Feeling the Cold – Dramatic Temperature Drop Started Dinosaur Demise

Sudden Fall in Northern Sea Temperatures Started Dinosaur Extinction

A sudden and dramatic fall in sea temperatures, triggered by the melting of polar ice in northern latitudes started the demise of the dinosaurs and other mega fauna at the beginning of the Cretaceous claim British scientists.

In a scenario somewhat reminiscent of the 2004 film “The Day After Tomorrow”, directed by Roland Emmerich in which a palaeoclimatologist predicts an Ice Age following the impact of global warming leading to the melting of the polar ice caps, the British researchers claim that a similar event occurred approximately 137 million years ago (Valanginian faunal stage).

The team studied fossils of marine organisms and mineral deposits from the Arctic Svalbard of Norway and they conclude in a scientific paper, that the sea temperatures dropped some 16F. (9 Celsius) and this sudden climate change began the demise of many of the sea creatures and land animals around at the time.  This study claims that the change in the young Atlantic’s Gulf Stream during the early Cretaceous would almost have certainly have wiped out the “abundance” of the world’s dinosaurs.

Small extinction events occur throughout the fossil record, these are triggered by environmental and/or climatic changes, although for the Dinosauria the early Cretaceous saw an increase in their diversity, particularly amongst the Ornithischians (bird-hipped dinosaurs).  It is certainly true that virtually all the non-avian dinosaurs become extinct along with many types of marine reptile and the Pterosaurs at the very end of the Cretaceous.  A number of theories have been put forward to explain this mass extinction event at the very end of the Mesozoic, perhaps the most widely accepted theory is the impact of an extraterrestrial body in the Gulf of Mexico that triggered the extinction of something like 70% of all species on Earth.

At the 41st meeting of the Lunar and Planetary Science Conference in Texas in March this year, a paper was presented that attempted to end all the debate over what exactly caused the demise of the Dinosaurs 65 million years ago.  The impact of an extraterrestrial object was stated as being the number one cause – naturally, this has led to extensive debate.

To read more about the paper presented at the Conference: Extraterrestrial Impact Did Cause the end Cretaceous Mass Extinction

This new research suggests that mega fauna such as the dinosaurs were wiped out by a series of environmental changes starting with a drop in sea temperatures.  Such a dramatic fall in sea temperatures would have had a serious impact on fauna and flora.  The common perception is that the Cretaceous period had a uniform, and constant environment.  This is not the case, a rapid rise in atmospheric carbon dioxide at the beginning of the Cretaceous may have led to extensive global warming but from earlier studies on zonal fossils and mineral deposits it seems that for much of the Cretaceous there was a fluctuation between hot and relatively cold periods every two million years or so.

One of the Svalbard Invertebrate Fossils in the Study

Picture Credit: SWNS

The picture shows the fossilised impression of an Ammonite (Lytoceras?), the strong ribs of this fossilised shell of this Cephalopod can be clearly made out at the top of the fossil.  A Norwegian coin has been placed next to the fossil to give scale.

Scientist Gregory Price, from Plymouth University (United Kingdom), who led the study stated that his team’s work showed the drop in temperature occurred when the Earth was in a “greenhouse” climate, which was very similar to the climatic phase seen today.

The team concluded that the drop in sea temperatures was so severe that this would have had an enormous impact upon, not only marine creatures such as Ammonites but also many species of dinosaur and other large animal previously living in warm coastal areas would have been affected.

Paul Gregory commented:

”We believe dinosaurs were most likely to be cold-blooded creatures and would have needed the warmth to keep them alive.  If they were unable to migrate south they could have been wiped out.  Climate change is now very much on the agenda in trying to determine how the dinosaurs became extinct.  We now believe that they died out gradually and it is very possible that this could have been caused by a series of climatic changes.”

The drop in temperature is thought to have occurred because high levels of carbon dioxide was in the atmosphere this caused global temperatures to rise and polar ice to melt – a phenomenon currently predicted for Earth, so what may have happened to some of the dinosaurs may be about to happen to the mammals, including one particularly highly evolved species of ape – us.

Ontogenic Characteristics of Feathered Dinosaurs

Baby Dinosaurs may have had Different Feathers from their Parents

In a few weeks time those garden birds that have nested and raised a brood successfully will be seeing their youngsters fledge and leave the nest.  A baby Blackbird for example, will moult, losing its downy insulation of feathers and develop feathers that are indistinguishable from its parents.  This youngster, that just a short while ago was an embryo, will look very similar to an adult of its species.  However, in a new paper published in the scientific journal “Nature” it seems that juvenile dinosaurs may have looked strikingly different from their parents.

In a study of two fossils one of an adult, the other of a juvenile dinosaur of the same species; by Chinese scientists, there is evidence to suggest that Theropod dinosaur species at different growth stages may have had dramatically different feathers.  The fossils may indicate that as dinosaurs grew, their feathers changed dramatically.  This is the first time that such evidence has been seen in the fossil record and the interpretation of these two fossils, both recovered from the fossil rich Yixian Formation of western Liaoning (northern China), is being hotly debated by both palaeontologists and ornithologists.

The sedimentary rock formations of Liaoning Province are world famous due to the remarkably well-preserved Cretaceous fossils that they contain.  Much of our knowledge about feathered dinosaurs is due to the myriad of amazing and superbly well-preserved fossils of small Theropod dinosaurs that have been discovered in quarries from this part of China.  The fine-grained, siltstones were formed by volcanic ash from nearby volcanoes that frequently erupted during the early Cretaceous.  Animal and plant remains that had become deposited in lakes in the area were rapidly buried by the ash and this has led to the remarkable state of fossil preservation.  A number of small, feathered Theropod dinosaurs are known from the area, dinosaurs such as Sinosauropteryx and Sinornithosaurus as well as birds, plant remains and even insects.

The dinosaur fossils that have attracted so much interest over how feathers may have changed dramatically as dinosaurs grew and reached maturity; are those of the small, Oviraptorid Similicaudipteryx (Similicaudipteryx yixianensis).  This particular Theropod is known from three specimens and it was formerly named and described in 2008.  Crucially, the local farmers who help the scientists to find fossils, found examples of an adult, whilst the other two fossils represent younger animals.

The Fossils of Similicaudipteryx (Similicaudipteryx yixianensis)

Picture Credit: Zheng Xiaoting

The picture above shows a fossil of a juvenile Similicaudipteryx on the left with the fossilised remains of an adult on the right.  A team of researchers from the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP) from Beijing have interpreted the fossils and produced a paper suggesting that unlike modern birds, the plumage and feathers of dinosaurs changed as these animals grew and reached maturity.

Similicaudipteryx was a small, bipedal, feathered dinosaur it was closely related to Caudipteryx (another feathered dinosaur discovered in Liaoning).

An Image of Caudipteryx

Picture Credit: Everything Dinosaur

To view a model of Caudipteryx: Dinosaur Toys for Boys – Dinosaur Models

The fossils indicate that this little Theropod had a maturation pattern not seen in modern birds.

Commenting on the paper, one of the authors, Xing Xu of the IVPP stated:

“This baby dinosaur has bizarre flight feathers, which are strikingly different from those of adults.  These 125-million year old fossils expand our knowledge of feather evolution.”

The wing and tail feathers of the more mature dinosaur resemble quill pens. These ‘pennaceous’ or contour feathers have a central shaft that runs through its entire length. Conversely, the feathers of the younger dinosaur have a flat, ribbon-like stem at one end, but the more familiar pennaceous feather at the tip.  The early juvenile also has smaller wing feathers than tail feathers, but this size difference is less significant in the specimen that represents an older more mature specimen.  Neither adults or juveniles could fly, it is likely primitive feather-like structures first developed to help insulate and keep warm these small active animals.  In mature adults, the feathers may have become more ornate and might have played an important role in communication and display.

Palaeobiologists say that if the Chinese team’s interpretation of the fossils is correct, it would be the first time that juvenile dinosaurs have been shown to have a different type of feather from adults.

Mike Benton from the University of Bristol (UK) added:

“Modern birds don’t make such a transition.  Apart from the downy feathers of newborns, all later stages of modern birds are characterised by the same flight feathers. This paper marks the first step in attempts to disentangle the evolution of developmental sequences among birds and their ancestors.”

However, some ornithologists and developmental biologists have questioned the conclusions made in the Chinese paper.  They query whether the younger fossil shows a ribbon-like feather or is instead from the bird’s moulting phase.

Yale University’s Richard Prum, a leading ornithologist and expert on bird plumage stated:

“Feathers are complicated.”

When modern birds regenerate their feathers, the new ones grow rolled-up in a tube sheath.  Prum has commented that the fossilised feathers of the younger dinosaur could be interpreted as a preserved image of feathers emerging from their sheath; like modern feathers in active moult.

But IVPP scientist Xu maintains that this finding is “not an artefact of preservation or temporary morphology” based on the proportions of the feathers.  If the juvenile feathers were simply in active moult, he would expect the ribbon-like part of the feather to be shorter.  If the Chinese interpretation of the fossil data is correct then this will be the first demonstration that these feathered dinosaurs could undergo changes of plumage as they grew and matured.

An Artist’s Illustration of a Juvenile and Adult Similicaudipteryx

Adult and juvenile feathered dinosaurs

Picture Credit: Xing Lida and Song Qijin

The picture shows an artist’s interpretation of the Similicaudipteryx fossils, the juvenile is in the foreground with the adult just behind.

Using work done by Prum, Chuong and others, Xu and his colleagues at the IVPP suggest that the unusual partially-pennaceous feather might be a result of the delayed expression of genes that are activated earlier in modern birds.

Canadian palaeontologist Phil Currie commented:

“Dinosaurs had been experimenting with feathers and feather-like structures for a period of at least 25 million years before the dinosaurs described here [Similicaudipteryx].  The wonderful thing about this paper is that it provides developmental clues that may force palaeontologists, ornithologists and developmental biologists to recognise a broader spectrum of possibilities rather than looking for some simple answer.”

Scientists Find Evidence of Water on Asteroid

Scientists find Evidence of Ice on Large Asteroid

Could life on Earth have been kick started thanks to the impact of asteroids and other celestial bodies that brought raw materials to encourage the right conditions for organisms to flourish?

This is the fascinating question that is being posed by scientists in a study published in the scientific journal “Nature”, for ice has been detected on a large 200 kilometre-wide asteroid in an area of our solar system between Mars and the gas giant Jupiter.

Analysis of the asteroid, known as 24 Themis shows evidence of organic matter as well as ice crystals.  Impacts from extraterrestrial bodies such as asteroids and comets could have led to the deposit on Earth of the chemical ingredients required to start or even speed up the development of life forms on planet Earth.  the discovery of ice and carbon elements on this asteroid adds weight to the theory put forward by many astronomers that Earth was relatively arid in its early history and water and other organic compounds were seeded on the planet due to the impact of asteroids and other space debris.

Planetary scientist Dr Josh Emery, of the University of Tennessee, (United States), one of the authors of the astronomical study commented:

“The organics we detected appear to be complex, long-chained molecules.  Raining down on a barren Earth in meteorites, these could have given a big kick-start to the development of life.”

Archives Reveal British Authorities Believed in the Loch Ness Monster

Senior Police Officers Believed in “Nessie” in the 1930s

Loch Ness, the largest expanse of freshwater in the British Isles is a very beautiful and tranquil place, however, this part of the Scottish Highlands is perhaps best known as the lair of a strange beast – “Nessie”.  Many sightings, pictures and even sonar and video images have been taken of the “wee beastie” that is supposed to lurk in the peaty waters of the Loch, indeed, many other Lochs in Scotland have their own stories of strange creatures in the water.  This phenomenon is not just restricted to Scotland, many locations in the northern hemisphere have their own stories and myths of strange lake monsters.  There is “Champ” in Lake Champlain and a myriad of similar strange animals reported from Lakes as far apart as Norway, Sweden, the United States, Ireland and Turkey.

However, perhaps the most famous (or should that be infamous) lake monster of them all is Nessie and papers from senior figures in authority dating from the 1930s, put on display for the first time; reveal that for many people at the time the Loch Ness Monster was very real.

With the upgrading of the A82 that skirts around the northern shore of the twenty-five mile long loch, there were more vehicles and travellers passing by the deep, dark waters and there were a spate of monster sightings, even one from a couple who claimed that Nessie left her watery home and hauled herself passed their car, perhaps the creature was going ashore to sample the night life of Fort William.

In a time, when movies like King Kong were causing a sensation and monsters (even dinosaurs) were big news, even bigger than they are today, it was one particular photograph, taken in 1934 that really set the world’s attention on the Loch Ness area and sent every would-be monster hunter to this part of the Highlands in a bid to “bag the beastie”.

In April 1934, a sensational photograph purportedly taken by a respectable London surgeon was published in many newspapers around the world.  It seemed to show the head and neck of a strange creature breaking the surface of the waters of the Loch.

The 1934 “Surgeon’s” Photograph

Picture Credit: Keystone/Getty

Colonel Robert Wilson’s photograph seemed to confirm the sightings and reports, that there was a strange animal unknown to science lurking in the waters of Loch Ness.  It was not until 1994 that the photograph was revealed to be a hoax, the picture shows a model of the “monster” taken just a few feet from the shore and not the head and neck of a large Plesiosaur (extinct marine reptile).  However, this photograph and the spate of sightings and reports seemed to convince a number of senior figures in authority as to the creature’s existence.  In papers and letters put on display at the National Archives of Scotland in Edinburgh, the then Chief Constable of Police in Inverness-shire, William Fraser, was even making plans to try to protect the monster from big game hunters.

As the new Chief Constable for the region, Mr Fraser wrote in August 1938 to the Under Secretary of State in the Scottish Office, urging the Government to do all it could to “protect the monster”.  Mr Fraser expressed his concern over the steady stream of trophy hunters and sportsmen who visited the Loch with the intention of capturing Nessie, the letter, one of a series of documents put on display, part of the “Secret Nessie Files”, reveals that Mr Fraser believed that the monster was real.

This letter along with other documents on display demonstrates the extent to which the belief in Nessie was established amongst senior authority figures and their determination to protect it.

Mr Fraser, who led the force until 1951, described a London couple, Peter Kent and Marion Stirling, who were “determined to catch the monster dead or alive”.  They planned to have a “special harpoon gun” made and intended to return with “twenty experienced men” the following week “for the purpose of hunting the monster down”.

It could be argued that Mr Fraser was thinking in terms of public safety when he wrote those comments but he goes onto add:

“That there is some strange fish creature in Loch Ness seems now beyond doubt, but that the police have any power to protect it is very doubtful.  I have, however, caused Mr Peter Kent to be warned of the desirability of having the creature left alone, but whether my warning will have the desired effect or not remains to be seen.”

It appears that the Chief Constable had a case of “monster fever”, perhaps he was an early cryptozoologist (a person who believes in the existence of strange and bizarre creatures, as yet unknown to science).

From time to time, remarkable discoveries of animals not known in the western world are made.  For example, recently a new species of giant monitor lizard was discovered in the Philippines.

To read more about this recent discovery: If You go Down to the Woods Today – Discover a new species of Monitor Lizard

A spokesperson for the archives stated that other authority figures were less convinced:

“It’s certainly remarkable that a senior police officer was prepared to accept the existence of a “strange fish” or rather “creature” in the Loch”.

The files put on public display for the first time, also reveal that other officials were more sceptical and certainly less inclined to express strong views in favour of the existence of a monster.

For Adrian Shine, a naturalist who founded the Loch Ness and Morar Project (Loch Morar is deeper than Loch Ness and has its own monster legend), believes that Mr Fraser was not alone in believing in Nessie.

He said:

“When the first stories began to burgeon from Loch Ness in the summer of 1933, people in fairly high and respectable positions were quite properly and respectably interested to see what was happening and wanted to investigate and protect whatever was there if necessary.”

Mr Shine commented that it was possible that Nessie was a species of migratory sturgeon.  Another theory behind the more than 1,000 sightings is that the unique environment of Loch Ness creates optical illusions, or perhaps there really is a marine reptile, a Plesiosaur swimming around the Loch.  Unlikely, but you never know, however, we at Everything Dinosaur don’t believe in the possibility of a Mesozoic relic such as a Plesiosaur being alive today, certainly not a population of them living in Loch Ness, a feature that was only formed a few thousand years ago.

A Model of a Plesiosaur (Elasmosaurus) – Could this be Nessie?

Bullyland Elasmosaurus from Everything Dinosaur

Picture Credit: Everything Dinosaur

To view a model of an Elasmosaurus and dinosaur models: Dinosaur Toys for Boys and Girls – Dinosaur Models and Toys

Strange things do turn up from time to time.  Not long after Mr Fraser wrote his letter in the Summer of 1938, the first live Coelacanth was discovered off the African coast.  Coelacanths belong to an ancient group of fish that were once thought to be the ancestors of land animals.  They are found in the fossil record in strata from the Devonian Period through to the Cretaceous.  Scientists believed them to be extinct, until by chance, one came to the notice of western science shortly before Christmas1938.

To read more about Coelacanth catches: Coelacanth caught off the island of Zanzibar

Periodically, there are more pictures published of the Loch Ness Monster and people still travel to the area in the hope of catching a glimpse of the beast.  Quite a large tourist industry has sprung up in the area, fuelled by the myth of the monster.

As Adrian Shine says:

“People still come and they still see.  We have to accept that we don’t have all the answers.”

The Ulitmate Dinosaur Sticker Book

The Ultimate Dinosaur Sticker Book

A welcome addition to the Everything Dinosaur Reading Activities range is this dinosaur sticker book, packed with lots of prehistoric animal stickers.  Designed for children as young as 3 years of age, this informative and educational sticker book, helps build observation skills and hand to eye co-ordination.

To view more details and to see more books about dinosaurs: Dinosaur Books for Kids

Young dinosaur fans can learn all about dinosaurs and other prehistoric creatures such as Pterosaurs (flying reptiles) and marine reptiles with this fun dinosaur themed sticker book.  Simply find the information and the sticker outline that matches the sticker and then place it in the correct position to create your very own dinosaur information book.  The easy peel stickers can be used more than once and they make attractive additions to any school project.

Dinosaur Sticker Book (Ultimate Dinosaur Sticker Book

Dinosaur sticker book.

Dinosaur sticker book.

Picture Credit: Everything Dinosaur

Our dinosaur themed publications include reference books about prehistoric animals as well as traditional story books, all approved by our teachers and dinosaur experts.  A dinosaur book is a great way to encourage young children with their reading and it can help them learn more about dinosaurs and other extinct prehistoric animals.

Review of Prehistoric Times Magazine (Spring 2010)

A Review of Prehistoric Times Magazine (Spring 2010) – issue 93

The countdown to the centenary edition of Prehistoric Times continues with the eagerly awaited arrival of issue 92 (Spring 2010).  Prehistoric Times is an American based magazine designed to cater for prehistoric animal fans, amateur fossil hunters, model makers, collectors and enthusiasts of all things dinosaur.  Now in its seventeenth year of production this quarterly magazine goes from strength to strength.

Issue 93 covers a whopping 63 pages.  The featured prehistoric animals in this edition are Mastodons and Spinosaurus.  There is some super artwork on these amazing creatures, really nice to see a “Kids Korner” feature (trust our American friends to alter the English spelling), with a number of Spinosaurus drawings sent in by younger dinosaur fans.  There is a super article on Spinosaurus written by Phil Hore, it explains how the excavation of this particular dinosaur by the famous German palaeontologist Ernst Stromer was interrupted by world events and tells the story of how much of the early 20th Century fossil material was destroyed.

The Front Cover of Prehistoric Times Spring 2010

Issue 93

Picture Credit: Mike Fredericks

Tracy Lee Ford, has written a fascinating article in the series “How to Draw Dinosaurs”, concentrating on the drawing and interpretation of feathered dinosaurs.  This feature fits nicely with the Paleonews section, as it covers the evidence of colouration in a dinosaur fossil – the recently published paper on the small Chinese Theropod Sinosauropteryx.

To read more about this discovery: Melanosomes provide Further Evidence of Feathered Dinosaurs

The news section covers the latest dinosaur and prehistoric animal discoveries, and provides a summary of some of the news stories surrounding palaeontology that have been published in the last few months or so.  The Everything Dinosaur blog provides a little more detail on many of these news stories but it is a handy compendium of what has been happening in the dynamic Earth Sciences since Christmas.  Our old friends, the creators of Jurassic Wars – the dinosaur themed combat game get a mention and a review in the magazine and as I write this a model of Amebelodon (Carnegie Safari) looks down on me from the shelf and it is very pleasing to see the in-depth article on Mastodons and other primitive elephants written by Mark Hallett.

To subscribe to Prehistoric Times: Prehistoric Times Magazine

All in all, a very good publication from Mike Fredericks and team, we are looking forward to discussing the magazine and its contents in the office tomorrow – something to look forward to on a Monday morning.

 

Providing a Key to the Prehistoric Animal Model Sets

Identifying the Creatures Represented in our Prehistoric Animal Model Sets (PAR)

At Everything Dinosaur we tend to pride ourselves in the product knowledge that we possess.  Certainly, nothing gets added to our ranges unless it has been thoroughly tested and approved by our dinosaur experts.  This can prove extremely handy when we get asked questions by Mums and Dads.

For example, we supply an in expensive range of prehistoric animal models.  These models can be purchased individually or in sets of 5, 10 or 20.  They make ideal party favour gifts and are very reasonably priced, however, we do get asked from time to time to identify all the models and name the creatures they represent.

The Prehistoric Animal Model Set from Everything Dinosaur

Picture Credit: Everything Dinosaur

To view the set of prehistoric animal models: Dinosaur Presents and Dinosaur Gifts

No matter how small, we look at every single item in our range very carefully and select new products based on our own testing and with the approval of our enthusiastic and knowledgeable dinosaur fans.  We want models to represent real prehistoric animals and we set out to identify the animals these animals are supposed to be.

This work comes in very handy when we are telephoned or emailed by a parent, whose dinosaur mad little boy or girl is insisting that they find out the names of the animals the models depict.  With this particular series of models, there is a key code printed unobtrusively on the underside of each model.  Our experts have then produced an identification key which is available for customers to download on request.  The key also contains a pronunciation guide and an explanation of the meaning of the scientific name.

Our experts like this particular model range as some of the more unusual prehistoric creatures are featured, animals such as Plateosaurus and Placerias from the Triassic as well as all the favourites such as Stegosaurus, Pteranodon and T. rex.

The Key to Identifying the Prehistoric Animal Models

Helping to identify prehistoric animals for customers

Picture Credit: Everything Dinosaur (PAR0 Model series)

This particular model series contains a total of 24 different models and our experts have studied each model in turn, identified it and created a key to help young palaeontologists identify which ones in the series are in their own sets.

Ethnicity in North American Cretaceous Dinosaurs

Researchers Refute Claims about Distinct and Separate Mega Faunas of North America

During the Late Cretaceous, North America was effectively split in two by a shallow sea.  The size of this sea fluctuated during the Campanian and Maastrichtian faunal stages.  At times it stretched northwards from the Gulf of Mexico extending all the way to the Arctic Ocean, this seaway is known as the Western Interior Seaway, it persisted until the early Tertiary, however, during the Cenozoic the sea levels gradually began to fall and the land was slowly exposed again.  By approximately 45 million years ago, much of the continent of North America we know today had been reclaimed as land, with only a small, shallow area of sea left remaining covering the south-west United States.  This sea is known by geologists as the Cannonball Sea.

A Map of North America Approximately 70 million years ago

Picture Credit: Oceans of Kansas

Some palaeontologists, as they review the dinosaur fossils found on the eastern side of the Western Interior Seaway, that is fossils of dinosaurs found in places such as Alberta in Canada, right down to Texas and Mexico in the south, believe that there were distinct and separate dinosaur faunas.  It seems that some types of dinosaur lived in particular parts of North America, with other dinosaurs, similar genera filling the same environmental niches in other parts of the continent.  This theory – a sort of dinosaur ethnicity was touched upon in an earlier article when we reported on the discovery of a new Pachycephalosaur in Texas – Texacephale langstoni.

To read more about this recent discovery: Hard-headed dinosaur, a new genus of Pachycephalosaur from Texas

In addition, the discovery of this Pachycephalosaur fossil in Texas seems to support a theory put forward by many North American scientists that the dinosaur fauna of Canada and the northern USA was very different from those dinosaurs found in Late Cretaceous southern USA. In  interpretating the fossil evidence, a number of scientists have concluded  that there was a sort of ethnicity amongst dinosaurs, with northern genera distinct from their southern neighbours.

Commentating on this, lead author of the research paper on the new Texas Pachycephalosaur; Nicholas Longrich said:

“Instead of roaming across the North American continent, we see pockets of different dinosaurs that are pretty isolated from each other.  Every time we get good fossils from Texas, they end up looking very different from those to the north.”

However, this concept of ethnicity is being challenged by a group of Canada scientists who have just published a paper refuting the dinosaur ethnicity theory in the scientific journal “Proceedings of the National Academy of Science”.  Those scientists who support the distinct fauna theory of North America suggest that some horned dinosaurs such as Triceratops lived in the interior of the west (ironically close to the coast of the Western Interior Seaway), whilst closely related Ceratopsians such as Torosaurus were to be found in the south.  Duck billed dinosaurs dominated in the northern latitudes but one of the last North American Sauropods the 20 metre long Alamosaurus, inhabited only the southern part of the United States.  Geological evidence seems to show that there were no physical boundaries to prevent dinosaur migration and a mixing of different faunas.  The climate does not seem to be a factor, as the Late Cretaceous climate of this part of the world was relatively uniform, warm and humid.

However, palaeontologists Matthew Vavrek and Hans Larrsson of McGill University (Montreal) have challenged this belief, stating that the ethnicity that is seen in the fossil record is a result of the paucity of the fossil material of dinosaurs found to date.  They conclude that because fossils survive and are found in a totally random way, and because some sites have been studied more extensively than others our understanding of the mega-fauna is skewed in favour of seeing distinct groups of animals in the fossil record.

Extrapolating from samples found at four areas that each contained large numbers of fossils, their analysis found no evidence of distinct ranges.  Instead, they found evidence of a single dinosaur community in the warm, uniform climate of the area.

We suspect the debate will rumble on and a couple of Everything Dinosaur team members are trying to put together a Key Stage 3 (UK National Curriculum) study pack so that school children can weigh up the arguments for themselves and see what they can make of the evidence.

The Movius Line – A Brief Explanation

What is the Movius Line?

The Movius line is named after the American archaeologist Hallam Movius (1907 -1987), it is a theoretical line that separates those parts of Europe, Africa and Asia with or without Acheulean handaxe technology.  An expert in Stone Age human remains and relics, Movius plotted the distribution of early hominid sites where advanced stone tools were found.  Sophisticated stone tools such as the Acheulean handaxe took a great deal of skill to make.  An ancient hominid would have had to carefully select a stone to work on, finding a suitable stone would have taken a lot of planning.  Then a variety of tools would have been employed to shape and cut the stone handaxe to the ideal size.  Each side of the stone would have had to be worked in turn and a number of other stone tools and even antler points would have been required to finish it off.

Movius discovered that there was a clear division between those parts of the world with the Acheulean stone technology and those parts without.  Across Africa and most of southern Europe, hominids had the advanced stone handaxe technology, but it was absent from large areas of Asia (although other types of stone tool were found at dig sites).

A number of theories have been put forward to explain this division.  The first hominids to leave Africa may have carried older types of stone tools, alternatively, areas without Acheulean axes may not have had suitable stones for the hominids to work.  Migrating groups of hominids may have lost the ability to make sophisticated handaxes (after all, how many of us these days can start a fire just using sticks).  Another theory put forward is that other materials may have been used by ancient humans living in Asia, for example, bamboo and any bamboo tools would not be likely to have been preserved as fossils.

Giant Sea Scorpion Tracks Discovered in Scotland

Ancient Eurypterid Trackway Discovered in Fife

330 million-year-old tracks made by a giant Arthropod which was longer than a man have been discovered in Fife (south-eastern Scotland).  The trackway which consists of three parallel lines representing the feet and in between a “scooped” out shape indicating that the tail was dragged; have been preserved in sandstone and were discovered by chance when Dr Martin Whyte from the University of Sheffield was out walking.

The tracks have been ascribed to a sea scorpion called Hibbertopterus, fossils of which have been found in the area.  Sea scorpions, or to be more precise Eurypterids (pronounced You-ree-ip-ter-ids) were Chelicerate Arthropods that evolved around 480 million years ago and flourished worldwide in marine and freshwater environments until their demise towards the end of the Permian.

Fossils of Eurypterids are relatively common in ancient marine strata, particularly, as like Trilobites, they had to shed their body armour (exoskeleton) when they grew and the cast shells had a high preservation potential.  Most Eurypterid fossils are not the fossilised carcase of a dead animal but instead the fossilised remains of a cast shell from a moult.

Some types of Eurypterids grew to enormous sizes and until the rise of vertebrates such as fish, they were some of the top predators of the Palaeozoic.  To read an article about the discovery of an enormous 3 metre long sea scorpion: Claws! Giant Sea Scorpion of the Devonian

This Scottish discovery is the largest known walking trackway of an Arthropod, or indeed any invertebrate discovered to date.

A Diagram of a Huge Eurypterid like Hibbertopterus

Illustration Credit: Bristol University

The tracks were probably made as this huge animal hauled itself out of the water.  Eurypterids with their simple gills were adapted to absorb oxygen from both water and the atmosphere.  It is likely these animals moved into the shallow margins in order to breed, just like a relative of these creatures, the Horse-shoe Crab does today.

The tracks are already quite badly eroded but removing the sandstone rock in which they are preserved may be too difficult.  Instead, Scottish Natural Heritage, is funding a project to create silicone copies of the trackway which will enable these ancient “footprints” to be studied in detail.  A spokesperson for Scottish Natural Heritage, described this discovery as “unique and internationally important because the creature was gigantic.”

Richard Batchelor from Geoheritage Fife, commented:

“The trackway is in a precarious situation, having been exposed for years to weathering.  The rock in which it occurs is in danger of falling off altogether.  Removing it and housing it in a museum would be prohibitively costly but moulding it in silicone rubber and making copies for educational and research purposes means that we can still see and research this huge creature’s tracks in years to come.”

The Eurypterid Trackway In-Situ

Track made by Sea Scorpion

Picture Credit: BBC News

The person stood next to the trackway is pointing to the impression (groove as the fossil has been made by infilling sediment), made by the tail dragging over the sand, the scale of trackways can clearly be seen when compared in size to the person stood adjacent to them.  The trackways suggest that they were made by an animal at least 1 metre wide.  The three rows of crescent shaped footprints on each side of a central groove made by the tail can be clearly made out.  The length of the entire trackway is approximately 6 metres.

A geologist for Scottish Natural Heritage, Colin MacFadyen stated:

“Helping to conserve this important find is vital for our understanding of this period in evolution.  Such finds as this highlight that all over Scotland there are no doubt other geological treasures awaiting discovery.”

The sandstone has been dated to approximately 330 million years ago (mid Carboniferous).  This area of eastern Scotland is world famous for its Carboniferous fossil sites.  For example, at East Kirton a number of important fossil rich Mississippian (Lower Carboniferous) strata are known.  It seems that around 330 million years ago, this area of Scotland was low lying with many freshwater lakes.  Many early Tetrapod fossils as well as numerous invertebrate fossils and plants are known from this region.

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