How Dinosaurs Grew So Huge

How did some dinosaurs reach such soaring heights -- up to 100 feet high in some cases? Efficient lungs and respiration, along with egg laying, might have given dinos a growth edge when compared to other animals, suggests new research.

The study also negates a popular theory that animals tended to become bigger over the course of their evolution.

While some dinosaurs grew ever larger over subsequent generations, not all did.

"We look at the early history of archosaurs, including some early dinosaurs," said Roger Benson who co-authored the study published in the Proceedings of the Royal Society B. "We can see that some lineages obtained gigantic body sizes, but others remained small and a few showed evolutionary size reductions."

Benson, a vertebrate paleontologist at the University of Cambridge, explained that "pterosaurs, the flying reptiles, are a good example of a lineage that remained small during our study interval. There were also many small herbivores, like the dinosaurHeterodontosaurus, and small predators like the dinosaur Coelophysis."

Benson and colleagues Roland Sookias and Richard Butler analyzed more than 400 species spanning the Late Permian to Middle Jurassic periods. The animals' pattern of growth during 100 million years supports a theory called "passive diffusion." This just means that various evolutionary lineages did a bunch of different things, from growing larger to growing smaller.

The findings counter a theory known as "Cope's rule," which claims that some groups, such as dinosaurs, tended to always evolve bigger bodies over time.

There is no question, however, that many dinosaurs were mega huge, at least when compared to today's land animals.

Read more:  http://www.livescience.com/18314-dinosaurs-grew-huge.html

Oldest dinosaur nursery found in South Africa

An ancient dinosaur nursery – the oldest nesting site ever found – has been unearthed in an excavation at a site in South Africa.

The 190-million-year-old nesting site of the prosauropod dinosaur Massospondylus reveals significant clues about the evolution of complex reproductive behaviour in early dinosaurs.

It discover clutches of eggs, many with embryos, as well as tiny dinosaur footprints, providing the oldest known evidence that the hatchlings remained at the nesting site long enough to at least double in size.

“This research project, which has been ongoing since 2005 continues to produce groundbreaking results and excavations continue. First it was the oldest dinosaur eggs and embryos, now it is the oldest evidence of dinosaur nesting behaviour,” said Prof. Bruce Rubidge, Director of the Bernard Price Institute (BPI) at Wits.

The authors say the newly unearthed dinosaur nesting ground is more than 100 million years older than previously known nesting sites.

At least ten nests have been discovered at several levels at this site, each with up to 34 round eggs in tightly clustered clutches. The distribution of the nests in the sediments indicate that these early dinosaurs returned repeatedly (nesting site fidelity) to this site, and likely assembled in groups (colonial nesting) to lay their eggs, the oldest known evidence of such behaviour in the fossil record.

The large size of the mother, at six metres in length, the small size of the eggs, about six to seven centimetres in diameter, and the highly organised nature of the nest, suggest that the mother may have arranged them carefully after she laid them.

“The eggs, embryos, and nests come from the rocks of a nearly vertical road cut only 25 metres long,” explained Canadian palaeontologist Prof. Robert Reisz, a professor of biology at the University of Toronto at Mississauga, who led the study.

“Even so, we found ten nests, suggesting that there are a lot more nests in the cliff, still covered by tons of rock. We predict that many more nests will be eroded out in time, as natural weathering processes continue,” he said.

The fossils were found in sedimentary rocks from the Early Jurassic Period in the Golden Gate Highlands National Park in South Africa. This site has previously yielded the oldest known embryos belonging to Massospondylus, a relative of the giant, long-necked sauropods of the Jurassic and Cretaceous periods.

The discovery was published in the prestigious international journal Proceedings of the National Academy of Sciences (PNAS).

http://www.discoveryon.info/2012/01/oldest-dinosaur-nursery-found-in-south-africa.html

Leaping lizards and dinosaurs inspire robot design

University of California, Berkeley, biologists and engineers ‑ including undergraduate and graduate students ‑ studied how lizards manage to leap successfully even when they slip and stumble. They found that lizards swing their tails upward to prevent them from pitching head-over-heels into a rock.

But after the team added a tail to a robotic car named Tailbot, they discovered that counteracting the effect of a slip is not as simple as throwing your tail in the air. Instead, robots and lizards must actively adjust the angle of their tails just right to remain upright.

“We showed for the first time that lizards swing their tail up or down to counteract the rotation of their body, keeping them stable,” said team leader Robert J. Full, UC Berkeley professor of integrative biology. “Inspiration from lizard tails will likely lead to far more agile search-and-rescue robots, as well as ones having greater capability to more rapidly detect chemical, biological or nuclear hazards.”

Agile therapod dinosaurs like the velociraptor depicted in the movie Jurassic Park may also have used their tails as stabilizers to prevent forward pitch, Full said. Their tail movement is illustrated in a prescient chase sequence from the 1993 movie in which the animated animal leaps from a balcony onto a T. rex skeleton.

“Muscles willing, the dinosaur could be even more effective with a swing of its tail in controlling body attitude than the lizards,” Full said.

Continued: http://newscenter.berkeley.edu/2012/01/04/leaping-lizards-show-robots-the-value-of-a-tail/

German marine reptile find rewrites fossil record

German experts have found a new species of prehistoric marine giant from a time when most of that family of reptiles were thought to have died out.

The rare ichthyosaur find from the Braunschweig area, northern Germany, is 130 million years old, dating from the Lower Cretaceous era.

Most ichthyosaur fossils date from the Jurassic era, millions of years before.

The Braunschweig fossil revelations were reported in the science journal Plos One on Tuesday.

The new type of ichthyosaur, discovered during roadworks in 2005, has been called Acamptonectes densus - "Stiff Swimmer".

The neck vertebrae were so tightly packed that "it couldn't move its neck, so it must have shot through the water like a dart", said palaeontologist Ulrich Joger of the Braunschweig Natural History Museum.

"It's a spectacular find. It raises new questions about the [Jurassic] extinction theory," he said.

The specimen is similar to the Speeton Clay ichthyosaur found in the north of England in 1958.

The experts say the predator fed on fish and squid and looked like a dolphin, though the species are not related.

The main dinosaur extinction event was at the end of the Cretaceous, about 65 million years ago. It is widely believed a meteorite impact caused it.

http://www.bbc.co.uk/news/world-europe-16432364

Dino-Chicken: Wacky But Serious Science Idea of 2011

Paleontologist Jack Horner has always been a bit of an iconoclast. In the 1970s, Horner, the curator of paleontology at the Museum of the Rockies in Bozeman, Mont., and his friend Bob Makela discovered a Maiasaura nesting site, painting the first picture of dinosaurs as doting moms and dads. He's also been at the forefront of research suggesting that dinosaurs were fast growing and warm-blooded.

But Horner's newest idea takes iconoclasm to a new level. He wants, in short, to hatch a dinosaur.

Or something very much like one, at least. Horner, who served as a technical advisor for the "Jurassic Park" movies, has no illusions that the technique in that movie — extracting dino DNA from mosquitoes in amber — would work. DNA degrades too quickly, for one thing. Dinosaur DNA has proved impossible to extract from actual dinosaur bones, never mind blood-sucking insects.

"If you actually had a piece of amber and it had an insect in it, and you drilled into it, and you got something out of that insect and you cloned it, and you did it over and over and over again, you'd have a room full of mosquitoes," Horner said in a February 2011 TED Talk in Long Beach, Calif. TED, or Technology, Entertainment and Design, is a nonprofit focusing on "ideas worth spreading."

Read more here:
http://www.livescience.com/17642-chickenosaurus-jack-horner-create-dinosaur.html

‘Biggest’ dinosaur bones unveiled in US

Paleontologists have discovered what they claim are bones of the “biggest” dinosaur in the US.


A team from the Museum of Rockies in Montana State and the State Museum of Pennsylvania has described two gigantic vertebrae and a femur that it collected in New Mexico from 2003 to 2006 in a research report.

The bones belong to the sauropod dinosaur Alamosaurus sanjuanensis: A long-necked plant eater related to Diplodocus which roamed what is now the southwestern region of the US and Mexico about 69 million years ago.

In their report, the palaeontologists have written how carrying the the vertebrae alone was a “killer” task taking up an entire day because they carried them 1.2 miles through 100- degree heat, a website reported.

Denver W Fowler at Montana State University, who led the team, said: “Alamosaurus has been known for some time, its remains were first described in 1922 from the Naashoibito beds of New Mexico.

“Since then, more bones have been discovered in New Mexico, Utah, some really nice material from Texas, and Mexico, including a few partial skeletons.”

He said the sheer size of the new bones had caught the researchers by surprise, who had believed that a fully grown Alamosaurus measured around 60 feet long and weighed about 30 tons.

The enormity of the new bones puts Alamosaurus in the same size league as other giant sauropods from South America, including Argentinosaurus which weighed about 70 tons, and is widely considered to be the biggest dinosaur of all.

Dr Fowler said: “Over the past 20 years, Argentinean and Brazilian paleontologists have been unearthing bigger and bigger dinosaurs, putting the rest of the world in the shade.

“However, our new finds not only show that Alamosaurus is newly recognised as the biggest dinosaur from North America, but also that it was right up there with the biggest South American species…”

He added: “We found a shed Tyrannosaurus tooth with another Alamosaurus neck bone that we were excavating. The Tyrannosaurus may have lost its tooth while feeding on an Alamosaurus carcass.”

http://www.discoveryon.info/2011/12/biggest-dinosaur-bones-unveiled-in-us.html

Dinosaur that acted like a Vegas showgirl!

Palaeontologists have claimed that a species of bird-like dinosaur acted like Las Vegas showgirls by wiggling tail feathers to attract mates.

A new research, by the University of Alberta, has found that Oviraptor dinosaurs had a fan of feathers, similar to the fan of a flamenco dancer, attached to a flexible tail, the 'Daily Mail' reported.

They may have flashed these feathers to attract attention in a similar way to the modern-day peacock -- or a Las Vegas showgirl, say the palaeontologists who found that Oviraptors, which lived 75 million years ago, had tails with a peculiarly dense arrangement of bones.

"The tail of an Oviraptor by comparison to the tail of most other dinosaurs is pretty darn short," Scott Persons, who led the research team, said.

He added: "But it's not short in that it's missing a whole bunch of vertebrae, it's short in that the individual vertebra within the tail themselves are sort of squashed together. So they're densely packed.

"This dense arrangement of bones would have made the tails flexible."

Read more ...

Tiny Fossil Fragment Reveals Giant-But-Ugly Truth: Part of Biggest-Ever Toothed Pterosaur from Dinosaur Era

ScienceDaily (Oct. 13, 2011) — New research from the Universities of Portsmouth and Leicester has identified a small fossil fragment at the Natural History Museum, London as being part of a giant pterosaur -- setting a new upper limit for the size of winged and toothed animals.

Dr David Martill from the University of Portsmouth and Dr David Unwin from the University of Leicester examined the fossil -- which consisted of the tip of a pterosaur snout that had been in the Museum collections since 1884.

Their identification of the fossil as being part of the world's largest toothed pterosaur has been published in Cretaceous Research.

Dr Unwin, from the School of Museum Studies at the University of Leicester, said: "Our study showed that the fossil represented a huge individual with a wingspan that might have reached 7 metres. This is far larger than, for example, any modern bird, although some extinct birds may have reached 6 metres in wingspan.

"What this research shows is that some toothed pterosaurs reached truly spectacular sizes and, for now, it allows us to put a likely upper limit on that size -- around 7 metres in wingspan."

Dr Martill, from the University of Portsmouth, added: "It's an ugly looking specimen, but with a bit of skill you can work out just exactly what it was. All we have is the tip of the upper jaws -- bones called the premaxillae, and a broken tooth preserved in one socket.

"Although the crown of the tooth has broken off, its diameter is 13mm. This is huge for a pterosaur. Once you do the calculations you realise that the scrap in your hand is a very exciting discovery.
"The specimen was placed in the collections of London's Natural History Museum by Sir Richard Owen, perhaps the world's greatest vertebrate palaeontologist. In his day, Owen reconstructed a giant New Zealand Moa from a single bone. We might never achieve Owen's calibre, but it is nice to think that we are following in his footsteps."

Pterosaurs are flying reptiles, famously seen in Jurassic Park, that lived in the Mesozoic Era alongside dinosaurs between 210 and 65 million years ago.

There are six or seven major groups of toothed pterosaurs, but in this study the researchers focused on just one: the ornithocheirids. Unlike other toothed groups, all of which were of relatively modest size (wingspans at most of 2 or 3 metres), they are known to have achieved very large and possibly even giant sizes with wingspans of 6 meters or more. Ornithocheirids were specialised fish-feeding pterosaurs that used a fiercesome set of teeth in the tips of the jaws, to grab their prey as they flew low and slow over the surface of the water.

Dr Unwin said: "We found that, generally speaking, large ornithocheirids reached wingspans of 5 or 6 metres which was consistent with previous ideas about this group. However, we also came across one fossil, collected in the mid-19^th century from a deposit in Cambridgeshire called the Cambridge Greensand that seemed to be unusually large.

"This fossil, now in the collections of the Natural History Museum, London, consisted of the tip of a pterosaur snout. The shape of the snout and the broken-off tooth that it contained allowed us to identify the new find as belonging to Coloborhynchus capito, a very rare ornithocheirid represented only by a few fossil fragments from the Cambridge Greensand. Calculating the original size of the animal based on just a fragment is difficult, but we were able to take advantage of some recent finds in Brazil of almost complete skeletons of ornithocheirids that are closely related to the Cambridge Greensand jaw fragment."

"Our study showed that the fossil did indeed represent a very large individual with a wingspan that might have reached 7 metres."

Significantly, though, this is still far short of the giant size achieved by some toothless pterosaurs. Several species of a group called azhdarchids achieved wingspans of around 10 metres.

The challenge for the researchers now is to try to understand why some groups, such as azhdarchids, reached these giant sizes, while toothed forms, such as the ornithocheirids, did not. Teeth are heavy, so part of the explanation may lie in weight reduction by losing these.

Dr Unwin said: "This research is important because it helps us to better understand patterns of evolution over millions of years, and in groups that are now extinct. At a more general level, it feeds into TV documentaries such as the current series 'Dinosaur Planet' on BBC1, ensuring that they have the 'ring of authenticity' that ensures successful reception, by experts and the lay public alike. Indeed, these programs are enormously popular, as viewing figures show, allowing us to comfort ourselves with the thought that the research we carry out is helping to satisfy the interests of a not insignificant portion of the viewing public.

"For Dave Martill and I, this was to some extent the 'bread and butter' stuff that we do everyday. But it's this slow piling up of data and, critically, its connection into our general understanding, that leads to the really big discoveries. Dave likes to refer to the fossil as the ugliest fossil he ever studied, and I can see his point, but as I did my PhD on Cambridge Greensand pterosaurs they have a special place in my affections and, no matter how ugly, I still love them."

http://www.sciencedaily.com/releases/2011/10/111013085107.htm

Origin of Dinosaur-Killing Asteroid Is Still a Mystery

The source of the asteroid that killed off the dinosaurs 65 million years ago remains a mystery, a new study finds.

Some researchers had thought the deadly asteroid was a piece of a larger space rock called Baptistina. Baptistina broke apart after a massive in-space collision about 160 million years ago, the theory went, spawning a swarm of mountain-size chunks of rock. One of those eventually slammed into Earth, killing off the dinosaurs and many other species.

Scientists are confident that a 6-mile-wide (10-kilometer asteroid) is indeed what wiped out the dinosaurs. But new observations from NASA's Wide-field Infrared Survey Explorer (WISE) space telescope suggest the space rock didn't come from Baptistina.
The timing just isn't right, according to the new study.

Read on...

Old fossils solve mystery of earliest bird extinction

Many early bird species suffered from the same catastrophic extinction as the dinosaurs, new research has shown.

The meteorite impact that coincided with the disappearance of the dinosaurs 65 million years ago, also saw a rapid decline in primitive bird species.

Only a few bird groups survived through the mass extinction, from which all modern birds are descended.

Researchers at Yale University have published their findings in PNAS this week.

There has been a long standing debate over the fate of the earliest "archaic" birds, which first evolved around 200 million years ago.

Whether their populations declined slowly towards the end of the Cretaceous period, or whether they suffered a sudden mass extinction at the Cretaceous-Tertiary (K-T) boundary is unresolved, owing to conflicting evidence.

DNA studies have attempted to date the origin of modern birds; some suggest that they appeared before the extinction of dinosaurs, with large numbers of them surviving through the extinction event.

But the molecular clock suffers from "method issues", explains Dr Longrich of Yale University, and well-dated fossils are needed for "stratigraphic constraint" of the extinctions.

There are problems with the fossil record however. It is incomplete, owing to the extreme rarity of bird fossils.

Bird bones are very difficult to preserve as fossils as they are small and light, and easily damaged or swept away in rivers.

But the new research, headed by Dr Longrich, has made use of fragmentary bird fossils collected up to 100 years ago, from locations across North America.

New diversity
The fossil deposits, in North and South Dakota and Wyoming in the US, and Saskatchewan in Canada, date from the last 1.5 million years of the Cretaceous period.

More precise dating places the bird fossils to within 300,000 years of the extinction event - a very short period on geological timescales.

These fossils had been studied before, but they have been "shoehorned" into modern groups on the basis of their overall similarity.

Dr Longrich and his team have reanalysed and reclassified these important fossil fragments, using features of the shoulder joint to assign the fossils to modern and ancient groups.

The shoulder bone, or "coracoid" is used for classification because it is the most common bone fragment preserved, and it doesn't vary much between individuals of the same species.

Analysing 24 specimens, the researchers identified 17 species, seven of which were "archaic birds" that are not seen after the K-T mass extinction.

These findings show for the first time a diversity of archaic birds alive, right up until the end of the Cretaceous.

This would mean that the archaic birds went extinct abruptly 65 million years ago, and that modern birds must have descended from just a few groups that survived the event.

'Nail in the coffin'
Among the primitive species identified, there is considerable variation in size, but there are few other specific adaptations.

Modern birds, on the other hand, have a huge range of adaptations to their particular behaviours or living environments.

This variation would have therefore come about during an explosive evolutionary radiation from the few surviving groups, during the first 10 million years or so following the K-T mass extinction.

"It's similar to what happened with mammals following the age of the dinosaurs." said Dr Longrich.

"Given that the extinction affected mammals, reptiles, insects and plants, it would be remarkable if birds survived the event unscathed," the scientists say in an introduction to their research.

There is growing evidence for the theory that the archaic birds survived until the extinction; more and more bird fossils are being found in Madagascar, Mongolia and Europe.

But these fossils are not well dated, unlike the newly analysed fragments from North America.

Dr Longrich said that this evidence was "a nail in the coffin of the idea of a slow decline".
By Leila Battison Science reporter
http://www.bbc.co.uk/news/science-environment-14979905

Dinosaur-Era Mammal Possibly "Mother" of All Humanity

A tiny, dinosaur-era mammal may have been the mother of all humanity -- at least in a sense, National Geographic News reports.

According to a new study, the newly discovered 160-million-year-old fossil species, named the "Jurassic mother from China" [Juramaia sinensis], is the earliest known ancestor of placental mammals -- that is, animals, such as humans, that give birth to relatively mature, live young.

Although it's unclear if the creature is a direct ancestor of modern placentals, it's "either a great grand-aunt or a great grandmother," the study’s authors told National Geographic.

According to the study, the newfound eutherian scurried about temperate Jurassic forests, dined on insects under the cover of darkness, and weighed about half an ounce (15 grams), making it lighter than a chipmunk.

"The great evolutionary lineage that includes us had a very humble beginning, in terms of body mass," Zhe-Xi Luo, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh, who led the team that discovered the fossil, told National Geographic.

The discovery brings the fossil record in line with DNA evidence that indicates that the split between ancestral marsupials and placentals occurred around 160 million years ago, Luo added.

"What is clear is that, besides the fact that marsupials and placentals start to differentiate, we also have the other mammals that diversified as well," he continued. "But we don't know what would be the specific environmental trigger for that."

Placentals, which includes creatures ranging from mice to whales, are all that remain of the eutherian mammals.

The findings of the study will be published Thursday in the journal Nature.

http://www.thirdage.com/news/dinosaur-era-mammal-possibly-mother-of-all-humanity_08-25-2011

World's largest dinosaur tooth marks found in S. Korea

South Korean researchers said Monday that they have discovered the world's largest fossilized tooth marks of a carnivorous dinosaur in the country's southeastern province.


The unusual tooth scores, found on the tailbone of the adult herbivorous dinosaur Pukyongosaurus from the early Cretaceous period of the Mesozoic Era, measured 17 centimeters long, 2 centimeters wide, and 1.5 centimeters deep, the longest and deepest scores ever discovered in the world, according to Paik In-sung, a professor at Pukyong National University, who led the research.


The tailbone fossil itself was found in 2008 in Hadong, South Gyeongsang Province, some 470 kilometers southeast of Seoul, Paik added.

The W-shaped marks showing the two teeth of the dinosaur form sharp grooves in the bone and were presumably etched there when the predator bit meat off the carcass, according to Paik.

Apart from the largest tooth marks, many tooth scores of different sizes and shapes were also detected on the tailbone, which offers insight into the feeding behavior of meat-eating dinosaurs that lived on the earth some 120 million years ago, Paik said.

"The discovery of both large and small tooth marks on a single bone of a plant-eating dinosaur serves as telltale evidence that the meat-eating dinosaurs in the past had eating habits of exploiting a single sauropod carcass, identical to that of modern carnivores," he added.

The study, funded by the country's Ministry of Education, Science and Technology and the National Research Foundation of Korea, was published on the online version of the journal Palaeogeography, Palaeoclimatology, Palaeoecology last week.

Palaeontologists say dinosaurs lived in South Korea from 120 million to 80 million years ago, throughout much of the Cretaceous period, the last stage of the Mesozoic era and the heyday for dinosaurs. Their fossils, relatively well-preserved and discovered in a richly diverse spectrum across the southern South Korean coasts, are currently registered on a tentative list of U.N. World Heritage sites, en route to gaining major recognition.

Source: Yonhap News Agency [July 18, 2011]

http://archaeologynewsnetwork.blogspot.com/2011/07/worlds-largest-dinosaur-tooth-marks.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)

Ancestor of all birds knocked from its perch

The winged Archaeopteryx, long venerated as the forebear of birds, has been knocked off its hallowed perch on the tree of evolution, according to a new study.


A new dinosaur species unearthed in northern China reveals that the iconic 150 million year old "original bird" is probably just another dino with feathers, of which there are many, the researchers said.

It is hard to imagine a harder fall from evolutionary grace.

Since its discovery 150 years ago in Bavaria, most scientists placed Archaeopteryx squarely at the root of the broad group of proto-birds, known as Avialae, from which our modern feathered friends have emerged.

The emblematic creature was also held up as a case study -- THE case study during the late 19th century -- of evolutionary transition, to wit, from dinosaur to bird.


Over the years, a few scientists have gingerly expressed doubts, pointing to supposedly defining bird-like characteristics -- feathers, the wishbone, three-fingered hands -- that were also showing up in non-avian dinosaurs.

But without hard proof that Archaeopteryx was not really where it belonged on the so-called phylogenetic tree, the presumed progenitor continued to reign over its feathered kingdom.

Enter Xing Xu, a professor at Linyi University in China's Shandong Province and discoverer extraordinaire of dinosaur fossils.

In the new study, published in Nature, Xu and colleagues describe the attributes of a previously unknown dinosaur the fossil of which was found in Liaoning Province, in China's northeast.

About the size of a chicken and probably weighing less than a kilo (about two pounds), Xiaotingia shared a host of key characteristics with Archaeopteryx but seemed, at the same time, to fall into another group of non-avian dinos called Deinonychosauria.

A standard computer analysis confirmed as much, but at the same time produced a stunning result: Archaeopteryx had been reclassified into the same group.

"In other words, Archaeopteryx was no longer a bird," Lawrence Witmer, a professor at Ohio university's Heritage College of Osteopathic Medicine, said in a commentary, also in Nature.

Xiaotingia, it turns out, was the smoking gun that sceptical scientists had been looking for.

Surprised by their findings, Xu and his team ran the analysis again, but this time without the newly discovered species. Archaeopteryx was restored -- in error, they now knew -- to its previous perch.

Xu has called for further confirmation, but suggests that his discovery will overturn long-held assumptions about the "avian ancestral condition."

"Perhaps the time has come to finally accept that Archaeopteryx was just another small, feathered, bird-like theropod fluttering around in the Jurassic," Witmer said.

One reason it has been so hard for biologists to embrace this idea may have more to do with history than science.

The first Archaeopteryx specimen was discovered, with uncanny timing, less than two years after the publication of Charles Darwin's game-changing Origin of the Species.

With an evenly matched blend of avian and reptilian features, it became -- in textbooks and public debate -- "Exhibit A" in explaining the transformative power of natural selection and evolution.

"The familiar fossils have guided almost all scientific thought about the beginnings of birds," Witman said, including himself among those led astray.

It's reclassification, he added, is likely to "rock the palaeontological community for years to come."

Who are the new candidates for king of the roost?

No single species is likely to ever gain the stature that Archaeopteryx once had, said Xu.

But among the new pretenders, three newly discovered creatures stand out: Epidexipteryx, Jeholornis, and Sapeornis.
http://uk.news.yahoo.com/ancestor-birds-knocked-perch-161509323.html

Dinosaur tracking in Bolivia

I'm staring at what was, until very recently, the largest set of dinosaur footprints on earth – 581 metres of vicious slashes gouged by a carnivore's razor-sharp claws. But now, a third of the way into the run, as the predator salivated at the prospect of supper, the spoor suddenly vanishes, replaced by a slab of fresh, smooth rock.

It reappears 10 metres further on. The hunt has recommenced. But it's too late. A landslide has left a savage rip across the rock face, interrupting the trail laid down 65m years ago in Bolivia's central highlands. To palaeontologists it's almost iconoclasm, like a theologian finding a page torn from the Gutenberg Bible.

The lost footsteps of "Johnny Walker", as the dinosaur is known, are the latest tweak to the prehistoric landscape outside the elegant city of Sucre. Cal Orko is a constantly evolving record of life in the Cretaceous era – an epic canvas that due to erosion and local mining will always be a work in progress.

"It's just amazing," says chief guide Maria Teresa Gamón as we inspect the damage. "We see fresh footprints and fossils all the time. We lose some, we find some. It's always changing."

Whatever the latest tally, the vast wall of sedimentary rock still bears the largest, most diverse collection of dinosaur tracks on the planet. Across a limestone slab 1.2km long and 80m high, Cal Orko sports more than 5,000 footsteps, with 462 individual trails.

My own trail is slightly longer. Sedate Sucre breaks up the schlep from tropical Santa Cruz to the altiplano mining town of Potosí. With a student population served by great bars and cafes it's the perfect place to kick back for a few days, particularly in the dreamy Parador Santa María la Real, where colonial-era rooms surround light-filled courtyards.

But Spain's conquistadors are a pinprick in history compared with the dinosaurs. The Bolivian prints belong to eight main species, including the unpleasant carnotaurus with its terrible dentistry and laughably tiny upper limbs, and the herbivorous ankylosaurus – a sort of heavyweight armadillo. But they and their footsteps are dwarfed by those of the clumsy plant-guzzling titanosaur, weighing up to 100 tonnes.

Cal Orko lies three miles from downtown Sucre, where red, brown and ochre folds of earth smudge into the Andean foothills. I know it's inside a quarry – miners spotted many footprints after the first discoveries in 1985 – but it's still shocking to find heavy industry cheek by jowl with a fragile landscape of world significance. The extraction company's work covers everything – trees, buildings, men – in a fine fuzz of dust. Its vast lorries, titanosaurs of earth moving, are a surreal juxtaposition with the palaeontologists' delicate work.

The Parque Cretácico, opened in 2006, lies further up the hill, with a museum, vast models of dinosaurs and B-movie roars piped through loudspeakers. So far so Spielberg. It's only when I reach the viewing platform, 150 metres from the rock face, that it starts to become marvellously real – a widescreen view of prehistory. My eyes need to adjust. Cal Orko is a vast optical puzzle requiring time to decipher. Those dots, dashes and holes like super-sized horse hoofprints aren't random designs – they're rock-solid semaphore explaining Cretaceous life.

Visitors aren't normally allowed up to the wall, but with mining temporarily suspended, I'm granted rare access. The immense vertiginous rock face is slightly overwhelming, in the dust and searing heat. Maria, the palaeontologistss assistant, uses a mirror to transform the sun's rays into a spotlight, picking out specific tracks.

Her enthusiasm is infectious. "Look! Six footprints going up. Ankylosaurus. And over there! Those are about 80cm in diameter. It's a titanosaur coming down the wall for about 25m. See where they stop? That soft outer rock will soon crumble and you'll follow them right to the ground."

Maria uses the footprints to explain how meat-eaters walked with straight feet "while herbivores were pigeon-toed like Charlie Chaplin – apart from the long-necked ones, who had the same hips as carnivores".

The spoors reveal mundane details of daily Cretaceous life. It's CSI: Sucre. "That ankylosaur was running. It sank its four toes into the ground, rather than its heel." There's even a large carnivore that, like any true gentleman, preferred the female to stay on its left side.

Most fun of all is gauging the beasts' size from their tracks. For two-legged dinosaurs you multiply the length of the footprint four times to discover leg-to-hip length. Once you've got the legs, you know if it was Joe Average or Godzilla. A large titanosaur had 6m pins – without stilettos.

By the time we're placing our hands next to the tracks – a quick way to feel extremely insignificant – I've mutated into teacher's pet. I fear I'm raising my hand to ask questions.

"What's that?" demands Maria, pointing to a splatter of prints.

"Two round toes. A hoof. Waddling like Chaplin. A herbivore," I snap back. "Possibly an iguanodont."

"Very good, Ian" I feel stupidly proud.

But Cal Orko is about geology as well as palaeontology. Unless dinosaurs wore crampons, and size 72 ones at that, how the hell did they leave tracks up a vertical rock face? It's all very complicated, so pay attention at the back.

The Cretaceous era, starting 145m years ago and ending with mass extinction 80m years later, saw South America drift away from Africa and and join with North America, sparking wildlife migrations. Cal Orko, kissing a huge lake and boasting the continent's first flowers, attracted herbivores and subsequently carnivores.

But it was unique climate fluctuations that made the region a palaeontological honey pot. The creatures' feet sank into the soft shoreline in warm damp weather, leaving marks that were solidified by later periods of drought. Wet weather then returned, sealing the prints below mud and sediment. The wet-dry pattern was repeated seven times, preserving multiple layers of prints. The cherry on the cake was added when tectonic activity pushed the flat ground up to a brilliant viewing angle – as if nature was aware of its tourism potential.

Not surprisingly, Cal Orko has applied for Unesco listing, but the fate of Johnny Walker's steps underlines the vulnerability of this place.

Far from preserving the site, man is adding to the ravages of time. As I leave, a low explosion thumps across the quarry's fragile earth and reverberates through my chest. More tracks will disappear, more emerge – the endless dance of conservation and industrial progress.

Ian Belcher
guardian.co.uk

 http://www.guardian.co.uk/travel/2011/jul/15/dinosaur-tracking-bolivia-cal-orko

Fossil Forensics Reveals How Wasps Populated Rotting Dinosaur Eggs

ScienceDaily (July 16, 2011) — Exceptionally preserved fossils of insect cocoons have allowed researchers in Argentina to describe how wasps played an important role in food webs devoted to consuming rotting dinosaur eggs. The research is published in the scientific journal Palaeontology.

The approximately 70 million year old eggs, from gigantic titanosaur sauropod dinosaurs were discovered in 1989 in the Patagonia region of Argentina, well known for yielding fossils of sauropod dinosaur eggs and even embryonic dinosaurs. Only recently it was discovered that one of the broken eggs contained tiny sausage-shaped structures, 2-3cm long and 1cm wide. The structures closely resembled fossilised insect cocoons, and were most similar in size and shape to the cocoons of some species of modern wasp.

There are many records of fossilised dinosaur eggs, and even several records of fossil cocoons, but, as author Dr Jorge Genise of the Museo Argentino de Ciencias Naturales states "this is the first time that these cocoons are found closely associated with an egg." Such a study of organismal behaviour (e.g. burrows, footprints) is known as ichnology.

The results indicate "that wasps probably participated in the food web, mostly composed of scavenging insects, which developed on the rotten egg." The make-up of carrion communities -- spiders, beetles and other creatures populating rotting organic matter -- is more familiar to us from the screens of crime scene investigation documentaries.

The numbers and different types of creatures indicate the length of deposition and the time since death. In this particular CSI, it appears that the dinosaur egg was broken by force, and subsequent fractures in the egg shell allowed scavenging creatures to feed upon the contents. At egg sizes of around 20cm, this represents a sizable amount of yolk! Other creatures later appeared to feed not upon the egg contents, but on the initial scavengers themselves. The wasps represent the top of the food web, and could have been feeding on insects or spiders gorging on rotting egg contents.

These scavengers also played an important role in cleaning up nest sites. Palaeontologists believe that some dinosaurs revisited nest sites year after year to lay new clutches of eggs. Carrion communities were essential to removing decaying material in advance of new nesting seasons. This new discovery gives us an insight into the murky world of insect communities that thrived at the feet of gigantic dinosaurs.

http://www.sciencedaily.com/releases/2011/07/110715135200.htm

Last dinosaur before mass extinction discovered

A team of scientists has discovered the youngest dinosaur preserved in the fossil record before the catastrophic meteor impact 65 million years ago. The finding indicates that dinosaurs did not go extinct prior to the impact and provides further evidence as to whether the impact was in fact the cause of their extinction.

Researchers from Yale University discovered the fossilized horn of a ceratopsian – likely a Triceratops, which are common to the area – in the Hell Creek formation in Montana last year. They found the fossil buried just five inches below the K-T boundary, the geological layer that marks the transition from the Cretaceous period to the Tertiary period at the time of the mass extinction that took place 65 million years ago.

Since the impact hypothesis for the demise of the dinosaurs was first proposed more than 30 years ago, many scientists have come to believe the meteor caused the mass extinction and wiped out the dinosaurs, but a sticking point has been an apparent lack of fossils buried within the 10 feet of rock below the K-T boundary. The seeming anomaly has come to be known as the "three-meter gap." Until now, this gap has caused some paleontologists to question whether the non-avian dinosaurs of the era – which included Tyrannosaurus rex, Triceratops, Torosaurus and the duckbilled dinosaurs – gradually went extinct sometime before the meteor struck. (Avian dinosaurs survived the impact, and eventually gave rise to modern-day birds.)

"This discovery suggests the three-meter gap doesn't exist," said Yale graduate student Tyler Lyson, director of the Marmarth Research Foundation and lead author of the study, published online July 12 in the journal Biology Letters. "The fact that this specimen was so close to the boundary indicates that at least some dinosaurs were doing fine right up until the impact."

While the team can't determine the exact age of the dinosaur, Lyson said it likely lived tens of thousands to just a few thousand years before the impact. "This discovery provides some evidence that dinosaurs didn't slowly die out before the meteor struck," he said.

Eric Sargis, curator of vertebrate paleontology at the Yale Peabody Museum of Natural History, and graduate student Stephen Chester discovered the ceratopsian last year while searching for fossilized mammals that evolved after the meteor impact. At first, Lyson said, the team thought it was buried within about three feet of the K-T boundary, but were surprised to learn just how close to the boundary – and hence, how close in time to the impact – it was. They sent soil samples to a laboratory to determine the exact location of the boundary, which is marked by the relative abundance of certain types of fossilized pollen and other geological indicators but is difficult to determine visually while in the field.


Because the dinosaur was buried in a mudstone floodplain, the team knew it hadn't been re-deposited from older sediments, which can sometimes happen when fossils are found in riverbeds that may have eroded and re-distributed material over time.

The team is now examining other fossil specimens that appear to be buried close to the K-T boundary and expect to find more, Lyson said. He suspects that other fossils discovered in the past may have been closer to the boundary than originally thought and that the so-called three-meter gap never existed.

"We should be able to verify that using the more sophisticated soil analysis technique rather than estimating the boundary's location based solely on a visual examination of the rock formations while in the field, which is what has typically been done in the past," Lyson said.

http://archaeologynewsnetwork.blogspot.com/2011/07/last-dinosaur-before-mass-extinction.html

Dinosaurs were animal world's top bone heads

http://www.bbc.co.uk/news/science-environment-13968525

Scientists have compared a dinosaur with several modern-day animals to settle who wins the heavy-weight head-butting title.

The new findings confirm that the ancient bipedal dinosaur Stegoceras could knock out any of today's top head-butters.

Stegoceras probably used their domed skulls to ram each other over access to fertile females.

Read on...

That's some party trick: Model-maker produces life-size replica of Tyrannosaurus Rex in 55 hours, using 1,400 balloons... and a LOT of hot air

http://www.dailymail.co.uk/news/article-2009036/Thats-party-trick-Model-maker-produces-life-size-replica-Tyrannosaurus-Rex-55-hours-using-1-400-balloons--LOT-hot-air.html

Try competing with this balloon artist and you would definitely be wasting your breath.

Mark Verge has been perfecting the art form for more than 16 years and has created a 39ft life-size replica of a Tyrannosaurus Rex out of 1,400 balloons.

It was just one of the sculptures made by the model-maker along with a triceratops, spinosaurus, stegasaurus and utahraptor for his show in Ontario, Canada.

Read on...

Big Dinos Stayed Cool

http://news.discovery.com/animals/dinosaurs-sauropods-body-temperature-110623.html

Sauropod dinosaurs, the enormous plant-eating dinos with long tails and necks, had body temperatures ranging from 96.3 to 100.8 degrees Fahrenheit -- making them as warm as most mammals -- including people. Because body temperature usually rises the larger an animal gets, the findings, published in the latest issue of Science, suggest huge sauropods had mechanisms for cooling themselves off.

Read on...

T. rex's arms helped them stand up

It is one of the most enduring mysteries of paleontology - what the fearsome T. rex used its arms for, and why they were seemingly so small.

Now Japanese and American scientists think they have come up with an answer.

By running computer simulations and examining the joints of dinosaur fossils, researchers at the University of Oregon and the Tokyo's National Museum of Nature and Science found that the Tyrannosaurus could often be found crouching down or lying prone.

The arms, it transpires, were a very good design for righting the beast when it wanted to stand up.

http://news.uk.msn.com/world/articles.aspx?cp-documentid=158326144