Category: Dinosaur and Prehistoric Animal News Stories

Research to Get Your Teeth Into

Structural Secrets of Theropod Teeth

Theropod dinosaurs, the majority of which were carnivorous, had a distinct advantage over other Mesozoic predators.  Their teeth had a deeply folded, serrated tooth structure that allowed them to rip and tear into the bodies of their victims.  This crucial, layered structure to the teeth has been identified by researchers from the University of Toronto Mississauga, with the assistance of colleagues from Taiwan and published today in the academic journal “Scientific Reports.”

A Specialised Tooth Structure for Feeding on Large Prey

Gorgosaurus feeding - thanks to its specialised teeth.

Gorgosaurus feeding – thanks to its specialised teeth.

Picture credit: Daniele Dufault

The picture above shows a feathered Gorgosaurus, a member of the Tyrannosauridae family, feeding on a young Corythosaurus.  The research team used scanning electron microscopes and a synchrotron located in Taiwan to study a wide variety of Theropod teeth from the collections of Canadian museums, including the Royal Tyrrell, and the Royal Ontario Museum.  Meat-eating dinosaurs in the study, included Gorgosaurus, the Triassic predator Coelophysis, Tyrannosaurus rex, Allosaurus, and the giant African Theropod Carcharodontosaurus.  Other non-Dinosauria creatures involved in the teeth study were Smilodon spp. and the shark C.  megalodon, as well as early Archosaurs, as the scientists tried to identify the evolutionary origins of these rather unique inter-dental folds.  Extant animals were also included in the research.  The only living animals with similar dentition and internal teeth structures are the Monitor Lizards, most notably the formidable Komodo dragon (Varanus komodoensis).  It is the largest lizard alive today and specialises in hunting large animals, thus reinforcing the theory put forward by the Canadian research team that these inter-dental folds evolved specifically to assist with predation of large herbivores.

Dr. Kirstin Brink, a post-doctoral researcher in the Department of Biology, one of the authors of the paper commented:

“What is so fascinating to me is that all animal teeth are made from the same building blocks, but the way the blocks fit together to form the structure of the tooth greatly affects how that animal processes food.  The hidden complexity of the tooth structure in Theropods suggests that they were more efficient at handling prey than previously thought, likely contributing to their success.”

Dr. Kristin Brink with one of the Theropod Teeth Examines the Evidence

A special arrangement of layers of dentine at the base of each serration in the tooth.

A special arrangement of layers of dentine at the base of each serration in the tooth.

Picture Credit: University of Toronto Mississauga

The picture above shows Dr. Brink examining the special arrangement of layers of dentine at the base of the each tooth serration (denticle).  She is holding a tooth from the giant Theropod Carcharodontosaurus.

A lot of research has been undertaken into the bite forces of extinct animals, but this is the first time a study of this type has been carried out.  The teeth may have an outer coating of enamel, just like our teeth, but the tough dentine inside has a unique configuration of dental folds and this gives the teeth of Theropod dinosaurs enlarged serrations, ideal for tearing into flesh.

The shape of the teeth (morphology) and their development, both in terms of their evolution and how they develop in an individual. can provide palaeontologists with a lot of information on the evolution of extinct animals and provide insights into feeding behaviour.  Theropod teeth, the only group of the Order Dinosauria, known to have produced meat-eaters, are characterised by the presence of serrations, known as denticles on the cutting edges of their teeth.  These serrations vary between genera, with troodontids for example, having relatively large denticles, whilst spinosaurids have proportionately much smaller ones.

Teeth that are serrated along the cutting edge are referred to as ziphodont teeth.  In a study, Everything Dinosaur reported upon last year, the same University research team, examined the ziphodont teeth of Dimetrodon (D. grandis).  They concluded that the serrations gave this Pelycosaur an evolutionary advantage over other Permian predators.

To read more about this study: Dimetrodon with Teeth Like a Steak Knife

In this new paper, the researchers conclude that the structures previously thought to prevent tooth breakage, instead, first evolved to shape and maintain the characteristic denticles throughout the life of the tooth.  The relatively novel and complex dental folds produced at the base of the teeth characterises the Theropods, with the exception of those genera that evolved a modified diet and a less meat intensive diet.  The scientists conclude that these teeth structures are vital for allowing the predation and consumption of large prey animals.

A Close up of a Gorgosaurus Tooth (Royal Ontario Museum Collection)

A close up of the tooth of Gorgosaurus

A close up of the tooth of Gorgosaurus – G. libratus

Picture Credit: Scientific Reports

The picture above shows an illustration of the skull of the tyrannosaurid Gorgosaurus (A), drawing by Danielle Dufault.  The complete tooth (ROM 57981) is shown in (B) with extreme close ups of the denticles on the cutting edges of the tooth.  The tooth illustrated is from the upper jaw (maxilla).

Key

  • dej = dentine/enamel junction
  • e = enamel (outer coating of the tooth)
  • if = inter-dental fold
  • is = inter-dental sulcus
  • pd = primary dentine

The Sharp Edges of Predators Teeth Viewed Under Scanning Electron Microscopy

c

Theropod teeth have two sharp edges these are called carinae.

Picture Credit: Scientific Reports

The cutting edges (carinae) of various predators (all are examples of ziphodont teeth).  Pictures are from scanning electron microscopy images.  Note the scale bars and the pictures to the right of the black and white images are thin cross sections showing internal structure.

Key

  • C = unknown Phytosaur
  • D = Coelophysis bauri
  • E = Allosaurus fragilis
  • F = Carcharodontosaurus saharicus
  • G = Gorgosaurus libratus
  • H = Tyrannosaurus rex

This adaptation may have played an important part in the initial radiation and subsequent success of the Theropoda as terrestrial apex predators.  After all, the Theropod body shape and bauplan, especially those teeth, permitted them to dominate terrestrial ecosystems for the best part of 160 million years.

Updating the Winged Dragon – Zhenyuanlong

How do we Know that Zhenyuanlong was Quite Big?

A few days ago, on July 16th, Everything Dinosaur team members published an article that featured the newly described Chinese dromaeosaurid dinosaur known as Zhenyuanlong suni.  We explained why the dinosaur called Velociraptor was used to help give this new dinosaur discovery context and outlined some of the more intriguing aspects of the fossil, that perhaps had been missed by more general media outlets.  However, we did receive an email about our article from a young dinosaur fan so we thought it best if we followed up our original article by providing some additional information about this little feathered carnivore.

To read our article (July 16th) on Z. suniThe Winged Dragon from Liaoning Province

A Newly Described Dromaeosaurid from China

Very probably a ground-dwelling predator.

Very probably a ground-dwelling predator.

Picture Credit: Zhao Chuang

Young Alex, wrote into Everything Dinosaur to ask, how do scientists know how big this dinosaur was and how big was it compared to other feathered dinosaurs found in China?  We wrote to Alex explaining in a little more detail about what the scientists who studied the fossil material concluded.

The academic paper describing this new type of “raptor” was published in the journal “Scientific Reports”.  The authors were Professor Junchang Lü (Institute of Geology, Chinese Academy of Geological Sciences, Beijing) and Dr. Stephen Brusatte (School of GeoSciences, University of Edinburgh).  Around 125 million years ago, the area of north-eastern China, now known as Liaoning Province was covered in a lush, temperate forest.  Large lakes featured in the environment and nearby volcanoes occasionally erupted and buried the area in fine ash, this explains the exceptional state of preservation of much of the Liaoning fossil material.  Living in the forests were a large number of different types of “raptor”, members of the Dromaeosauridae dinosaur family.  So far six genera have been described but it is very likely that more feathered dinosaur discoveries will be made in the future.

The six genera of dromaeosaurids described so far (with date described):

  1. Sinornithosaurus (named in 1999)
  2. Microraptor (named in 2000)
  3. Graciliraptor (named in 2004)
  4. Tianyuraptor (named in 2010
  5. Changyuraptor (named in 2014)
  6. Zhenyuanlong (2015)

So How Does Zhenyuanlong Compare?

The fossilised remains of Zhenyuanlong are nearly complete, but the end of the tail is missing.  The skeleton measures 126.6 cm long, when compared to the large dromaeosaurid Tianyuraptor it has been estimated that with the whole of the tail, this animal would have measured more than five feet (165 cm) in length.  It was probably not quite fully grown when it died so it might have reached a length of around 1.8 metres.

When it comes to comparing the sizes of different types of dinosaur, it is the limb bones that palaeontologists turn to.  The thigh bone (femur) for example, is often used to make comparisons between dinosaurs.  To estimate how big a dinosaur was, the length and the circumference of the femur is often measured.  In simple terms, the bigger and the more robust the femur, the bigger the dinosaur.  As all the Liaoning dromaeosaurid species discovered so far have at least one thigh bone as part of their fossil material, and as the size of the thigh bone strongly correlates to body size, measuring the length and overall size of the thigh bone is a useful way of comparing the sizes of different dinosaurs.

A Table Comparing the Femur Lengths and Overall Size of Liaoning Dromaeosaurids

Size comparisons between Liaoning dromaeosaurids.

Size comparisons between Liaoning dromaeosaurids.

Table Credit: Everything Dinosaur

* Depends on the species and the specimens measured

** Depends on the species as there are three species of Microraptor currently known.

So based on the length of the thigh bone, scientists can see that Zhenyuanlong (Z. suni) is much bigger than most of the other dromaeosaurids known from Liaoning.  It seems to be about the size of Tianyuraptor.

What Does Zhenyuanlong Mean?

Time to answer one other question about this new dinosaur, this time sent in by Sophie.  Sophie asked what does Zhenyuanlong mean?

The Holotype Specimen of Zhenyuanlong suni

 Large-bodied, short-armed Liaoning dromaeosaurid

Large-bodied, short-armed Liaoning dromaeosaurid

Picture Credit: Chinese Academy of Geological Science

Zhenyuanlong suni means “Mr Zhenyuan Sun’s dragon”.  The word “long” means dragon in Chinese (hence other dinosaur names such as Guanlong and Dilong) and the rest of the name honours Mr. Zhenyuan Sun, who was able to acquire the holotype specimen for the scientists to study.

Fossilised spermatozoa preserved in Annelid Cocoon from the Eocene

Fossilised Spermatozoa from Ancient Annelid

Dinosaurs and other large vertebrates might grab all the headlines when it comes to fossil discoveries but share a thought for those parts of the Kingdom Animalia which do not readily fossilise.  Invertebrate palaeontologists working on the Annelida (segmented worms and leeches), soft bodied creatures, have very few body fossils to study.  As a result, the dedicated scientists which work on them don’t have anything like a complete fossil record of these extremely important creatures.  Trace fossils, such as preserved burrows can help, but the evolutionary history of these ancient animals remains poorly understood.

In contrast, the distinctive egg cases, often referred to as cocoons of the worms that make up the Class Clitellata, are relatively common in the fossil record.  Everything Dinosaur team members have read published papers that explore the fossilised remains of the cocoons from worms that once lived in freshwater environments back in the Triassic.  These preserved cocoons provide valuable additional information as to the diversity of micro-faunas within ancient biotas.  Unfortunately, little work has been carried out so far on the possibility of using such fossils to establish phylogenetic relationships between families and genera.

The worms that make up the Class Clitellata are distinguished from other types of segmented worm, in that they have a “collar”.  It is this “collar”, called the clitellum that gives this Class its name and it is from the Clitellum that the reproductive cocoon is formed.

A Diagram of a Common Earthworm Showing the Clitellum

The Clitellum is marked by an arrow.

The Clitellum is marked by an arrow.

Picture Credit: Everything Dinosaur

A team of scientists from the University of Milan, the Swedish Natural History Museum and the Museo de la Plata (Argentina) have published a paper in the academic journal “Biology Letters” that details the discovery of fossilised spermatozoa (sperm) preserved within the secreted wall layers of a fifty million year old clitellate cocoon found in Antarctica.  This material represents the oldest fossil animal spermatozoa yet described.

The specimen was collected during a field expedition to the remote Seymour Island, one of a group of small islands at the tip of the Antarctic Peninsula.  The Island is extremely significant to palaeontologists as the strata exposed dates from the Late Cretaceous, the Palaeogene and into the early part of the Neogene (Eocene Epoch).  Fossils found on Seymour Island include marsupials, proving that in the past terrestrial mammals lived on Antarctica, but the rocks have proved most useful in helping scientists to plot climate change, including the global cooling during the Eocene that led to the glaciation of the Poles.

Strontium isotope dating gives an age of approximately fifty million years for the fossilised spermatozoa (Ypresian faunal stage of the Eocene), the fossil find was made by chance as a single worm fragment just 0.8 mm wide was studied using a scanning electron microscope.  A three-dimensional model was then created using sections of the fragment that had been examined under X-ray microscopy.

A Fragment of the Fossilised Worm Spermatozoa

Ancient remains - scale bar = 1 micron.

Ancient remains – scale bar = 1 micron.

Picture Credit: Swedish Museum of Natural History (Department of Palaeobiology)

When closely examined, the clitellate was found to consist of a solid inner wall, just one fortieth of a millimetre thick.  In addition, there was a spongy, outer layer of loosely interwoven cables between 100th and 200th of a millimetre in thickness.  The scientists were able to observe images of the microscopic cells embedded in the cocoon wall, including rod-shaped structures with a whip-like tail.

Modestly commenting on the discovery, Benjamin Bomfleur, a palaeobotanist at the Swedish Natural History Museum remarked:

“It was an accidental find.  We were analysing the fragments to get a better idea of the structure of the cocoon.  When we zoomed into the images, we started noticing these tiny biological structures that look like sperm.”

A Worm Mystery

Working with biologists the team were able to conclude that the fossils resemble the sperm of extant freshwater crayfish worms (Branchiobdellida), although since these worms are only found in the northern hemisphere it remains a mystery as to whether or not the Antarctic fossil specimen is closely related.  How the fossils came to form in the first place is a little bit of a puzzle too.

Diagram Illustrating the Inferred Method of Fossilisation of Microorganism (Clitellate Cocoons)

Inferred fossilisation process.

Inferred fossilisation process.

Picture Credit: Biology Letters

In the diagram above, the common medicinal leech is used to illustrate a potential theory of how the fossil preservation occurred.  Two leeches mate (a), a cocoon is secreted from the clitellum (b), then eggs and sperm are released into the cocoon before the animal retracts and eventually deposits the sealed cocoon on a suitable substrate.  Spermatozoa and microbes become encased in the solidifying inner cocoon wall (d).

The scientists anticipate that this accidental discovery will permit systematic surveys of cocoon fossils coupled with advances in non-destructive analytical techniques that will open up new opportunities to explore the evolutionary relationships of minute, soft-bodied animals that are otherwise so rarely found in the fossil record.

The New Winged Dragon from Liaoning Province

Zhenyuanlong – A Big Bird, well, Almost

This week we have seen the latest feathered and fluffy dinosaur revealed from the Lower Cretaceous deposits of Liaoning Province, north-eastern China.  Scientists from the University of Edinburgh including the very talented Dr. Steve Brusatte, in collaboration with colleagues from the Institute of Geology (Chinese Academy of Geological Science, Beijing), have published a paper in the journal “Scientific Reports”, that describes Zhenyuanlong suni, the latest in an ever growing flock of feathered dinosaurs from Liaoning.

An Illustration of Zhenyuanlong suni

Very probably a ground-dwelling predator.

Very probably a ground-dwelling predator.

Picture Credit: Zhao Chuang

We do understand why many of the media reports have focused on this Early Cretaceous dinosaur’s more famous relative – Velociraptor.  Dr Steve Brusatte of Edinburgh University’s School of GeoSciences refers to Velociraptor in interviews, although, Velociraptor and Zhenyuanlong (pronounced jen-won-long), are separated by some forty-five million years.  As Zhenyuanlong suni has been classified as member of the Dromaeosauridae family, it is indeed distantly related to the more famous Late Cretaceous “raptor”.  By discussing Velociraptor, it helps members of the public to put this new dinosaur into context.  Zhenyuanlong is most certainly not Velociraptor’s direct ancestor, but if these dinosaurs were feathered, then the point that Velociraptor, shown as a scaly-skinned reptile in dinosaur movies, is in all likelihood not being accurately depicted, is well made.  Although no evidence of feathers or any other integumental covering for that matter has been found in association with Velociraptor fossil material.  This has probably got more to do with the fossilisation process and the coarse sandstone matrix than any lack of feathers on Velociraptor’s part.

Velociraptor – Most Probably Feathered

Very probably feathered (V. mongliensis and V. osmolskae)

Very probably feathered (V. mongoliensis and V. osmolskae)

Picture Credit: Everything Dinosaur

The picture above shows the new for 2015, Velociraptor dinosaur model by Safari Ltd.  The model depicts Velociraptor as a dinosaur that was covered in a coat of feathers.  To view Everything Dinosaur’s range of Safari Ltd prehistoric animal models, including feathered dinosaur models: Safari Ltd Prehistoric Animal Models

The Liaoning Dromaeosaurids – Now There are Six Genera

A total of six genera of dromaeosaurids are now known to have lived in the forests that once covered north-eastern China.  Several of these genera have more than one species associated with them and there are going to be more feathered dinosaurs described from the Yixian and Jiufotang Formations.  Everything Dinosaur team members will do their best to keep up to date with new discoveries and to write about them on this blog.

The six genera described to date:

  1. Sinornithosaurus (named in 1999)
  2. Microraptor (named in 2000)
  3. Graciliraptor (named in 2004)
  4. Tianyuraptor (named in 2010
  5. Changyuraptor (named in 2014)
  6. Zhenyuanlong (newly described)

Please don’t imagine all six of these dinosaurs roaming the forests that would have covered Liaoning Province about 125 million years ago, at the same time.  As the fossils come from different layers of strata, they are not all contemporaneous, in fact accurately dating Liaoning fossil material is known to be extremely tricky.  However, it is likely that many different types of feathered dinosaur co-existed and indeed many of them were specially adapted to a particular ecological niche.

The Holotype Fossil Material – Zhenyuanlong suni

 Large-bodied, short-armed Liaoning dromaeosaurid

Large-bodied, short-armed Liaoning dromaeosaurid

Picture Credit: Chinese Academy of Geological Science

The type specimen (pictured above), measures 126.6 cm in length, however, much of the tail is missing and this dinosaur was probably over 160 cm long.  This makes it one of the larger dromaeosaurids from Liaoning, the skull, although badly crushed reveals that this little dinosaur was carnivorous and a closer examination of the fossil revealed that it was covered in feathers, (pennaceous feathers = feathers with a central vane).  Pennaceous feathers are found in most modern birds, however, given the large body size and disproportionately small forelimbs when compared to other Liaoning domaeosaurids, it is unlikely that Zhenyuanlong was capable of powered flight.

Feathered Zhenyuanlong – Just Like a Big Bird

Our "feathered friend".

Our “feathered friend”.

Picture Credit: Chinese Academy of Geological Science

The picture above shows, the complete holotype (A) with a close up of the posterior portion of the tail showing feather impressions (B), the skull and part of the forelimb (C), the right manus (hand) with extensive feathers (D) and (E) a close up of the ulna and radius (forearm) showing evidence of pennaceous feathers on this region of the body too.  Unlike other Liaoning dromaeosaurids, Graciliraptor and Microraptor for example, there is no evidence for feathers on the hind limbs.

Zhenyuanlong and Tianyuraptor

The describing of Zhenyuanlong does not just add to the diversity of dromaeosaurids known from China, it confirms the fact that short-armed dromaeosaurids were also covered in feathers too, just like their longer-limbed cousins.  There have been two basic Dromaeosauridae body plans (bauplans) described from the Jehol Biota.  Most of the Dromaeosauridae family members known from this part of the world had small bodies, with proportionately long forelimbs and accompanying broad wings covered in pennaceous feathers.  Then there is the other body plan, a much larger dinosaur with a heavier body and short arms. Tianyuraptor (T. ostromi) was the only example known, until the discovery of Zhenyuanlong, but unlike Z. suni, the Tianyuraptor fossil specimen does not show any preserved evidence of feathers.

A Phylogenetic Analysis of Zhenyuanlong suni Amongst the Dromaeosauridae

The Liaoning dromaeosaurids nested within the Dromaeosauridae.

The Liaoning dromaeosaurids nested within the Dromaeosauridae.

Picture Credit: Chinese Academy of Geological Science with additional annotation by Everything Dinosaur

The “big bird” that is Zhenyuanlong although distantly related to Velociraptor (the Velociraptorinae sub-family), does suggest that more famous dinosaurs like Velociraptor were indeed probably feathered.

Let’s Hear It for Mammalian Evolution

The First Detailed Analysis of the Stapes In Triassic Cynodonts

The smallest bone in the human body and how it evolved has been the subject of a major research project conducted by scientists at the University of Witwatersrand (Johannesburg, South Africa).  That small bone is called the stapes and it forms part of the three bones of the middle ear, the malleus, incus and the stapes which together are known as the ossicles.  All modern mammals possess these three bones, which are also called the hammer, anvil and the stirrup, these names relate to their shapes, as the stapes for example, resembles a stirrup, the support for a rider’s foot.

A Diagram Showing the Shape of a Extant Mammal’s Stapes

The three middle ear bones of a modern mammal.

The three middle ear bones of a modern mammal.

Picture Credit: Everything Dinosaur

A team of scientists from the University of Witwatersand’s Evolutionary Studies Institute which includes Dr. Leandro Gaetano and Professor Fernando Abdala have completed the first detailed comparative analysis of ancient ear bones of Triassic Cynodonts, ancient synapsids that are ancestral to the Mammalia.  Until this study was carried out, it had long been thought that the stapes showed no differences between species.  However, in this new research, published in the academic journal PLoS One, the researchers map variations in the morphology of this bone, even amongst animals of the same species.

Commenting on their findings, Dr. Gaetano stated:

“No one has really paid attention to this small bone before.  In studying this ear bone of Triassic Cynodonts, the forerunners of mammals, including humans, over the past two years we now start to see these differences.”

Reptiles have a different hearing mechanism when compared to mammals.  As the synapsid clade evolved and modern mammals came about, they evolved more sophisticated and sensitive hearing.  Scientists believe that the three middle ear bones gave the early mammals, which were probably nocturnal, an improved ability to detect high-frequency sounds – useful if you spent your waking hours in the dark and you relied on your hearing to detect prey as well as to sense danger.  Bones in the reptilian jaw, the articular (lower jaw) and the quadrate (upper jaw) evolved into the middle ear bones, connecting to the stapes and forming the ossicles.

Mammalian Middle Ear (Evolution)

The evolution of the mammalian middle ear.

The evolution of the mammalian middle ear.

Picture Credit: Everything Dinosaur

Embryo studies and the discovery of a number of transitory fossils have provided evidence for this, however, in this study it was the stapes as found in many Triassic Cynodonts which lived between 250 and 22o million years ago, that was central to this new analysis.  The stapes is the only ear bone in mammalian ancestors, the evolution of the middle ear configuration as found in modern Mammalia had not yet occurred when the animals featured in this study were alive.

The Variation in the Shape of the Stapes of Triassic Cynodonts

Shape of the stapes bone in different Cynodonts studied.

Shape of the stapes bone in different Cynodonts studied.

Picture Credit: Witwatersrand University

The picture above shows morphological variation in the stapes of Triassic Gomphodont Cynodonts.

A, Diademodon; B, Trirachodon; C and D, Massetognathus.

Below is the ventral view of the skull of a Cynodont showing the position of the stapes.

Dr. Gaetano explained:

“Few contributions studied the stapes in Cynodonts and it has been historically regarded as a conservative element, showing no difference among species.  Surprisingly, we discovered that there are noticeable variations in the morphology of this bone, even within representatives of the same species.

This research is helping to unravel a mystery surrounding the origins of the middle ear bones and their configuration.  Professor Abdala suggests that the sound waves in Cynodonts  were transmitted to the inner ear from an eardrum at the posterior part of the lower jaw through the stapes and quadrate bones.  The research is on-going, utilising the extensive Permian and Triassic vertebrate fossil record found in South Africa (the biota of the Karoo basin).  The next stage is to try to calculate the impact on hearing ability of the differently shaped stapes bones that the team have identified.  In addition, the scientists will focus on ontogenic changes (changes in the shape of the stapes from the youngest to the oldest animal in one extinct species).

Wendiceratops pinhornensis from southern Alberta

North America’s Newest Centrosaurine is Also One of its Oldest

The Royal Ontario Museum (Canada) put on exhibit this week the horned dinosaur Wendiceratops (W. pinhornensis) and what a splendid new addition this exhibit is.  There has been lots of media coverage regarding this dinosaur, but we at Everything Dinosaur wanted to clarify three points that had been made in a number of publications, this is not a newly discovered Ceratopsian, the bone bed containing the fossils of these one tonne dinosaurs was found way back in 2010.  It has taken over five years to prepare the bones, study them and then to publish a scientific paper on this new dinosaur.

An Illustration of Wendiceratops pinhornensis

An early, very ornate Centrosaurine.

An early, very ornate Centrosaurine.

Picture Credit: Danielle Dufault

Not Closely Related to Triceratops

Secondly, this horned dinosaur that roamed southern Alberta approximately 79 million years ago (78.7 to 79.0 million, according to radiometric dating from nearby Kennedy Coulee Ecological Reserve which is believed to be of the same geological age), was not that closely related to Triceratops.  Mention a new type of horned dinosaur and Triceratops comes trotting out as a comparison.  We think this is because, since Triceratops is one of the best known of all the dinosaurs, journalists use “Trike” as a sort of “dinosaur clothes horse” upon which the story can be hung.  True, the horn configuration between Wendiceratops and Triceratops is very similar, both have large brow horns and a smaller nose horn, but in reality Wendiceratops and Triceratops are separated by at least ten million years and they are members of two different sub-families of the Ceratopsidae.

  • Wendiceratops is a member of the Centrosaurines
  • Triceratops belongs to the Chasmosaurine group

 On Display at the Royal Ontario Museum (Toronto, Canada) a Cast of Wendiceratops

A reconstruction of the dinosaur's skeleton.

A reconstruction of the dinosaur’s skeleton.

Picture Credit: Royal Ontario Museum

A reconstructed skeleton of the dinosaur called Wendiceratops pinhornensis is pictured above, the fossils in the type locality represent at least four individuals, three adults and a juvenile.  This dinosaur has been described from approximately 220 bones that were found in a single bone bed.  The scientific paper that has been published reaffirms the very high diversity of North American Ceratopsians and this supports the theory that around 80 million years ago there was a rapid evolutionary radiation of the Ceratopsidae.  Although a large and prominent, (although somewhat flattened) nose horn has been inferred, the nasal bone is only represented by fragmentary specimens and the actual shape of the nose horn is not known.  Wendiceratops can claim to provide the earliest evidence of a tall nose horn being found in the Ceratopsians.  Not only does this Centrosaurine tell scientists that by 79 million years ago, horned dinosaurs existed with large, nose horns, the research reveals that a large, cone-shaped nose horn evolved in this group at least twice in the evolutionary history of the Ceratopsidae.

Those Necks and Horns

It used to be thought that horn and neck frill configuration was a good methodology when it came to tell Centrosaurine and Chasmosaurine dinosaurs apart.  Back in the old days (pre-2000), when a lot fewer species of North American horned dinosaur had been described, a number of writers classified these types of dinosaurs based on the size, orientation and morphology of those nose horns and their accompanying neck frill.  For example, in general it was thought that Centrosaurine dinosaurs such as (Brachyceratops, Einiosaurus, Xenoceratops and Centrosaurus) had short frills (relatively), combined with a large nose horn and much smaller horns over the eyes.  In contrast, the Chasmosaurine dinosaurs such as Pentaceratops, Triceratops and Torosaurus had much more elongated neck frills, a small nose horn and much larger brow horns.  With the spate of recent discoveries these ideas have proved to be too simplified, Ceratopsidae classification has got a lot more complicated as new genera have been described.

A case in point is the recently described (June 2015) Regaliceratops, a member of the Chasmosaurine group but with characteristics of a Centrosaurine.

To read more about the research into Regaliceratops: A Right Royal Rumble

A Skeletal Drawing of Wendiceratops (W. pinhornensis)

The bones marked in blue have been found to date.

The bones marked in blue have been found to date.

Picture Credit: Danielle Dufault

Last but not Least that Trivial Name

The third point we wanted to clear up was the specific or trivial name “pinhornensis”.   The species name has nothing to do with the shape, size or orientation of any horn, it refers to the Pinhorn Provincial Grazing Reserve in southern Alberta, where the bone bed is located.

The genus name honours the remarkable Wendy Sloboda, who discovered the type locality back in 2010.

Wendy has a Dinosaur Named After Her

Naming a new dinosaur after Wendy.

Naming a new dinosaur after Wendy.

Picture Credit: Michael J. Ryan (one of the authors of the scientific paper published in the journal PLOS One)

Today we pay tribute to all those field workers, scientists and technicians that have helped prepare the Royal Ontario Museum exhibit, special mention to all those that helped remove the enormous rock overburden that permitted the bone bed to be fully explored.  Along with the fossilised remains of a Ceratopsian, the scientists found two tyrannosaurid teeth (genera not known), along with other reptilian remains, notably turtles and crocodilian.

Nosing Around a Coloborhynchus Rostrum

Pterosaur Rostrum Discovered on the Isle of Wight

Thanks to sharp-eyed, local fossil collector Will Thurbin, a fragment of bone from an Early Cretaceous Pterosaur has established that a another member of the Ornithocheiridae flew over the skies of what was to become the Isle of Wight.  Whilst searching for fossils along Chilton Chine beach on the south-west coast of the Isle of Wight, Mr Thurbin spotted a strange looking, well worn pebble that when examined more closely showed traces of eroded teeth.  Unsure of what the object was, he brought the specimen to the Dinosaur Isle museum on the island so that the experts there could examine it.  After consulting Dr. Dave Martill (School of Earth and Environmental Sciences at the University of Portsmouth), an expert in vertebrate fossils from the Isle of Wight, the find was identified as the tip of the rostrum the upper jaw of a Pterosaur genus known as Coloborhynchus.

To give readers an idea of which part of the animal the fossil belongs, we have taken the excellent model of Guidraco made by CollectA, another ornithocheirid, but this time from China and used this replica to show you where the rostrum is located.

The tip of the upper jaw.

The tip of the upper jaw.

Picture Credit: Everything Dinosaur

Although very worn, the fossil still retained enough detail to provide the scientists with the opportunity to identify the family (Ornithocheiridae) and the Pterosaur genus.  The specimen, which is just a few centimetres long has gone on display at the Dinosaur Isle Museum.

The Isle of Wight Coloborhynchus Pterosaur Fossil

posterior view for Isle of Wight fossil.

posterior view for Isle of Wight fossil.

Picture Credit: Isle of Wight Council

The fossil may not look much, but this fossil fragment, the tip from the upper jaw (rostrum), represents the world’s oldest example of the Coloborhynchus genus.  It pre-dates earlier Coloborhynchus fossils by around ten million years.  In all likelihood it is a new species, but that’s the trouble with the Pterosauria, lots of species have been named from just fragments of fossil material.  This tends to “muddy the waters somewhat” when it comes to Pterosauria taxonomy, let’s look into this in a bit more detail.

The Problem with those “English Pterosaurs”

Coloborhynchus belongs to a very enigmatic family of Pterosaurs, the Ornithocheiridae.  The fossil record for the ornithocheirids is a bit of a “curates egg”, that is to say, that the fossil record is good in parts.  Thanks to beautifully preserved specimens from China and South America, this family is amongst the best known of all the flying reptiles, but it has only been in the last twenty-five years or so that these specimens have come to light.  Before that much of what we knew (or thought we knew) about these widespread Cretaceous Pterosaurs came from the study of extremely fragmentary specimens found in southern England.  These very poorly preserved fossils probably would not get a lot of attention these days, but back in the latter part of the 19th Century these remains were studied by some of the most eminent scientists around at the time.  The likes of Sir Richard Owen and Harry Govier Seeley examined and described these specimens, as a result, a range of different genera were erected, most of them now regarded as nomen dubium.  Much of these fossil were excavated from the Cambridge Greensand of southern England, marine deposits laid down in the Cretaceous, with most of the material dating from around 105 to 115 million years ago.

The fossils are preserved in three-dimensions, just like the Isle of Wight Coloborhynchus specimen but they are the remains of Pterosaurs that died far out to sea.  The corpses were scavenged, the bones once they had sunk to the bottom of the sea became encrusted with shelled animals such as barnacles and they were drilled into by marine worms.  These bones were eventually buried only to be exposed again by violent storms and finally buried as part of the fossil record several million years after the flying reptile had actually died.  As a result, these fossils are extremely difficult to interpret, let alone assign to a new species.

Coloborhynchus clavirostris Holotype Fossil Material (Hastings Group)

Rostrum from the Hastings Group (West Sussex)

Rostrum from the Hastings Group (West Sussex)

Picture Credit: Natural History Museum

The picture above shows one of the Pterosaur fossils from the 19th Century.  This is the holotype for C. clavirostris, (A) = anterior view (view from the front), with (B) a line drawing of the same view.  The fossil is viewed from the side, a left lateral view (C) with a corresponding line drawing (D).  Numbers and arrows indicated teeth sockets (alveoli) and individual teeth.

Scale bar = 1cm.

When the Isle of Wight fossil is compared to the holotype fossil material (both seen in anterior view), these two specimens look very similar, but it was the position, orientation of the alveoli (teeth sockets) that aided identification.

The Isle of Wight Fossil Material with Teeth Sockets Labelled (anterior view)

Teeth sockets can clearly be seen, it was the orientation, shape and position of the teeth sockets that led to the Coloborhynchus identification.

Teeth sockets can clearly be seen, it was the orientation, shape and position of the teeth sockets that led to the Coloborhynchus identification.

Picture Credit: Isle of Wight Council with additional annotation by Everything Dinosaur

It is very likely that these toothy Pterosaurs were mainly fish-eaters and they lived on the coast, or at least in estuarine environments.  The paper detailing this 2014 discovery has just been published in the Proceedings of the Geologists Association.

Intriguingly, in 2014, two fragmentary pieces of Pterosaur rostrum were found on the Isle of Wight.  They were found at different locations and they are shaped differently.  The second fossil, donated by Mr Glyn Watson (Nottinghamshire), is currently being researched in order to identify the Pterosaur family.  This too, is likely to be a new species, although whether a species can be assigned from the rostrum alone has yet to be determined.

An Illustration of Coloborhynchus

An illustration of the Pterosaur called Colobrhynchus (C. clavirostris)

An illustration of the Pterosaur called Colobohynchus (C. clavirostris)

Picture Credit: Mark Witton

 Coloborhynchus was certainly a sizeable Pterosaur, although not the biggest member of the Ornithocheiridae.  Size estimates are difficult to calculate based on fragmentary material, but a maximum wingspan between four and six metres has been cited by a number of authors.

Karoo Rocks Provides Fresh Insight into Extinction Event

Shedding Light on an Extinction Event from 260 Million Years Ago

One global extinction event may have affected both terrestrial and marine biotas at the same time, some 260 million years ago.  With all the news recently of our planet entering a sixth mass extinction, studies into previous extinction events can help scientists to model and predict the impact of future events on environments and the species that live within them.

An international team led by researchers from the Evolutionary Studies Institute (ESI) at the University of the Witwatersrand, (Johannesburg), has obtained an age from rocks of the Great Karoo that shed light on the timing of a mass extinction event that occurred around 260 million years ago.  The Great Karoo refers to a enormous sequence of rocks often cited as the “Karoo Supergroup”, which consists of mostly non marine sandstones and shales that represent a vast tract of geological time, from the Carboniferous through to the Jurassic.  This research focused on exploring fossils from the Beaufort unit, a sequence of rocks that were laid down in South Africa from the Mid Permian through to the Early Triassic.  These rocks provide a record of the plants, invertebrates and vertebrates that thrived in the semi-arid conditions found in southern Africa during the Permian and Triassic.  In particular, they provide evidence of the wide variety of terrestrial vertebrates that lived at this time, the forerunners of today’s reptiles and mammals.

The mass extinction event of 260 million years ago led to the disappearance of a diverse group of early mammal-like reptiles called dinocephalians, which were the largest land-living animals of the time.  Dinocephalians, were large bodied and evolved into a variety of forms including carnivores and herbivores.  They were synapsids and as such, ancestral to modern mammals.

The research project was led by Dr. Michael Day, (postdoctoral fellow at Wits University), the findings have been published today in the Royal Society’s biological journal, “Proceedings of the Royal Society B.”  The paper is entitled:  “When and how did the terrestrial Mid-Permian mass extinction occur?  Evidence from the tetrapod record of the Karoo Basin, South Africa.”

The Karoo is very rich in fossils of terrestrial animals from the Permian and Triassic geological periods, which makes it one of the few places to study extinction events on land during this time.  As a result, South Africa’s Karoo region provides not only a historical record of biological change over a period of Earth’s history but also a means to test theories of evolutionary processes over long stretches of time.  By collecting fossils in the Eastern, Western and Northern Cape Provinces the team was able to show that around 74–80% of species became extinct along with the dinocephalians in a geologically short period of time.

Dr Michael Day with Some of the Fossils Used in the Study (Cranial Material)

Dr. Michael Day and some of the fossils used in the study.

Dr. Michael Day and some of the fossils used in the study.

Picture Credit: Wits University

The new date was obtained by high precision analysis of the relative abundance of uranium and lead in small zircon crystals from a volcanic ash layer close to this extinction horizon in the Karoo.  This provides a means of linking the South African fossil record with the fossil record in the rest of the world.  In particular, it helps correlate the Karoo with the global marine record, which also records an extinction event around 260 million years ago.

Dr. Day explained:

“A Mid-Permian extinction event on land has been known for some time but was suspected to have occurred earlier than those in the marine realm.  The new date suggests that one event may have affected marine and terrestrial environments at the same time, which could mean its impact was greater than we thought.”

The Mid-Permian extinction occurred near the end of what geologists call the Guadalupian epoch that extended from 272.3 to around 259.1 million years ago.  It pre-dated the massive and much more famous end-Permian mass extinction event by 8 million years.

Mid Permian Terrestrial Extinction Plotted Against Proposed Marine Extinction Dates

Table examining the impact of the Mid Permian extinction event on terrestrial fauna.

Table examining the impact of the Mid Permian extinction event on terrestrial fauna.

Table Credit: Proceedings of the Royal Society B.

The table shows that in this new study of Karoo fauna, the demise of the Dinocephalia can be clearly mapped to a marine extinction event (marked by the yellow star).  The marine extinction event has been identified through a study in the change of marine fossils deposited in strata from China (Wuchiapingian age, which has been dated to around 260 million years ago).  The scientists have therefore concluded that one global event may have affected both marine and terrestrial environments simultaneously.  The impact of this event was greater than previously thought.

Dr. Day added:

“The South African Karoo rocks host the richest record of Middle Permian land-living vertebrate animals.  This dataset, the culmination of 30 years of fossil collecting and diligent stratigraphic recording of the information, for the first time provides robust fossil and radioisotopic data to support the occurrence of this extinction event on land.”

Jahandar Ramezani (Massachusetts Institute of Technology), was responsible for dating the stratigraphic sequences using the zircon uranium to lead degradation study (CA-TIMS method).  Dr. Ramezani, of the Department of Earth and Planetary Sciences at the Massachusetts Institute of Technology commented:

“The exact age of the marine extinctions remains uncertain, but this new date from terrestrial deposits of the Karoo, supported by palaeontological evidence, represents an important step towards a better understanding of the Mid-Permian extinction and its effect on terrestrial faunas.”

Super-duper Dinosaur Cooper

“Cooper” Australia’s Biggest Dinosaur Awaits Scientific Description

The largest dinosaur discovered to date in Australia is set to go on public display for the first time with the opening of the Eromanga Natural History Museum (Eromanga, south-western Queensland).  The fossilised bones, part of a treasure trove of Cretaceous dinosaur fossils, were found back in 2007, but it has taken years of careful, painstaking research to reveal details of this enormous plant-eating dinosaur, a creature that exceeded thirty metres in length.  The huge dinosaur, a Titanosaur which has been nicknamed “Cooper” will go on display when the museum opens in a few months time.

An Illustration of the Giant Titanosaur

Australia's giants.

Australia’s giants.

Picture Credit: ABC News/David McSween

This part of Queensland has been suffering from severe drought, it is hoped that the dinosaur themed museum will bring in much needed tourist revenue to the town.  At the moment a number of dig sites in Queensland are being excavated, this is the “digging season” Down Under, the slightly cooler weather permits such excavations to take place as scientists and local volunteers strive to uncover Australia’s rich dinosaur fossil heritage.

To read more about current excavations in the Queensland area: Annual Queensland Dig Yields Dinosaur Fossils

Everything Dinosaur team members did predict that 2015 was going to be an important year for dinosaur discoveries in this part of the world, in fact, we made it one of our New Year predictions, to read more about our predictions for breaking news stories in 2015:

Everything Dinosaur’s 2015 predictions: Our 2015 Palaeontology Predictions

Commenting on the importance of regional museums, Dr. Scott Hocknull (Queensland Museum) stated:

“The opportunity for this small town to actually become a point of real national pride, there’s a great opportunity that we can’t miss.”

Titanosaurs are Sauropods.  The Titanosauria consists of about four dozen genera and they seem to have replaced the diplodocids and the brachiosaurids that thrived during the Late Jurassic.  Titanosaur fossils have been found on all the continents, including Antarctica, but they seem to have been most successful and diverse in the southern hemisphere.  Some Titanosaurs are amongst the largest terrestrial vertebrates known.  Dr. Hocknull and his colleagues are currently working on the scientific paper which will describe and formally name “Cooper”.  This Australian dinosaur, whose fossils were found on a remote sheep station, will be amongst the largest Titanosaurs so far described.  Bodyweight estimates suggest that “Cooper” weighed about as much as ninety Merino rams, that’s around 40,000 kilogrammes (a lot of sheep)!

A Scale Drawing Illustration of Australia’ Biggest Dinosaur Known to Date (2015)

Scale drawing of "Cooper".

Scale drawing of “Cooper”.

Picture Credit: Dr. Scott Hocknull

Several other dinosaur specimens have been found in and around the Eromanga basin area since this location was first identified as a “hot spot” for southern hemisphere Cretaceous dinosaurs back in 2004.    Soon after the first large dinosaur fossils were found, plans were put forward to build a local dinosaur museum (Eromanga Natural History Museum), after ten years and a great deal of fund raising from the locals, the museum is nearly ready to open its doors.

The Enormous Pelvis of “Cooper” will be on Display

Giant Aussie dinosaur bones.

Giant Aussie dinosaur bones.

Picture Credit: ABC News/Josh Bavas

“Cooper” may not hold the title of “Australia’s biggest dinosaur” for long.  Over the last few years a number of titanosaurid specimens have been discovered, the majority have been given nicknames such as “Zac”, “Tom”, “George” and “Sid”.   “George,” may be bigger still, but it too has yet to be formally described.

The Giant Femur (Thigh Bone) of “Cooper”

Giant limb bone of Australian Titanosaur.

Giant limb bone of Australian Titanosaur.

Picture Credit: ABC News/Josh Bavas

The 1.9 metre long femur (thigh bone) can be seen in the foreground.  Like the pelvis pictured earlier, it is still partially in its protective plaster jacket.  The distal end (articulating with the lower leg bones, is towards the left of the photograph).  The picture is not too clear but the second femur might be just behind.

Palaeontologists think that both Cooper and Sid (Titanosaurs) became trapped in mud and subsequently died.  The fossils also show evidence of trampling from other Titanosaurs.  As the bones lay on the ground, other Titanosaurs walked over them.  This is not the first time that such incidents have been preserved in the fossil record.  In addition, field workers found a preserved tree branch stuck in the femur, the bones of these dinosaurs were so massive that they formed “log jams” in rivers trapping other material and debris.

Dr. Hocknull explained that cutting edge technology such as photogrammetry to make three-dimensional models coupled with CT scans are changing the way palaeontologists work.

He stated:

“All this is completely revolutionising the way we even do our science.  Instead of just taking a happy snap of the actual bone we can recreate the bone in three-dimensions and that gives us more data than we can ever poke a stick at.”

Everything Dinosaur team members would not advise poking sticks at dinosaur bones, no matter how big the fossils might be.  However, we look forward to the grand opening of the Eromanga Natural History Museum as well as learning more about Australia’s ancient and most impressive mega-fauna.

New Oviraptorid from the Late Cretaceous of Southern China

Huanansaurus ganzhouensis – Demonstrating the Diversity of the Oviraptorids

Some very peculiar things can turn up at railway stations, just ask anyone who works in a lost property office.  However, for one group of construction workers helping to build the new Ganzhou Railway Station in Jiangxi Province (southern China), they got rather a big surprise when they unearthed the partial remains of a new type of Theropod dinosaur.  The new dinosaur has been identified as a member of the Oviraptoridae family, an extremely bird-like group of dinosaurs, it has been named Huanansaurus ganzhouensis and it suggests that there were many different types of Oviraptorids living in the same environment but each type may have evolved a different feeding and foraging habit.

An Illustration of H. ganzhouensis (Male and Female)

A new feathered dinosaur from China.

A new feathered dinosaur from China.

Picture Credit: Chuang Zhao

Although no feather impressions have been found with the fossils, it is assumed that this lithe dinosaur was indeed feathered.  The illustrator has also assumed that the males had different colouration when compared to the females.  In this imagined scene, one of a breeding pair approaches the other which is sitting on a nest of eggs.  More than two hundred Oviraptorosaurian nests have been found in the Ganzhou area and this part of the world seems to have been a hot bed of Oviraptorid evolution with a total of five genera now known from the strata around the city of Ganzhou.

Size estimates vary, but based on skull measurements and comparisons with other Asian Oviraptors, Everything Dinosaur’s team members estimate that Huanansaurus would have measured around 1.5 metres long and stood over a metre tall, making this dinosaur about half the size of its closest relative Citipati (C. osmolskae), fossils of which come from the Gobi Desert (Djadokhta Formation), that lies some 1,800  miles to the north-east of Jiangxi Province.  It is analysis of the beautifully preserved skull material that has permitted the research team to conduct a phylogenetic analysis placing Huanansaurus close to the Citipati genus in the Oviraptoridae family.  Huanansaurus is distinct from the other four other types of Oviraptorid discovered to date from the Upper Cretaceous rocks (Nanxiong Formation),  located around Ganzhou city.

The four other types of Oviraptorosaurs found in this area are:

  • Banji long (named and described in 2010)
  • Ganzhousaurus nankangensis (named and described in 2013)
  • Jiangxisaurus ganzhouensis (also named and described in 2013)
  • Nankangia jiangxiensis (named and described in that bumper year for southern Chinese Oviraptorosaurs, 2013)

 

A Line Drawing of the Skull and Cranial Material (HGM41HIII-0443)

Left side (lateral view) of the skull and jaws.

Left side (lateral view) of the skull and jaws.

Picture Credit: Journal Science with additional annotation by Everything Dinosaur

Like most of the later Oviraptorosaurs, Huanansaurus lacked teeth, the shape and size of the skull along with the morphology of the jaws suggests that lots of different types of feathered Oviraptorid dinosaur were able to live in the same environment.  These little dinosaurs co-existed as they probably had different foraging and feeding strategies.  The prevalence of Oviraptorosaurs in southern China indicates that other parts of Asia may have had different types of Oviraptorid present within their biota, but these fossils may not have been found as yet.

The researchers involved in this study include scientists from Japan, South Korea, Uppsala University (Sweden), Henan Geological Museum and the Chinese Academy of Scientists.  The fossils are currently stored in the vertebrate fossil collection of the Henan Geological Museum.

A spokesperson from Everything Dinosaur explained:

“In simple terms, the jaw shapes and sizes are different in the Jiangxi Province Oviraptors.  Although these feathered dinosaurs all lived at the same time, the very late Late Cretaceous and they shared the same environment, they probably specialised in eating different types of food.  For example, the lower jaw tip of Banji long is very strongly curved downwards, whilst the same part of the jaw found in Nankangia jiangxiensis is not.  Both Jiangxisaurus and the newly described Huanansaurus come somewhere in between these two extremes.  It is likely that each type of dinosaur occupied a different ecological niche in the Late Cretaceous palaeoenvironment.”

What did Oviraptor-like dinosaurs eat?  That remains a bit of a mystery, we suspect that they were omnivorous with perhaps each animal adapted to eating different types of seed, fruit and nuts as well as catching and eating amphibian, small mammals and insects.

Staypressed theme by Themocracy