Dinosaur discoveries in Spain


Artist's rendering of small dromaeosaur from the South Pyrenees. Credit: Sydney Mohr (artist), University of Alberta

From the University of Alberta in Canada:

Big dinosaur discoveries in tiny toothy packages

August 7, 2015

Researchers have examined one of the smallest parts of the fossil record—theropod teeth—to shed light on the evolution of dinosaurs at the end of the Cretaceous. Findings published in the prestigious journal Acta Palaeontologica Polonica have effectively quadrupled the dinosaur diversity in the area of study, eight localities from Treviño County, Huesca and Lerida—including the exceptional site of Laño. There were previously only two known species in the area.

The study of 142 isolated teeth from the Campanian-Maastrichtian of the South Pyrenean Basin suggests six additional species of toothed theropods (five small, one large) were present in the region. “Studying these small parts helps us reconstruct the ancient world where lived and to understand how their extinction happened,” says lead author Angelica Torices, post-doctoral fellow in biological sciences at the University of Alberta. “Teeth are especially important in the study of Upper Cretaceous creatures in Spain and the rest of Europe because we don’t have complete skeletons of theropods from that time in those locations. We have to rely on these small elements to reconstruct the evolution of these dinosaurs, particularly the theropods.”

Carnivorous dinosaurs replaced their teeth continuously, with just one dinosaur producing a huge number of these dental pieces and an endless number of clues for understanding these mysterious creatures. This study demonstrates the value of isolated teeth in reconstructing the composition of dinosaur paleofaunas when other, more complete material is not present, allowing interpretation of the evolution of diversity through time.

The findings provide huge strides in understanding not only the diversity of carnivorous dinosaurs at the end of the Cretaceous in Europe, but also how the diversity of large animals responds to climatic changes. “It completely changes the vision of the ecosystem,” says Torices. “Moreover, we now understand that these dinosaurs disappeared very quickly in geological time, probably in a catastrophic event. Climatic models show that we may reach Cretaceous temperatures within the next century, and the only way we can study biodiversity under such conditions is through the fossil record.”

More information: “Theropod dinosaurs from the Upper Cretaceous of the South Pyrenees Basin on Spain” appeared in Acta Palaeontologica Polonica in August, 2015.

Big dinosaur age shark discovery


Cretaceous fossil sharks reconstruction. Credit: Frederickson et al.

From LiveScience:

20-Foot Monster Shark Once Trolled Mesozoic Seas

by Tia Ghose, Senior Writer

June 03, 2015 02:01pm ET

A giant shark the size of a two-story building prowled the shallow seas 100 million years ago, new fossils reveal.

The massive fish, Leptostyrax macrorhiza, would have been one of the largest predators of its day, and may push back scientists’ estimates of when such gigantic predatory sharks evolved, said study co-author Joseph Frederickson, a doctoral candidate in ecology and evolutionary biology at the University of Oklahoma.

The ancient sea monster was discovered by accident. Frederickson, who was then an undergraduate at the University of Wisconsin-Milwaukee, had started an amateur paleontology club to study novel fossil deposits. In 2009, the club took a trip to the Duck Creek Formation, just outside Fort Worth, Texas, which contains myriad marine invertebrate fossils, such as the extinct squidlike creatures known as ammonites. About 100 million years ago the area was part of a shallow sea known as the Western Interior Seaway that split North America in two and spanned from the Gulf of Mexico to the Arctic, Frederickson said.

While walking in the formation, Frederickson’s then-girlfriend (now wife), University of Oklahoma anthropology doctoral candidate Janessa Doucette-Frederickson, tripped over a boulder and noticed a large vertebra sticking out of the ground. Eventually, the team dug out three large vertebrae, each about 4.5 inches (11.4 centimeters) in diameter. [See Images of Ancient Monsters of the Sea]

“You can hold one in your hand,” but then nothing else will fit, Frederickson told Live Science.

The vertebrae had stacks of lines called lamellae around the outside, suggesting the bones once belonged to a broad scientific classification of sharks called lamniformes that includes sand tiger sharks, great white sharks, goblin sharks and others, Frederickson said.

After poring over the literature, Frederickson found a description of a similar shark vertebra that was unearthed in 1997 in the Kiowa Shale in Kansas, which also dates to about 100 million years ago. That vertebra came from a shark that was up to 32 feet (9.8 meters) long.

By comparing the new vertebra with the one from Kansas, the team concluded the Texas shark was likely the same species as the Kansas specimen. The Texan could have been at least 20.3 feet (6.2 m) long, though that is a conservative estimate, Frederickson said. (Still, the Texas shark would have been no match for the biggest shark that ever lived, the 60-foot-long, or 18 m, Megalodon.)

By analyzing similar ecosystems from the Mesozoic Era, the team concluded the sharks in both Texas and Kansas were probably Leptostyrax macrorhiza. Previously, the only fossils from Leptostyrax that paleontologists had found were teeth, making it hard to gauge the shark’s true size. The new study, which was published today (June 3) in the journal PLOS ONE, suggests this creature was much bigger than previously thought, Frederickson said.

Still, it’s not certain the new vertebrae belonged to Leptostyrax, said Kenshu Shimada, a paleobiologist at DePaul University in Chicago, who unearthed the 1997 shark vertebra.

“It is also entirely possible that they may belong to an extinct shark with very small teeth so far not recognized in the present fossil record,” Shimada, who was not involved in the current study, told Live Science. “For example, some of the largest modern-day sharks are plankton-feeding forms with minute teeth, such as the whale shark, basking shark and megamouth shark.”

Either way, the new finds change the picture of the Early Cretaceous seas.

Previously, researchers thought the only truly massive predators of the day were the fearsome pliosaurs, long-necked, long-snouted relatives to modern-day lizards that could grow to nearly 40 feet (12 m) in length. Now, it seems the oceans were teeming with enough life to support at least two top predators, Frederickson said.

As for the ancient shark’s feeding habits, they might resemble those of modern great white sharks, who “eat whatever fits in their mouth,” Frederickson said. If these ancient sea monsters were similar, they might have fed on large fish, baby pliosaurs, marine reptiles and even full-grown pliosaurs that they scavenged, Frederickson said.

First four-legged snake fossil discovery


This video says about itself:

Tetrapodophis amplectus – A four-legged snake from the Early Cretaceous of Gondwana

24 July 2015

Tetrapodophis amplectus appears to be a four-legged snake from the Early Cretaceous of Gondwana. Dr. Dave Martill, from the University of Portsmouth, says that this discovery could help scientists to understand how snakes lost their legs.

From the BBC:

Four-legged snake ancestor ‘dug burrows’

By Jonathan Webb Science reporter, BBC News

24 July 2015

A 113-million-year-old fossil from Brazil is the first four-legged snake that scientists have ever seen.

Several other fossil snakes have been found with hind limbs, but the new find is estimated to be a direct ancestor of modern snakes.

Its delicate arms and legs were not used for walking, but probably helped the creature to grab its prey.

The fossil shows adaptations for burrowing, not swimming, strengthening the idea that snakes evolved on land.

That debate is a long-running one among palaeontologists, and researchers say wiggle room is running out for the idea that snakes developed from marine reptiles.

“This is the most primitive fossil snake known, and it’s pretty clearly not aquatic,” said Dr Nick Longrich from the University of Bath, one of the authors of the new study published in Science magazine.

Speaking to Science in Action on the BBC World Service, Dr Longrich explained that the creature’s tail wasn’t paddle-shaped for swimming and it had no sign of fins; meanwhile its long trunk and short snout were typical of a burrower.

“It’s pretty straight-up adapted for burrowing,” he said.

When Dr Longrich first saw photos of the 19.5cm fossil, now christened Tetrapodophis amplectus, he was “really blown away” because he was expecting an ambiguous, in-between species.

Instead, he saw “a lot of very advanced snake features” including its hooked teeth, flexible jaw and spine – and even snake-like scales.

“And there’s the gut contents – it’s swallowed another vertebrate. It was preying on other animals, which is a snake feature.

“It was pretty unambiguously a snake. It’s just got little arms and little legs.”

Deadly embrace?

At 4mm and 7mm long respectively, those arms and legs are little indeed. But Dr Longrich was surprised to discover that they were far from being “vestigial” evolutionary leftovers, dangling uselessly.

“They’re actually very highly specialised – they have very long, skinny fingers and toes, with little claws on the end. What we think [these animals] are doing is they’ve stopped using them for walking and they’re using them for grasping their prey.”

That comparatively feeble grasp, which may have also been applied during mating, is where the species gets its name. Tetrapodophis, the fossil’s new genus, means four-footed snake, but amplectus is Latin for “embrace”.

“It would sort of embrace or hug its prey with its forelimbs and hindlimbs. So it’s the huggy snake,” Dr Longrich said.

In order to try to pinpoint the huggy snake’s place in history, the team constructed a family tree using known information about the physical and genetic make-up of living and ancient snakes, plus some related reptiles.

That analysis positioned T. amplectus as a branch – the earliest branch – on the the very same tree that gave rise to modern snakes.

Neglected no more

Remarkably, this significant specimen languished in a private collection for decades, before a museum in Solnhofen, Germany, acquired and exhibited it under the label “unknown fossil”.

It was there that Dr Dave Martill, another of the paper’s authors, stumbled upon it while leading a student field trip. He told the Today programme on BBC Radio 4 they were principally visiting to see the museum’s famous Archaeopteryx fossil.

“All of a sudden my jaw absolutely dropped, when I saw this little fossil like a piece of string,” said Dr Martill, from the University of Portsmouth.

As he peered closer, he managed to spot the four tiny legs – and immediately asked the museum for permission to study the creature.

Dr Bruno Simoes, who studies the evolution of snake vision at the Natural History Museum in London, told the BBC he was impressed by the new find because the snake’s limbs are so well preserved, and appear so well developed.

“It’s quite a surprise, especially because it’s so close to the crown group – basically, the current snakes,” he said.

“It gives us a good idea of what the ancestral snake was like.”

Dr Simoes suggested that alongside several other recent findings, this new fossil evidence had clinched the argument for snakes evolving on land.

“All [the latest findings] suggest that the ancestor of all snakes was a terrestrial animal… which lived partially underground.”

Plesiosaur discovery in Alberta, Canada


Plesiosaur skeleton

In Alberta, Canada, a fossil plesiosaur from the Cretaceous age has been discovered in November 2011: here.

Talking about fossils: Oldest Hairy Microbe Fossils Discovered.

Romanian fossil Balaur, dinosaur or bird?


This 2011 video is called Ancient Reptile Tribute Three: Balaur bondoc / Dromaeosaurid – Dinosaur.

From PeerJ:

The phylogenetic affinities of the bizarre Late Cretaceous Romanian theropod Balaur bondoc (Dinosauria, Maniraptora): dromaeosaurid or flightless bird?

June 18, 2015

Abstract

The exceptionally well-preserved Romanian dinosaur Balaur bondoc is the most complete theropod known to date from the Upper Cretaceous of Europe. Previous studies of this remarkable taxon have included its phylogenetic interpretation as an aberrant dromaeosaurid with velociraptorine affinities.

However, Balaur displays a combination of both apparently plesiomorphic and derived bird-like characters. Here, we analyse those features in a phylogenetic revision and show how they challenge its referral to Dromaeosauridae. Our reanalysis of two distinct phylogenetic datasets focusing on basal paravian taxa supports the reinterpretation of Balaur as an avialan more crownward than Archaeopteryx but outside of Pygostylia, and as a flightless taxon within a paraphyletic assemblage of long-tailed birds.

Our placement of Balaur within Avialae is not biased by character weighting. The placement among dromaeosaurids resulted in a suboptimal alternative that cannot be rejected based on the data to hand. Interpreted as a dromaeosaurid, Balaur has been assumed to be hypercarnivorous and predatory, exhibiting a peculiar morphology influenced by island endemism.

However, a dromaeosaurid-like ecology is contradicted by several details of Balaur’s morphology, including the loss of a third functional manual digit, the non-ginglymoid distal end of metatarsal II, and a non-falciform ungual on the second pedal digit that lacks a prominent flexor tubercle. Conversely, an omnivorous ecology is better supported by Balaur’s morphology and is consistent with its phylogenetic placement within Avialae. Our reinterpretation of Balaur implies that a superficially dromaeosaurid-like taxon represents the enlarged, terrestrialised descendant of smaller and probably volant ancestors.

Some time round about 165 million years ago, the group of small, feathered dinosaurs that we call birds evolved from within the theropod radiation (theropods are the so-called ‘predatory dinosaurs’: the great group that includes animals like Tyrannosaurus and Velociraptor as well as the birds). As anyone reasonably familiar with recent palaeontological discoveries will know, we’re now aware of a large number of fossils that blur and smudge whatever distinction there might have been between ‘dinosaur’ and ‘bird’: here.

Canadian dinosaurs’ blood discovery


This video from Britain about dinosaur research says about itself:

4 June 2015

Scanning electron micrographs and 3D reconstructions from serial sections of erythrocyte-like structures. Credit: Bertazzo et al., Nature Communications.

This video shows scanning electron micrographs being reconstructed into 3D shapes based on the serial sections taken of the red blood cell-like structures.

From daily The Guardian in Britain:

75-million-year-old dinosaur blood and collagen discovered in fossil fragments

Scientists accidentally discover what appear to be red blood cells and collagen fibres during analysis of ‘crap’ fossils dug up in Canada 100 years ago

Ian Sample, Science editor

Scientists have discovered what appear to be red blood cells and collagen fibres in the fossilised remains of dinosaurs that lived 75 million years ago.

Traces of the soft tissues were found by accident when researchers at Imperial College in London analysed eight rather shabby fossils that had been dug up in Canada a century ago before finding their way to the Natural History Museum in London.

The finding suggests that scores of dinosaur fossils in museums around the world could retain soft tissues, and with it the answers to major questions about dinosaur physiology and evolution. More speculatively, it has made scientists ponder whether dinosaur DNA might also survive.

Most of the fossils the scientists studied were mere fragments and in very poor condition. They included a claw from a meat-eating therapod, perhaps a gorgosaurus, some limb and ankle bones from a duck-billed dinosaur, and a toe bone from [a] triceratops-like animal.

Intact soft tissue has been spotted in dinosaur fossils before, most famously by Mary Schweitzer at North Carolina State University, who in 2005 found flexible, transparent collagen in the fossilised leg of a Tyrannosaurus rex specimen.

What makes the latest discovery so remarkable is that the blood cells and collagen were found in specimens that the researchers themselves describe as “crap”. If soft tissue can survive in these fossils, then museum collections of more impressive remains could harbour troves of soft dinosaur tissue. Those could help unravel mysteries of dinosaur physiology and behaviour that have been impossible to crack with bony remains alone.

“It’s really difficult to get curators to allow you to snap bits off their fossils. The ones we tested are crap, very fragmentary, and they are not the sorts of fossils you’d expect to have soft tissue,” said Susannah Maidment, a paleontologist at Imperial.

The fossils are a smattering of pieces collected last century, probably directly from the ground, at the Dinosaur Park Formation in Alberta, Canada. To analyse the remains, the scientists broke tiny pieces off the fragments to expose fresh, uncontaminated surfaces inside.

Sergio Bertazzo, a materials scientist at Imperial, had been working on the build up of calcium in human blood vessels when he met Maidment and asked if he could study some fossils with an array of electron microscope techniques.

Months after the specimens arrived, Bertazzo began to look at thin sections of the fossils. He began with the therapod [sic; theropod] claw. “One morning, I turned on the microscope, increased the magnification, and thought ‘wait – that looks like blood!’,” he said.

Bertazzo suspected the blood was historic contamination: a curator or a collector had a cut when they handled the specimen. But Maidment suggested a check. Mammals are unusual among vertebrates in having red blood cells that lack a cell nucleus. If the fossil’s blood cells had nuclei, they could not be human. When they sliced through one of the cells to check, they saw what looked like a nucleus. “That ruled out someone bleeding on the sample,” said Maidment.

Another surprise was to come. Bertazzo was examining another fossil fragment, a piece of rib from some unidentified dinosaur, which had been sliced in two inside the microscope. He spotted bands of fibres, which further tests found to contain amino acids known that make up collagen, the protein-based material that forms the basis for skin and other soft tissues.

More work is needed to be sure the features are genuine blood cells and collagen. The scientists now hope to scour more fossils for soft tissues, and then work out what sorts of burial and environmental conditions are needed for their preservation.

“It may well be that this type of tissue is preserved far more commonly than we thought. It might even be the norm,” said Maidment, whose study appears in Nature Communications. “This is just the first step in this research.”

A detailed study of the soft tissues could unravel some of the long-standing mysteries of dinosaur evolution. The dinosaurs evolved from cold-blooded ancestors, but their modern descendants are warm-blooded birds. When did the transition occur? Red blood cells may hold the answer.

If collagen and red blood cells can survive for 75 million years, what about dinosaur DNA, bearing the genetic code to design, or potentially even resurrect, the beasts?

“We haven’t found any genetic material in our fossils, but generally in science, it is unwise to say never,” said Maidment. Bertazzo is hedging his bets too: “This opens up the possibility of loads of specimens that may have soft tissue preserved in them, but the problem with DNA is that even if you find it, it won’t be intact. It’s possible you could find fragments, but to find more than that? Who knows?”

Anjali Goswami, a paleontologist at University College London, said that if dinosaur soft tissues were found in many more fossils, it could have a transformative effect on research. “If we can expand the data we have on soft tissues, from fossils that are poorly preserved, that has real implications for our understanding of life in deep time,” she said.

Fitting Tyrannosaurus rex bone fragments together


People trying to fit Tyrannosaurus bone fragments together

Translated from ANP news agency and RTL Nieuws in the Netherlands today:

Nearly two hundred people have this weekend worked in Leiden on a special puzzle. They tried to fit the tiny skeletal remains of a Tyrannosaurus rex together.

In Naturalis museum there are thousands of shards of neck vertebrae and ribs of the T-rex. Eventually, 30 bits were found to fit together.

The bone remnants are part of the skeleton of a T-rex which lived 66 million years ago. Scientists of Naturalis excavated the dinosaur’s remains in 2013 in the United States.

Five million euros

Last year, the museum bought the complete skeleton. Using crowd funding and sponsorship, the museum received the required 5 million euros. The whole skeleton will come in September next year to Leiden. In 2018, it will get a place of honour in the new museum building.