Category: Dinosaur and Prehistoric Animal News Stories

A Tale of Ancient Tails in the Ankylosauridae

How Did the Ankylosaur Get Its Club Tail?

Ankylosaurs are often described as “living tanks” these quadrupeds seemed to have taken body armour to the extremes with some specimens such as Saichania from Asia and the Late Cretaceous North American ankylosaurids Euoplocephalus and Ankylosaurus even having armoured eyelids.  They were a very diverse and widespread group of Ornithischian dinosaurs, in every sense of the world.  True, Ankylosaur fossils have been recorded from China, Mongolia, Canada, the United States, Australia and there have even been fragmentary bones attributed to an Ankylosaur found near Folkestone (Kent, England).  In addition, these animals have very wide pelvic regions in proportion to the rest of their robust bodies.  The wide pelvis is an adaptation to accommodate a large gut.

Heavily Armoured Dinosaurs with a Long Evolutionary History

Armoured dinosaur models.

Armoured dinosaur models.

Picture Credit: Everything Dinosaur

Most children can describe these herbivores, they may be very well known members of the Dinosauria, with an albeit brief appearance in the film “Jurassic World” adding to their popularity, however, a mystery surrounding the Ankylosauridae may finally have been solved.

How did the Ankylosaur Get Its Tail Club?

By mapping the evolutionary history of these armoured dinosaurs from their Jurassic origins through to the very end of the Cretaceous the answer as to how some members of the Ankylosauridae developed that distinctive tail club may have finally been resolved.  According to research published in the academic publication “The Journal of Anatomy”, the fused tail came first and the bony club evolved later. Postdoctoral researcher Victoria Arbour (North Carolina State University and the North Carolina Museum of Natural Sciences), authored the report, a study she started when at the University of Alberta under the tutelage and guidance of renowned palaeontologist Professor Phil Currie. Victoria has spent a large part of her career studying the Ankylosauridae and she is viewed by Everything Dinosaur team members as the “go to” person when it comes to the ankylosaurids.  For example, back in October 2014, Everything Dinosaur reported on a new species assigned to the Ankylosauridae named by Victoria – Zaraapelta (Z. nomadis), fossils of which were found during an expedition to Mongolia led by Professor Currie.

To read more about Zaraapelta: Zaraapelta – In Praise of Victoria Arbour

This new study involved examining the fossilised remains of some of the earliest known ankylosaurids, dinosaurs like the Chinese Liaoningosaurus from Yixian County, Liaoning Province (north-eastern China), as well as many Late Cretaceous forms.  An Ankylosaur’s tail is composed of a handle and a bony knob.  The knob is comprised of fused osteoderms, a special kind of bone formed in the skin.  The handle is represented by the distal end of the tail (caudal vertebrae) that support the weight of the knob.

Victoria explained:

“In order for an Ankylosaur to be able to support the weight of a knob and swing it effectively, the tail needs to be stiff, like an axe handle.  For that to occur, the vertebrae along the tail had to become less flexible, otherwise the momentum generated by the knob’s weight could tear muscle or dislocate vertebrae.”

Gobisaurus – A 90 Million Year Old Ankylosaur

Tracing the tale of the Ankylosaurus tail.

Tracing the tale of the Ankylosaurus tail.

Picture Credit: Sydney Mohr

Other ankylosaurids included in the analysis were Gobisaurus (Turonian faunal stage of the Cretaceous) and Pinacosaurus from the younger Campanian faunal stage of the Cretaceous.

Three Ways in Which the Ankylosaurid Tail Could Have Evolved

There are three ways in which the bony club and the fused, stiffened tail could have evolved:

  1. Bony club first – early ankylosaurids would show evidence of osteoderms forming and enveloping the end of the tail
  2. Handle first – primitive members of this family would have overlapping or fused tail bones
  3. The club and handle could have evolved simultaneously, if this was the case, then Early Cretaceous ankylosaurids would show both anatomical features, perhaps with tails getting stronger and tail clubs getting heavier over time

How Did the Ankylosaurs Get their Unusual Tails?

Three different theories of ankylosaurid tail evolution.

Three different theories of ankylosaurid tail evolution.

Picture Credit: Journal of Anatomy

The comparative analysis revealed that by the Early Cretaceous, ankylosaurids had begun to develop stiff tails with fused caudal vertebrae.  The bony knob feature did not appear in the fossil record until the Late Cretaceous.

Dr. Arbour concluded:

“While it’s possible that some of the species could still have developed the handle and knob in tandem,” it seems most likely that the tail stiffened prior to the growth of the osteoderm knob, in order to maximise the tail’s effectiveness as a weapon.”

The upshot of this conclusion is that Ankylosaurs used their tails as defensive weapons first and then only later did the heavy club on the tail evolve.   Commenting on this work a spokesperson from Everything Dinosaur stated:

“This is a fascinating study, one can speculate that the bony club tail evolved in response to the emergence of bigger and more dangerous Theropod predators such as the tyrannosaurids that could be regarded as the apex terrestrial predators in the northern hemisphere towards the end of the Mesozoic.”

The Tail Bones of Ankylosaurs

Caudal anatomy of Ankylosaurs.

Caudal anatomy of Ankylosaurs.

Picture Credit: Journal of Anatomy

The picture above shows (A) an oblique dorsal view of the tail club of Dyoplosaurus acutosquameus from Canada, the fossils of which are around 76 million years old (Campanian).  This is typical of the derived Ankylosaurine tail  with a fused tail and a bony club.  Gobisaurus (G. domoculus) line drawing is (B) a left lateral view of this earlier ankylosaurid’s tail showing fusing of the bones.  Picture (C) shows the same fossil specimen as (B), but this time viewed from the other side, the deep groove running along the bottom is the haemal canal.  X-ray (D) and the interpretive drawing (E) are from an ankylosaur tail from Alberta, the last tail bone is small and rounded when compared to the long distal caudal bones.  Picture (F) shows two tail bones from Mymoorapelta maysi, a basal member of the Ankylosauria known from the Late Jurassic of the United States.  This anatomy is typical of nodosaurids and other basal Ankylosaurs, the prezygapophyses (forward projecting points of bone located on the neural arch of the vertebrae), overlap the adjacent vertebrae by about 25% of the centrum (the main part of the vertebra situated below the neural arch).  In contrast, picture (G) shows the fossilised remains of Liaoningosaurus (L. paradoxus) which dates from the Aptian faunal stage making the fossil some 120 million years old.  The boxed area in (G) is highlighted and magnified (H).  In Liaoningosaurus the prezygopophyses overlap the preceding vertebra by at least 50% including a much more fused and stiffened tail, more typical of later ankylosaurids.

 This research has provided new evidence to help scientists understand the evolution of ankylosaurid tails.  Fossils from China such as those of Liaoningosaurus suggest that the mechanism to support a tail club may have evolved at least forty million years before it was taken to extremes by the Late Cretaceous Ankylosaurs such as Euoplocephalus and Pinacosaurus.  Early ankylosaurids evolved the handle first, those distal ossified osteoderms came later.

The Oldest Known Eurypterid

Not Jaws but Claws Pentecopterus decorahensis

Named after an ancient Greek ship (penteconter) which was renowned for its speed and agility, a new and somewhat surprising addition to the mega-fauna of the Middle Ordovician has been described in a paper published in the academic journal “BMC Evolutionary Biology – Bio Med Centre”.  Enter Pentecopterus decorahensis (pent-tee-kop-ter-rus dek-kor-rah-en-sis), which at around 1.7 metres in length suggests that this was an apex predator of the brackish, shallow marine environment represented by shale deposits located in north-east Iowa (United States).

A Very Fearsome Arthropod – P. decorahensis

Ancient predator of the Middle Ordovician.

Ancient predator of the Middle Ordovician.

Picture Credit: Patrick Lynch/Yale University

This armour-plated, marine predator is a member of the Order Eurypterida, an extinct group of Arthropods distantly related to spiders and lobsters.  These creatures are often referred to as sea scorpions as they are distantly related to modern-day scorpions too.  With its streamlined body, grasping limbs for trapping prey and large, well-protected head this formidable carnivore would have dined on a variety of invertebrates as well as jawless fishes.  The fossils are part of the extraordinary Winneshiek Lagerstätte fauna (Iowa) and have been dated to around 467 million years ago (Darriwilian faunal stage of the Middle Ordovician).  Something in excess of 250 different eurypterid species have been described, but only eleven species have been documented from the Ordovician (488-443 million years ago) to date.  P. decorahensis is the oldest known, extending the documented range of the eurypterids by more than nine million years.

Commenting on the fossils, James Lamsdell of Yale University and the lead author of the study stated:

“This shows that eurypterids evolved some ten million years earlier than we thought and the relationship of the new animal to other eurypterids shows that they must have been very diverse during this early time of their evolution, even though they are very rare in the fossil record.”

Some of the Fossil Specimens that have been Found

Examples of fossil specimens.

Examples of fossil specimens, scale bars = 1o mm

Picture Credit: Lamsdell et al

The highly fossiliferous strata was discovered by an Iowa Geological Survey team (University of Iowa), close to the Upper Iowa River.  A temporary dam had to be constructed to allow the fossil site to be excavated. More than 150 fossils of Pentecopterus have been found, many of them representing juveniles.

University of Yale palaeontologist Derek Briggs, a co-author of the study explained that the shale deposits represent an ecosystem that became established when the sea flooded a meteorite impact crater some three miles across.  The weak currents coupled with the oxygen depleted bottom contributed to the remarkable state of preservation of the fossil material.  Even tiny hairs on the limbs can still be seen.

Although, enormous for an Arthropod, it is not the biggest eurypterid known, Everything Dinosaur has reported on a number of very large fossil sea scorpions

To read more about giant eurypterids: Giant Eurypterid Tracks Discovered in Scotland

Giant Devonian Sea Scorpion: Claws! of the Devonian

The largest living member of this Phylum today is the Japanese spider crab (Macrocheira kaempferi), the diameter of the legs of the largest males can be in excess of 3.5 metres and some specimens have weighed more than fifteen kilogrammes.

A spokesperson from Everything Dinosaur stated:

“Thanks to the remarkable Winneshiek Lagerstätte scientists have been able to look into a window of marine life from some 467 million years ago.  Anyone taking a dip in the brackish waters that linked this part of Iowa to the seas surrounding the ancient land mass of Laurentia had better watch out.  This was one Arthropod capable of giving you more than just a “nip” with its claws.”

Will We Ever Know All the Dinosaurs?

How Good is the Fossil Record of the Dinosaurs

With something like 1,200 different genera of dinosaur now described, our knowledge of the Dinosauria has increased a great deal, especially over the last twenty years or so.  Many different types of dinosaur have been discovered and we at Everything Dinosaur try to keep a database using this blog.  For example, since the beginning of July, we have written articles about a newly discovered, very bird-like oviraptorid from southern China (Huanansaurus ganzhouensis), North America’s latest Ceratopsian discovery (Wendiceratops), the new dromaeosaurid from Liaoning Province (Zhenyuanlong suni) and most recently, the basal Sauropod Pulanesaura from South Africa.  Just over the weekend, we reported on a giant horned dinosaur skull from South Dakota that might well turn out to be a new species of Centrosaurine, albeit, one that would be very closely related to Triceratops.

However, will palaeontologists ever be able to create a definitive list of all the dinosaurs?  What percentage of the Dinosauria will ever be known?  Scientists at Bristol University have set about trying to find out by assessing just how good the fossil record for the dinosaurs actually is.

So Many Different Types of Dinosaurs Described

So many different types of dinosaur.

So many different types of dinosaur.

Picture Credit: Everything Dinosaur

Trying to Calculate How Good the Dinosaur Fossil Record Is

Professor Mike Benton of the University of Bristol, set out to assess how good the fossil record is for the Dinosauria and for early Tetrapods in a bid to answer the question as to whether the fossil record adequately represents the patterns of diversity of animals through time.  A number of other authors have attempted to assess the quality of the fossil record and in this new study, published in the journal “Palaeontology”, the journal of the Palaeontological Association, Professor Benton set out to plot how the knowledge of dinosaurs has been accumulated since the first scientific description (Megalosaurus) back in 1824.  The research does not provide a definitive answer with regards to how representative the vertebrate fossil record actually is, but this study does suggest caution needs to be taken when using some popular methods to try and remove bias from the known fossil record of the Dinosauria as well as the other Tetrapods included in the analysis.

Plotting the Number of New Species Named Against the Number of Newly Discovered Fossil Bearing Formations

Number of species against number of new fossil bearing formations.

Number of species against number of new fossil bearing formations.

Graph Credit: Bristol University

Professor Benton explained:

“In the past ten years, many palaeontologists have tried to find the true pattern of evolution by using measures of sampling to estimate where the fossil record is well known or poorly known.  But it turns out that many of the popular methods are not doing what they are supposed to.”

The Bristol-based palaeontologist plotted the history of research into the Dinosauria from 1820 to the present day.  He logged the number of new species described and how the patterns of discovery match the patterns of discovery of new geological formations.  He noted that the patterns of discovery are closely linked, one or two new dinosaurs for each fossil-bearing geological formation that is newly explored.

More Fossil Bearing Geological Formations Discovered = More Dinosaurs Described

If there is a significant link between the number of dinosaurs described and the number of new geological formations discovered then how does this connection work?  This link can be explained in two ways:

  1. Rock formation discoveries drives dinosaur fossil finds
  2. Dinosaur fossil finds drives the discovery of new fossil-bearing formations

The usual view is that (1) is correct, that rocks drive fossil finds.  Palaeontologists are keen to find new dinosaur species, but the new species could only be found if they explored new rock formations around the world.  It could be argued that our ability to discover new types of dinosaurs (or any fossil group for that matter) is dependent on the availability of suitable rock formations to explore.

Plotting the Link between Early Tetrapod Discoveries and Rock Formations

Early Tetrapod discoveries 1820-2015.

Early Tetrapod discoveries 1820-2015.

Graph Credit: Bristol University

The graph above shows the same relationship in early Tetrapod fossil discoveries from 1820 to the present day, but if there is a causal relationship between fossil finds and formations then how does this relationship work?

The opposite view is that fossil discoveries drives the search for new rock formations.  Palaeontologists set out to look for new dinosaurs in a very focused and disciplined way.  When new dinosaurs are found they would often add a new dinosaur-bearing formation to the known list.  In this case, the limiting factor is not simply the availability of suitable rock formations to explore because scientists do not search systematically but they go straight to areas when they hear there are bones to be excavated.

Professor Benton added:

“I have been worried for a while that some of the popular correction methods actually make things worse.  By removing the numerical signal of the formations, localities or collections they were actually removing a huge amount of real information, and producing a resulting curve that is meaningless.  The fossil record is clearly incomplete, and it is clearly biased by many factors, but many of the supposedly “corrected” diversity curves we have seen recently may actually be further from the truth than the raw data.”

This new analysis does not provide us with a definitive answer as to the diversity of the Dinosauria, or indeed, for any other fossil group of vertebrates.  However, we can infer from what we already have discovered that there are very probably a lot of weird and wonderful dinosaurs yet to be found.  It is not possible to state that we, after 195 years of research (1820 to 2015), have identified 10%, 50% or even 1% of all the types of dinosaurs that have ever existed, such statements by their very nature are likely to be invalid.  This new research does provide a clearer picture of why there is such a close correlation between dinosaur species numbers with formations, localities or collections.  The numbers of all four are connected because they are all telling much the same story, they are measuring the same history of life on Earth and our knowledge.  Professor Benton concludes that it is not possible to isolate one or other of these measures and then try to use it as an independent yardstick for sampling.

There is one certainty, well, it’s almost a certainty.  New types of dinosaur will be discovered in the future and if the graph developed by Professor Benton is anything to go by, a lot of new dinosaurs (at least compared to the historical data), will be discovered in the next few years and Everything Dinosaur will do its best to blog about them.

Everything Dinosaur acknowledges the help of a Bristol University press release in the compilation of this article.

Stem Acrodontan Lizard – The First of Its Kind from South America

Revising Lizard Evolution in Gondwana

The Squamata (lizards and snakes), might be the most diverse and specious of all the extant reptiles but their evolutionary history remains a mystery.  The preservation potential of these reptiles can vary dependent on the characteristics of the ancient ecosystems which they inhabited.  In addition, the small size of many of the early species of lizard and snake makes finding fossilised bones and other clues as to the history of this Order all the more difficult.  However, a team of scientists including Tiago R. Simões (Dept of Biological Science, University of Alberta), have published a paper in the journal “Nature Communications” that sheds light on the evolution of the iguanas and their near relatives.

The family of extant reptiles known as the iguanians (iguanas and agamids) are one of the most diverse and widespread type of lizard today.  However, like other types of lizard, their evolutionary origins are uncertain.  There are two main divisions within this family, firstly there is a sub-group called the acrodonts, these lizards have no root or socket to their teeth and the teeth are attached to the top of the jaw bones.  In the other sub-group, the pleurodonts they do not have roots on their teeth either, but instead the teeth attach to the inside portion of the jaw.

Acrodont iguanians are confined to the Old World, while pleurodont iguanians are found only in the Americas.  A newly described fossil however, breaks this pattern.  The international team of scientists have published a paper on a Late Cretaceous acrodont iguanian, the oldest known New World acrodont iguanian.

An Illustration of the First New World Acrodont Iguanian – G. sulamericana

The fossils date from around 80 million years ago.

The fossils date from around 80 million years ago.

Picture Credit: Julius Csotonyi

The fossils, including the holotype material, a partial lower jaw come from the Goio-Erê Formation, exposed near Cruzeiro do Oeste, in Paraná State, southern Brazil.  Fossils found in this locality represent an arid, very dry environment dominated by Pterosaurs and large dinosaurs.  However, scurrying around the hot, desert-like environment was a short, rather stubby lizard.  It has been named Gueragama sulamericana, which translates from the local dialect and Portuguese as “ancient agama from South America”.

The discovery of these fossils of an ancient, New World acrodont means that in the distant past, lizards with the acrodont dentition had a worldwide distribution and were very probably widespread across the ancient landmass of Gondwana.

The Holotype Jaw Fossil (Various Views)

An ancient toothy lizard.

An ancient toothy lizard.

Picture Credit: Universidade do Contestado, Santa Catarina, Brazil.

Scale bar in the picture = 2mm.

A number of questions have been raised with this discovery, for example, if only the pleurodont iguanians are found in the New World today, then what happened to the acrodonts that once lived in this part of the world too?

Lead author of the scientific paper, Tiago R. Simões stated:

“It becomes clear acrodontan iguanians migrated throughout the southern continents much earlier than previously thought (actually reaching regions where they do not inhabit today) by the order of tens of millions of years.”

This new research extends the fossil diversity of Late Cretaceous Brazil and suggests that the arid deserts of this part of the world may have supported a greater range of lizards than previously thought.  The scientists hope to find more lizard fossils, including material representing Gueragama so that they will be better able to understand the evolution and radiation of the stem acrodontans.  As for the date given to the G. sulamericana fossil material, we at Everything Dinosaur estimate these fossils to be more than 80 million years of age.  The strata which makes up this part of the Goio-Erê Formation is believed to date from the Turonian to the early Campanian faunal stages of the Late Cretaceous (90-80 million years ago, approximately).

Late Cretaceous South America

South America in the Late Cretaceous

South America in the Late Cretaceous

Picture Credit: Nature Communications

Between the Aptian/Albian faunal stages and the Campanian faunal stage of the Late Cretaceous, sphenodontians were thought to be the dominate animals filling the iguanian niche.  Sphenodontian fossils have been found in northern Patagonia, in the provinces of Chubut (Tres Cerros), Río Negro (Los Alamitos, Cerro Tortuga, Cerro Bonaparte and La Buitrera) and Neuquén (El Chocón), these discoveries are represented by black circles on the map above.  Lizards were present in the state of Ceará in north-eastern Brazil (Araripe Basin), as well as in the south-eastern/southern states of Minas Gerais (Peirópolis), São Paulo (Marília and Presidente Prudente) and Paraná (Cruzeiro do Oeste), and in the province of Río Negro (Cinco Saltos and La Buitrera), Argentina, represented by yellow stars on the map. The red star indicates the type locality of G. sulamericana in southern Brazil.

Recently, Everything Dinosaur reported on another Brazilian Squamata fossil discovery.  Spotted by chance on a tour of a German museum, scientists have identified the first example of a four-footed snake, an animal believed to be a transitional creature between limbed lizards and true snakes.

To read this article: Fossil Snake with Four Limbs Described

Super-sized Ceratopsian Skull Might be New Species

Horned Dinosaur Skull Found in South Dakota Might Be New Species

The small town in Buffalo in the north-west of South Dakota was so named as back in the 19th Century vast herds of buffalo (American bison), roamed across this part of the world.  However, another type of horned animal has got local townsfolk excited, one that would have dwarfed even the largest of today’s hoofed giants, a very-well preserved partial skull and jaws of a huge horned dinosaur which might turn out to be a new species.

Fossil collector and dealer Alan Detrich purchased the dinosaur skull found in Harding County from another fossil collector John Carter back in 2012, but it has taken more than two and a half years to prepare the specimen ready for sale.  When the fossil skull and lower jaw were first excavated it was thought that the bones represented a very large specimen of Triceratops (T. horridus).  However, with the fossil completely exposed, Alan along with Neal Larson (Larson Paleontology Ltd) who was tasked with preparing the fossil, believe that this could be a brand new species of horned dinosaur.

Alan Detrich with the Burlap and Plaster Specimen After Transport (2012)

The fossilised skull in its protective burlap and plaster jacket.

The fossilised skull in its protective burlap and plaster jacket.

Picture Credit: Rapid City Journal

Over the last fifteen years or so, a number of new North American horned dinosaurs have been named and described, however, if proved to represent a new species, this dinosaur skull could be heralded as one of the most spectacular dinosaur discoveries of all, the nasal horn alone measures nearly forty-five centimetres long and the skull itself is over 1.82 metres in length.

Commenting on the unusually large nasal horn, Alan Detrich stated:

“They are [Triceratops nose horns] usually half that size and the skull is eight feet long, which would be a monster skull for a Triceratops.”

Neal Larson, the founder of Larson Paleontology Unlimited and a co-founder of the Black Hills Institute of Geological Research with his brother Pete Larson, who coincidently is also working on a Centrosaurine specimen at the moment, was given the task of trying to prepare the specimen.  It took over 1,000 pain-staking hours to carefully excavate the fossil from its iron siderite matrix.  The preparation work was extremely difficult, as despite the robust nature of the fossil bones, the matrix with its iron component (iron carbonate) was extremely hard.

Neal Larson Stands by the Huge Dinosaur Skull

Huge horned dinosaur skull could be a new species.

Huge horned dinosaur skull could be a new species.

Picture Credit: Rapid City Journal

A spokesperson from Everything Dinosaur exclaimed:

“It’s only when you see a person stood next to the beautifully preserved skull that you can really appreciate just how big the animal actually was.  This is certainly one of the largest Centrosaurine skulls that we have seen.”

For Neal, who holds a degree in geology and has been excavating fossils for some forty years now, the Ceratopsian skull represented a tough challenge given the hardness of the surrounding matrix.

He stated:

“I immediately had my suspicions this was something new because of the size and placement of the nasal horn.  They’re usually in the middle of the nose, not the front and it’s twice as large as most of them.  On top of that, the frill at the top of the skull curves upward. They usually lay back.”

The Super-sized Ceratopsian Skull

Huge Ceratopsian skull (Harding County, South Dakota)

Huge Ceratopsian skull (Harding County, South Dakota)

Picture Credit: Rapid City Journal

The skull has a strange ridge under the jaw, something that is not seen in Triceratops skull material.  Mr Detrich is now trying to find a museum to house this specimen, preferably in the United States, potential buyers for this huge dinosaur skull are currently being contacted.

The Ceratopsians of North American seem to have evolved into a very diverse range of forms during the Late Cretaceous.  Some of the skulls of these herbivorous dinosaurs were truly immense.  As a clade, the Ceratopsians are considered to have the largest skulls in proportion to the rest of their bodies of any known vertebrate.  A few years ago, Everything Dinosaur reported on the discovery of another enormous horned dinosaur skull, this time from Alberta, Canada, a dinosaur that was believed to be an ancestor of Triceratops.

To read about this fossil discovery: Enormous Skull of Eotriceratops Discovered

The Colour of Dinosaurs?

Fossilised Dinosaur Feathers Do Contain Evidence of Original Colours

Over the last five years or so, a number of scientists from around the world have been trying to crack a dinosaur-sized puzzle.  Could fossils preserve some evidence of the colouration of long dead animals?  Could palaeontologists and that talented body of palaeoartists that work with them, finally be able to depict a prehistoric animal as it would have looked like in real life?  A new paper published in the academic journal “Scientific Reports” moves the debate forwards to some extent.  Researchers, led by Johan Lindgren (Lund University, southern Sweden), including graduate students from the aptly named Brown University (Rhode Island, U.S.A) have analysed the fossilised remains of a Middle Jurassic dinosaur and found that the melanosomes preserved within the fossil not only resemble animal pigment structures found today but they also have a very similar, almost identical chemical signature.

This study supports the hypothesis and indeed, strengthens it, that scientists can work out the colouration of long extinct animals including feathered dinosaurs.

The Specimen Used in the Study – Anchiornis Fossil

Feathers reveal chemical signatures that supports colour hypothesis.

Feathers reveal chemical signatures that supports colour hypothesis.

Picture Credit: Thierry Hubin

Anchiornis huxleyi

Named and described back in 2009, from fossil material found in Liaoning Province (north-eastern China), this little dinosaur was covered in feathers.  It stood about twenty centimetres tall and it had long flight feathers on its forelimbs and hind legs.  Three specimens have been described in detail, but there are believed to be many more examples held in private collections.  The exact geological age of this very bird-like dinosaur remains controversial.  It has proved very difficult to date the lake environment deposits where these fossils have been found.  Some palaeontologists have suggested that Anchiornis could be as young as 150 million years old, other scientists have proposed that the fossils date from around ten million years earlier.

To read about the scientific description of Anchiornis (A. huxleyi): Older than Archaeopteryx?

Colour analysis on the very well preserved second specimen (see picture above), has been carried out before, but this time, as well as finding melanosome structures, the researchers conducted two different kinds of chemical analysis to see if animal eumelanin pigment could be detected.  Melanin is a natural pigment found in most animals, there are three main sub-components of melanin, the most common form is the pigment eumelanin.   The researchers conducted an ion mass spectrometry test and also an infrared reflectance spectroscopy analysis to discern the chemical signatures of the rod-like structures that have been observed in the fossilised feathers of the dinosaur once the fossil had been subjected to electron microscopy.  The team then compared the molecular signatures of the fossil sample to the signature of melanin in living animals.  The observed signatures were almost identical.  The only small difference in the chemical make-up was attributed to the presence of sulphur in the fossil material.

Electron Microscopy Shows Tiny Structures in the Fossil Feathers

Structures identified under extreme magnification.

Structures identified under extreme magnification.

Picture Credit: Lund University (Johan Lindgren)

A Palaeontological “Hot Potato”

The hypothesis that the structures which produce the melanin pigmentation, the melanosomes could be preserved in fossils is controversial.  Electron microscope studies of a number of feathered dinosaur fossils has revealed strange structures which have been interpreted as melanosomes by some scientists.  The shape of these structures providing clues to the colouration of the animal.  For example, in the case of Anchiornis, the rod-like, sausage-shaped structures, if they are melanosomes, indicate that this little Chinese dinosaur was mostly covered in dark, probably black feathers.

Such conclusions have been hotly debated.  Some opponents have argued that the structures observed could be other types of organic residue such as the fossilised remains of microbes.  Other scientists have argued that there is a “fossilisation bias” when it comes to the colour spectrum and that melanosomes that give dark pigments may be more likely to survive the fossilisation process than other types, so there is a strong, black bias when it comes to interpreting the colour palette of a long, extinct animal.

Rod-Like Structures the Melanosomes

Sausage-shapes - potential melanosomes.

Sausage-shapes – potential melanosomes.

Picture Credit: Lund University (Johan Lindgren)

Commenting on this latest research, Ryan Carney (Brown University) stated:

“We have integrated structural and molecular evidence that demonstrates that melanosomes do persist in the fossil record.  The evidence of animal-specific melanin in fossil feathers is the final nail in the coffin that shows that these microbodies are indeed melanosomes and not microbes.”

In essence, what this team has done is to move on the debate.  Morphological evidence (structures that look like melanosomes), are no longer the only evidence being put forward to suggest the colour of feathered dinosaurs.  There is now chemical evidence to support the theory that melanosomes can be preserved in fossils.

In order to help rule out a misinterpretation of the data, the team also analysed the observed spectral signatures of the melanins produced by microbes.  The closest match the team achieved was between the fossil material and the signature from extant animal melanin.

Student Carney, went onto add:

“This is animal melanin, not microbial melanin and it is associated with these melanosome-like structures in the fossil feathers.”

To read other articles published by Everything Dinosaur which relate to the colour of extinct animals:

Melanosomes in feathered dinosaurs: Melanosomes Provide Further Evidence for Feathered Dinosaurs

Working out the colour, a problem: Working Out the Colour of Prehistoric Animals just got Harder

Marine Reptiles and colour: Marine Reptiles Dressed in “Little Black Numbers”

“Lucky Find” Puts Welsh Theropod Discovery on a Firm Footing

Fossilised Dinosaur Foot Bones Found on Welsh Beach

Serendipity and palaeontology are often strange bedfellows, but luck does play a part especially when you consider the difficulties in finding very rare and exceptional items such as Early Jurassic dinosaur bones.  Take the example of palaeontology student Sam Davis who has been lucky enough to have been in the right spot at the right time to find the fossilised foot bones of the first meat-eating dinosaur known from Wales.  The bones belong to an, as yet, not scientifically described species of Theropod dinosaur found by brothers Nick and Rob Hanigan in 2014.  The bones come from the Lower Jurassic strata exposed at Lavernock beach (Vale of Glamorgan).

An Illustration of the Newly Discovered Welsh Dinosaur

Significant dinosaur discovery.

Significant dinosaur discovery.

Picture Credit: National Museum of Wales/Bob Nicholls

To read more about the 2014 dinosaur discovery: Welsh Dinosaurs – New Early Jurassic Theropod Discovered

A significant proportion of the skeleton, including skull material, was found by the brothers after spring storms revealed the specimen last year.  However, student Sam Davies decided to visit the beach to explore the fossil location after his tutor explained to him about the geology of the area and the nature of the fossils likely to be found eroding out of the steep cliffs.  Sam duly arrived at Lavernock Point just a few hours after a rock fall had exposed the fossil.  Had he decided to visit the site just a few days later, the fossil specimen would very likely have been washed away by the tide and lost to science forever.

The Foot Bones of the Welsh Theropod Dinosaur

The bones are located on a 20cm slab of rock.

The bones are located on a 20 cm slab of rock.

Picture Credit: National Museum of Wales

Third year student Sam, had visited the beach hoping for inspiration for his third year project as part of his studies at the University of Portsmouth, it looks like he has hit the jackpot with his lucky discovery.  We suspect that Welsh Theropods are going to feature in his individual research project this semester.

Commenting on his lucky fossil find, Sam stated:

“It was pure luck that I found it.  It was just sitting on top of a slab of rock.  It was obvious the fossil was fingers or toes, because there were three in a row, but the first thing that came to mind was that it was some sort of Plesiosaur [marine reptile fossils are occasionally found in this area].”

The fossil has been donated to the National Museum of Wales, joining the rest of the Theropod material.  Sam’s tutor is renowned vertebrate palaeontologist Dr. David Martill, he has been tasked with the job of studying the Welsh fossils and producing a scientific paper on the 200 million year old dinosaur.  Everything Dinosaur expects the paper, along with a name for this three metre long, meat-eater to be published next year.

Sam admits to “jumping up and down like a little boy” when he realised the significance of his discovery.

Set for a Bright Future in Vertebrate Palaeontology

Third year palaeontology student Sam Davies.

Third year palaeontology student Sam Davies.

Picture Credit: BBC News

Dr. Caroline Butler, (Head of Palaeontology, National Museum of Wales) exclaimed:

“The dinosaur found by Nick and Rob Hanigan is the first skeleton of a Theropod found in Wales.  Sam’s find adds to its significance because we can learn more about the animal and how it is related to the dinosaurs that eventually evolved into birds.”

The fossil was actually found some weeks ago, but the announcement of this latest discovery coincides nicely with a television documentary being aired on ITV1 on Monday 31st August with part two the following evening.  The documentary entitled “Dinosaur Britain” explores the rich dinosaur heritage of the British Isles and the Welsh Theropod is featured in the second programme of this two-part documentary.

For information on “Dinosaur Britain”: Dinosaur Britain Scheduled for Bank Holiday Monday

A spokesperson from Everything Dinosaur explained:

“The first dinosaurs to be scientifically studied, were described from fossils found in the British Isles, but even today something like one in twenty of all the known dinosaurs is represented by fossil material discovered in this part of the world.  The finding of the additional Welsh Theropod bones was extremely serendipitous and we wish Sam every success with his studies.”

Here’s one palaeontology student who has helped to put Welsh Theropods on a firmer footing.

Cave in the Urals Reveals Haul of Cave Lion Bones

Imanai Cave – Strange Significance to Stone Age People

A team of Russian archaeologists have been putting on display some of the huge collection of prehistoric cave lion bones and other artefacts recovered from a cave in the Russian republic of Bashkiria close to the Ural mountains.  The small cave has yielded some five hundred cave lion bones so far, plus a number of flint spearheads and a cave bear skull that shows evidence of having been pierced by a spear.  The cave, known locally as the Imanai cave, shows no signs of sustained hominin habitation and it has been suggested that prehistoric people considered part of the cave to have some special, perhaps even religious significance and these items were brought into the cave deliberately.

Scientists Show some of the Flint Tools and Cave Lion Skulls

Imanai cave lion skulls on display.

Imanai cave lion skulls on display.

Picture Credit: Pavel Kosintsev

The concentration of cave lion bones in the cave is unique, nowhere else in the world has such a mass concentration of cave lion bones been discovered.  The bone assemblage probably represents six individual animals.

Pavel Kosintsev, a senior researcher at the regional Institute of Plant and Animal Ecology (Urals Branch of the Russian Academy of Science) stated:

“We found about five hundred bones and fragments of bones of the giant cave lion, but there could be more, after we finish with sorting the collection.  Such a large quantity of giant cave lion bones at one site is really unique, the only one in the world so far discovered.”

Giant Cave Lions

The cave lion (Panthera leo) shares the same scientific name of the modern African lion of the savannah.  Although some scientists believe that it is sufficiently different from its African relative to be classified as a sub-species (P. leo spelaea) It may be classified as the same species, by many academics, but the cave lion looked very different from its modern African counterpart.  It was around 15-20% bigger and it had longer legs.  It also possessed a thick, shaggy coat which during the winter months, when snow covered a large part of this animal’s range, that coat might well have turned white to help camouflage this large predator.  It seems that in the past, the lion as we know it today lived over a much wider area of the northern hemisphere.  Its range extended out of Africa and into Europe, indeed cave lion fossils have been found in the UK, most notably Kents Cavern near Torquay (Devon).

Despite their name, cave lions were not adapted to a life in caves, they were creatures of the open tundra, forests and plains.  Their bones may have been washed into caves or brought into cave dens by scavenging animals and as a result, since the bones of these large cats are associated with caves and rock overhangs the term cave lion was adopted to distinguish them from extant species.

An Illustration of a Cave Lion (note the light coloured coat)

An illustration of a cave lion.

An illustration of a cave lion.

Picture Credit: Russian Academy of Science/Pavel Kosintsev

Earlier excavations had found isolated bones deep inside the caves, but these were interpreted as having been sick or injured lions, or lost cubs.  The researchers believe that the cave may have been an ancient sanctuary and that these sick and injured animals could have been brought to the cave by ancient people.  This suggests that the Imanai cave had some significance to the ancient humans that inhabited this part of the Urals, perhaps it was a place of worship.  A number of other such sites were bone deposits have been made are known, the scientists hope to compare their cave data with similar sites from Austria and the Czech Republic.

The human relics found include ten stone spearheads, identified as being from the Mousterian culture, previously only two such spearheads had been found in the entire Urals region of Russia.

Inside the Cave (Imanai Cave Ural Mountains)

Going down to the bone deposit site.

Going down to the bone deposit site.

Picture Credit: Pavel Kosintsev

The Mousterian culture is defined by the style of stone tools associated with European hominins.  It relates to the Old Stone Age and dates from around 600,000 years ago with the youngest tools associated with this culture dating to around 30-40 thousand years ago.  This technology has been found in sites across southern Europe, Turkey and parts of the Middle East.  Mousterian flint tools have been discovered as far west as Wales and the Imanai cave represents one of the eastern margins for this stone tool culture.  During the Mousterian, Europe was populated by a range of hominin species, including Homo heidelbergensis, Homo neanderthalensis and latterly our own species which migrated into this part of the world from Africa – H. sapiens.

Spearheads the Only Sign of Human Activity

The spearheads and the cave bear skull with its spear hole are the only signs of human activity.  If ancient hominins had lived in this cave, even for a short period, the archaeologists would have expected to find a lot more evidence of human habitation.  For example, signs of fire having been used, animal bones with cut marks from being butchered and other stone tools.  The lack of other human artefacts supports the hypothesis that this site might have been a sanctuary of some sort or perhaps a shrine.

The latest finds have not been dated, but the upper layers of the cave floor mapped during an earlier reconnaissance are believed to be around 30,000 years old.  The lower layers are much older, how much older will have a significant bearing on the study, as the scientists cannot be sure what species of people (indeed, the cave could have been an important location to more than one type of hominin) they are dealing with.  Preliminary estimates place the lower, bone yielding layers at around 60,0000 years ago, so this site could be very significant in terms of Neanderthal research.  However, different populations of humans occupied different parts of Europe as the climate swung dramatically from very cold periods to much warmer inter-glacial periods during this part of the Pleistocene Epoch.  Further dating of material is currently being undertaken by scientists from the University of St Petersburg.

 

Archaeologists Working in the Cave at the Bone Deposit Site

Scientists carefully examining in situ evidence.

Scientists carefully examining in situ evidence.

Picture Credit: Pavel Kosintsev

Explaining the team’s future plans Pavel stated:

“We plan to continue the excavations next year, but the amount of finds we made this year is very large.  There are about twenty sacks with ground and small fragments and about twenty to twenty-five boxes with bones.  We need to examine all this and I think that some significant updates may appear as soon as this year.”

All the bone and tool finds come from an area of just six square metres in the cave, which has been excavated to a depth of around sixty centimetres.  The research team are excited at the prospect of exploring other parts of the cave and finding many more artefacts.  The greater the number of artefacts, then more information can be obtained which should help the scientists to understand more about the cave, its occupants and how it fitted into ancient human cultures.

Little Finger Points to Changes in Hominin Evolution

Ancestors May Have Come Down From the Trees Earlier than Thought

A tiny finger bone, representing the proximal phalanx of the fifth digit of a hominin’s left hand has led scientists to reconsider the date of our ancestor’s descent from the trees.  Put simply, the discovery of one of the world’s oldest little finger bones from a human-like species suggests that at around 1.8 million years ago hands had already become much more readily adapted to using tools than to climbing trees.  The finger bone, is not curved, curved bones in the digits are indicative of a grasping, weight bearing role very typical of apes that live in trees.  The bone is very similar in shape to that of a modern human little finger bone (Homo sapiens).

Various Views of the Little Finger Bone (Proximal Phalanx)

Various Views of the ancient hominin finger bone.

Various Views of the ancient hominin finger bone.

Picture Credit: M. Domínguez-Rodrigo

The bone was discovered in the Olduvai Gorge region of Tanzania and it is estimated to be about 1.8 million years old.  The fossil find suggests that by 1.8 million years ago, a human-like species had already made the transition to terrestrial living whilst co-existing with more arboreal hominins such as Homo habilis and a member of a distantly related sub-branch to the hominin family tree that led to modern humans Paranthropus boisei.

According to researchers such as Manuel Domínguez-Rodrigo (co-director of the Olduvai Gorge-based project The Institute of Evolution in Africa), this discovery pushes back the origin of dextrous human digits some 400,000 years.

Commenting on the fossil find, Manuel Domínguez-Rodrigo, one of the team members who analysed the bone stated:

“This bone belongs to somebody who’s not spending any time in the trees at all.  Hanging from branches tends to bend bones like this one that extend from the knuckle, whereas in modern humans, and in this case they are straighter.”

The Position of the Fossil Proximal Phalanx in a Modern Human Left Hand

The location of the bone in the left hand.

The location of the bone in the left hand.

Picture Credit: M. Domínguez-Rodrigo

The scientist, who has been involved in research projects in Tanzania since 2006 explained that this was evidence supporting a significant change in the behaviour of our ancient ancestors.  If the hands were no longer being used to climb trees, then they could be being used for other purposes such as making tools.

Biological anthropologist Brian Richmond (American Museum of Natural History, New York) and another specialist in early human history commented:

“This provides good evidence supporting the hypothesis that, by about two million years ago, our early ancestors lost the anatomy linked to our tree-climbing past.”

Although the finger bone is a different shape from the bones of contemporary Australopithecines, other scientists, such as Richard Potts of the Smithsonian Human Origins Programme (Washington D.C.) has suggested that a single bone is not enough evidence to conclude that the hand it came from truly resembles that of a modern human ancestor.

Earliest Baboon Fossil Identified from World Heritage Site

Papio angusticeps – An Ancestor of Modern Baboons

A team of international scientists including researchers from Witwatersrand University (South Africa), have discovered the fossils of the earliest known baboon.  The partial skull of a new species, which has been named Papio angusticeps has been dated to around 2.026 to 2.36 million years ago was found at Malapa, in the Cradle of Humankind World Heritage Site, which is located about thirty miles north-west of Johannesburg in Gauteng Province, South Africa.

The baboon fossils come from the same site where the partial remains of the early hominin species, named Australopithecus sediba, were discovered in 2010.

To read Everything Dinosaur’s article on the discovery of A. sedibaNew Fossils May Shed Light on Human Ancestry

Baboons and Hominins May Have Competed for Resources

Commenting on the study, lead author Dr. Christopher Gilbert (Hunter College of the City University of New York), explained that the rise of the baboons was contemporaneous with the rise of that part of the hominin family tree that resulted in our own species.

Various Views of the Skull Fossil (Papio angusticeps)

Various views of the baboon skull fossil.

Various views of the baboon skull fossil.

Picture Credit: Witwatersrand University

He commented:

“Baboons are known to have co-existed with hominins at several fossil localities in East Africa and South Africa and they are sometimes used as comparative models in human evolution.”

As one of the largest, non-hominin members of the primate Order, these intelligent animals would have competed with our ancestors for food, shelter and other resources.  The skull fossil is very similar to that found in a modern baboon species, (Papio hamadryas), one of five species in the Papio genus and the species of baboon that lives the furthest north.  Its range is from the horn of Africa across the Arabian Sea into the Arabian peninsula.

Despite the record of baboon fossils from a number of hominin sites, the evolution of modern baboons is not well understood and the fossil record for these large Old World monkeys is very poor.

Dr. Gilbert added:

“According to molecular clock studies, baboons are estimated to have diverged from their closest relatives by 1.8 to 2.2 million years ago.  However, until now, most fossil specimens known within this time range have been either too fragmentary to be definitive or too primitive to be confirmed as members of the living species Papio hamadryas.  The specimen from Malapa and our current analyses help to confirm the suggestion of previous researchers, that P. angusticeps may, in fact, be an early population of P. hamadryas.”

An Extant Male Baboon

A male baboon.

A male baboon.

Picture Credit: Andrea Baden

Dr. Gilbert, a specialist in early primate evolution explained:

“If you placed a number of P. angusticeps specimens into a modern osteology collection, I don’t think you’d be able pick them out as any different from those of modern baboons from East and South Africa.”

In addition, the estimated age of the Malapa specimen (2.026 to 2.36 million years old), is an almost perfect fit with molecular clock analyses for the initial appearance of modern baboons.  The skull may help to solve the evolutionary origins of these highly adaptive mammals.  Furthermore, as monkeys are widely recognised as key time-sensitive elements in the fossil record, the fact that the Malapa P. angusticeps specimen is well-dated allows future studies to better estimate the age of fossil sites where the species is found.  This may prove particularly helpful when attempting to date early hominin sites in South Africa.  The presence of these baboon fossils, may be able to help scientists achieve more accurate age estimates for any early hominin remains found in situ.

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