Exhibition of Prehistoric Animals starts in Chongqing

A new prehistoric animal exhibit is due to open in China.

Residents and visitors to the Chinese city of Chongqing in Sichuan Province can get a glimpse into China’s prehistoric past as a new exhibition featuring a number of dinosaurs and ancient mammals opens at Liberation Monument Square.

A herd, or considering how closely some dinosaurs are related to birds, should that be a flock of animals ranging from sauropods and theropods to Woolly Mammoths are on display.  In total over thirty specimens are available for viewing including a reconstruction of a huge long-necked dinosaur.

Prehistoric Animal Exhibit

The exhibition includes animatronic models that roar, bellow and move, it can be quite daunting for a Chinese school child to have a mammoth wave their trunk at them.  The animatronic mammoth is a reconstruction of a 2.5 metre tall fossil mammoth that has been mounted as part of the exhibit.  The mammoth skeleton has been estimated to be 3 million years old.

The bones of nine dinosaurs are also on display.  Sichuan Province is a very important area for dinosaur fossil discoveries.  The Dashanpu quarry, near the city of Zigong is the world’s most famous Middle Jurassic dinosaur site.  Over the last forty years or so, many tonnes of dinosaur fossils have been excavated.  The mudstone quarry represents a wet, lowland area with dense conifer and fern forests.  There was a vast river delta that existed in a stable environment for many millions of years.  Dead animals were washed into the river system and deposited in areas of calmer water, slowly covered in sediments and a number became fossils.

Scientists have been able to gain a unique insight into a mid Jurassic environment.  Fossils of stegosaurs, allosaurs and a large number of different types of sauropod have been discovered.  Each type of sauropod seems to have had its own niche in the food chain, with some long-necked genera such as Mamenchisaurus specialising in browsing between trees whilst smaller species such as Shunosaurus (S. lii, S. ziliujingensis), were grazers of shorter trees and cycads.

Shunosaurus

Shunosaurus is one of the best known sauropods from China, in fact one of the best known long-necked dinosaurs in the world.  A number of skeletons have been discovered including near complete individuals.  It was very abundant in the region and probably lived in large herds.  The most unusual feature of Shunosaurus is the spiked club, (like an ankylosaur) on its tail.  When the first fossils of this dinosaur were discovered in the late 1970s the strange caudal bones were thought to be the site of a disease or injury in the animal, armour and weapons on sauropods were largely unknown.  However, as more skeletons were found showing the same feature scientists concluding that this nine metre long dinosaur had a spiked club on the end of its tail.

An Illustration of Shunosaurus

Picture credit: Everything Dinosaur

To view a model of Shunosaurus and other members of the Sauropoda: Dinosaur and Prehistoric Animal Models.

The Chongqing exhibition is open until May 24th (2009).

A Replica of the Sauropod Shunosaurus

Available from Everything Dinosaur – Shunosaurus.

Cretaceous Extinction Event – Further Evidence

Researchers examine evidence associated with the Cretaceous mass extinction.

A team of American and Swiss based scientists have added to the debate regarding the demise of the dinosaurs, an extinction event that heralded the start of the Cenozoic.  The reasons why the mass extinction event occurred approximately 66 million years ago, have been debated for many years by scientists.  It had been thought that a large extra-terrestrial object crashed into the Earth and this disaster ended the Age of Reptiles.  Evidence for this theory, an enormous impact crater was found in the Yucatan peninsula in Mexico.

The impact theory of extinction is most widely associated with Luis and Walter Alvarez, an American father and son team who, in 1980 announced the discovery of a global layer of iridium enriched clay sediment present in rocks dating to 66 million years ago.  They argued that the iridium, a rare Earth element, was deposited due to the impact of a meteorite or asteroid.  The discovery of the Yucatan crater was evidence of the “smoking gun” that added impetus to their theory.

To read an article on the Yucatan crater: Geologists get to the bottom of the Yucatan Crater.

Cretaceous Mass Extinction

In new research, published by the scientists from Princeton University, New Jersey and their colleagues from Lausanne (Switzerland), it is claimed that the impact event strata show little sign of species decline, but extinction events did occur approximately 300,000 years after the impact.  In a scientific paper published in the Journal of the Geological Society, the theory that the catastrophic impact of the extra-terrestrial body wiped out many hundreds of genera in a few days or weeks is challenged.

Commenting on the team’s findings, Gerta Keller (Professor of Geosciences at Princeton University) stated:

“We found that not a single species went extinct as a result of the Chicxulub impact”.

Calling their results “astonishing” the team have questioned the accepted scientific thinking with regards to the Cretaceous extinction.

The research team studied sediments that were linked to the time of the mass extinction event and discovered that they were laid down later than the sediments that are associated with the meteor or asteroid impact.  Their work indicates that the asteroid or meteor impact may not be directly linked to the mass extinction – a time on Earth when an estimated 65% of all life forms, including the dinosaurs, ammonites, marine reptiles and pterosaurs became extinct.

Everything Dinosaur stocks a wide range of dinosaur, ammonite, marine reptile and pterosaur models and figures: Prehistoric Animal Models and Figures.

Examining Sediments

Examination of the sediments that separate the extinction strata and the layer of clay saturated with iridium were characteristic of normal geologic sedimentation over a long period of time, perhaps 300,000 years or so.  The team have challenged the scientific supposition that the sediments in the immediate vicinity of the impact strata were rapidly deposited and are the results of earthquakes and tsunamis, as the world literally rocked after the huge impact.

The team’s research suggests that the Yucatan peninsula impact was not a blow to species diversity, while the event thousands of years later may have killed 31 out of 44 species recorded at the Mexican research site.

A number of theories have been put forward to try to explain the Cretaceous mass extinction, some of them wildly imaginative to say the least.  For example, it has been suggested that the dinosaurs and other large animals were hunted to extinction by aliens visiting Earth.

A more likely candidate and probably a strong contender, is the evidence of massive volcanic eruptions on the Indian sub-continent.  The deposits of basaltic lava, known as the Deccan Traps are evidence of huge volcanic activity that lasted for millions of years.  The enormous amounts of ash, gas and debris thrown up into the atmosphere would have had a dramatic effect on global climate.

One of the research team stated:

“The impact-kill theory is beautiful in its simplicity, the ground truth, the data that supports the impact theory at the same time refutes it, the theory is messy and complicated by normal geological processes”.

Much like the aftershocks from a meteor impact, the debate between scientists as to the cause of the Cretaceous mass extinction is going to rumble on.  In truth, a number of factors could have contributed to the extinctions, not just a single catastrophic event.

To read more about the Deccan Traps: Asteroid Impact Theory Challenged – Blame the Deccan Traps.

To view on article on the impact theory: Sulphureous Skies Linked to Mass Extinction.

Belgian Expedition Provides Further Information on Arctic Dinosaurs

The versatility and adaptability of the Order Dinosauria is quite extraordinary.  It is certainly a very diverse order, what with tiny plant-eaters such as Micropachycephalosaurus and huge sauropods such as Paralititan at the other end of the size and scale spectrum.  Recent discoveries at high latitudes in northern Canada have shown that dinosaurs were capable of living in the far north and in cold climates, environments where, perhaps the mean annual temperature was not much above 50 degrees Farhenheit.

Dinosaurs of the Arctic

Now a team of palaeontologists from the Royal Belgian Institute of Natural Sciences (Brussels), have found evidence that dinosaurs roamed the cold regions of northern Asia.  A number of Late Cretaceous dinosaur fossils have been discovered in north-eastern Russia including theropod teeth and evidence of nesting sites that indicate that dinosaurs were at home in relatively cold climates.

The fossils have been found in the valley of the Kakanaut River, the strata has provided a wealth of Late Cretaceous vertebrate fossils, dinosaur such as hadrosaurs, tyrannosaurs, ankylosaurs and dromaeosaurs are represented.  The Kakanaut Formation has not yielded any small reptiles or amphibians (presumed to be cold-blooded).  It seems that the climate was just too cold for them.  Dinosaurs seem to be well adapted to this high latitude ecosystem, one dominated by polar conifer forests.  The presence of egg shells indicate that these animals were not migrants but possibly permanent residents, although there is some doubt over the evidence supporting this theory.

Even accounting for shifting continents, these dinosaurs from the Kakanaut Formation (Maastrichtian Faunal stage), would have lived at a latitude of over 70 degrees, putting them well inside the Arctic circle.

A Model of a Feathered Tyrannosaur – Feathered Polar Dinosaurs

One of our field rulers provides scale.  Polar tyrannosaurids were probably feathered to help insulate their bodies against the cold.

Picture credit: Everything Dinosaur

Feathered Dinosaurs

The photograph (above) shows a model of a feathered dinosaur.  Many polar dinosaurs including tyrannosaurs were probably feathered to help insulate their bodies against the cold.

Everything Dinosaur sells a range of feathered dinosaur models and figures, many of which are associated with palaeoenvironments that represent high latitudes.  For example, take a look at the: CollectA Prehistoric Life model range.

The Arctic may have been warmer 68-65 million years ago compared to today but it would still have had freezing winters and darkness for a good part of the year as the sun dipped below the horizon.  However, in summer there would be periods of almost 24-hour sunlight, an ecosystem “boom” time with vegetation growing 24-hours a day.  A rich environment dinosaurs seem equipped to exploit.

The research paper from the Belgian team has been published in the scientific journal Naturwissenschaften.

To read the article on the Canadian fossil finds indicating dinosaurs living on the American continent at high latitudes: North American Arctic Dinosaurs.

Baby Mammoth Reveals Secrets in Television Documentary

An almost perfectly preserved fossilised baby woolly mammoth is slowly and surely providing scientists with an insight into prehistory.  The 4 foot high, grey and brown mammoth carcass was discovered by a reindeer herder a couple of years ago in the relatively remote Yanmal-Nenets region of Siberia.  The calf, a female, is one of the best preserved mammoth specimens recovered to date and the almost perfect state of preservation has enabled scientists to gain fresh information on this ancient elephant species.  The mammoth has been nicknamed Lyuba (after the reindeer herder’s wife); was studied by a team of scientists from the Russian Academy of Sciences before travelling to Japan for further analysis.

To view the article on the baby mammoth’s discovery: Baby Mammoth Found.

Stomach contents have been studied and the researchers have found faecal residues and traces of prehistoric milk in the digestive track.  Analysis of the stomach contents of adult mammoths has provided evidence of what these huge herbivores ate, but to be able to study such a young animal is a very rare event.

Baby Woolly Mammoth

The baby was approximately one month old when she died, approximately 40,000 years ago (Pleistocene Epoch).  The international team of scientists charged with researching the animal have suggested that this animal was healthy when she died, perhaps drowning or becoming trapped and suffocating in mud near the edge of a lake.

Using high tech equipment such as computer tomography and other forms of electronic scanning the research team have studied her bones, soft tissues and teeth.  The stomach contents and digestive tract contained traces of her mother’s milk and the fat hump on the back of the head indicates that the calf was well looked after.

Commenting on the presence of a reserve of fatty tissue, one of the researchers, Daniel Fisher of the University of Michigan stated that the hump generated heat and was used by baby mammoths to stay warm during the first months of their lives.  It has been presumed that mammoths would give birth in the spring to allow their youngsters to grow up in the warmer spring and summer months, but even if this assumption is correct, baby mammoths would have faced a harsh environment.

Fisher stated:

“This is the first time we have a really healthy specimen to study”.

“In the Pink”

Referring to Lyuba as being a mammoth very much “in the pink”, the scientists are excited about how much information the carcass will provide.  Other baby mammoths that had been found including the famous preserved baby mammoth called Dima were not in very good shape when they died.  For example, Dima was about nine months old when he died.  Analysis of the carcass indicated that this mammoth was under nourished and very small for his age.  The stomach had a high level of parasites preserved within it and their presence indicates that this particular animal was poorly.

A Model of a Baby Mammoth with an Adult Animal

The CollectA Deluxe Woolly Mammoth model in 1:20 scale and the CollectA Prehistoric Life Woolly Mammoth calf. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

To view the CollectA range of scale prehistoric animal models including an adult Woolly Mammoth replica: CollectA Deluxe Prehistoric Animal Models.

The faecal material found in the female calf’s intestines was similar to an adult mammoth’s. It was likely that the mother encouraged her baby to eat dung to help establish a healthy microbial presence in the gut.  This is typical behaviour seen in a number of extant mammals.

Daniel Fisher went on to state:

“We are learning more about what [mammoths] ate and how to recognise animals that are healthy versus stressed”.

Further study of Lyuba’s teeth may provide information on the environment at the time of her death providing clues as to what caused many Ice Age mammals to vanish at the end of the Pleistocene Epoch.

Scientists remain unsure as to what caused the extinction of a number of a large mammal species approximately 10,000 years ago (the demise of megafauna).  The extinction of the mammoths is believed to have occurred relatively rapidly, some scientists believe human hunters may have played a significant role in the extinction of mammoths, others believe that climate change may have been the cause.

To view a model of a baby mammoth and other replicas of Pleistocene mammals including Ice Age animals: Prehistoric Animal and Dinosaur Models.