Dinosaurs from the Southern Supercontinent Exhibition Opens

Gondwana, or as it is sometimes called Gondwanaland, was a supercontinent formed in the southern hemisphere by the joining together of several large land bearing crustal plates.  The land masses of South America, Australia, Antarctica, India and Africa, as well as several other significant land masses were joined together for much of the Palaeozoic.  They only began to break up to start the formation of the continents we are so familiar with today towards the end of the Mesozoic.

The plates that make up the Earth’s crust are in constant motion, the effects of the break up of Gondwana are still being seen today with the Indian plate pushing into the Asian plate, the impact of this collision resulted in the formation of the Himalayas.

The southern land masses had their own unique and diverse fauna and flora and although during the Mesozoic parts of the southern continents were joined to other land masses, those forming the periphery of Laurasia for example, dinosaurs in the southern areas of the planet evolved into different forms when compared to their northern counterparts.  For meat-eating dinosaurs in the Northern Hemisphere, the Allosauridae were gradually replaced by tyrannosaurs, but in the more isolated south, certain types of dinosaur such as the allosaurs persisted for much longer.

Dinosaurs of Gondwana

A three-month long exhibition showing some of the amazing dinosaur fossils found in countries such as Argentina, that once formed part of Gondwana will open this week (March, 2009) in Tokyo.  The exhibition entitled “Dinosaurs of Gondwana” showcases some of the amazing Theropod discoveries that have been made recently.  The exhibit is being held by the National Science Museum, in Japan’s capital and with all the interest in dinosaurs from the Japanese it will certainly attract large crowds.

A star exhibit are the reconstructed skeletons of a family group of Mapusaurus (Mapusaurus roseae).  Two adults and a juvenile are depicted together, giving the impression of a family group.  This reconstruction is based on interpreting evidence from the fossil bone bed from which Mapusaurus fossils were extracted.

A Model of the Giant Theropod Mapusaurus (M. roseae)

CollectA Mapusaurus hunting dinosaur model.

Picture credit: Everything Dinosaur

The reconstruction of this meat-eating dinosaur family group is based on the fact that the Mapusaurus fossils were found together, in a fossil bone bed that contained at least seven individuals of varying ages and sizes.  The scientists who named and described this dinosaur (Rodolfo and Currie, 1996), speculated that the accumulation of bones in this one location could be coincidental, but it could also be evidence that all these animals lived together and subsequently died together.  This could be evidence of pack behaviour amongst carcharodontosaurids.

Formidable Predators

These animals were certainly formidable predators.  Related to Giganotosaurus, these particular meat-eaters may have reached lengths in excess of 13 metres and if they did hunt in packs they would have been capable of bringing down even the largest titanosaurs.

The exhibition runs from the 14th March until June 21st and features a number of theropods from Gondwanaland, including the 8 metre long Megaraptor (Megaraptor namunhuaiqui) and the bizarre looking Cryolophosaurus, (C. elliotti) an Early Jurassic meat-eater; fossils of which have been found in Antarctica.

To view a model of Cryolophosaurus, Giganotosaurus, Mapusaurus and other dinosaurs: Dinosaur and Prehistoric Animal Models.

Amateur Palaeontologist pleads Guilty to Theft Charges

In an update of a web log article first published in January, amateur palaeontologist Nathan Murphy has pleaded guilty to the State charge of theft.  The theft concerns a fossil of a small, bipedal dinosaur called a dromaeosaur.

To view the original web log article: Local Fossil Collector Charged with Theft.

Palaeontologist

In the late autumn of 2006, Nathan Murphy, a well-known and highly regarded amateur palaeontologist and fossil collector took a specimen of a small, dromaeosaur to be studied at his local dinosaur study centre – the Dinosaur Field Station.

Mr Murphy had identified the fossil bones as belonging to a new type of dromaeosaur, a turkey sized animal that he had nick-named “Sid Vicious”, after the infamous English punk rock singer.  If Mr Murphy had owned the rights to this fossil, then it could have proved to be an extremely lucrative discovery, as there would be a considerable amount of money to be made selling casts to museums and private collectors.

Theft of the Specimen

However, Montana State law enforcement officers accused Mr Murphy of theft as the specimen had been discovered several years earlier, not where Mr Murphy claimed to have found it, but on private land and this means that this particular dinosaur fossil probably belongs to someone else.

The charge of theft is appropriate in relation to dromaeosaur fossils.  These dinosaurs are often termed “raptors” which can be defined in Latin to mean robber or thief, very apt under these circumstances.

Nathan Murphy, has pleaded guilty to the charge of theft of a fossil from private land.  The Federal authorities have also charged Mr. Murphy with a felony for the alleged theft of dinosaur fossils from public land. These charges are pending.

Unfortunately, with the high prices dinosaur fossils fetch these days, allegations of theft and wrong-doing are becoming more common amongst fossil collectors.

For prehistoric animal models and replicas: Dinosaur and Prehistoric Animal Models and Figures.

In a Flap over Pterosaur Anatomy that enabled them to Fly

A team of US/UK based researchers have published a paper outlining their findings on how the flying reptiles (pterosaurs) were able to take to the air and fly so efficiently.

In a new study published in the online palaeontological journal “PLoS ONE”,  the joint Anglo/American research team state that the hollow bones of pterosaurs, coupled with large air sacs inside their bodies, reduced the density of the animals and helped them to take to the skies.  The team’s study indicates that pterosaurs had a very efficient breathing system, similar in structure to modern birds and it was this system in conjunction with the light skeletons that enabled these flying reptiles to have an aerial lifestyle.

Pterosaurs are not Dinosaurs

Pterosaurs are not dinosaurs, but flying archosaurs, closely related to Dinosauria.  The earliest pterosaur fossils date from the Triassic, although their exact evolutionary path is unclear due to the limited amount of fossils found so far.  A pterosaur’s wings were made of a large membrane of skin that stretched from the end of an extremely long fourth finger to its body and back legs.  The wing membrane was strengthened with stiffening fibres (actinofibrillae), tests on models show that they were efficient fliers not simply gliders.

The first pterosaurs such as the anurognathids were small, some no bigger than a blackbird.  They had shortened wrist bones, blunt snouts and other features indicative of a primitive pterosaur group.  Later forms such as the Late Cretaceous azhdarchids, such as Quetzalcoatlus were much more advanced.  Some of the azhdarchid pterosaurs grew into giants.  Quetzalcoatlus, one of the largest pterosaurs known to date had a wingspan in excess of 11 metres.  These pterosaurs has long, toothless beaks, long necks and immense wingspans.  Many scientists believe that this type of flying reptile soared and glided using air currents and hot thermals.

A Scale Drawing of the Giant Azhdarchid Quetzalcoatlus

Picture credit: Everything Dinosaur

Stalking Predators

Recently,  a new theory about the lifestyle of these huge reptiles was put forward by a team of English researchers.  These animals may have had more of a terrestrial existence than previously thought.  Fossils of many large pterosaurs are associated with marine sediments, indicating that they lived in coastal areas.  Air currents hitting cliffs and rising up and the onshore breezes would have assisted these large animals in their bid to get airborne.  However, fossils of Quetzalcoatlus (Quetzalcoatlus northropi) are associated with non-marine sediments.  It has been suggested that these huge animals were mainly ground dwellers, stalking the Cretaceous plains, flushing out prey and snapping them up with their long beaks.

An Alternative View of Azhdarchid Pterosaurs

Picture credit: Mark Witton

To read more about this viewpoint: Getting Stalked by a Flock of Quetzalcoatlus.

One of the problems scientists have with the larger Pterosaurs is that their fossils are extremely rare, their delicate pneumatised bones (filled with air), were light and strong but not as robust as even the bones of smaller theropods (which also had pneumatised bones), therefore not able to survive the preservation process.  A number of theories have been put forward as to the lifestyles of the largest pterosaurs, everything from vultures to giant herons.  The azhdarchids were some of the very last pterosaurs to evolve and lived at the very end of the Cretaceous (Campanian and Maastrichtian faunal stages).  By this time in the Earth’s history most of the other types of flying reptiles were extinct, replaced by another type of animal more suited to life in the air – Aves (the birds).

To view a model of a Quetzalcoatlus and other pterosaur figures and replicas: Dinosaur, Pterosaur and Prehistoric Animal Models.

Growing to the size of a small aircraft in some cases, the American and British research team were puzzled as to how these large reptiles were able to soar in the air.

Pterosaurs

According to this new study, the pterosaurs were equipped with balloon-like air sacs that extended from the lungs throughout the body and in conjunction with their hollow bones, this provided these flying reptiles with a super efficient breathing system.  The less dense bones would also have helped reduce weight helping them in their bid to become aerial.

A couple of years ago, a team of scientists at the University of Manchester, England, published research into dinosaur breathing systems and concluded that many types of dinosaur (especially saurischian dinosaurs), were equipped with a very efficient bird-like breathing system.

To view this article: Insight into Dinosaur Respiration – A Breathe of Fresh Air.

Birds have a much more efficient breathing system than mammals.  This new paper suggests that the pterosaurs also possessed an advanced and efficient respiration system, better than our own for example.

Instead of just one entrance/exit point in the lungs they have openings at both ends, plus the addition of a series of balloon-like air sacs in front and behind the lungs.  It is these air sacs, not the lungs that inflate and deflate with each breathe.  Acting like a set of bellows they pump air through the lungs and out of a different tube than it went in.  This one-way system, with old expired air never mixing with fresh air, rich in oxygen to power muscles is a very efficient system.  Like birds, the pterosaurs may have had large hearts to help provide the power required to make this breathing system operate, but unfortunately, soft tissues such as internal organs are extremely rare in the fossil record and none of the team members at Everything Dinosaur can remember reading a research paper on fossilised pterosaur hearts.

Commentating on the research, Dr David Unwin, a palaeobiologist in the Dept. of Museum Studies at the University of Leicester, a co-author of the study stated:

“We have identified the breathing system of a pterosaur.  It’s a surprisingly efficient mechanism with the same essential structure of a modern bird’s lung apparatus — except 70 million years earlier”.

The research project began to take shape following a visit to Berlin by Assistant Professor Leon Claessens from the College of the Holy Cross in the United States and Assistant Professor Patrick O’Connor from Ohio University.  The Americans studied the well-preserved rib cage of a pterosaur, the same fossil had been examined by Dr Unwin a few years earlier.  The fossil showed that the rib cage was mobile and that it could articulate with the sternum or breast plate.  Projections on the topmost ribs provided important leverage for the muscles that allowed the rib cage to move, expanding and contracting – a prerequisite for a bird-like respiration system.

The three scientists then decided to work together to find out how these flying reptiles were able to achieve sustained, powered flight.

Studying Pterosaur Body Fossils

As well as studying a number of pterosaur body fossils, the researchers also compared the anatomy and structure of pterosaurs with modern bird skeletons.  Medical CT scans and X-rays were used to get a better impression of the internal structure of the bones.

In a statement, the researchers commented:

‘The air sacs extend all the way to the tips of the wings which opens up a wide range of possibilities for the use of air sacs during flight and for social behaviours.  We found a direct relationship between the proportion of the skeleton invaded by air sacs and the absolute body size of an animal”.

Smaller flying animals have fewer pneumatised bones.  They have a lower mass and so require less energy to get and remain airborne.  Large flying animals such as pterosaurs have many more pneumatised bones, giving them less bone density and making it easier for them to sustain flight.

Studies of the skulls and endocasts of pterosaur brains indicate that they had a very good sense of balance and keen eyesight, all very helpful if you are going to fill an environmental niche based on flying.  As a group, the pterosaurs rapidly diversified during the Triassic and Jurassic before, towards the end of the Mesozoic, encountering competition from the new types of flying creature – the birds.

The last of the pterosaurs went extinct at the end of the Cretaceous, approximately 66 million years ago.

Reverse Genetic Engineering turning a Chicken into a Dinosaur

Darwin devoted a proportion of his scientific studies in preparation for the publishing of his theory on natural selection “The Origin of Species” first published in 1859 to a study of animal and human embryos, however, we think he would have been surprised as scientists aim to manipulate bird genes in a research programmed nicknamed the “dinochicken” project.  The great English scientist was keen to examine the development of different species demonstrating the “complex relations of all animals and plants throughout nature”; as Darwin put it.

For Darwin, he could see the linkages that supported his theory, but he was not sure what the mechanism for natural selection was.  It was not until the 20th Century and the developments in genetics, that gave scientists a greater insight into the structure and make up of organisms.

The link between the ancestry of birds and dinosaurs had been postulated during Darwin’s lifetime.  Indeed it was scientists such as Huxley, the great Darwinist supporter who had put forward the treaty that small, bipedal dinosaurs could have given rise to birds.  Such a theory was supported by the Solnhofen fossils of Archaeopteryx, a creature with both avian and reptilian characteristics.

The “Dinochicken” Project

Now a team of palaeontologists and researchers from the University of Montana want to go further and reverse engineer dinosaur features from a chicken embryo.  It has been known for some time that by manipulating proteins in a developing embryo ancient characteristics buried deep in the genetic make up of an organism can be “turned on”.  Extended elements of the birds tail bones, the pygostyle has been achieved in the past.  The pygostyle is the remnant of the dinosaur tail, it consists of the last five caudal vertebrae that have been reduced and eventually fused to form a plate of bone.  Small needle-like teeth have also been formed by chicken embryos, reflecting their meat-eating dinosaur ancestors.  Modern birds (neornithes) do not have teeth in their beaks.  Teeth are heavy and require robust jaws to house them, so to reduce weight (very helpful in fliers), the toothless beak has evolved.  However, more primitive birds such as the Hesperornithiforms from the Cretaceous had teeth.

However, the Montana University team intend to go further than other scientists and try to develop a number of reptilian characteristics at the same time.  Project leader Jack Horner referring to the plan to reverse engineer a chicken embryo suggested that the American team would create a “chickenosaurus” or perhaps a “dinochicken”.

Reverse Engineering a Chicken – Could Dinosaurian Traits be Produced?

Picture credit: Everything Dinosaur

Caudipteryx

The picture above is of the small, feathered dinosaur Caudipteryx (Caudipteryx zoui).  Caudipteryx fossils show that this animal was a close relative to birds but not a direct ancestor.  This dinosaur is one of a number of feathered dinosaurs found in Cretaceous aged sediments in the Liaoning Province of China.

This is the first time that genetic experts have tried to bring back several dinosaurian characteristics, such as a teeth, tail and forearms, by changing the levels of regulatory proteins that have evolved to suppress these characteristics in Aves.

To see a model of Caudipteryx and other feathered dinosaur figures: Dinosaur and Prehistoric Animal Models.

Similar experiments have been performed on mice and insects, but for Horner this is not really playing God or meddling with the DNA, just turning on the genes to bring the dinosaur tail back on a creature whose ancestors would have possessed one anyway.  This type of research could be carried out on any member of the neornithes, but the chicken has been chosen as their genome has already been precisely mapped and their embryos extensively studied.

It is the research team’s intention to extend the vertebrae to grow the tail, reverse engineering the pygostyle and producing an animal with unfused caudal vertebrae.  Already, tail-like structures have been developed in birds using these protein juggling methods, but this is the first time that such extensive re-programming of an embryo will have taken place.

There is no chance that a fearsome meat-eating dinosaur will be produced, but this research is helping to improve our knowledge relating to spinal cord development. Studies and research work such as this could have important benefits for medical science.

Jurassic Handprint Demonstrates Link to Birds

Marks left in the mud next to an ancient Jurassic lake by a meat-eating dinosaur and preserved as fossils; reveal that dinosaurs had hands that were not suitable for walking upon very early in their evolution.  In a report published in the online palaeontological journal PLos ONE, a team of American scientists have concluded that the fossil handprints, perhaps the best theropod handprints discovered to date, indicate that these dinosaurs abandoned the use of their forelimbs as legs early in their evolutionary development.

The term theropod (it actually means “Beast Foot”), or to be more scientifically accurate and to use the formal classification – Theropoda; refers to a group of lizard-hipped, bipedal dinosaurs.  The majority of the sub-order Theropoda are meat-eaters, dinosaurs such as Tyrannosaurus rex, Spinosaurus and Megalosaurus are theropods.  The primary classification of dinosaurs took place in the latter half of the 19th century when our knowledge of these animals and their diversity was only just beginning to develop.

The term theropod for example, was first attributed to the American palaeontologist Charles Othniel Marsh.  He used the classification Theropoda to help determine the relationship of the Allosauridae fossils from the Western USA to other types of dinosaur.  The term replaced the earlier classification for large, bipedal dinosaurs of Goniopoda “angled feet” which had been proposed by Marsh’s great rival Edward Drinker Cope.  Ironically, the term Goniopoda is more appropriate, as scientists are now certain that it is the theropods or the “Beast Feet” that are the ancestors of birds.

Commenting on the scientific paper, the lead author, Andrew R. C. Milner of the St George Dinosaur Discovery Site at Johnson Farm in Utah, stated that due to the disproportionately small forelimbs of most theropods trace fossils of them as they rested on the ground are extremely rare.  Only a few other examples of theropod handprints are known, but the discovery of a beautifully preserved set of impressions in 2004, have enabled scientists to shed more light on the range of movement of dinosaur hands and arms.

Impressions in the Sediment

Vertebrate palaeontologist Milner and his colleagues describe in the paper, a clear set of 5 cm deep impressions preserved amongst hundreds of other trace fossils in the sediment that has been dated to the early Jurassic (Sinemurian faunal stage), approximately 198 million years ago.  The rock preserves trace fossils of worm borings, tracks made by crabs as well as body fossils of fish.  The sediment represents a part of a shoreline adjacent to an ancient lake.  The water level seems to have altered and as a result the sediment shows signs that the water levels fell and the muddy sand cracked and dried in the sun.

Milner commented:

“The now-hardened rocks preserve many details of the lakeside topography of that time”.

The theropod handprints, form part of a fossilised trackway that appears to have been made when the dinosaur walked up a slight incline and then crouched down to rest.  Although the actual genera of dinosaur cannot be identified from the footprints and no theropod dinosaur bones have been associated with the trackway, the Utah based team have calculated that the marks were made by a meat-eating dinosaur that would have measured approximately 4.5 metres long.  Little is known about dinosaurs from this time in the early Jurassic, the fossil record is particularly poor.

However, Dilophosaurs are known to have lived in this part of the world at the time the handprints were made and the scientists have speculated that a Dilophosaurus or some such similar animal could have made the tracks.

An Illustration of Dilophosaurus

Picture credit: Everything Dinosaur

To see a model of a Dilophosaurus: Dinosaur and Prehistoric Animal Models.

A Model of A Dilophosaurus (Procon/Collecta Range)

“Double crested lizard”

Picture credit: Everything Dinosaur

In the model above, the sculptor has attempted to show the hands of the Dilophosaurus slightly turned into the body, moving away from the classic “bunny” position of most theropod dinosaur models, and indeed museum exhibits.  In this, the sculptor has attempted to demonstrate the limited range of movement of the forelimbs of saurischian, theropods.

Dinosaur Handprint

Each handprint was made by the edge of the hand, not its palm, and indicates that the fingers on each forelimb curled inward, says Milner.  This configuration backs up anatomical studies of later theropods, suggesting that those creatures couldn’t rotate their palms to face downward, indeed the range of movement of theropod forelimbs was very different to the range of the arm movement in humans.

In discussing the findings, Thomas R. Holtz Jr. (vertebrate palaeontologist at the University of Maryland) stated:

“If there is any situation when you would expect a theropod to plant its palm facedown, then this is it – and the fact that it didn’t in this case is strong evidence that it couldn’t”.

In the typical tone associated with many palaeontologists who get really excited about new discoveries Holtz went on to state that:

“It is a really neat paper, it shows that even early theropods had abandoned the use of the forelimbs as legs”.

The Fossilised Handprints and an Illustration of the Dilophosaur Resting

Picture credit: H. K. Luterman of Cedar City, Utah

The fossilised handprints (picture left, see arrows), were presumed to be made by a resting theropod dinosaur.  The prints left in the sediment indicate that this dinosaur could not rotate its palm to face downwards.   The illustration on the right shows how a crouching theropod might have made such marks in the sand.

In contrast to the way that most theropods are depicted in books, pieces of art and even in museum exhibits, the range of movement of theropod’s arms was limited in comparison to our own.  Theropods and other bipedal lizard-hipped dinosaurs could not rotate the forearm so that the palms faced the ground or backwards towards their hind legs.  This ability to rotate the hands is called pronation.  It is achieved by motion of the two bones in the forearm, the radius and the ulna in relation to each other.  From studies of dinosaur bones it seems that in most theropods the radius and ulna were less mobile in relation to each other, so movement was limited.  The freedom of movement around the shoulder joint and the wrist bones was also much reduced when compared to human anatomy.  However, studies of the structure of some theropod forelimbs, such as the early Cretaceous meat-eater Acrocanthosaurus show that the digits could be flexed backwards against the wrist, perhaps an adaptation to enable the sharp claws on this dinosaur’s three fingers to dig into struggling prey.

Theropod Arm Movement

Scientists have speculated that the range of arm movement in many theropods reflects their relationship with the Aves (birds).  In theropods, the only way for the palm to face the ground would perhaps have been by splaying out the entire forelimb, as in a bird raising its wing.  The range of possible movement for forelimbs in later theropods such as the Troodonts does reflect their close kinship to birds.

It seems from the trace fossils found at the site of an ancient lake in Utah, the forelimbs in certain dinosaurs had become much more specialised and no longer useful for walking upon much earlier in their evolution than previously thought.

Evolution Rocks! – Lyme Regis Fossil Festival is On

Evolution Rocks – the Lyme Regis Fossil Festival is on for May 22nd to May 24th 2009.  Some doubts had been raised about the festival taking place this year after it was cancelled in 2008.  However, funding has been secured and the organisers have been given the go ahead to run the event again this year, linking into the Darwin 200 celebrations, marking the 200th anniversary of the birth of Charles Darwin.

We reported on whether this event was going to happen or not last year, when the event was very much “in the balance” according to one official.

To read this story and learn more about the Fossil Festival: Update on the Fossil Festival.

Lyme Regis, in Dorset, England  is at the heart of the world heritage site known as the “Jurassic Coast” it is a popular and attractive tourist destination and is world famous for the Jurassic fossils that can be found along the shoreline and eroding out of the cliffs.

The Fossil Festival was begun around 2004 (we think), Everything Dinosaur staff have been involved since the project’s inception and have attended every single one so far, either as volunteers helping to stage the event or as exhibitors.  This year we are booked to go down south again, but probably as a bit of a “busman’s holiday” rather than to exhibit or hold a seminar.

Our reasoning behind this is very straight forward, what with all the new product development work, teaching, museum work and everything else some of the staff have not had a proper holiday for 2 years.

Glad to see the Festival is back on, and by visiting Lyme Regis we will be able to pay homage to Mary Anning by visiting her grave in the churchyard on the hill.  Mary Anning was a pioneering English fossil collector.  She was born in Lyme Regis in 1799 and she became famous for her ability to find fossils in and around the cliffs.  She discovered the first Plesiosaur in 1821 and the first Pterosaur fossils in England in 1828.  During her lifetime she did not get the recognition her work deserved, but scientists today owe a great deal to Mary.

Mary Anning’s Tombstone at Lyme Regis

Picture credit: Everything Dinosaur

Everything Dinosaur stocks a range of replica ammonites, belemnites, marine reptile and pterosaur figures, models of animals that Mary Anning would have been familiar with: CollectA Prehistoric Life Models and Replicas.