Mitchell, by Greg Retallack, a researcher from the university. The find was described as "the first Oregon dinosaur fossil ever reported in a peer-reviewed scientific journal' in a post on the university's website.

Those last five words are an important caveat, though, says Dave Taylor, previously a researcher at U of O and now president of the Northwest Museum of Natural History.

After the November story was posted, Taylor emailed the Oregonian/OregonLive to point out that a fossil was discovered at Oregon's Cape Sebastian in the mid-1960s, excavated in the 1990s and was, just recently, confirmed to be that of a duck-billed dinosaur.  

A discovery in fits and starts

In the early 1960s, Taylor said, a crew from the U.S. Geological Survey happened upon the fossil at Cape Sebastian, an outcropping of sandstone near Gold Beach on Oregon's southern coast.

In 1969, a pair of professors from the University of California, Berkeley, traveled north to inspect the fossil and confirmed that it was the sacrum, or fused vertebrae, of a duck-billed hadrosaur.

And then the fossil sat in the rock for nearly 30 years, much as it had for the previous 80 million or so, before Taylor and a team went back to the cape in 1994 to excavate the ancient bone.

"The fossil appeared in grainy, brownish-gray relief, like a rock inlay, in the otherwise light gray slab of sandstone at the tip of the cape," The Oregonian reported in 1994. "At low tide on a calm day, it was 15 feet above the crests of the gently rolling swells. Just above it, the forested nose of the cape rose sharply toward U.S. 101."

More than 2 feet long and roughly 70 pounds, getting the fossil out of the rock proved no easy task. With the help of a cadre of volunteers, many of them children from around Oregon, Taylor pulled the fossil from the rock and showed it to a number of experts, all of whom agreed that the bone came from a hadrosaur.

And then he brought it up to Portland where, again, it would sit for a three-decade spell before he could turn his attention to it.

It wasn't until he retired in 2013 that Taylor finally had time to prepare the fossil, carefully chipping away at the sandstone that still clung to it, for description in a peer-reviewed paper. 

A second 'first'

In 2015, while Taylor was working to prepare the Cape Sebastian fossil, University of Oregon earth sciences Professor Greg Retallack was in central Oregon, leading a field expedition of students looking for fossilized plants near the town of Mitchell at a hotspot for ancient rocks called the Hudspeth Formation.

The group came upon a pile of ammonites, spiral shaped sea creatures that went extinct around the same time as the dinosaurs. Sitting there, on top of the pile, was a bone, Retallack recounted.

"I knew immediately what it was," he said. "The students were a bit mystified, but I was thrilled."

Kristin Strommer, publicist for the University of Oregon's Museum of Natural and Cultural History, poses with the fossil. Courtesy/University of Oregon

The fossil, a toe bone, belonged to a creature called an ornithopod, a 17-foot-long herbivore that weighed up to 1,500 pounds and walked on two legs. The fossil is thought to be roughly 103 million years old, dating back to the Cretaceous period.

Back then, the Pacific Ocean stretched far inland from the beaches we know today, and the coast started at the Blue Mountains in what is now eastern Oregon. The shoreline was rocky and rugged, and everything west of present day Wallowa was under water.

Courtesy/Liz White/University of Oregon

Source: www.oregonlive.com

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