All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
10 11, 2007

Dinosaur Pencil Sharpeners – an Ideal Stocking Filler

By | November 10th, 2007|Everything Dinosaur Products, Main Page, Press Releases|0 Comments

Dinosaur Pencil Sharpeners – 8 Dinosaurs to Choose From

Every week the team at Everything Dinosaur gets together to have a meeting, this usually takes place on a Friday or after we have finished work on a Saturday afternoon.  The first item on the agenda is to “put the kettle on” and whilst one of us makes the tea the rest of the team draw up an agenda and make sure all the points, issues and ideas that have arisen over the last few days are recorded so that they can be discussed amongst ourselves.

One item raised a couple of weeks ago was to add Dinosaur Pencil sharpeners to our product range, we had looked a this product a while ago and although it had favourable reviews from our testers at the time, we never got round to adding it to our product range.

We reviewed the comments that had been made about these little plastic sharpeners with a model of a dinosaur on top.  Customers liked the quality of the item, it certainly sharpened pencils – which is always a promising start for a pencil sharpener.  They also liked the choice of eight different dinosaurs in the product range we had examined.

With one eye on all the school visits and Christmas Fairs that Everything Dinosaur attends at this time of year we decided to give these sharpeners a go.

Dinosaur Pencil Sharpeners – Eight to choose from

Picture Credit: Everything Dinosaur

To see Dinosaur stationery: Back to school and stationery supplies

There are eight different Dinosaur pencil sharpeners to choose from.  I don’t know whether the manufacturers were aware of what they had done but there are are four Saurischian (lizard-hipped) Dinosaurs represented an Ornithomimid (ostrich mimic), a Sauropod and two Theropods plus four Ornithischians in the mix.   The Ornithischians represented are an Ankylosaur, Stegosaur, Ceratopsian and a Pachycephalosaur.

My these manufacturer’s are clever!  They have created a simple product range that just about covers the diversity of the Dinosaur family.  Somehow I don’t think this was done as a deliberate attempt to represent the main Dinosaurian types, more likely the different models were chosen because they looked good.  However, this little set illustrates the diversity of the Dinosaurs very nicely – and that will do for us.  It is an excellent example of the dinosaur themed school supplies that are available from Everything Dinosaur.

9 11, 2007

Very Ancient Udders! Mesozoic Cow Discovered in India

By | November 9th, 2007|Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

Evidence of Ancient Cow from India

A team of scientists from Northern India working in the Narmada river valley have unearthed evidence of a prehistoric mammal, an ungulate (hoofed mammal), from the very end of the age of Dinosaurs.

The Narmada valley is a well known geological site with an extensive range of exposed strata dating back to the late Cretaceous and the early Palaeocene.  The scientists discovered a single 2.5 cm long tooth in sediments estimated to be 65 million years old.  Comparing the tooth to living mammals the team has speculated that it could belong to a cow-like mammal.

Teeth are made from enamel, which is the hardest substance in vertebrates bodies, and excellent material for preservation and fossilisation.  Mammalian teeth have many distinctive characteristics when compared to reptilian dentition, indeed broad generalisations can be made between placental and monotreme mammals based on the crown shape and structure of single finds such as this one.

The “Cow Tooth” from the Narmada Valley

Source: NDTV

The picture above shows the tooth in several views (top left dorsal view, top right diagram of top of tooth).  Lower pictures ventral views of the tooth, showing typical features of a molar.  The fossil predates any other similar discoveries and it places India as one of the places where ungulates first evolved.The research has just been published in the American Journal Science.  The authors of the paper on the discovery of this ungulate mammal are Dr. G V R Prasad, Omkar Verma, Dr. Ashok Sahni, Varun Parmar, Dr. Ashu Khosla.
The Narmada valley is notorious for causing palaeontologists problems with dating specimens, particularly early hominid remains.  An ancient cranium of modern being (H. sapiens), was discovered in the area.  It was controversially dated to 700,000 years ago, making it the earliest remains of H. sapiens ever found.  However, recent research by notable Indian scientists Rajeev Patnaik and Parth R Chauhan suggest that this isolated hominid fragment is not as old as previously stated.
8 11, 2007

Ideas on Dinosaurs Breathing – A Breath of Fresh Air

By | November 8th, 2007|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|2 Comments

Study shows Dinosaurs were Super Efficient Breathers

A recent study carried out by a team of scientists from the Faculty of Life Sciences at the University of Manchester (England) has added further evidence to the theory that dinosaurs and birds are closely related.

One view of dinosaurs is that many of them were active, highly mobile and busy animals rather than the very slow, cumbersome leviathans depicted by earlier scientists and illustrators.  To be able to move quickly animals need efficient lungs to provide enough oxygen to muscles in their bodies.  For the real heavyweights of the dinosaur world – the Sauropods and Titanosaurs, their sheer size led to their own set of anatomical problems.

The long necks on the likes of Diplodocus, and Brachiosaurus were to long for air to reach their lungs on the first breath, without super efficient lungs to process air and a large and powerful heart to pump blood round their enormous bodies, they would not have been able to function properly.  In the case of a Brachiosaur, having to pump oxygen rich air from the centre of the body 40 feet up into the air to reach its head (and the tiny brain that perched on top of a fifty tonne body), would have been a momentous task without some sort of super efficient breathing system.  If a sauropod did not have a very efficient heart and lungs then its blood pressure would have been very difficult to manage.  If it dropped its head suddenly, the dramatic change in blood pressure could have caused the animal to lose consciousness; had they been burdened by a mammalian type set of lungs.

The good news for dinosaurs, revealed in this new study from the Manchester team, is that it looks like many of them had super efficient breathing systems, much superior to our own lungs and hearts.

Mammalian Breathing – the Downside

I am not one to put a downer onto our own mammalian anatomy, after all, if my lungs and heart did not work I certainly would not be able to finish this article.  However, our breathing processes although perfectly adequate for our needs are not very efficient.  In order for us to be active our blood needs to supply oxygen to our organs and muscles, and then take the waste products away.  When we breathe in, air enters the two sack like objects in our chest (the lungs), through capillaries and other tiny vessels the oxygen seeps through into the blood stream and is carried away to all parts of the body by the blood cells.  Waste products such as carbon dioxide is dumped back into the lungs by the blood stream and this is exhaled.  A strong heart enables more oxygen to be pushed through our bodies.  Although this is something of a very simplified explanation, I am sure you get the idea.

The mammalian system does have a major drawback, the lungs have only one entrance/exit point for the air.  We mix up the exhaled air with new air being breathed in.  We never get rid of all the used air inside us, every time we inhale we just mix fresh air with oxygen extracted air we are going to breathe out.  This is not a very efficient process and as a result this contributes to the physical limitations of our bodies.

Bird, in contrast, are much more efficient breathers.  Instead of just one entrance/exit point in the lungs they have openings at both ends, plus a series of 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 bellows they pump the air through the lungs and out a different tube than it went in.  This is a one-way system with old, stale air never mixing with fresh oxygen rich air and as a result is a very effective system.  For their size, birds have disproportionately large hearts, these provide the pumps to enable the whole system to function.

A Comparison of Mammalian and Avian Breathing

Picture Credit: Dorothy Sigler Norton reproduced from Bones Rock (Larson and Donnan)

The diagram above shows the air sacs and one-way breathing system in a bird compared to the less efficient lungs of a typical mammal (us).

The trouble with air sacs is that you have to make room for them inside your body.  Birds allow for the air sacs by having hollow bones which can accommodate these specialised features.  Hollow bones are found in the fossil record in Pterosaurs, Sauropods and the Theropods – as well as certain other groups such as Sphenodonts.

Taking the Pterosaurs first, although they are not closely related to birds, they may have evolved a similar solution for the need to get lots of oxygen into their bodies as they too were fliers.  You need a super efficient oxygen transport system if you are going to do something as aerobically challenging as fly.

The Sauropods and Theropods (lizard-hipped dinosaurs – Saurischian dinosaurs) show honeycomb like structures linked by tiny passageways in their fossilised bones.  These structures would have helped these animals by keeping their skeletons light to aid mobility and to assist with balance but could they also be indicators of a super efficient air-sac breathing system?

The Manchester University Team, led by Dr Jonathan Codd studied the breathing processes of modern birds and crocodiles (the closest living relatives to dinosaurs).  They then compared these specimens to the fossils of small, bipedal Coelurosauria which are known to have hollow bones and the honey comb arrangement of structures.  A specific group of Coelurosauria was studied – the Maniraptorians, animals such as Oviraptor, Velociraptor and Microraptor, believed by many palaeontologists to be the group of dinosaurs that actually gave rise to birds.

Dr Codd and his colleagues (including palaeontologist Dr Phil Manning) focused on tiny bones associated with ribs called uncinate processes.  These tiny bones stretch between the ribs and are found in modern birds.  Initially it was thought that these bones helped to strengthen the rib cage and enable birds to cope better with the physical stresses of flying.  Now it is thought that they also act as levers helping to inflate the air sacs by pushing the rib cage outwards.  Birds breathe with their beaks closed, air travels along the nasal cavity before filling the lungs and multiple air sacs.  Air can flow in and out efficiently, thanks in part to the squeezing and pumping action of bones such as the uncinate processes.

The dinosaur species studied were found to have tiny L-shaped uncinate processes, could these bones have helped these animals expand their rib cages and sternums to enable the air sacs within their bodies to have been filled?  In proportion to the birds; the dinosaurs have relatively larger uncinate processes, comparable to the scale seen on super efficient bird breathers such as penguins.  As penguins dive for food they need to be able to keep a great deal of oxygenated blood inside their bodies.  This new work, due to be published in the Proceedings of the Royal Society B: Biological Sciences, presents an explanation as to how groups of dinosaurs such as the Theropods and Sauropods were able cope with the problem of getting a lot of oxygen to their muscles.

So certain types of dinosaurs breathed like birds.  How the Ornithischians such as the Hadrosaurs and the Thyreophorians managed is still open to debate, perhaps their extensive and highly complicated nasal passages seen in the skulls of certain genera may provide a clue.

7 11, 2007

Little boy from Wisconsin Finds Mammoth Tooth

By | November 7th, 2007|Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

American Boy Finds Mammoth Tooth

Three-year old Kaleb Kidd from La Crosse, Wisconsin found a Woolly Mammoth tooth whilst playing at a family friends property just outside the town of La Crosse.  Mammoth teeth as they are so large and robust are found occasionally in this area.  The enamel in the tooth readily fossilises and is resistant to erosion.  For the Kidd family this find makes it a remarkable double, as grandfather, Gary Kidd had found a mammoth tooth in the Mississippi area several years earlier.

The American mid-west has revealed lots and lots of Mammoth fossils, both the Woolly Mammoth (M. primigenius) and the larger Columbian Mammoth (M. columbi) are known to have lived in this area during the Pleistocene epoch.

Ironically small children make excellent fossil hunters, not only are they usually bubbling over with enthusiasm, but their eyes being younger are better able to distinguish between objects on the ground.  Also because they are physically lower to the ground than adults this makes them better spotters.

The distinctive ridges of the tooth would have made it stand out from other rocks, now Kaleb and his grandfather need to find the rest of the mammoth!

The tooth has been provisionally dated from between 30,000 and 10,000 years ago.  Mammoths went extinct in the United States after the Ice Ages ended, perhaps their demise was hurried along with the improved hunting techniques of Clovis Man.

We have lots and lots of Mammoth products at Everything Dinosaur.  Woolly Mammoths appear regularly in our top ten prehistoric animal surveys.

Woolly Mammoth soft toys: Dinosaur Stuffed Animals

6 11, 2007

Game on this Christmas

By | November 6th, 2007|Everything Dinosaur News and Updates, Everything Dinosaur Products, Main Page, Press Releases|0 Comments

Dinosaur Dino-opoly Featured in National Women’s Magazine

The November edition of “Prima” – a women’s magazine with a strong practical content featuring crafts, cookery, fashion and beauty as well as shopping tips and ideas, carried a feature on Dinosaur Dino-opoly.

In an article, which featured on the “Family Notebook” page of the magazine, the top five suggested family games for Christmas were reviewed.

Lovely to see Dino-opoly given the number one spot.

This is what the reviewer said:

“Have hours of fun with Dino-opoly (age 7 and up), a prehistoric version of a classic family board game.  Players can buy their favourite dinosaur, collect bones and trade them in for museum exhibits.”

The Dino-opoly Board Game

Picture Credit: Everything Dinosaur

To view Dinosaur Dino-opoly board game: Dino Board Games and Puzzles

It certain is a twist on the traditional family board game, there is even a quick 1 hour whizz round the board version.  The best thing of all is that it provides children with lots and lots of facts and information about dinosaurs, helping them learn.

5 11, 2007

Megalodon Makes its Debut

By | November 5th, 2007|Everything Dinosaur News and Updates, Main Page, Press Releases|0 Comments

Carcharodon megalodon Makes its Debut

At Everything Dinosaur we get lots of requests for our team members to find unusual prehistoric animals through our “Dino Hunt” service.  Customers and prospective customers can e-mail us with requests to help them find a particular model or item for their collection or to satisfy the curiosity of a young dinosaur fan.

With our connections to manufacturers and our links to a number of museums and other educational bodies, we can help out most of the time.  This can save our customers, a lot of time and effort.

We have received over the last twelve months or so Dino Hunt requests to help people find a suitable model for a Megalodon, a giant shark that lived during the Miocene and Pliocene periods (about 16 -1.6 million years ago).  In response to these requests we did some research into shark models in order to try and find a Megalodon model to add to our range.  Unfortunately, at this moment in time, there are no specific Megalodon models widely available so we changed tack and began to look at models of modern shark species in order to find a suitable alternative.

We had no idea how many model sharks were out there!  However, drawing on the expertise of our contacts with museums – particularly helpful were our friends in the educational department at the Royal Tyrrell museum – Canada; who advised us and supplied us with our own Megalodon cast tooth.

A short-list of potential candidates was drawn up including the Great White Shark model from the Sea Animal series of Schleich of Germany and the Wild Safari Dinos Megalodon shark model.

Megalodon Alternative – Schleich Great White Shark

Giant Shark Model

Picture Credit: Everything Dinosaur

The model displays the five gill slots, so typical of a modern shark species and the appropriate layout of fins that Megalodon is believed to have had.  The aggressive posture is a nice touch, particularly for an animal calculated to require about ten percent of its body-weight in food each week, just to keep going – no wonder it ate whales!

To view the model Megalodon: Dinosaur Toys for Children – Dinosaur Models

The colouration is also important, like modern Great Whites, this animal was an active predator of surface waters, its large eyes supplemented the other senses that sharks have to help close in our prey.  The white underside would have made it difficult for mammals to spot this huge predator if it was swimming above them.  The white markings would have made it blend into to the sun dappled surface waters.  The slightly curved posture of the model mirrors a big shark’s swimming style accurately and we liked the little touches such as the strongly forked tail and the darkened tips on the pectoral and caudal fins.

Carcharodon megalodon, is sometimes referred to as Carcharocles megalodon, as this animal had a skeleton made of cartilage few elements of the body have been preserved, but we have plenty of teeth – form the large, broad daggers of the anterior dentition to the smaller posterior teeth to be found at the back of the mouth.  It is estimated that estimated had about 290 teeth in its jaws.  Like Dinosaurs these teeth were replaced constantly, with new ones erupting from the jaws as older teeth were broken and worn down.

This giant shark, estimated to reach lengths of perhaps 16 metres or more was named from its spectacular teeth.  Carcharodon megalodon means “sharpen, huge tooth”.  Scientists still debate whether this animal was very closely related to modern Great White sharks, or whether it shared a common ancestor.  Some marine biologists see Megalodon as being more akin to the Tiger Shark (Galeocerdo cuvier).  Like Great Whites, Tiger sharks are solitary hunters, palaeontologists believe that adult Megalodons were also solitary.

The Tiger shark was named in honour of Georges Cuvier, the great French naturalist.  The Tiger shark is the only member of the genus Galeocerdo, it has been given a separate classification because of its strangely shaped, heavily serrated teeth.  The fossil teeth of Megalodon resemble very closely the teeth of a modern Great White, this is why some scientists classify Megalodon with the Great Whites (Carcharodon carcharias).

However, the teeth may be similar as these two animals shared a similar lifestyle and the dentition may be an example of parallel evolution and not indicate that these two genera were closely related.

Slightly worryingly, especially for all those surfers and divers out there, a small group of dedicated cryptozoologists believe that Megalodon is not extinct and that populations are still roaming the oceans of the world today.  However, most scientists doubt this; believing that the sightings are possibly over-sized Great Whites or figments of people’s imaginations.

As the Coelacanths have proved anything is possible…

4 11, 2007

Humble Ferns – Evidence to support the Impact Theory?

By | November 4th, 2007|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Fossil Fern Pollen – Evidence to support the Asteroid/Meteorite Theory?

With the recently published paper citing the volcanic activity that caused the Deccan Traps as the main driving force behind the mass extinction that occurred 65 million years ago, it might be time to review some of the other evidence gathered by scientists to help explain what exactly went on.

In Denmark, about 40 kilometres south of the capital city, Copenhagen there is an area of exposed Cretaceous/Tertiary chalky cliffs that over look the Baltic sea.  The cliffs are white like the famous cliffs on the coast of southern England but closer examination reveals a strange looking grey band of clay about 8 cm wide running across them.  The locals call this fisk ler, translated this means fish-clay, due to the large number of fish bones found within it.  This clay band has been dated to 65 million years and is one of the few sites around the world where the K-T boundary layer is exposed.

Analysis of this clay layer has revealed evidence that supports the impact theory as the cause of the mass extinction.  Firstly the clay layer contains soot.  An asteroid impact would have thrown molten rocks up into the air and these would have caused forest fires when they landed.  An impact of the magnitude  of the Chicxulub event, would have thrown red-hot rocks all over the planet.  Any material ejected into the upper atmosphere would have become hot due to friction as it plunged back down to Earth, adding to the rain of incendiaries.  Some scientists claim that the soot layer is so dense in the deposits studied on the Baltic that if they had been laid down in just 1 or 2 years they could have produced by half the world’s vegetation burning.

Whatever the reason for the event, life on Earth was devastated, not only did the Dinosaurs, marine reptiles and Pterosaurs perish but also about 90% of all protozoan genera and algae went extinct too.  Marine plankton disappears from the micro-fossil record so abruptly that it forms a distinct boundary.   Deposits which show this distinct phase have been nicknamed the plankton line by geologists.

However, it is the humble fern that provides the strongest evidence of a sudden and dramatic single event devastating life on Earth. Studies of fossil spores and pollen (important elements making up micro-fossil sites), show that prior to the end of the Cretaceous fern spores make up about 25% of the percentage of total spore and pollen micro-fossils.  Flowering plants were dominant by the end of the Cretaceous period and it is the angiosperms that make the major part of fossil plant elements at micro-fossil level.  At the K-T boundary few spores and pollen fossils are found.   In the first part of the Palaeocene epoch (lower Danian faunal stage deposits), there is a sudden and dramatic rise in the fern spore component of the micro-fossil fauna and flora.  Indeed, in some sediments, fern spores make up 99% of micro-fossils recorded immediately post the end of the Cretaceous.

As the Palaeocene progressed the percentage of fern spores in the fossil record falls, eventually reaching levels seen prior to the mass extinction event.  This surge in fern spores is called the Fern Spike.

A Diagram showing Dramatic Fern Spike after the Cretaceous

Chart source: Everything Dinosaur (ref: R. C. Moran)

Many Palynologists (scientists who study pollen and spores), claim that the fern spike indicates a sudden and dramatic climatic catastrophe such as an impact event and not the thousands of years of volcanic eruptions as indicated by supporters of the Deccan Traps hypothesis.  Ferns are often the first plants to recover after forest fires and other natural disasters.  They are often at the vanguard of re-populating areas that have been severely polluted.  Could they provide evidence to support a collision with a body from outer space?

The fern spike seems to be a phenomenon that passes quite quickly in geological time.  It is certainly true that ferns are some of the first plant species to re-colonise ground that has suffered from a forest fire, but equally ferns are some of the first plant species to establish themselves on volcanic slopes and lava flows.  So perhaps the fern spike was caused by the dramatic and immense volcanic eruption phase 65 million years ago in India that led to the deposition of the thickest layers of basalt that now make up the Deccan Traps?

3 11, 2007

Dinosaur Asteroid Impact Extinction Theory Challenged – Blame the Deccan Traps

By | November 3rd, 2007|Main Page, Palaeontological articles|0 Comments

New Studies Point Finger at Deccan  Traps for Demise of the Dinosaurs

In 1980, American scientists Luis and Walter Alvarez published their theory regarding an extra-terrestrial body impacting with the Earth, causing the mass extinction event that marked the end of the Age of Reptiles.  The discovery of the Chicxulub crater in the Gulf of Mexico, the “smoking gun” evidence in the 1990’s added credence to this theory put forward by the father and son team.

Recent studies of the asteroid belt that lies between Mars and the outer planets had led one group of scientists to deduce the fate of the dinosaurs was sealed back in the Jurassic when an impact between huge asteroids sent one immense lump of space rock on a collision course with Earth:

Article here: Dinosaur extinction set in motion by asteroid collision in the Jurassic

Now a second team of American scientists have challenged the asteroid/meteorite theory and proposed that massive volcanic eruptions in India led to the demise of the Dinosaurs and about 65% of all life on Earth.  New studies of the enormous basaltic lava flows of western and central India – known as the Deccan Traps, indicate that the most violent and devastating eruptions are dated very closely to the mass extinction event.

Volcanic activity on this scale would have thrown out into the atmosphere huge volumes of carbon dioxide and sulphur dioxide, dramatically changing the world’s climate and leading to the collapse of entire ecosystems.

The Deccan Traps is one of the largest volcanic provinces on the planet.  The basaltic lava flows that occurred around 70-65 million years ago, cover an area of over 500,000 square kilometres, this is twice the size of the whole of the United Kingdom.  In parts, the basalt is over 2 kilometres deep.  Plate movements and other tectonic factors have broken up the lava deposits, some scientist estimate that the volcanic activity at the end of the Cretaceous deposited enough lava to cover 1,500,000 square kilometres – this would have covered half of India.

Map Showing the Extent of the Deccan Traps

Picture credit: BBC

It has been accepted for some time that these enormous eruptions would have had a devastating effect on the Earth’s climate.  Apart from the damage caused by the eruptions themselves, the smoke and the ash clouds would have been vast and disrupted the climate.  The sulphur dioxide pumped into the air would have led to acid rain and the carbon dioxide and other gases, as well as being toxic to life would have led to global warming.  This new study by the American team dates the most massive volcanic activity right up against the K-T boundary and as a result the research team has published a paper claiming that it was these eruptions and not the asteroid impact that led to the wipe-out.

The main period of eruptions has been linked chronologically to the estimated date for the beginning of the extinction phase, during this period geologists estimate that ten times more climate changing gases would have been released compared to the Chicxulub impact event.  So it was probably the volcanic activity that did for the Earth’s climate, although the huge extraterrestrial impact could not have come at a worse time and would have added to the environmental chaos.  As indeed with other impacts (some scientists believe there were two such impacts, only 300,000 years apart, in geological time very close to each other – a real double whammy.

Previous dating techniques involved paleomagnetic signatures of crystals formed in the lava as it cooled.  These indicated that the main eruptions occurred around 800,000 years before the geological boundary between the Mesozoic ending and the Cenozoic beginning.  More recent studies measuring the radioactive decay of argon and potassium isotopes in the lava deposits placed the biggest period of volcanic activity within 300,000 years of the K-T boundary.  However, it is evidence from tiny marine micro-fossils that the American researchers believe prove the volcanic activity to be a direct cause of the mass extinction.

Scientists are confident that shortly after the mass extinction event, one of the first signs of ecosystems beginning to recover was the establishment of new types of planktonic foraminifera (similar to the animals that helped form the white cliffs of Dover).  Analysis of deposits in Bay of Bengal region of the Deccan traps has shown that marine sediments were deposited on top of the basaltic lava from the most active phase of the Trap’s formation.  In these marine deposits, evidence of the foraminifera micro-fossils have been found, indicating that these marine deposits were laid down almost immediately after the extinction event.  It is therefore logical to deduce that the lava deposits immediately preceding the marine sediments must have been laid down about the time of the death of the dinosaurs and the wiping out of much of life.

The American team’s paper has already received support from a number of notable academics from Europe.  It was formerly presented at the annual meeting of the Geological Society of Denver has received widespread comments and reviews.  The sheer magnitude of the volcanic activity certainly played a role in climate change but this study of the micro-fossils puts the worst of the eruptions immediately prior to the mass extinction, as if these eruptions triggered the extinction event.

The American team has cited a number of other studies which support their conclusions and state that their work sheds light on an anomaly that the Chicxulub impact theory supporters have not been able to resolve.  Analysis of other sites around the world along the K-T boundary and from sediments laid down thousands of years after the extraterrestrial impact show that life on Earth was very slow to recover.  The micro-fossils do not enter the fossil record for another 300,000 years post the asteroid/meteorite collision.  The fact that the marine environment does not show any signs of recovery for about 300,000 years after the impact, can be explained by looking at the lava deposits above the tell-tale marine deposits in the Bay of Bengal.  These younger deposits of lava were laid down after the mass extinction event, but still caused enough disruption to delay the recovery of life on Earth.  According to the American researchers the last period of Deccan Trap eruptions occurred in the early Palaeocene (Danian faunal stage) about 280,000 years after the end of the Mesozoic.  It was these eruptions that caused the delay in the recovery of life forms and the building up of ecosystems.

The fossil record indicates that there have been a number of mass extinction events in the history of life on Earth.  It is certain that the K-T boundary represents a period of dramatic environmental change.  The dual effect of the formation of the Deccan Traps coupled with asteroid impacts would explain the mass extinction, the dying out of the non-avian dinosaurs, marine reptiles, pterosaurs, certain birds, ancient crocodiles, and many kinds of invertebrates could be due to a number of factors.  This is not doubted, what remains in dispute is the contribution to the mass extinction each of these factors played.

2 11, 2007

A Picture of the Head of Megalodon

By | November 2nd, 2007|Everything Dinosaur Products|0 Comments

A Picture of the Head of Megalodon (Carcharodon megalodon)

We get lots of young palaeontologists asking us about the fearsome prehistoric fish known as Megalodon (C. megalodon), so team members at Everything Dinosaur have created a picture of the “business end” of this ferocious marine predator.

A Close up of the Jaws of the Giant Shark (C. megalodon)

Giant Shark Model

Picture Credit: Everything Dinosaur

Scientists estimate that his shark may have reached lengths in excess of sixteen metres.  Fossils of its triangular shaped teeth have been found in Europe, Asia, Australia, Africa and the Americas.

1 11, 2007

Fossil Jellyfish dated from the Cambrian Period

By | November 1st, 2007|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|2 Comments

Exceptionally well preserved Ancient Jellyfish

Anyone who has ever found a jellyfish washed up on the beach, knows how peculiar looking these creatures are with their soft body parts and long delicate tentacles.  Scientists know that soft-bodied jellyfish have existed for hundreds of millions of years and represent examples of the first complex multi-cellular organisms to evolve on Earth, now some amazing fossils discovered in the western USA shed more light on their evolution.

A team of American researchers from the University of Kansas have uncovered the remains of ten jellyfish in Utah, from strata dating back to the very end of the Cambrian period, making these particular animals 500 million years old.

As jellyfish have no bones, shells, beaks or other hard calcified body parts they rarely fossilise and very little is known about their origin or evolution.  Several indistinct “blobs” which may represent the remains of jellyfish and their ancestors have been found from ancient marine deposits such as the Burgess shales in Canada, but these new discoveries show the jellyfish in fantastic detail.

Two of the Fossil Jellyfish Remains (with photos of similar animals alive today)

Credits: Top Fossil Photos: B. Lieberman, Cunina photo (top right) – K Raskoff

Periphylla photo (bottom right) – Dhugal Lindsay

Copyright: JAMSTEC

The specimens remarkable state of preservation allows scientists to compare the fossils with species of jellyfish alive today.  These finds are the best preserved specimens from the Cambrian period found to date and mark a period in the evolution of life when many new body forms and types of creature appeared.  This period has been named “the Cambrian explosion”.  Scientists are still not sure why at this time in the Earth’s history that evolution began to accelerate.  Perhaps increasing levels of oxygen in the atmosphere stimulated the emergence of new life forms, or maybe the abundance of warm, shallow seas encouraged life.  There may not have been a huge increase in marine animals at all, simply that with more hard-bodied animals evolving such as Trilobites the fossil record is richer.

Such is the quality of the preserved remains that researchers from the University of Kansas were able to liken the fossils to living specimens of jellyfish alive today.  The researchers have suggested that these animals may represent early ancestors of three modern families of living jellyfish.  The picture above shows a comparison between two of the fossils and pictures of modern jellyfish genera.  If these relationships are proved, two contrasting theories as to the evolution of these animals can be put forward.

Did jellyfish evolve slowly and by the end of the Cambrian they were already complex organisms like their modern descendants?  If this is the case, then the origin of jellyfish and other soft bodied creatures would have to be pushed back into the Proterozoic era.

Alternatively, did jellyfish evolve into their current complex forms very quickly around 500 million years ago, perhaps as a reaction to the Cambrian explosion?

As with many fossils, new finds ask as many questions as they provide answers.  So very little is known about the Cambrian and Pre-Cambrian periods.  Scientists cannot even agree how best to divide up and classify these ancient times, but it was during this time that all the main animal groups alive on Earth today, including the chordates, our ancestors evolved.

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