Dinosaur age fossils colour discovery


This video is called DINOSAUR FOSSILS – THE ONE THAT CHANGED THE WORLD (Documentary).

From AFP news agency:

Traces of pigment on dinosaur fossils a first clue to their skin colour

Traces of pigment in reptile fossils may lead to recreations of how extinct beasts looked

Sunday, 12 January, 2014, 3:36am

What did Tyrannosaurus rex really look like?

Depending on which artist’s impression you look at, the carnivorous king of the Cretaceous was a dull grey, an earthy brown, or maybe a dark green.

But now, new insights into prehistoric fossils, published last week, may one day help determine what the great dinosaurs looked like in real life.

Scientists have uncovered the first traces of pigment in reptile fossils – a dark hue found in three extinct deep-sea beasts distantly related to today’s leatherback turtle.

“This is the first time that… remains of original pigments have been detected in any (extinct) reptile, including dinosaurs,” Johan Lindgren of Sweden’s Lund University said.

The next challenge will be to identify more pigments, helping palaeontologists to reconstruct the colouring of extinct animals.

“This finding potentially allows us to reconstruct the colours of T. rex in future,” said Lindgren, though for now experts are limited to distinguishing dark areas from light ones.

Lindgren and colleagues studied molecular remains found on the skin of three marine monsters. The samples came from a forerunner 55 million years ago of the leatherback turtle; a giant, finned lizard known as a mosasaur dated to 86 million years ago; and a toothy dolphin-like reptile called an ichthyosaur, around 190 million years old.

The remains took the form of structures a micrometre (a millionth of a metre) in size that, according to previous studies, were either pigment traces or the vestiges of bacteria.

The new investigation claims to have settled that debate with in-depth microscopic analysis – revealing the remains to be traces of the most common skin pigment, melanin.

Colouration in animals serves multiple purposes – from camouflage or sexual display to UV protection and heat retention. Little is known about the colouring of long-extinct animals, given that pigmentation is carried in quickly decaying skin. But sometimes, as in this case, scientists are lucky to find soft tissue preserved as an “organic film”.

The team pointed out there was a close correlation between the amount of melanin in skin and how dark the skin’s colour is.

The fossil tissue of all three extinct sea beasts contained very tightly packed pigment granules. This led the scientists to conclude the creatures had “an overall dark colouration” similar to that of the modern leatherback turtle, whose top is almost entirely black, said Lindgren.

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Dutch mosasaur discovery news


Lower jaw details of the newly discovered mosasaur, photo ANP/Marcel van Hoorn

Translated from L1 regional radio in the Netherlands:

Researchers at the Natural History Museum in Maastricht have unearthed approximately one-third of the mosasaur which was discovered last week.

The rest of the skeleton had probably already been excavated during the marl extraction in the ENCI quarry and so, it disappeared.

The scientists are pleased that most of the head has been recovered. In addition, they found, inter alia, the collar-bone and a so-called bud tooth of a few millimeters in size.

This is a new tooth hidden in the jaw which only emerges as an old tooth falls out.

Daily De Telegraaf again makes the mistake of calling the fossil a dinosaur. While mosasaurs are much closer related to, eg, monitor lizards of today then to dinosaurs.

Mosasaur discovered in Maastricht


Mosasaurus hofmanni

Yesterday, the natural history museum in Maastricht in the Netherlands did not yet want to say which huge fossil animal from the age of dinosaurs they had discovered near the local ENCI factory.

Today, at a press conference, there was more clarity.

They said it was a big mosasaur, probably a Mosasaurus hofmanni, or a closely related species.

Mosasaurus hofmanni was the first mosasaur ever discovered amidst much publicity in the eighteenth century, also in Maastricht. The original fossil was stolen from Maastricht by French soldiers, and brought to the Paris museum where it still is.

The fossil is 13 meter long, 68 million years old, and is called Carlo, after the ENCI worker who first discovered it.

A twitter message from the museum says that the skull of the newly discovered mosasaur (the only part of the animal recovered completely so far, though an important part) is about 10% bigger than the Paris specimen’s.

Dutch NOS TV says that probably, after the death of the mosasaur, scavenging sharks dispersed its remains. The search for other parts of the skeleton is still continuing.

Mosasaur’s tail bent like ichthyosaur’s


This video is called Dinosaur Revolution – Mosasaur Rampage.

70 million year Mosasaur in Bonhams Natural History Auction. One of only a few Mosasaurus baugei from Dinosaur Age is nearly 30 feet in length: here.

By Brian Switek:

The Mosasaur‘s kinky tail

For centuries scientists routinely straightened the tails of Mosasaur fossils in their reconstructions. But a recent re-examination changed overnight the way they see the sea-going lizards

On 6 April 1821 – a little more than two decades before their countryman Richard Owen would coin the term “Dinosauria” – the English naturalists Henry de la Beche and William Conybeare presented a report on a peculiar group of fossil animals to their fellows in the Geological Society of London. One of the subjects of their paper, the long-necked marine reptile Plesiosaurus, made its academic debut that night, but the others were already familiar to the scholars in attendance. Called Ichthyosaurus, these fossil creatures seemed to have been cobbled together out of equal parts fish and crocodile, and even during this era of pre-evolutionary palaeontology, de la Beche and Conybeare could not help but place Ichthyosaurus in what they believed to be a graded series of forms between fish, the newly discovered Plesiosaurus, and crocodiles.

At the time of their report, de la Beche and Conybeare did not have much to work with. Popular accounts of the marine reptile had made Ichthyosaurus famous, yet a significant portion of its skeleton remained unknown. The tireless efforts of one of the first expert fossil collectors – Mary Anning, of “She sells seashells on the seashore” fame – provided naturalists with more complete specimens, showing the various species of Ichthyosaurus to be crocodile-like reptiles with straight, tapering tails. Restorations remained true to the animal’s “fish lizard” moniker, and when Richard Owen examined an Ichthyosaurus with a kink in the distal part of its tail, he came up with a series of scenarios by which the tail of the dead individual may have become bent. (My personal favorite: that part of the tail had become bloated with gas during decomposition and pulled the spinal column out of place.)

But Owen, as well as the various scientists and artists who had reconstructed Ichthyosaurus with a straight tail, was wrong. Exceptionally well-preserved ichthyosaur specimens discovered in the 1890s from Holzmaden, Germany, exhibited dark-coloured “halos” – created by bacteria that ate away at the carcasses as they laid on the bottom of the Jurassic seas – which represented the body shapes of these animals. Not only did Ichthyosaurus have a fleshy dorsal fin, but the downward tailbend was not a pathology – it was a normal feature which supported a large tail in the shape of a crescent moon.

Re-examined in this light, it became clear that even specimens preserved without soft-tissue impressions had vertebrae near the end of their tails that were wider at the top than at the bottom; a sure sign of a downward-kinked tail that supported a large caudal fin.

The image of Ichthyosaurus changed overnight. The piscivorous predator was not a big amphibious lizard with paddles where its hands and feet should be; it was a streamlined, fusiform creature which more closely resembled a shark than any lizard. By the close of the 19th century, the issue was settled, but spectacular specimens continue to change what we thought we knew about prehistoric life.

One such skeleton, found in the middle of Kansas in the 1960s, sat in storage for years, but a re-examination has caused scientists to reconsider what they thought they knew about another marine reptile – a mosasaur called Platecarpus.

Many books and documentaries cast mosasaurs among the many “also-rans” that lived alongside the dinosaurs between 98 and 65 million years ago.

A genus or two – usually Mosasaurus and Tylosaurus – get mentioned now and again, but the larger swath of mosasaur diversity is rarely elucidated. These marine reptiles, which were much more closely related to today’s Komodo dragons than any dinosaur, were the fiercest predators of the Cretaceous seas, with many species occupying a range of habitats from near-shore to the open ocean. Most were not streamlined speed hunters like the ichthyosaurs, but instead looked like seagoing lizards; they were ambush predators that propelled themselves out of their hiding places with their long tails.

Among the most common of these marine predators was the species Platecarpus tympaniticus (named by the notorious “bone sharp” Edward Drinker Cope in 1869), and one century after it was first described an unusually complete specimen was collected from the well-known Niobrara Chalk in Kansas – a formation representing a time when a shallow sea covered much of western North America.

Shortly after it was excavated in the 1960s, the Platecarpus skeleton (known as LACM 128319) was stored in the collections at California’s Natural History Museum in Los Angeles County. For one reason or another, it sat there, undescribed for decades, but in August of this year a team of palaeontologists led by Johan Lindgren of Sweden’s Lund University at long last published a report on the specimen in the journal PLoS One.

Not only did it retain traces of soft tissues – including skin impressions and a reddish residue on its ribs that may be the remnants of its heart or liver – but its tail contained a distinctive set of vertebrae that were wider at the top than at the bottom. Platecarpus, just like Ichthyosaurus, had a downward-kinked tail that probably supported at least a modest tail fin.

Specimen LACM 128319 was not the first mosasaur skeleton to show signs of a tail fluke. In 2007, Lindgren led a different set of colleagues in describing the skeleton of a specialised form of mosasaur found in California called Plotosaurus (a specimen of which has also been found sporting soft-tissue impressions). The end of its tail sported a modified portion of vertebrae that looked extremely similar to the tail arrangement of sharks (just flipped down inside of up).

Along with a streamlined body that was deep from top-to-bottom, Plotosaurus was a mosasaur adapted to cruising in the open ocean – it was a mosasaur built like an ichthyosaur.

The skeleton of Platecarpus was not as specialised for pelagic life as that of Plotosaurus, but the examination of the new specimen shows that it was an intermediate form between the early, lizard-like mosasaurs and the last, highly streamlined types.

What is curious, however, is that the new specimen of Platecarpus represents yet another case of a marine reptile that independently evolved a downward tailbend. Ichthyosaurs did, some seagoing crocodiles (such as Geosaurus) did, and now we know that some mosasaurs did. Putting this in an even wider context, sharks have the same kind of tail, but their spinal column kinks upward and the fleshy part of their tail is below. In marine reptiles it is the other way around – with the spinal column bent downward – and perhaps there is some kind of shared evolutionary constraint, inherited from their last common ancestor, that caused the tails of marine reptiles to consistently bend downward when evolving this kind of propulsion.

As yet, such an evolutionary constraint has not been identified, but if it could be discerned, such a quirk of natural history might help us better appreciate how contingency and constraint shape evolution’s grand pattern.

Brian Switek blogs at brianswitek.com

Amateur Fossil Hunter Pieces Together Ichthyosaur Skull: here.

DINOSAURS: Say hello to Sinoceratops: here.

A vegetarian crocodile seems impossible like a lion eating fruits only, but it existed in a very ancient past: it was the Chimaerasuchus and we can neither consider it as an ephemeral presence, given that it lived in the middle Cretaceous, from 125 to 100 million years ago. Its name witnesses the many problems palaeontologists had to describe correctly this animal: “Chimaerasuchus“, in fact, means “Chimera crocodile” and Chimera was a famous symbolic monster of Greek mythology, formed by parts of different animals: here.

A major drop in temperature 137 million years ago briefly interrupted the warm, equable climate of the Cretaceous Period. The water temperature in the Arctic Ocean fell from around 13 C to between 4 and 7 C, possibly causing the poles to freeze over. Gregory Price from the University of Plymouth, UK and Elizabeth Nunn from Johannes Gutenberg University Mainz, Germany investigated rock samples with fossil belemnites and glendonites from Svalbard in order to determine the temperature of the Arctic Ocean between 140 and 136 million years ago. Such paleoclimate reconstructions help to improve predictions for future climate and environmental development and to gauge the impact of the human race on climate. The temperature of the oceans plays an important role in the history of the Earth’s climate: here.

Prehistoric marine reptiles move into museum – Xinhua: here.

USA: mosasaurs of the ancient Kansas ocean


Platecarpus, a Kansas mosasaur

From the Google cache of Dear Kitty ModBlog:

8/13/05 at 9:03PM

Mood: Looking Playing: Smoke on the waters, by Deep Purple

Sat, Aug. 13, 2005

Fossil hunter publishes love for sea creatures in new book

MIKE CORN
Associated Press

HAYS, Kan. – Most likely, Mike Everhart lies awake at night, being chased by what would be the Oceans of Kansas equivalent of Tyrannosaurus rex.

Rather than dinosaurs, however, they are mosasaurs, seagoing lizards that rivaled T. rex in terms of sheer size and ferocity.

Of course, that was of a time long ago – about 80 million years – when mosasaurs roamed the Kansas ocean, terrorizing hordes of seagoing creatures and wiping out vast numbers of sharks.

Ironically, Kansas – landlocked as it might be – is able to give Everhart, a Derby paleontologist, a relatively good look into the life of the seagoing lizards.

In fact, northwest Kansas is perhaps the best place on earth to search, discover and learn about mosasaurs.

Thousands of the feared sea creatures have been discovered and today serve as centerpiece exhibits for big museums worldwide, as well as in the United States.

But, mosasaurs – despite how ferociously predatory they were – just aren’t as sexy as dinosaurs, Everhart says.

Nor are they as sexy as plesiosaurs, the stuff that the Loch Ness monster is supposed to be made of – if it existed, of course.

Kansas isn’t quite as sexy as dinosaur bones from Mongolia or other remote locations where Kansas paleontologists have spent much of their time.

Only a small number of people still scour the northwest Kansas countryside in search of fossils.

Some are professional fossil collectors who offer their finds to the highest bidder, and some are university affiliated. That is another war entirely.

Although Everhart is a retired Boeing employee, he is also an adjunct curator of paleontology at Sternberg Museum of Natural History in Hays.

He’s also the owner and developer of the ever-growing Oceans of Kansas Web site.

Mosasaurs ate plesiosaurs: New data on the gut contents of a Tylosaurus proriger (Squamata; Mosasauridae) from the Smoky Hill Chalk of western Kansas: here.

Hainosaurus: here.

Swimming dinosaur in Wyoming: here.

See also here.

Dinosaur books: here.

Dinosaur classification: here.