Category: Palaeontological articles

Extracting an Ichthyosaur Fossil

Newly Discovered Ichthyosaur Fossil Removed from Beach

After the exhilaration of finding a fossil specimen such as a near complete Ichthyosaur, comes the hard work of extracting the specimen.  This has to be done with great care and planning, as the aim is to remove the material as intact as possible without damaging any of the actual fossils.  For Ben and his dad Dave, they also had to cope with the threat of an incoming tide as Ben found his Ichthyosaur on the eastern beach of Lyme Regis (Dorset, England) and although the specimen was exposed at low tide, once the tide starts to turn, it comes in really quickly, so there is added pressure.  The specimen, representing a young Ichthyosaur was found by Ben a couple of days ago.  He and his father then set about working most of that day and into the evening trying to prepare the fossil for that all important lift, the first time that the Ichthyosaur would have been moved for 180 million years or so.

Our chum Brandon, a local fossil expert himself, was on hand to record the moment when the fossil was ready for extraction.

Carefully Extracting an Ichthyosaur Specimen from the Beach at Lyme Regis

Video Credit: Brandon Lennon

The specimen was quite fragile, so glue was used to help secure the fossil and keep it intact.  Once this had been done,  it was time to prepare the block of Blue lias in which the fossil was located for lifting.  Chisels were then hammered into key points underneath the block to allow it to be freed from the bed.  Once this process had been completed it was time to get ready to lift the specimen and remove it.  This in itself is a tricky process, in the video you can see just how much water was seeping into the dig site and Ben and Dave were aware of the oncoming tide.  With skill and care the two intrepid fossil hunters were able to lift out the fossil.  The tail section broke, if you look carefully on the video you can see that there is a natural fault on the block and as a result the end piece broke off.  However, we can report that the rest of the specimen was removed safe and sound.  The two pieces of rock will now be prepared so that the skeleton can be fully exposed.

Lyme Regis is a great place to visit and fossil hunting on the beach is a lot of fun, however, we at Everything Dinosaur suggest that visitors take advantage of a guided fossil walk led by a local expert.

To read more about guided fossil walks: Lyme Regis Fossil Walks

Congratulations to Ben and Dave, glad all their hard work paid off.

The Weird and the Wonderful – Chinese Triassic Marine Reptiles

Parahupehsuchus longus – Armoured Marine Reptile with a “Corset”

As life on Earth recovered from the devastating End Permian mass extinction event which took place some 250 million years ago, it seems that a myriad of strange and bizarre vertebrates evolved to take advantage of vacant niches in ecosystems that had arisen due to the extinction of so many different types of organism.  One of the strangest marine creatures known to science has just been described in the on line scientific journal PLOS One.  It seems that as environments and ecosystems recovered in the Early Triassic, so marine Tetrapods evolving the capability to eat other marine Tetrapods came about in earnest and the first Tetrapod apex predators of the sea appeared.  This led to the evolution of body armour and other forms of protection in smaller marine Tetrapods that were now the potential prey.  Step forward the bizarre Parahupehsuchus longus, around a metre long, marine reptile that evolved a bony tube that completely surrounded its body wall, like a sort of armoured corset.  Just like a corset, breathing movements and body movements may have been restricted, but the primary role for this unusual pseudo carapace was probably protection against attacks from a much larger predatory marine reptile that shared P. longus’s watery world.

Back in 2011, scientists from the Wuhan Centre of China Geological Survey undertook a field excavation in Yuan’an County, Hubei Province, (east central China), to find Early Triassic marine reptile fossils.  The strata in this part of China represents exposures of marine sediments laid down in a shallow tropical sea around 248 million years ago (Jialingjiang Formation).  The area had been mapped and studied since the late 1950′s and a number of marine reptile genera unique to this part of the world had already been named and described.  However, when Chinese scientists first studied these fossil rich deposits, the strata was believed to be younger, dated to the Anisian faunal stage of the Middle Triassic.  The rocks at this location were thought to be roughly the same age as Triassic marine strata found in the provinces of Yunnan and Guizhou (south-western China).  More recent studies have assigned the sediments exposed around Yuan’an County to be up to three million years older than most of the sedimentary rocks bearing marine reptile fossils in Yunnan and Guizhou.  The rocks which entombed Parahupehsuchus longus date to around 248 million years ago (Olenikian faunal stage of the Lower Triassic).  This is significant because the vertebrate fossils found in Yuan’an County are much closer to the End Permian extinction event than those from south-western China, the ecosystem represented is one that is at an earlier stage of recovery from the most devastating extinction event known.

Parahupehsuchus longus (Holotype Material WGSC 26005)

Scale bar = 10cm

Scale bar = 10cm

Picture Credit: PLOS One

In the diagram above the strange bony carapace-like structure surrounding the body of this new species of marine reptile can be clearly made out.  The labels in red have been added by Everything Dinosaur to help readers gain a better understanding as to the layout of the fossil as the skull and much of the tail is missing.

The research team identified more than ten marine reptile specimens, one partially complete fossil represents this new genus.  Most of the marine reptile specimens discovered represented animals of around a metre in length, but one fossil suggests a marine reptile of around 4 metres in length.  Although not formally described yet, the skull is robust and the teeth that of a meat-eater.  It has been suggested that this reptile was the apex predator.  Parahupehsuchus evolved its corset-like body to resist attacks from this much larger marine reptile.  Surprisingly, very few fish fossils have been found in the strata that contains the marine reptile fossils.  This might be a reflection of fossil preservation bias, but if there were few fish species present and this may not be that surprising as something like 57% of all marine families died out at the end of the Permian, it seems that marine reptiles evolved to attack and hunt other marine reptiles.  The corset of Parahupehsuchus may have evolved as a response to the predatory pressure.

Parahupehsuchus has been assigned to the Hupehsuchia Order of marine reptiles.  This Order currently consists of just three genera, all of which are found in the Lower Triassic sediments of Hubei Province.  The first named and described was Nanchangosaurus, then in 1972 a near complete specimen of a new type of marine reptile that had been discovered was named this was Hupehsuchus.  Palaeontologists consider that Parahupehsuchus was closely related to Hupehsuchus.

Parahupehsuchus pronounced “par-rah-hoop-pay-sook-cus” means beside Hupehsuchus which refers to the taxonomic relationship between these two genera.  The term Hupehsuchus is derived from Hupeh, an alternative spelling for Hubei Province and the Greek word for crocodile.

Hupehsuchus nanchangensis  Fossil Material (specimen number WGSC 26004)

Scale bar = 10cm

Scale bar = 10cm

 Picture Credit: PLOS One

The more complete specimen (diagram B) above, provides scientists with clues to how Parahupehsuchus might have looked.  It may have had a long narrow, toothless snout like its close relative Hupehsuchus.  It was probably capable of moving around on land as well as being adapted to a marine environment and although the tail is missing in the holotype specimen it is likely that the tail was quite powerful and Parahupehsuchus propelled itself through the water with sideways movements of its tail, in a similar to modern Crocodilians today.

If indeed Parahupehsuchus had a toothless jaw, then it may have eaten soft-bodied creatures such as squid.  This bizarre marine reptile remains unique amongst vertebrates for the strange configuration of its trunk.  Its body is completely surrounded by a bony tube, around fifty centimetres long and nearly seven centimetres deep.  The tube is made up of overlapping ribs and gastralia (belly ribs).  This tube and the presence of dermal armour on the dorsal surface of the skeleton (back) have been interpreted as defensive features to withstand the bites of larger marine reptiles.  This is evidence that by the Early Triassic, ecosystems had recovered enough from the End Permian extinction event to permit the establishment of complex marine Tetrapod food chains dominated by large apex vertebrate predators.

The Front Dorsal Region of Parahupehsuchus longus

White scale bar shown on actual fossil material = 1cm

White scale bar shown on actual fossil material = 1cm

Picture Credit: PLOS One

The unique corset-like body protection is made up of a combination of fused true ribs, belly ribs (gastralia) and neural spines.

Key

red = dermal armour, scales and ossicles (da)

dark brown = first segment of neural spine (ns1)

dark green = second segment of neural spine (ns2)

grey = ribs (ri)

orange = lateral gastralia (lg)

white = median gastralia (mg)

green = bones of the left forelimb

arf (pink) = anterior rib facet extending from the parapophysis, dia (light brown) = diapophysis of the neural arch, para (yellow) = parapophysis main facet.

Note that ribs and gastralia overlap in a complex manner and the double rib articulation prevents rib motion.  This would have made chest movements difficult for breathing and restricted the body movements to aid swimming and locomotion on land.

Although, the ribs are expanded in a similar way to that of a turtle’s shell, Parahupehsuchus is not closely related to the Chelonia (turtles, tortoises and terrapins).  This might be an example of convergent evolution.

Scientists hope to find more fossils of this strange marine reptile in rocks that make up the Jialingjiang Formation and with further research they intend to build up a more detailed picture of the food chain that is represented by this Lower Triassic fossil material.

Bizarre New Triassic Marine Reptile Described

Atopodentatus unicus from Yunnan Province

The fossils of a bizarre marine reptile with a unique mouth have been discovered in south-western China.  Although its body resembles other types of marine reptile, the skull and the mouth are extremely unusual and nothing like them has been seen before in the fossil record.   A number of scientists have speculated about this strange anatomical arrangement, the upper jaw resembles a vertical slit with fine teeth arranged to form sieve-like structure. A prehistoric animal that has a “zipper” for an upper jaw.   These adaptations indicate that this three-metre long sea creature evolved to fit a very specialist niche in the marine ecosystem of 245 million years ago.

The animal has been named Atopodentatus unicus, the name translates from the Latin to mean “peculiar teeth of unique shape” and one glance at an illustration of this particular beastie shows why the nomenclature is so appropriate.

An Illustration of A. unicus

Strange Triassic marine reptile.

Strange Triassic marine reptile.

Picture Credit: Nobu Tamura 2014

This is one of those occasions when the interpretation of the fossil material and a resulting illustration needs to proceed any further discussion so that the reader can gain an impression of just how weird this animal was.

The land that makes up the border between the south-western Chinese provinces of Guizhou and Yunnan is very important to palaeontologists as they try to reconstruct how life on Earth bounced back following the End Permian mass extinction.  The rocks laid down in this region represent Early and Middle Triassic marine faunas, the fine sediments that were deposited at the bottom of a shallow, tropical sea have preserved a wealth of marine reptile fossils, along with fishes and a vast array of invertebrates.  By recording the diversity of life preserved within this series, scientists can see how life on Earth recovered from the mass extinction event that marked the end of the Permian geological period.  The Atopodentatus fossil material was found in  Luoping County (Yunnan Province), the strata in this area has been dated to around 245 million years ago (Anisian faunal stage of the Middle Triassic), a little over five million years since the extinction event that saw an estimated 95% of life on the planet wiped out.  At this time in the Triassic, a number of different types of marine reptile had evolved, all of which were descended from terrestrial ancestors.

A large number of Ichthyosaur specimens have been discovered, some Ichthyosaurs co-existed with Atopodentatus but in younger Triassic rocks (Ladinian to Carnian faunal stages 230 to 225 million years ago), it seems that Ichthyosaurs has established themselves as the largest and most important marine reptile group.  The other types of marine reptile that lived alongside Atopodentatus are almost as bizarre.  There are primitive Sauropterygians, such as Nothosaurs and animals that are ancestors of the much more familiar Plesiosaurs and Pliosaurs, Protorosaurs, partially marine reptiles that were to give rise to the long-necked Tanystropheus and other peculiar Archosauriforms.  It seems that this part of the world was a “melting pot” for marine reptile evolution with some groups, surviving into the Jurassic, with other types completely dying out within a few million years.

A Specimen of the Sauropterygian Nothosaur called Keichousaurus

Keichousaur Fossil

 These rocks have been explored and mapped for more than ten years, by an international team of scientists. The report on the strange Atopodentatus has been published in the academic journal “Naturwissenschaften”, the study into A. unicus was conducted by scientists from the Canadian Museum of Nature, the Wuhan Institute of Geology and Mineral Resources as well as the Chinese Academy of Sciences.

Dr Xiao-Chun Wu (Canadian Museum of Nature) and his colleagues named the new prehistoric creature Atopodentatus unicus and suggest it belonged to a Superorder of reptiles called the Sauropterygians.  Staff from Everything Dinosaur, having reviewed the fossil bones have suggested it might be a type of Nothosaur, but one with a very specialised feeding method.  The body of the animal was quite long, the neck short and the skull much deeper than other similar sized Triassic marine creatures.  Most Nothosaurs were fish-eaters, but the dentition and the morphology of the jaws suggest that this newly discovered reptile had a weak bite and teeth unsuitable for tackling struggling prey.

On each side of the mouth, A. unicus had around 35 small, pointed teeth in the front of the upper jaw.  There were around 140 similarly shaped teeth in the rest of the upper jaw, with at least 100 located in the horizontal portion  with reminder located in the vertical, zipper-like portion of the top jaw.  There were nearly 200 teeth located in the lower jaw, over half of which were in the horizontal portion with the reminder located in the shovel-headed front part. All the teeth were covered in enamel, indicating even wear across all parts of the crown of the tooth, but the teeth do not look very worn, perhaps this hints at the sort of prey this animal specialised in catching.  Whatever it was eating, it probably had this food resource all to itself amongst the vertebrates as no other creature found to date has anything approaching the jaw anatomy of this marine reptile.

The Prepared Fossils (Atopodentatus unicus)

Bizarre Triassic marine reptile.

Bizarre Triassic marine reptile.

Picture Credit: Long Cheng/Wuhan Institute of Geology and Mineral Resources

The picture shows the long, serpentine body of the reptile with the deep, shovel-shaped skull shown as an inset.  Note the well developed limbs, particularly the large humerus.  This prehistoric animal was probably only partially marine, still capable of venturing out onto land, although the broad wrist bones and elongated fingers and toes enabled the limbs to be used to help the animal swim.

As to what this animal actually ate, no one knows for sure, there is nothing similar living today that seems to have anything remotely like its specialised feeding apparatus, or is there?  The Bowhead Whale (Balaena mysticetus), has plates of baleen made from keratin in its mouth which it uses to sieve out planktonic organisms as it swims through Arctic waters.  The mouth of Atopodentatus may have been adapted for sieving out small creatures but not from open water like the huge-mouthed Bowhead, but from soft mud on the sea floor.  Dr. Wu and his colleagues, suggest that the broad, shovel-like head of this marine reptile may have ploughed through soft sediments with its teeth sieving out soft-bodied creatures such as marine worms.

The doctor added:

“It is obvious that such delicate teeth are not strong enough to catch prey, but were probably used as a barrier to filter micro-organisms or benthic invertebrates such as sea worms.  These were collected by the specialised jaws, which may have functioned as a shovel or push-dozer and a grasper or scratcher.”

At the moment, the actual function of the jaws remain a mystery.  Perhaps a specimen will be found with stomach contents preserved or perhaps some trace fossils will be discovered the reveal a ploughed up seabed.  One of the few certainties surrounding this bizarre creature is that like a number of the strange marine reptiles that existed in the Mid Triassic seas of China, within a few million years this particular branch of the marine family tree had become extinct.

Earliest Cardiovascular System Described from Chinese Cambrian Arthropod

Oldest Known Cardiovascular System Identified – Fuxianhuia protensa

The fossil of an Arthropod found in rocks laid down around 520 million years ago with an exquisitely preserved cardiovascular system has been described by a team of scientists led by researchers from the Natural History Museum in London.  The specimen represents the oldest known fossil showing a rudimentary heart and blood vessels known to science.  Thanks to remarkable fossil sites such as the Burgess Shale deposits in British Columbia and beautifully preserved remains of Cambrian creatures from highly fossiliferous strata from south-western China, palaeontologists have built up an astonishing amount of data on life in the seas and oceans of the world around 520 to 500 million years ago, a period in the geological history of planet Earth known as the Cambrian explosion due to the range and diversity of organisms that had evolved at that time.

The exquisitely preserved specimen represents Fuxianhuia protensa from the Middle Cambrian aged strata of the Chengjiang Formation (the Moatianshan shales of Yunnan Province, south-west China).  Fossils of this shrimp-like creature are very common in these marine shales, sixteen different phyla that have been identified from the Chengjiang Formation, a location that rivals the Burgess Shales in terms of the rich fossil record that has been preserved, although the material from the Chengjiang Formation is slightly older than the fossils from the Walcott Quarry section of the Burgess Shale deposits.  Until this particular specimen had been studied, it has been assumed that most of the internal organs of early Arthropods would not survive the fossilisation process.  Some fossils had been found that indicated the presence of a digestive tract and back in October 2013, Everything Dinosaur reported the discovery of an Arthropod (Alalcomenaeus spp.) from the same region of Yunnan Province that showed signs of a brain and the soft tissue preservation of a nervous system, here we report on the discovery and mapping of a complete cardiovascular system in a 520 million year old Arthropod.

To read more about this earlier discovery: Ancient Arthropod Brain and Nervous System Studied

Although many fossils of F. protensa are known, its taxonomic position with the Arthropoda remains unclear, it is thought to be a basal member of this phyla, which today is the largest phylum of animals and includes crustaceans, insects, spiders, mites, scorpions, centipedes, king crabs millipedes and a number of extinct Orders such as the Trilobita.  The external skeleton is most commonly preserved, either as parts shed as the animal grew or as complete specimens that represent animals that died, however, due to the exquisite degree of preservation in some specimens from the Chengjiang Formation, scientists now have a much better understanding of the internal anatomy of early Arthropods.  What is remarkable, is that sophisticated cardiovascular and nervous systems seem to have evolved in the Arthropoda at an early stage in the history of life on Earth.

Fuxianhuia Fossils that have been used in the Study

Cardiovascular system in 520 million year old Arthropod preserved.

Cardiovascular system in 520 million year old Arthropod preserved.

Picture Credit: Journal of Nature Communications

The photograph shows examples of the F. protensa fossil material used in the study.  Diagram (a) is a view of specimen YKLP 11336 from above (dorsal view), the location of the digestive tract running down the centre of the body is indicated by the black arrows.

Illustration (b) shows the head and the front of the animal (anterior view), specimen number YKLP 11337, the white arrows indicate the mouth of the creature.  Part (c) shows the filled gut within the abdominal segments, the gut has been preserved as carbon in this specimen (YKLP 11338).  Diagram (d) shows empty gut area marked by arrows in abdominal segments Ab9 to Ab14.

Diagram (e) shows the preserved outline of the cardiovascular system (YKLP 11335), A1 in the photograph marks the position of the left antenna and ey marks the position of the right eye.  The black triangles towards the top of the picture indicate the position of the bottom portion of the animal’s headshield.  The white outlined triangles towards the bottom of photograph (e) show the end of the thorax portion of the animal’s body.

Scale Bars

Most complete specimens of F. protensa are around 30 mm in length, the scale bars in the photographs are:

(a) = 5 mm

(b, c and d) = 1 mm

(e) = 4 mm

Commenting on the significance of this fossil discovery, palaeontologist Xiaoya Ma (Natural History Museum, London), one of the authors of the scientific paper published in the journal “Nature Communications” stated:

“It is an extremely rare and unusual case that such a delicate organ system can be preserved in one of the oldest fossils and in exquisite detail.  However, under very exceptional circumstances, soft tissue and anatomical organ systems can be preserved as fossils.”

Scientists now have an excellent understanding of the internal organisation of the anatomy of this Arthropod.  Usually, soft tissue decays rapidly after death and fossils typically only preserve the hard parts of an organism, such as the exoskeleton in the case of the Arthropoda.  With Fuxianhuia protensa the fossils show a tubular heart in the middle of the body with a complex system of blood vessels leading to the creature’s antennae, eyes, brain and limbs.  The cardiovascular system consists of the heart and the blood vessels.  It allows blood to circulate and to deliver oxygen and nutrients around the body.  Most higher forms of life in the Kingdom Animalia have such a system, although those organisms without a real body cavity such as flatworms and jellyfish do not.

The specimens studied suggest that as early as 520 million years ago, Arthropods had evolved a complex internal anatomy which is very similar in structure to the internal anatomy found today in extant Arthropods such as shrimps.

Like the Burgess Shales, the Chengjiang Formation material has preserved much of an ecosystem that thrived in a shallow marine environment more than half a billion years ago.  It seems that these two ancient environments suffered much the same fate as each other even though just like today, in the Cambrian, these two locations were thousands of miles apart.  Both the Burgess Shale Formation and the Chengjiang Formations represent shallow marine environments which were on slopes.  From time to time mudflows, buried entire ecosystems and as a result, a wealth of organic material has been preserved.  A large number of Fuxianhuia fossil material is known from Yunnan Province, scientists believe that this Arthropod was benthic (living on the sea floor), although it is not known whether this animal was an active hunter or a scavenger.

A Schematic Diagram of the Internal Anatomy of Fuxianhuia protensa

Digestive tract and cardiovascular system of Fuxianhuia protensa

Digestive tract and cardiovascular system of Fuxianhuia protensa

Picture Credit: Journal of Nature Communications

The diagram above shows the internal anatomy of F. protensa.  Diagram (a) shows the cardiovascular system (red) shown in relation to the brain and central nervous system (blue).  Diagram (b) shows the whole reconstruction, with brain and segmental ganglia (blue) overlaid against the external skeleton of the animal.  Diagram (c) shows the cardiovascular system in relation to the digestive tract (green).  In all three diagrams, the tubular heart organ can be seen running down the central region of the thorax.

Thanks to highly detailed fossils from British Columbia and south-western China, scientists have been able to acquire a lot of knowledge about life in the oceans of the world during the Cambrian geological period.  Although, advanced and highly evolved cardiovascular systems were present in many organisms, the paucity of the fossil record that pre-dates the Cambrian prevents scientists from calculating when key structures such as hearts and brains first evolved.  Given the degree of sophistication seen in the Fuxianhuia material two competing theories have been put forward.  Firstly, such specialised internal structures such as hearts, brains and a cardiovascular system must have evolved gradually with incremental changes many millions of years before the Cambrian.  Secondly, the evolution of such specialised internal organs occurred relatively quickly in response to the development of predator/prey interactions and the increased availability of food resources.

The research team are able to conclude that organisms had cardiovascular systems before Fuxianhuia, but evidence of lacking in the fossil record so no further light on the subject can be cast for the time being.

The genus name Fuxianhuia is after Lake Fuxian in Yunnan Province, the specific or trivial name “protensa” means “elongated” a reference to the elongated thorax of the creature.

Dinosaurs Beginning with “Z”

Dinosaurs Whose Names Start with the Letter “Z”

With a number of new Chinese dinosaur fossil discoveries being announced over the last few years or so, the number of dinosaurs, whose names begin with the letter “Z” has increased dramatically.  For example, the Thyreophoran (armoured dinosaur) from China called Zhejiangosaurus and the Hadrosaur called Zhuchengosaurus.  These are both examples of Ornithischian dinosaurs known from Cretaceous aged strata.  However, Jurassic, lizard-hipped dinosaurs (Saurischians) get a look in to at the end of the alphabet thanks to the discovery of Zigongosaurus (long-necked Sauropod dinosaur from the Jurassic).

It is not just dinosaurs from China that dominate the very last letter of the alphabet.  Our experts at Everything Dinosaur can think of two dinosaur genera from Argentina that both begin with the letter “Z”.  Firstly, there is the poorly known Triassic Theropod called Zupaysaurus, whose fossils date from the Middle Triassic.  Then there is the much larger Zapalasaurus, a Diplodocid Sauropod from Cretaceous aged strata.

Our favourite dinosaur beginning with the letter “Z” is the horned dinosaur from North America called Zuniceratops (Zuniceratops christopheri) which was formally named and described in 1998.

An Illustration of the North American Ceratopsian Zuniceratops

Reconstruction based on the likes of Zuniceratops.

Reconstruction based on the likes of Zuniceratops.

Picture Credit: Everything Dinosaur

In 2011, a giant Tyrannosaurine dinosaur was named and described from a bone bed found in Shandong Province in China.  This dinosaur was named Zhuchengtyrannus magus.  Unfortunately, the press releases announcing the discovery were sent out by the Chinese press agency on March 31st and they arrived in UK news rooms the next day.  Many media groups thought the story some kind of elaborate April Fool’s joke.  However, roaming north-eastern China in the Late Cretaceous was a very large, Tyrannnosaurine dinosaur that may have been about the same size as Tyrannosaurus rex.

To read more about Zhuchengtyrannus: New Tyrannosaur Named and Described from China

With so many new Chinese dinosaurs, we can expect many more dinosaurs to have names starting with the twenty-sixth letter of the western alphabet.

Digitally Reconstructing a Famous Dinosaur Trackway

Dinosaur Tracks Lost to Science for Decades Recreated Using Digital Technology

A set of dinosaur tracks, one from a large Sauropod dinosaur, the second set from a meat-eating dinosaur, have been digitally recreated permitting scientists to study the complete tracks for the first time in more than seventy years.  The footprints, which cover a distance of approximately forty-five metres, are part of a number of dinosaur trackways preserved in near marine sediments that were laid down between 113 and 110 million  years ago (Cretaceous geological period).  The Theropod dinosaur’s three-toed prints overlie the larger Sauropod prints and this indicates that the large herbivorous dinosaur passed first, perhaps the carnivore was stalking the Sauropod.  The tracks, now forming part of the bed of the Paluxy River in Texas are often referred to as the “dinosaur chase tracks”, although scientists cannot be certain whether or not the Theropod was stalking its prey.

The Famous Dinosaur “Chase” Tracks (Paluxy River, Texas)

Famous dinosaur tracks - Theropod and Sauropod tracks.

Famous dinosaur tracks – Theropod and Sauropod tracks.

Picture Credit: Everything Dinosaur

The picture above shows a potential interpretation of the Paluxy River tracks, with the huge, plant-eating dinosaur being stalked by the bipedal, Theropod dinosaur.  It is difficult to assign a genus to these dinosaur footprints, but it has been speculated that the Theropod may have been a member of the Acrocanthosaurus genus, as fossils of this large predator have been found in similar aged rocks and a dinosaur bone from the Glen Rose Formation, has been assigned to Acrocanthosaurus.

Using a technique called photogrammetry, scanning and combining photographs taken during research at the location back in the 1940′s, the scientists were able to build a digital model of the site.  The computer model created is the only complete record available to study as some of the physical tracks themselves have been lost.

The Paluxy River dinosaur tracksite is among the most famous in the world.  In 1940, Dr. Roland T. Bird, a American palaeontologist from the American Museum of Natural History (New York), described and excavated a portion of the site containing associated Theropod and Sauropod trackways, the so-called “dinosaur chase tracks.  As the river flow was in danger of completely eroding away the dinosaur footprints, it was decided to remove the tracks in a serious of carefully excavated blocks.  The trackway was thus broken up into a number of sections.  Split up as it was, the fossil specimens were housed in different museum collections and over the years the slabs have deteriorated and a portion of the track has been lost.

The research team, which included scientists from Liverpool University, the Royal Veterinary College (London) and Indiana-Purdue University, Indiana, applied state-of-the-art photogrammetric techniques to seventeen black and white photographs of the tracks that had been taken by Dr. Bird during the 1940 trace fossil study.  By producing highly detailed scans of the original photographs and their corresponding negatives the researchers were able to digitally reconstruct the site prior to its fateful excavation.  Furthermore, the three-dimensional study was able to corroborate sketches drawn by Dr. Bird when the trackway was first scientifically described.

Sixteen of the Photographs from the 1940 Expedition Used to make the 3-D Digital Map

Some of the original photographs used to create the 3-D image.

Some of the original photographs used to create the 3-D image.

Picture Credit: PLOS One

This new mapping technique demonstrates the exciting potential for digitally recreating palaeontological, geological, or archaeological specimens that have been lost to science, but for which photographic documentation still exists.

Using dinosaur footprints made back in the Aptian/Albian faunal stage of the Cretaceous, this work has dramatically illustrated the potential for the technique of historical photogrammetry, permitting the creation of highly detailed and precise 3-D maps of sites that may have been physically lost and just preserved in photographs.  In this instance, the last time the set of dinosaur tracks was complete was back in 1940 prior to the removal of the footprint blocks.

A Digital View of the Reconstructed Tracks

Video Credit: PLOS One

Commenting on the significance of this study, lead researcher Dr Peter Falkingham (Royal Veterinary College) stated:

“Here we’re showing that you can do this to lost or damaged specimens or even entire sites if you have photographs taken at the time.  That means we can reconstruct digitally, and 3-D print, objects that no longer exist.”

New Data on Mesozoic CO2 Levels Can Help Map Today’s Climate Change

Mesozoic CO2 Levels Much Higher than Today

A new study published by University of Utrecht researchers and published in the “Proceedings of the National Academy of Sciences” suggest that for much of the Mesozoic, carbon dioxide levels in the Earth’s atmosphere were much higher than they are today, even with global warming caused by greenhouse gases such as higher levels of CO2.  Earlier studies had come to similar conclusions but this new research suggests that at the onset of the Triassic and into the Jurassic global CO2 levels could have been as much as five times their current levels.

The new methodologies used to model the ancient CO2 levels could have implications for how climatologists plot changes in our environment as CO2 levels rise.

Scientists have known for some time that a large amount of volcanic activity results in more CO2 being released, but with previous analytical methods, it had been tricky to weigh up all the variables and to come up with an overall assessment of CO2 concentrations.

Lots of CO2 Around in the Mesozoic with the Dinosaurs

A warm and humid Earth back in the early Mesozoic.

A warm and humid Earth back in the early Mesozoic.

Picture Credit: Everything Dinosaur

As the Mesozoic progressed so the super-continent of Pangaea began to break up into two smaller landmasses, essentially Laurasia in the northern hemisphere and Gondwana further south.   The huge amount of plate movements led to extensive subduction and a great deal of volcanic activity.  It was this volcanism that drove the release of CO2 into the Earth’s atmosphere, thus leading to a “greenhouse” world which was warm and humid and the dinosaurs thrived in.

Lead author of this new study, geoscientist Douwe van der Meer, (Utrecht University), explained that previous research had led to widely varying amounts of CO2 in the atmosphere, making such work of limited use when trying to model current climate change.

The Utrecht University research team used a state-of-the-art imaging technique called seismic tomography to reconstruct 250 million years of volcanic CO2 emissions.  Seismic waves were analysed as they travelled through the rock layers that make up the Earth’s crust, this gave the team the opportunity to create a model of the structure of the Earth’s interior.

Lead author, van der Meer stated:

“This method is comparable to CT scans used in hospitals to image inside bodies.  With sufficient earthquake wave travel times, we can create a velocity model of the Earth.  Faster regions are more dense, colder material plates that sank into the Earth as a result of subduction processes due to plate tectonics.”

Carbon Dioxide is not the only greenhouse gas.  Herbivorous dinosaurs may have played an indirect role in global warming by producing a lot of methane as they digested large amounts of plant matter.

To read an article about the role of Sauropod dinosaurs in global warming: The Winds of Change – Methane Produced by Dinosaurs May Have Led to Global Warming

Nanuqsaurus hoglundi – An update on “Polar Bear Lizard”

Nanuqsaurus hoglundi – Tyrannosaur from the High Arctic

Earlier this month, an academic paper was published on a newly discovered Tyrannosaur which once roamed the very far north of an ancient Cretaceous strip of land called Laramidia.  This new dinosaur might only be known from a few fragmentary fossils, fossils which were overlooked at the time they were first found back in 2006, but it is believed that this member of the Tyrannosaurine may have been very closely related to T. rex.

Named Nanuqsaurus hoglundi the fossils of this predatory dinosaur were found in a well-known horned dinosaur excavation site more than five hundred kilometres inside the Arctic Circle.  The site is called Kikak-Tegoseak and it represents Upper Cretaceous deposits that form part of the extensive Prince Creek Formation in North Slope Borough, Alaska.  The fossil material consists of three disarticulated pieces of skull including elements from the front of the jaw.  These pieces were found in close proximity to each other and are believed to represent fragments from the same skeleton.  Based on comparisons with better known Tyrannosaurs, this dinosaur is believed to have been a “pygmy Tyrannosaur”.  It bucks the trend seen in Tyrannosaurids known from the Maastrichtian faunal stage of the Cretaceous, when if anything, the Tyrannosaurs roaming North America at the very end of the Cretaceous period tended to be bigger than their forebears from the Campanian faunal stage.

The Fossil Material Discovered to Date - Nanuqsaurus hoglundi 

The fossil material.

The fossil material.

Picture Credit: PLOS One

Diagram A indicates where on the Tyrannosaur skull the three pieces of fossil would be located.  The actual shape of the skull is based on more complete specimens.  The research team led by Dr Anthony Fiorillo and Dr Ronald Tykoski of the Perot Museum of Nature and Science in Dallas, Texas came across the fossils in 2006 when trying to locate more material related to a horned dinosaur, one that would turn out to be a new species of Pachyrhinosaurus (P. perotorum).  It was only later, back in the preparation laboratory that the scientists realised the importance of their discovery.

To read more about the discovery of the third species of Pachyrhinosaur: New Species of Polar Horned Dinosaur is Announced

This latest edition to the Tyrannosaur family tree, measured around six metres in length.  It was approximately half the size of its more illustrious cousin from the south, Tyrannosaurus rex.  The name Nanuqsaurus hoglundi  is derived from the local dialect for Polar Bear, a reference to the fact that as far as any one knows, this dinosaur was the apex predator in the environment.  The specific or trivial name honours Forrest Hoglund in recognition of his career in the Earth Sciences and his work to help fund the Perot Museum.

A team member from Everything Dinosaur commented:

“Although this part of the world was not as cold back in the Late Cretaceous as it is now, Nanuqsaurus lived in a high-latitude continental environment with seasonal extremes.  It may have been covered in a thick, coat of shaggy feathers, helping to insulate this dinosaur from the worst of the winter weather.  For a significant amount of the year, the sun would not have risen above the horizon, its world would have been a very dark place, which explains why analysis of the skull material discovered to date suggests that this predator had a powerful sense of smell.  Helpful when you live in a world of almost perpetual twilight for much of the year.”

Everything Dinosaur’s Illustration of Nanuqsaurus hoglundi

Potentially a very, shaggy coated Tyrannosaur!

Potentially a very, shaggy coated Tyrannosaur!

Picture Credit: Everything Dinosaur

The academic paper’s authors have suggested the smaller body mass of Nanuqsaurus hoglundi compared to other Late Cretaceous Tyrannosaurs may reflect an adaptation to the fluctuating amount of food resources available in its Arctic environment.  In the summer, when daylight was almost constant, it is likely that large numbers of herbivorous dinosaurs migrated northwards up Laramidia to take advantage of the huge amounts of plant food available.  As the days grew shorter, the carnivores had much slimmer pickings as many prey animals probably moved out of the area.  Of course, this is just speculation, this Tyrannosaur may have migrated northwards from lower latitudes following the herds of herbivores.

The diversification of the Dinosauria in this part of the Americas at the end of the Cretaceous may stem from the partial isolation of the very northernmost parts of Laramidia with the pushing up of a mountain range (the Brooks Range), which may have cut-off part of the north of Laramidia during the Late Campanian faunal stage.

A Comparison of Nanuqsaurus hoglundi with other Tyrannosaurs

N. hoglundi compared to other Tyrannosaurs and predators from the Arctic.

N. hoglundi compared to other Tyrannosaurs and predators from the Arctic.

Picture Credit: PLOS One

The diagram above compares N. hoglundi with T. rex (B – Sue from the Field Museum), a second Tyrannosaurus rex from the American Museum of Natural History (gracile form) – (C).  Other Theropods depicted include Daspletosaurus torosus (D) and Albertosaurus sarcophagus (E).

The other two Theropods featured in the diagram above are not Tyrannosaurs.  The discovery of a “pygmy Tyrannosaur” has intrigued a number of palaeontologists who are trying to build up a detailed picture of the fauna at the “top of the world” during the Late Cretaceous.  Back in 2008, Dr. Fiorillo discovered some super-sized Troodon teeth from the Colville River area.  The Alaskan fossils represented animals that were 1.5 times bigger than the Troodons known from more southerly latitudes.  In the diagram, Troodon formosus is represented by (F), the much large Troodon species from Alaska is (G).

In the diagram the scale bar equals 1 metre.

Why should we have much larger Troodon type predators yet evidence of a “pygmy” Tyrannosaur living in the same environment?  A number of theories have been proposed.  Perhaps the proportionately larger eyes of the Troodons enabled them them to hunt larger prey than their southern cousins which did not have the predatory advantage of all that darkness.

Man Charged over Dinosaur Footprint Theft In Utah

Man Charged with Stealing Fossilised Dinosaur Footprint

A grand jury has charged a resident of the town of Moab (Grand County, eastern Utah), with four federal offences related to the theft and subsequent loss of a fossilised dinosaur footprint from Bureau of Land Management administered land.  Thirty-five year old, Jared Frederick Ehlers has been indicted on one count each of removal of palaeontological resources, depredation of government property, destruction of evidence and theft of government property.  The motive for the removal of the three-toed dinosaur footprint from a sandstone ridge near to the Hell’s Revenge off-road jeep trail and the alleged subsequent dumping of the fossil in the Colorado river remains unclear, however, given the high prices the sale of such fossil material can fetch on the black market, it is suspected that the fossil was stolen for commercial gain.

Staff have been monitoring the progress of the investigation closely since Everything Dinosaur team members carried the story of the fossil theft on this blog back on February 22nd.

To read about the fossil theft: Dinosaur Footprint Stolen in Utah

Over the weekend of 8th/9th March, Utah State officials organised a dive team to search an area of the Colorado River as it was believed that the fossil specimen had been thrown into the water from the Dewey Bridge but despite an intense search the fossil was not retrieved.

Explaining how difficult it was to search the riverbed, Grand County Sheriff Steven White stated:

“You’re searching by Braille, everything is by hand.  You have zero visibility, you’re dealing with changing currents, you’re dealing with obstacles.  It was very hazardous diving conditions.”

The river search was instigated after a suspect came forward and informed State officials where the 190 million year old, Early Jurassic print had been allegedly dumped.  It remains unclear as to whether this person was Jared Ehlers.

Ehlers is facing prosecution under the Paleontological Resources Preservation Act, (American spelling), a law that was passed by the United States Government to help prevent the theft of fossils from public land and to prosecute any person or persons who vandalises fossils.  Violators face civil and criminal penalties including fines and possible incarceration.

Moab Man Charged with Four Federal Offences Related to Fossil Footprint Theft

Jared Ehlers facing four federal charges over alleged fossil theft

Jared Ehlers facing four federal charges over alleged fossil theft.

Picture Credit: Grand County Jail

The most serious count, that Elhers is facing, the destruction of evidence, carries a maximum prison sentence of twenty years.  The other three counts carry a maximum prison sentence of between five and ten years.  No date has been set yet for Mr Ehler’s first court appearance, if he is convicted on all four counts, he could face a maximum possible sentence of forty-five years in prison.

A spokes person from Everything Dinosaur commented:

“The federal authorities are to be congratulated for the swift and speedy way in which they have pursued this case.  However, the fossil specimen itself remains lost and as it is sandstone, it will quickly begin to erode and abrade if it remains in the river.  At this juncture, it is very hard to say whether or not the fossil will ever be recovered.  Even if the fossil is found, it may be virtually destroyed as a trace fossil.”

Putting the “Chicken from Hell” into Context

Anzu wyliei – Probably Feathered and an Omnivore from the very end of the Cretaceous

With the publication of the scientific paper on the newest member of the very bird like Oviraptorosauria published this week in the on line journal PLoS One (Public Library of Science),  team members at Everything Dinosaur attempt to put the discovery of the “chicken from Hell” into context.  The dinosaur has been named Anzu wyliei and this genus has been erected based on the fossils of three individual dinosaurs discovered in Upper Cretaceous deposits of North and South Dakota (United States).  The fossil sites are around fifty kilometres apart and they represent a dinosaur, whose presence in the Hell Creek Formation (Maastrichtian faunal stage) had long been suspected but these fossils provide definitive proof that such creatures roamed the western United States at the end of the Cretaceous.

Most discoveries of Oviraptorosaurs have been made in Asia, most notably in China and Mongolia.  Much of what has been inferred about A. wyliei has been based on comparisons with Asian Oviraptors, even though the remains of the three individuals when combined together represent about 80% of the total skeleton.  For example, Anzu wyliei has been pictured as a feathered dinosaur, although no fossilised feathers have been associated with the Hell Creek Formation specimens.  The covering of a shaggy coat of feathers is inferred, as a result of Asian specimens preserved in finer grained matrices which have permitted feather preservation.  The discovery of skull material, including a hyper extended premaxilla indicates that this dinosaur had a large rounded crest on the top of its skull.  This feature is common to a number of Oviraptor genera.

An Illustration of Anzu wyliei

Scale bar = one metre

Scale bar = one metre

Picture Credit: PLoS One/Everything Dinosaur

The picture above gives an overall impression of what this new dinosaur species looked like.  The post cranial bones coloured grey represent fossil specimens.  The skull material indicated represents the extent of the fossil material found to date.  The Oviraptorosauria can be split into a number of families, one such family is the Caenagnathidae (the name means “recent jaws” – as the group were originally thought to be a Cretaceous clade of birds). The jaws are very bird-like and these dinosaurs had no teeth.  Intriguingly, compared to other North American members of the Caenagnathidae such as Chirostenotes spp. known from older rocks found in Alberta, Canada (Campanian faunal stage), Anzu wyliei was a real bruiser!  Body mass estimates based on femur (thigh bone) measurements suggest that this dinosaur weighed between 200 and 300 kilogrammes and that it probably stood around 1.5 metres high at the shoulder and had an overall length approaching 3.5 metres.  Some of the Canadian Caenagnathines were probably only around 20 kilogrammes in weight when fully grown.

The Reconstructed Skull of Anzu wyliei

A reconstruction of the skull (left side view)

A reconstruction of the skull (left side view)

Picture Credit: Donald E. Hurlbert (Smithsonian Institute)

 The American scientists from Utah University, the Smithsonian Institute and the Carnegie Museum of Natural History re-examined the fossil material that had been collected a few years earlier.  Their research helps palaeontologists to piece together a little more about the other types of dinosaur that shared the same environment with more famous dinosaurs like Triceratops and Tyrannosaurus rex.

Phylogenetic analysis suggests that this new species of dinosaur was most closely related to Caenagnathus collinsi (known from Campanian-aged strata from Alberta, Canada).  The fossils have also suggested that A. wyliei and other Caenagnathines may have preferred open expanses such as floodplains, as to what they might have been eating way back at the end of the Cretaceous, these animals were probably generalist omnivores.  It is likely that the bulky Anzu wyliei fed on small mammals, insects, lizards, baby dinosaurs and plants.  It may even have specialised in eating the eggs of other dinosaurs.  Scientists have nick-named this dinosaur the “chicken from Hell” a reference to the Hell Creek Formation where the fossils were found.

An Illustration of a Typical Oviraptor

Part of the Carnegie Collectibles Range from Safari Ltd

A typical feathered Oviraptor

Picture Credit: Everything Dinosaur

A spokes person from Everything Dinosaur commented:

“This research is extremely important as it helps to fill in the gaps in terms of the smaller, Theropods that lived at the very end of the Cretaceous.  These fossils represent some of the youngest Oviraptor fossils discovered to date.”

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