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Evolution and Extinction of the African Carcharodontosauridae

“Shark Toothed Lizard” – The Rise and Fall of Carcharodontosaurus

The Carcharodontosaurus genus currently consists of two species, the first of which Carcharodontosaurus saharicus  (originally called Megalosaurus saharicus), is known from fossil material found in North Africa.  The second species, named and described in 2007, was erected following fossil finds, including skull material from the Echkar Formation of Niger, this species is known as C. iguidensis.  Although both species are known from fragmentary material and a few isolated teeth, differences in the shape of the upper jaw and the structure of the brain case enabled scientists to confidently establish Carcharodontosaurus iguidensis as a second, distinct species.

An Illustration of a Typical Carcharodontosaurid Dinosaur

Fearsome "Shark Lizard"

Fearsome “Shark Lizard”

Picture Credit: Everything Dinosaur

Carcharodontosaurus means “shark-toothed lizard”,  a reference to the fact that the teeth of this huge carnivore, reminded scientists of the teeth of sharks belonging to the Carcharodon genus of sharks, such as the teeth of the Great White Shark (C. carcharias).  It is ironic that this terrestrial predator should be named after a marine carnivore, as changing sea levels very probably influenced the evolution of these dinosaurs and may have ultimately led to their extinction, at least from Africa.

To view Everything Dinosaur’s range of Collecta dinosaur models including a 1:40 scale Deluxe Carcharodontosaurus: Collecta Scale Dinosaur Models

Pronounced - Car-car-oh-dont-toe-sore-us, the oldest dinosaur currently assigned to the Carcharodontosauridae family is Veterupristisaurus (Vet-ter-roo-pris-tee-sore-us).  This dinosaur was named and described in 2011, although the fossil material was discovered over seventy-five years ago.   The fossils come from the famous Tendaguru Formation of Tanzania, it lived during the Late Jurassic and the trivial name V. milneri honours the now retired Angela Milner who worked at the Natural History Museum (London).

Carcharodontosaurus lived during the Cretaceous (Late Albian to mid Cenomanian faunal stages).  During this time, the great, southern super-continent called Gondwanaland continued to break up and as sea levels rose, so populations of dinosaurs became separated by the inflow of sea water.

Rising Sea Levels Influence Dinosaur Evolution

Rising sea levels but off dinosaur populations.

Rising sea levels cut off dinosaur populations.

Picture Credit: Everything Dinosaur

Communities became isolated and this may have provided a boost to the evolution of new species.  The map shows the approximate location of fossil material associated with C. saharicus and C. iguidensis.  Populations of carcharodontosaurids may have become cut-off from each other and this gave rise to new species of Carcharodontosaurus.  This may help to explain the abundance of super-sized predators that lived in this part of the world during the Cretaceous.  Both species of Carcharodontosaurus shared a common ancestor, but their separation led to the evolution of two, distinct species.  This natural process is called allopatric speciation.

Sadly for the mega fauna that inhabited the coastal swamps and verdant flood plains of North Africa, rising sea levels in the later stages of the Cenomanian led to the destruction of much of this habitat.  The loss of habitat probably led to the demise of the ecosystem and the vulnerable apex predators such as the carcharodontosaurids and the spinosaurids became extinct.

To read an article on the discovery of C. iguidensisNew Giant Meat-Eating Dinosaur from Africa

Record Breaking Apatosaurus Thigh Bone

Apatosaurus Femur Fossil – Biggest Apatosaurus Fossil Femur Found to Date

Reports received from Colorado state that a six foot seven inch long Sauropod femur has been safely removed from the Mygatt-Moore Quarry, a famous, highly fossiliferous site which has provided museums in the western United States with hundreds of Upper Jurassic dinosaur fossils.  The quarry has been excavated for many years but this new fossil extraction is something special.  The femur, believed to come from a species of Apatosaurus represents the largest thigh bone associated with the long-necked, plant-eating dinosaur to have been found to date.

An Illustration of Apatosaurus

Apatosaurus dinosaur model.

Apatosaurus dinosaur model.

Picture Credit: Everything Dinosaur

A number of Apatosaurus species have been described.  It was a member of the diplodocid clade of Sauropods and up until now the largest individuals of this species were around twenty-five metres in length.  However, this enormous femur (it measures 200.66 cm approximately), indicates that this genus could have reached lengths in excess of twenty-five metres.  Apatosaurus is one of the most popular of all the dinosaurs and it is often, still, referred to as Brontosaurus (Thunder Lizard).

For an explanation as to why the term Brontosaurus is no longer used to describe this dinosaur: Why Brontosaurus is no more

Volunteers and Scientists at the Fossil Dig Site

Giant dinosaur bone ready for lifting from fossil quarry.

Giant dinosaur bone ready for lifting from fossil quarry.

Picture Credit: Robert Gay (Museum of Western Colorado)

The excavation and extraction work was supervised by palaeontologists from the Museum of Western Colorado’s Dinosaur Journey Museum.   The fossil had been spotted back in 2010, but it has taken a number of summer expeditions to prepare the fossil for its removal.  Museum volunteers Kay Fredette and Dorothy Stewart originally spotted the fossilised thigh bone, slowly eroding out of the surrounding rock, at first, all that was exposed was a “pancake-sized” chunk of rock.

After the burlap and plaster fossil was lifted by crane onto awaiting transport, Kay Fredette commented:

“We’ve got to clean the bottom side of it and there’s so much other bone around it.  It is going to take a couple of years to finish this.”

In total, the fossil including the remaining matrix and its cradle weighed more than 1,270 kilogrammes, a spokes person from Everything Dinosaur explained that the plaster and burlap protected fossil would be transported to a laboratory and once installed inside, a team of preparators would begin the long process of cleaning the fossilised bone and extracting it from the surrounding rock.

Volunteer Kay Fredette (foreground) Next to Another Dinosaur Bone

Helping to dig up dinosaurs.

Helping to dig up dinosaurs.

Picture Credit: Robert Gay (Museum of Western Colorado)

The Everything Dinosaur spokes person stated:

“To give readers an idea of the weight of the object, the fossil bones, its matrix and surrounding cradle that had to be lifted weighed about as much as a Ford Focus motor car”.

The Mygatt-Moore Quarry is located in the Bureau of Land Management’s (BLM) McInnis Canyons National Conservation Area and the scientists at the Museum of Western Colorado hope to learn more about the potential maximum size of this iconic dinosaur.

Dr. Julia McHugh, who helped supervise the fossil extraction stated:

“So after the remaining matrix is removed and the bone is repaired it is going to be used to verify its taxonomic identity.  That means what animal it belongs to as well as whether it was a fully grown, mature adult.”

New Type of “Four Winged” Flying Dinosaur – A Liaoning Surprise?

Changyuraptor yangi – Let’s Not Get into Too Much of a Flap

And so on the 15th July, the paper on a new type of airborne dinosaur was published in the journal “Nature Communications”.  The world was officially introduced to Changyuraptor yangi or to interpret the genus name, “long feathered raptor”.  At about the size of a European Herring Gull (Larus argentatus), this newest member of the microraptorines, is the largest Theropod dinosaur discovered to date with long pennaceous feathers attached to the hind limbs.  At an estimated weight of around three to four kilogrammes, it is three times heavier than the largest species of Microraptor – M. zhaoianus (if indeed the fossils discovered to date do indeed represent three different species and not a single species but with extensive intra-specific variation), and four times heavier than that extant gull we mentioned earlier.  Changyuraptor has other claims to fame.  For example, its tail feathers are extremely long, measuring nearly thirty centimetres in length.  The longest tail feather is around 30% the length of the entire skeleton.

However, for us at Everything Dinosaur, the announcement of this fossil find comes as no real surprise.  The fossil material is from north-eastern China and it forms part of the amazing Jehol Biota which represents an Early Cretaceous ecosystem which has been preserved in strata that date from around 133 million years ago to 121 million years ago or thereabouts.  All the Microraptorine fossil material comes from this part of the world and the fossilised fauna and flora portray a habitat that had distinct seasons with a temperate forest habitat interspersed with large bodies of freshwater and swamps.  The area teemed with life and with the finding of one predatory Dromaeosaurid dinosaur with aerodynamic abilities (Microraptor), finding other examples of dinosaurs filling this ecological niche was always likely.

These hunters may not have caught their prey on the wing, but they probably spent a great deal of their lives high up in the tree canopy living an arboreal existence and stomach content analysis from Microraptor specimens indicate that these dinosaurs, closely related to the likes of Velociraptor, ate small mammals, lizards and even primitive birds.  One poor unfortunate perching bird seems to have been swallowed whole.

An Illustration of Changyuraptor yangi (Silhouette of Person shows Scale)

“Four winged” terror

Picture Credit: S. Abramowicz

The international team of scientists behind the scientific paper, such as Luis M. Chiappe (Natural History Museum of Los Angeles County), Michael Habib (University of Southern California), Gang Han, Shu-An Ji, Xueling Liu and Lizhuo Han (Bohai University, Liaoning Province), in collaboration with colleagues based in New York and South Africa have described the beautifully preserved fossil material and then analysed this animal’s flight characteristics. Why, for example, did this “four-winged terror” have such long feathers on its tail?

The Holotype Fossil Material (C. yangi)

The slab (a) and the counter slab (b) of the Holotype

Picture Credit: Nature Communications

At 1.32 metres in length and weighing close to four kilogrammes, taking to the air may not have been too much of a problem for our feathered friend here.  Especially if this dinosaur launched itself from the branches of trees and glided around.  However, controlling itself in flight and coming into land may have been somewhat more difficult for such a heavy, large-bodied animal.  The international research team examined the aerial competency of Changyuraptor and concluded that the tail may have acted as a pitch control structure, reducing air speed and helping to ensure a safe landing.  Those hind limbs with their feathers too, would have assisted with gliding and with the legs rotated down and underneath the body as it descended, then the feathers could have made effective air brakes, in a similar way to the “trousers” on Archaeopteryx.

To read an article on the feathered legs of Archaeopteryx: Feathers Evolved Before Flight – Archaeopteryx Had Feathered Trousers

Dr. Michael Habib (University of Southern California) stated:

“It makes sense that the largest microraptorines had especially large tail feathers, they would have needed the additional control.”

Dr. Alan Turner of Stony Brook University (New York), a co-author of the paper added:

“Numerous features that we have long associated with birds in fact evolved in dinosaurs long before the first birds arrived on the scene.  This includes things such as hollow bones, nesting behaviour, feathers…and possibly flight.” 

Bone structure analysis undertaken concluded that this was a fully grown, mature animal that rivalled the largest Pterosaurs known from Liaoning Province in size as it glided in the sky above this ancient Chinese landscape.  The holotype material was found back in 2012 and since its discovery the notion that flight preceded the origin of Aves has been consolidated.  Birds inherited flight characteristics from their near relatives the Dinosauria.  For the time being we shall give the last word to Luis Chiappe:

“This new fossil documents that dinosaur flight was not limited to very small animals but to dinosaurs of a more substantial size.  Clearly far more evidence is needed to understand the nuances of dinosaur flight but Changyuraptor is a major leap in the right direction.”

More Crocodile Attacks Reported from India

More Crocodile Attacks Reported in Gujarat State

The number of crocodile attacks reported by the authorities in Gujarat State (western India), continues to rise with the latest victim a sixteen year old boy who was attacked by a crocodile as he swam in a lake close to Dena village (Gujarat).  A day earlier, a woman was dragged into the water by a crocodile near the town of Goraj.  The boy, Moin Qureshi managed to escape but suffered injuries to his legs.  Villagers report that the lake is home to at least two large crocodiles.

A spokes person for the villagers explained that locals had been requested to stay away from the water, Moin is in hospital recovering from his ordeal.  This attack follows a similar incident reported  from northern India last month when two girls were attacked by a crocodile, one of these attacks proved fatal.

There have been a number of such incidents reported from India this year, back in April, Everything Dinosaur team members reported on the series of crocodile attacks in Gujarat State.

To read more about these attacks: Third Fatality as a Result of Crocodile Attack Reported

At certain times of the year, crocodiles are believed to be more aggressive and therefore more likely to attack people, when females are guarding nests or when males are competing for territory for example.  Loss of habitat and the increasing population pressure may also be a factor as people are coming into contact with large crocodiles more frequently.

Flags out for Collecta

New Collecta Models – Dinosaurs and Prehistoric Mammals

Fact sheets have been prepared, scale drawings commissioned and checked and its full speed ahead at the Everything Dinosaur warehouse as team members eagerly await the arrival of the latest batch of 2014 Collecta models. Staff have had prototypes of the new models for some time and indeed, Everything Dinosaur was one of the first organisations to get stocks of the Quetzalcoatlus with prey, the Ichthyovenator and the delightful Xenoceratops, soon we will be able to add a lot more including a replica of a palm tree.

New Collecta Models for 2014

New Collecta prehistoric animal models

Picture Credit: Everything Dinosaur

The full list of models due into stock goes something like this: Deluxe 1:20 scale Arsinoitherium, Deluxe 1:40 scale Therizinosaurus, more stock of the extremely popular Deluxe Carcharodontosaurus, the Coconut Palm Tree replica, Bistahieversor, Saurophaganax, Gastonia, the juvenile T. rex, and the mighty Mosasaurus.  Almost too many for us to remember.

New Collecta Models due to Arrive Shortly

Is there room in our warehouse for all of these?

Picture Credit: Everything Dinosaur

To view Everything Dinosaur’s range of Collecta models: Collecta Prehistoric Animals

For fans of prehistoric scenery, Everything Dinosaur will be adding the Collecta Coconut Palm model to its stock.  This model of a stand of palm trees is ideal for helping to create prehistoric scenes.  Palm trees are a relatively ancient group of flowering plants (angiosperms), with palm tree fossils associated with Upper Cretaceous and Early Palaeogene strata.

New for 2014 The Collecta Palm Tree Replica

Tropical Plants from Collecta

Picture Credit: Everything Dinosaur

So its full steam ahead for Collecta.

Ancient Creepy-Crawlies Resurrected

410 Million Year Old Arachnid Walks Again

A team of international researchers have used fossils of ancient Arthropods from the London Natural History Museum to recreate the movements of some of the world’s first terrestrial predators.  Researchers from the Museum für Naturkunde (Berlin) and Manchester University have used an open source computer programme called Blender to model the walking motion of a 41o million year old ancient Arachnid.  The video shows the most likely gait that this tiny prehistoric predator could achieve as it stalked across the Devonian landscape.  The paper, which details this research has been published in a special edition of the academic publication the “Journal of Palaeontology”.

The scientists took minute slices of the fossils of these early Arachnids and once the limb segments and their joints had been identified they worked out the range of limb motion possible.  From these measurements and using comparisons with extant Arachnids, the researchers modelled the walking action using the Blender software programme.  In this way, a creature dead for over 410 million years could once again walk.

Dr. Russell Garwood, (palaeontologist at Manchester University), stated:

“When it comes to early life on land, land before our ancestors came out of the sea, these early Arachnids were top dog of the food chain.  They are now extinct, but from about 300 to 400 million years ago, they seem to have been more widespread than spiders.  Now we can use the tools of computer graphics to better understand and recreate how they might have moved – all from thin slivers of rock, showing the joints in their legs.”

Supplemental Data Video 2 – Palaeocharinus Locomotion

Video Credit: University of Manchester Press Room

The video shows the ancient Arthropod (Palaeocharinus genus) walking.  Although a formidable looking animal, this early creepy-crawly was less than half a centimetre in length.  The fossils used in this study came from the famous Lower Devonian strata at Rhynie (Aberdeenshire, Scotland).  The Rhynie chert deposit contains evidence of one of the earliest terrestrial ecosystems known to science.  More than twenty primitive plant species have been identified along with Arthropods such as mites and trigonotarbids such as Palaeocharinus that hunted amongst the miniature forest made up of Rhyniophytes (primitive plants).

Co-author of the scientific paper, Jason Dunlop (Museum für Naturkunde), added:

“These fossils,  from a rock called Rhynie chert, are unusually well-preserved.  During my PhD I could build up a pretty good idea of their appearance in life.  This new study has gone further and shows us how they probably walked.  For me, what’s really exciting is that scientists can make these animations now, without needing the technical wizardry and immense costs of a Jurassic Park-style film.”

Although not true spiders, trigonotarbids are related to modern spiders but they lack certain spider features such as silk producing spinnerets.  As a group, they first appear in the fossil record in the Late Silurian.  The oldest trigonotarbid specimen, that we at Everything Dinosaur know about, comes from the Upper Silurian deposits of Ludow , Shropshire (Ludlow epoch around 420 million years ago).  It was Jason Dunlop who was responsible for describing this discovery (1996).

A Highly Magnified Image of a trigonotarbid (Palaeocharinus)

The highly magnified section shows leg segments clearly.

Picture Credit: Everything Dinosaur

The scale bar in the picture represents 2 mm.

Dr. Dunlop stated:

“When I started working on fossil Arachnids we were happy if we could manage a sketch of what they used to look like, now we can view them running across our computer screens.”

The development of sophisticated computer programmes is permitting scientists to re-create three-dimensional images of spectacular fossils.  In addition, new generation programming technology is now capable of bringing long extinct creatures back to life, at least in cyberspace.  The predatory Palaeocharinus might be quite frightening, but at half a centimetre long it would probably not even had got a second glance if you spotted on in the garden.  However, other specimens from Upper Devonian strata, as yet not fully described fossils, indicate that there were much larger creatures at home amongst the primitive plants such as the Rhyniophytes and Lycopsids (clubmosses), some fossils indicate Arthropods nearly an inch in length.  These creatures may not be trigonotarbids but perhaps represent an entirely new family of Arthropoda.

Dr. Garwood concluded:

“Using open source software means that this is something anyone could do at home, while allowing us to understand these early land animals better than ever before.”

Everything Dinosaur acknowledges the help of the Faculty of Engineering and Sciences (University of Manchester) in the compilation of this article.

A Neanderthal-like Inner Ear in Ancient Chinese Skull

Let’s Hear it for the Neanderthals

A team of international scientists including palaeoanthropologists from the Chinese Academy of Sciences, have been puzzling over the distinctive shape of the structures that make up part of the inner ear preserved in an ancient skull.  The 100,000 year old human skull has a similar inner ear structure to that thought to have only occurred in our near relatives the Neanderthals (Homo neanderthalensis).  CT scans have revealed to the researchers, something of a mystery, none of the other prehistoric human skulls dated to around 100,000 years ago and found in China show this inner ear formation.  This discovery opens up the debate between H. sapiens and Neanderthal interaction and blurs the line between these two hominin species.

The extremely detailed three-dimensional images revealed by the study, has raised important questions regarding the nature of late archaic human variation across Europe and Asia.  It also suggests, that the inner ear shape once ascribed as being diagnostic of Neanderthal skull material may be present in other types of ancient human.  This characteristic may not be a distinctive Neanderthal feature.

Researchers from the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP – Chinese Academy of Sciences), in collaboration with Washington University (St Louis) and Bordeaux University (France), discovered the controversial evidence after a meticulous CT scan of a skull found in the Nihewan Basin of northern China.  The skull, found in the late 1970′s along with other bone fragments and human teeth is known as Xujiayao 15, it was named after the archaeological dig site where it was discovered.  The skull morphology indicates that it comes from an early non-Neanderthal form of late archaic human.  It is probably the skull of a male.

Over the last two decades or so, the evolution of our own species and our relationship with other hominins has become somewhat blurred.  For example, it was thought until very recently that Europe around 250,000 years ago was inhabited by just two species of humans, ourselves and the Neanderthals.  New fossil discoveries and research on museum specimens has revealed that there may have been four different types of human in Eurasia at this time.  As well as H. sapiens and H. neanderthalensis, evidence for the presence of Homo erectus and the enigmatic Denisovans has also been found.

To read an article that suggests the Denisovan hominins and the Neanderthals were closely related: Denisovan Cave Material Hints at Mystery Human Species

The inner ear, also known as the labyrinth is located within the skull’s temporal bone.  It contains the cochlea, which converts sound waves into electrical impulses that are transmitted by nerves to the brain.  The inner ear also contains the semicircular canals, these chambers help us to balance and to co-ordinate our actions.  These structures although small, have been found preserved in a number of mammal skulls including prehistoric human fossils.  Research published almost two decades ago, which relied on less powerful CT scans and computer technology, established the presence of a particular pattern of the semicircular canals in the temporal labyrinth as being diagnostic of Neanderthal skull material.  The same pattern of the semicircular canals is found in all known Neanderthal labyrinths.  As a result, the labyrinth has been used extensively as a marker to distinguish Neanderthal skull fossil from other hominins.

The Fossil Location with an Overlay of the Temporal Bone and CT Scan showing the Inner Ear Structure

Temporal bone found at the Xujiayao site and inner ear structure

Picture Credit: Wu Xiujie (Chinese Academy of Sciences)

The academic paper that details the international team’s research has just been published in the “Proceedings of the National Academy of Sciences”.   The shape of the skull and structures such as the arrangements seen in the semicircular canals could be used to help resolve the evolutionary relationships between a number of closely related human species.

Dr. Erik Trinkaus (Washington University), one of the lead authors of the scientific paper, suggests that whilst it may be tempting to speculate on potential cross-breeding between the lineage that would lead to modern humans and Neanderthals, this may be over simplifying what is in effect a very complex relationship between different populations of prehistoric humans.  The finding of a Neanderthal-shaped labyrinth in an otherwise distinctly “non-Neanderthal” sample should not be regarded as evidence of population contact (gene flow) between central and western Eurasian Neanderthals and eastern archaic humans in China.  Dr. Trinkaus and his colleagues state that the broader implications of the Xujiayao skull CT research remain unclear.

Neanderthal-like Ear Structures Found in a Non Neanderthal Skull

Determining the shape of the inner ear structures.

Picture Credit: Wu Xiujie (Chinese Academy of Sciences)

The picture above shows the temporal bone of the Xujiayao specimen (brown) and CT scans (green) with the shape and position of the temporal labyrinth outlined in purple.

Dr. Trinkaus commented:

“The study of human evolution has always been messy, and these findings just make it all the messier.  It shows that human populations in the real world don’t act in nice simple patterns.  This study shows that you can’t rely on one anatomical feature or one piece of DNA as the basis for sweeping assumptions about the migrations of hominid species from one place to another.”

It looks like the human “family tree” has a more twisting branches than previously thought.

Everything Dinosaur acknowledges the help of the Chinese Academy of Sciences in the compilation of this article.

World’s Largest-Ever Flying Bird – Pelagornis sandersi

A Seagull on Steroids - Pelagornis sandersi

A team of scientists from the Bruce Museum (Greenwich, Connecticut, USA), have published a paper on a new species of giant bird, believed to be the largest flying bird known to science, eclipsing the giant, prehistoric condor Argentavis magnificens.  With a wingspan estimated to be between 6.1 and 7.4 metres, this is more than twice the size of the wingspan of the largest living flying bird today, the Royal Albatross (Diomedea epomophora) and places P. sandersi alongside the biggest members of the Pterosaur family the Pteranodontia in terms of size.  Its wingspan is only exceeded by a handful of flying reptiles, most of which belong to the Azhdarchidae Pterosaur family.

In simple terms, the wingspan of this newly described Oligocene bird was easily longer than the height of the tallest giraffes living today.

A Line Drawing Showing the Size and Scale of Pelagornis sandersi

Line drawing of World’s Largest-Ever Flying Bird, Pelagornis sandersi, showing comparative wingspan. Shown left, a California Condor, shown right, a Royal Albatross.

Line drawing of World’s Largest-Ever Flying Bird, Pelagornis sandersi, showing comparative wingspan. Shown left, a California Condor, shown right, a Royal Albatross.

Image Credit: Liz Bradford

The line drawing in the picture above also reveals how much of the fossil skeleton has been found (marked in white).

The fossil material was discovered by James Malcolm, a volunteer from Charleston Museum (South Carolina), when a fossiliferous bone bed representing a marine environment was exposed during the building of a new terminal at Charleston International Airport in 1983.  The strata forms a component of the Chandler Bridge Formation dated to the Late Oligocene epoch (Chattian faunal stage).  A number of fossils of other marine birds were identified including fragmentary and badly distorted fossil elements from a smaller pelagornithid, but it is not clear whether these fossils represent a juvenile P. sandersi or a new species.

The pelagornithids were a group of strange, “pseudo-toothed” birds, whose fossils have been found in a number of Cenozoic aged fossil sites which represent marine environments.  It is likely that these creatures evolved in the Late Palaeogene and survived up until the end of the Pliocene epoch, going extinct around three million years ago.  Although, a number of species had large wingspans, these birds were very lightly built with paper thin bones, as a result of which, their fossils are extremely rare.  They were great aeronauts and were geographically very widespread with a number of specimens known from places as far apart as Chile and Australia.

To read an article about the discovery of a giant pelagornithid from South America: Giant Seabird from Chile

Article about the discovery of fossils found in South Australia: Giant Toothed Birds once Soared over Australia

The “teeth” of these birds have no enamel.  They are in effect bony projections from the jawbones, they may not be true teeth but they were sharp and would have proved very effective in grabbing the prey of this large, ocean-going flyer.  It is likely that Pelagornis sandersi caught fish and squid at the sea surface.  Scientists remain uncertain as to whether this creature was capable of diving to catch prey.

Dr. Daniel Ksepka Examines the Skull of P. sandersi

Dr. Daniel Ksepka studies the skull of Pelagornis sandersi, World’s Largest-Ever Flying Bird.

Dr. Daniel Ksepka studies the skull of Pelagornis sandersi, World’s Largest-Ever Flying Bird.

Picture Credit: Bruce Museum

Dr. Daniel Ksepka is the author of an academic paper which appears this week in the “Proceedings of the National Academy of Sciences”.  This paper explores the flight capabilities of Pelagornis sandersi.  Although very large, the delicate bones suggest that this bird was very light.  Body weight estimates vary between 21 and 40 kilogrammes and the weight plus wingspan parameters have influenced the calculations of this creature’s ability to glide.  There is no doubt that this bird was an accomplished flyer, capable of travelling long distances, but the glide speed has been difficult to estimate because of the fragmentary fossil evidence.  A range of glide speeds have been stated, by Dr. Ksepka (lead author), from an impressive 10.6 metres per second to more than 17 metres per second.  To place this into context, Usain Bolt’s one hundred metres World Record of 9.58 seconds suggests an average speed over the race of around 10.4 metres per second, P. sandersi could effortlessly glide faster than Usain Bolt can sprint.  When the upper estimates are considered, Pelagornis sandersi could travel at speeds in excess of 38 miles per hour.

An Artist’s Reconstruction of the Giant Seabird Pelagornis sandersi

Giant pseudo-toothed sea bird.

Giant pseudo-toothed sea bird.

Picture Credit: Liz Bradford

Commenting on his study, Dr. Ksepka stated:

“Pelagornithids were like creatures out of a fantasy novel, there is nothing like them living today.”

It is very likely that this family of birds adapted to a long-range, marine soaring strategy just like extant albatrosses, the bigger the pelagornithid the greater distances it was able to travel.  The highly modified wing bones would have given this bird very long, slender wings, ideal for gliding.

Dr. Ksepka added:

“Pelagornis sandersi could have travelled for extreme distances whilst crossing ocean waters in search of prey”.

As well as the exceptionally well-preserved skull, bones from the right hind limb have been found.  These bones indicate that this bird would have been relatively clumsy on land.  It probably could not take off simply by leaping into the air and flapping its great wings, it probably needed to run down hill or jump off a cliff edge in order to take to the air.  Although it is difficult to ascertain the length of the primary feathers, it has been suggested that the primary feathers (the longest feathers found on the wing tips), would perhaps have measured more than a metre in length.

A spokesperson from Everything Dinosaur commented:

“This is a truly astonishing fossil.  Such delicate and fragile bones are rarely preserved in the fossil record and thanks to the work of Dr. Ksepka and his colleagues we are beginning to get a detailed insight into how these extraordinary birds lived.  The flight capabilities of this marine bird are simply astonishing.  For example, even at the lower end of the estimates for gliding speed, Pelagornis sandersi would have been capable of amazing feats of flight.  It would have been able to cross the entire Gulf of Mexico in less than a day!”

The species name honours retired Charleston Museum Curator Albert Sanders, who originally collected the fossil material.

Feathers Evolved Before Flight? Archaeopteryx had Feathered Trousers

Archaeopteryx Fossil Suggests Origins of Flight Complex

Adorning the front cover of the latest edition of the academic publication “Nature” is a beautiful colour photograph of the eleventh specimen of Archaeopteryx found.  The fossil might be in the hands of a private collector, but here is an example of wonderful co-operation between an individual and an academic institution.  For permission has been granted for this fossil, discovered in southern Germany in 2011, to be extensively researched and the first studies into this remarkable fossil have just been published.  We have a car manufacturer too, to thank for this research.

The Eleventh Archaeopteryx Specimen

Excellent feather preservation

Excellent feather preservation

Picture Credit: Helmut Tischlinger

The picture above shows the Archaeopteryx fossil that has been the subject of this research.  Although, like the majority of Archaeopteryx specimens the fossil has been crushed, the impressions of feathers on the wings, the tail and most significantly on the hind limbs can be clearly made out.  Everything Dinosaur has added labels to help readers to understand what this fossil shows.

The plumage is extremely well preserved and even under normal light, impressions of feathers can be clearly made out.  This has permitted a research team from the Ludwig Maximilian University of Munich (LMU) to study the feathers of this iconic creature and to compare them with feathered dinosaurs and bird fossils from China.

Palaeontologist Dr Oliver Rauhut of the Dept. of Earth and Environmental Sciences (LMU) and at the Bavarian State Collection for Palaeontology and Geology (Munich) and a co-author of the study commented:

“For the first time, it has become possible to examine the detailed structure of the feathers on the body, the tail and, above all, on the legs.”

Previous studies of this transitional fossil showed that Archaeopteryx possessed pennaceous feathers, the same sort of feathers associated with extant birds that can fly.  The feathers were asymmetrical and helped maintain an aerodynamic shape in the air of this “dino-bird”.  The presence of such pennaceous feathers on the hind legs had puzzled scientists.  Flight feathers on the hind limbs had led some palaeontologists to consider whether Archaeopteryx used its back legs in flight, it was, in effect, a four-winged glider.  Or did the feathers on the hind limbs serve another purpose, perhaps for display or for insulation, helping to keep this warm-blooded (very likely), little Theropod warm.

Specimen number eleven shows for the first time an imprint of virtually all of the plumage of Archaeopteryx including the tail feathers that measure up to 11.4 centimetres in length and those controversial feathers on the hind limbs that range in length from 4 to 4.5 centimetres.  Analysis of the feathers on the hind legs show that they were symmetrical on either side of the stem (rachis), unlike aerodynamic feathers that have one long side and one narrower side (like an asymmetrical aircraft’s wing).  It seems that the feathers on the hind limbs described as “feathered trousers” did not have a role in flight.

This finding contradicts the theory that the flapping flight of modern Aves was preceded by an intermediary stage involving four-winged gliding.

A Close up of the Feathers on the Hind Leg

Feather impression in the rock clearly visible.

Feather impression in the rock clearly visible.

Picture Credit: Helmut Tischlinger

The tail feathers, which were more than half the length of the caudal vertebrae (tail bones), were asymmetrical indicating that the tail could have been involved in flight, perhaps helping to provide lift and control.  Co-author of the study Dr. Christian Foth (LMU) along with De. Rauhut and photographer Helmut Tischlinger examined a number of feathered bird and dinosaur fossils.  They discovered that these specimens showed a great deal of variation in feathers.  Many of the feathered creatures in the study would have been incapable of flight as their arms were too short, other fossils had feathers in impractical places to permit a flight function.

The research team outline a new hypothesis that after feathers evolved, they became adapted for a range of different purposes, for display, for camouflage, to help keep animals warm and when the Dinosauria et al began to take to a more arboreal or aerial existence they evolved further to become more useful in flight and more aerodynamic in their shape.   This theory suggests that there was not one single origin of bird flight, but that it may have evolved in a number of species over a significant time period – an example of convergent evolution.

 A Model of an Archaeopteryx (Papo Archaeopteryx)

New from Papo for 2014 a model of Archaeopteryx.

New from Papo for 2014 a model of Archaeopteryx.

Picture Credit: Everything Dinosaur

The Papo Archaeopteryx model introduced in 2014, depicts Archaeopteryx with “feathered trousers”.  The feathers although unlikely to have a role in powered flight, may have helped keep the legs warm or offered protection from bites from any of the prey of this carnivorous creature.  Perhaps these feathers acted like air brakes helping to increase wind resistance as the animal came into land, thus slowing Archaeopteryx down and assisting with landing.

The German based researchers conclude that their study of the pennaceous feathers on Archaeopteryx, advanced Maniraptoran dinosaurs and primitive birds indicates that these structures evolved in a functional context and not specifically for flight.  Such feathers were slowly adapted for a role in the flight function, several lineages may have followed similar evolutionary developments leading to the aerodynamic, asymmetrical flight feathers occurring in a number of species.  If this is the case, then the origin of powered flight might be a whole lot more complex than previously thought.

We have the German car manufacturer Volkswagen to thank for this research.   The detailed analysis of the fossil was made possible by financial support from the Volkswagen Foundation.

A spokes person from Everything Dinosaur commented:

“The few fossils we have of Archaeopteryx may even represent sub-species or separate species.  We could imagine a scenario whereby on the relatively isolated islands of the Solnhofen archipelago, different types of feathered, Archaeopteryx evolved.  They may have once shared a common, mainland ancestor, but as populations became separated onto different islands, these weak-flyers evolved specific forms for each island habitat, a sort of Darwin’s finches as found on the Galapagos today but in this case, evolutionary dynamics driven by flight capabilities and not beak shape or size related to food resources.”

How Triceratops Got its Horns and Beak

Insights into the Evolution of Triceratops

It might sound like a Rudyard Kipling “Just So” story but scientists from Montana State University have been working out how Triceratops got its beak and horns.  The team of researchers had spent the past fifteen summers mapping and excavating Triceratops skull material from the Badlands of eastern Montana, from the world famous Hell Creek Formation.  University PhD candidate John Scannella and his three co-authors have published a paper in the “Proceedings of the  National Academy of Sciences”, that reports on the study of more than fifty Triceratops specimens and plots how this dinosaur gradually changed over two million years.

The team recorded the precise stratigraphic location for each Triceratops fossil.  The shape and characteristics of any skull material was then carefully analysed and this permitted the researchers to see evolutionary trends in the Triceratops genus through the Late Maastrichtian faunal stage.

The team noted that over one to two million years, the Triceratops skull specimens slowly changed.  They went from having a small nose horn and a long beak to having a longer nose horn and a shorter beak.  The two recognised species of Triceratops can be distinguished from each other by the shape and size of the beak and the shape and size of the nose horn.  Triceratops horridus has a small nose horn and a long beak, whereas, the second species in the genus Triceratops prorsus has a longer nose horn and a shorter beak.  Triceratops horridus fossils were confined to the older strata, the lower portions of the Hell Creek Formation, whilst fossils of T. prorsus were found in younger rocks at the top of the Hell Creek Formation.  Skulls found in the middle portions of the Formation displayed characteristics of both Triceratops species.

New Study Plots the Evolution of the Triceratops Genus

New study charts the evolution of Triceratops.

New study charts the evolution of Triceratops.

Picture Credit: Montana State University

The picture above shows that at rock layers dated to around 67.5 million years ago, fossils of Triceratops horridus with its large beak and short nose horn can be found.  In the Middle Hell Creek Formation, Triceratops skulls display a mix of T. horridus and T. prorsus traits.  In the youngest, top sediment layers, it is the T. prorsus skull morphology that dominates.

Commenting on this research, student John Scannella stated:

“This study provides a detailed look at shifts in the morphology of a single dinosaur genus over time.”

The Triceratops research, identifying that specimens of T. horridus and T. prorsus are found at different horizons, specifically Triceratops prorsus is confined to the upper third portion of the Hell Creek Formation.  The fact that these fossils are restricted to different stratigraphic levels confirms that there are indeed at least two species of Triceratops present.  A number of hypotheses had been proposed previously to help explain the different skull morphology, for example it had been suggested that the skull morphologies were a result of differences between males and females or due to ontogenetic (growth) variations between individuals of a single species.

 The Triceratops Family Tree is Explained

A colourful "Three-horned Face" Replica

A colourful “Three-horned Face” Replica (big beak, small nose horn = T. horridus)

Picture Credit: Safari Ltd

A number of academic institutions have been working together to map and record the flora and fauna preserved in the Hell Creek Formation.  The Hell Creek project involved Montana State University, The University of California plus the universities of North Dakota and North Carolina with the support of a number of academic and professional bodies.  The strata covers Montana, North and South Dakota and Wyoming in the Western United States and it represents a series of freshwater and brackish deposits laid down on the edge of the Western Interior Seaway.  The geology records the very end of the Cretaceous with the very youngest rocks ascribed to the Danian faunal stage (Palaeocene) , the first faunal stage after the Cretaceous mass extinction event.  The project examined both vertebrates, invertebrates and plants in a bid to learn about the changing ecosystems in that part of the world from the latter stages of the Cretaceous and into the Age of Mammals (Cenozoic).  Over the course of the project, the team discovered that the Triceratops species were the most common dinosaur in the Hell Creek Formation.  Although, it is very difficult to give an accurate figure, something like forty percent of all the dinosaur fossil material recovered from the Hell Creek Cretaceous layers represent the Triceratops genus.

Discussing the relative abundance of Triceratops fossil material, Scannella explained:

“Most dinosaurs are only known from one or a handful of specimens.  Some dinosaurs are known from a large number of specimens, but they’re often found all in one place – on a single stratigraphic horizon.  The great thing about Triceratops is that there are a lot of them and they were found at different levels of the Hell Creek Formation.”

The importance of the relatively large sample size (in excess of fifty specimens), was emphasized when he added:

“So we can compare Triceratops found at different [stratigraphic] levels.  When you have a larger sample size, you can learn much more about variation, growth and evolution.”

Evidence of a Genus Transformation in the Late Maastrichtian

Triceratops changed over time.

Triceratops changed over time.

Picture Credit: Holly Woodward

Other authors of the research paper that appears in the latest edition of the Proceedings of National Academy of Sciences, include Regents Professor of Palaeontology Jack Horner, Montana State University graduate student Denver Fowler and palaeontologist Mark Goodwin (University of California).

In July 2010, Everything Dinosaur team members reported on a paper produced by Scannella and John “Jack” Horner that proposed that Triceratops underwent such dramatic changes in its skull shape as it grew and matured that the dinosaur known as Torosaurus (T. latus), was not a separate genus at all, but the fossils of elderly Triceratops specimens.

To read more about this research: Torosaurus Extinction Second Time Around

PhD student Scannella added:

“The new study finds evidence that not only did Triceratops change shape over the lifetime of an individual, but that the genus transformed over the course of the end of the age of dinosaurs.”

This study represents one of the most thorough and detailed examinations yet on Ceratopsian head shields, their skulls and growth patterns.  Many of the specimens recovered from the Hell Creek Formation did not show signs of distortion or crushing, factors that could have skewed any analysis into skull shape and morphology, although a number of specimens were fragmentary and many others shattered into numerous pieces.  The project team are to be congratulated for the painstaking work carried out as scientists attempt to learn more about the evolution of one of the most famous dinosaurs of all “three horned face”.

It is fitting that the last word on Triceratops evolution (for now) should go to John Scannella.  He stated:

“The study emphasized how important it is to know exactly where dinosaur fossils are collected from.  A beautiful Triceratops without detailed stratigraphic data cannot answer as many questions as a fragmentary specimen with stratigraphic data.”

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