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Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

27 12, 2018

Convoluted Nasal Passages Helped Armoured Dinosaurs Cool Their Brains

By | December 27th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Armoured Dinosaurs Coped with the Mesozoic Heat Thanks to Nasal Air-conditioning

Being a very large dinosaur covered in armour, might help you to keep safe from attack by predatory dinosaurs, but this body plan does have its downsides.  For example, how do you keep cool when you have a very broad body?  New research from scientists based at Ohio University and the New York Institute of Technology College of Osteopathic Medicine at Arkansas State, suggests that those complicated Ankylosauria nasal passages acted like heat-exchanges helping to prevent these dinosaurs from overheating.  In essence, this study published in the academic, on-line journal PLOS One, suggests that members of the Ankylosauria clade had built-in air conditioning units in their noses.

Convoluted Nasal Passages Helped Armoured Dinosaurs to Avoid Overheating

Nasal air-conditioning in armoured dinosaurs.

Ankylosauria nasal passages used as heat exchanges.

Picture Credit: PLOS One with additional annotation from Everything Dinosaur

Panoplosaurus and Euoplocephalus Studied

The researchers, which included Jason Bourke (Assistant Professor at the New York Institute of Technology College of Osteopathic Medicine at Arkansas State), chose to examine the craniums of Euoplocephalus (E. tutus), a member of the Ankylosauridae family of dinosaurs along with the nodosaurid Panoplosaurus mirus.  A representative of the Nodosauridae family as well as a member of the Ankylosauridae was selected as Nodosaurs tend to have much narrower muzzles than the related Ankylosaurs.  In this way, the scientists were able to compare and contrast the different nasal passages associated with these two types of armoured dinosaur.

Assistant Professor Bourke commented:

“The huge bodies that we see in most dinosaurs must have gotten really hot in warm Mesozoic climates.  Brains don’t like that, so we wanted to see if there were ways to protect the brain from cooking.  It turns out the nose may be the key.”

Dr Victoria Arbour, an Authority on the Ankylosauria Poses Next to the Broad Skull of Euoplocephalus (E. tutus)

Dr Victoria Arbout next to a Euoplocephalus skull.

Victoria next to a skull of a Euoplocephalus tutus (University of Alberta).  Note the broad muzzle and the wide skull of this Late Cretaceous ankylosaurid.

Picture Credit: Angelica Torices

Computational Fluid Dynamic Analysis

The research team created three-dimensional, computer generated models of two famous skull fossils, a Panoplosaurus specimen housed in the Royal Ontario Museum collection and a Euoplocephalus skull from the American Museum of Natural History (New York).  A computational fluid dynamic analysis was then undertaken to map how air would have moved through the nasal passages as these dinosaurs breathed.  The scientists wanted to test the heat exchange capacity of the complex passages, to see how well the Ankylosauria noses transferred heat from the body to the inhaled air.

Co-author of the study, Lawrence Witmer (Ohio University), explained:

“A decade ago, my colleague Ryan Ridgely and I published the discovery that ankylosaurs had insanely long nasal passages coiled up in their snouts.  These convoluted airways looked like a kid’s ‘crazy-straw!’  It was completely unexpected and cried out for explanation.  I was thrilled when Jason took up the problem as part of his doctoral research in our lab.”

It is thought that these complex nasal passages gave members of the Ankylosauria clade, an exceptional sense of smell.  This may have been their primary function, however, noses are also heat exchangers, ensuring that air is warmed and humidified before it reaches the delicate lungs.  To accomplish this effective air conditioning, birds and mammals, including humans, rely on thin curls of bone and cartilage within their nasal cavities called turbinates, which increase the surface area, allowing for air to come into contact with more of the nasal walls.   Ankylosaurs and nodosaurids lacked turbinates, to compensate for this they evolved exceptionally long and twisty nasal passages.

Comparing Armoured Dinosaurs to Living Animals

When the researchers compared their findings to data from living animals, such as the nasal passages of an avian dinosaur (pigeon),  they discovered that the noses of armoured dinosaurs were just as efficient at warming and cooling respired air.  The length of the winding and twisting nasal passages in the two armoured dinosaurs studied were also measured.  In the narrow-snouted, nodosaurid Panoplosaurus, the nasal passages were a bit longer than the skull itself and in Euoplocephalus they were almost twice as long as the skull, which is why they are coiled up in the snout.

To see if nasal passage length was the reason for this efficiency in heat exchange, the researchers created alternative models with shorter, simpler nasal passages that ran directly from the nostril to the throat, as in most other animals.  The results clearly showed that nose length and the length of the nasal passages were indeed key to their air-conditioning ability.

Assistant Professor Bourke stated:

“When we stuck a short, simple nose in their snouts, heat-transfer rates dropped over fifty percent in both dinosaurs.  They were less efficient and didn’t work very well.”

Helping to Cool Brains

The blood vessels in the skull leading up to and surrounding the brain were mapped.  The scientists wanted to explore whether the internal plumbing of the snout helped to cool the brains of armoured dinosaurs.  The team found a rich blood supply running adjacent to the convoluted nasal passages.

Co-author Ruger Porter (Ohio University), explained:

“When we reconstructed the blood vessels, based on bony grooves and canals, we found a rich blood supply running right next to these convoluted nasal passages.  Hot blood from the body core would travel through these blood vessels and transfer their heat to the incoming air.  Simultaneously, evaporation of moisture in the long nasal passages cooled the venous blood destined for the brain.”

Euoplocephalus Kept a Cool Head

Cooling the brain of Euoplocephalus

Vascular pathways associated with the brain of Euoplocephalus tutus.  Red highlighted veins indicate main channels of heat transfer.

Picture Credit: PLOS One

Thermoregulation – A Problem for Large Animals

The large, broad bodies of Panoplosaurus and Euoplocephalus were really good at retaining heat, which might have some advantages, especially when you need to stay warm, but this does cause problems when large Tetrapods need to keep their cool.  This heat-shedding problem would have put them at risk of overheating even on cloudy days.  In the absence of some protective mechanism, the delicate neural tissue of the brain could be damaged by the hot blood from the body core.  In simple terms, the small brains of armoured dinosaurs might have been cooked inside the skull.

The complicated nasal airways of these dinosaurs were acting as radiators to cool down the brain with a constant flow of cooled venous blood.  This natural engineering feat also may have allowed some members of the Dinosauria to evolve into huge animals.

Lawrence Witmer added:

“When we look at the nasal cavity and airway in dinosaurs, we find that the most elaborate noses are found in the large dinosaur species, which suggests that the physiological stresses of large body size may have spurred some of these anatomical novelties to help regulate brain temperatures.”

26 12, 2018

“Little Foot” Reveals Her Secrets

By | December 26th, 2018|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Fourteen Years of Work to Tell the Story of “Little Foot”

Christmas is a time for family get togethers and spending time with relatives.  Today, we feature the astonishing story of the remarkable and nearly complete fossilised skeleton of an Australopithecine nicknamed “little foot” a member of the Hominidae family and as such, a long, distant relative of us all.  The Sterkfontein Caves in South Africa are located around twenty-five miles north-west of Johannesburg in Gauteng Province (South Africa).  Numerous fossils of hominids are known from the Caves and the surrounding area, which is called the Cradle of Humankind and Everything Dinosaur has reported on several recent and highly significant Australopithecine fossil finds, however, at an estimated 3.67 million years of age, “little foot” is the oldest Australopithecine specimen ever found in southern Africa.

The Partially Uncovered Remains of the Australopithecine Nicknamed “Little Foot”

In situ fossils of the Australopithecine "little foot" in the Sterkfontein Caves.

The fossilised remains of the Australopithecus nicknamed “little foot” found in the Sterkfontein Caves.  The skull can be seen in the bottom right corner of the photograph.

Picture Credit: PAST/Paul Myburgh

Lead researcher Professor Ron Clarke and his team have published the first, formal scientific description of the fossil material in the “Journal of Human Evolution”.  Such is the completeness of the skeleton, that anthropalaeontologists confidently predict that many more papers will be written, as this is the only known, virtually complete fossil skeleton of an Australopithecus discovered to date.  It has taken fourteen years of painstaking work to excavate the fossils and six years to clean and prepare them for detailed study.

Dedicated Research Leads to Scientific Breakthrough

In 1994 and 1997, Professor Clarke identified twelve foot and lower leg bones of one Australopithecus individual misidentified as animal fossils in boxes stored at Sterkfontein and at the University of Witwatersrand (Johannesburg).  Clarke and his assistants, Nkwane Molefe and Stephen Motsumi, then looked for and located the very spot where the bones had been blasted out by lime miners, probably sometime in the 1920’s deep inside the Sterkfontein Caves.  It was a real case of detective work, as Nkwane and Stephen worked in the caves to try to identify the very spot where the fossils that had been stored in the boxes, actually came from.  After one and a half of days of carefully searching the caves, they found that the pieces matched with two broken-through shin bones in a concrete-like cave infill and started the excavation process, first with hammer and chisel to remove the overburden, before turning to the painstaking process of locating and exposing the bones with an airscribe.

The Researchers were Able to Locate the Rest of the Skeleton by Matching Pieces Together

Identifying the rest of the "little foot" skeleton.

Researchers demonstrate how the rest of the skeleton was found by matching fragments of limb and ankle bones to fossil material exposed in the cave.

Picture Credit: PAST/Paul Myburgh

Unusual Taphonomy of the Female Australopithecine

The taphonomy of “little foot” is unusual.  The female (identified by the shape of the pelvis), fell into a cave and the body became mummified in the exceptionally dry conditions.  The absence of predators allowed the body to remain undisturbed but at some time in the past there was a slight displacement of some skeletal parts through slippage on the rock-strewn talus slope in the cave, crushing and breaking of some bones through rockfall and pressure, calcification after a change to wet conditions, and then slight downward collapse of part of the cave infill.  This partial collapse left voids that were later filled with stalagmitic flowstone that encased breaks through the femurs.  When the first attempts to date the fossils was made, an analysis of the stalagmite flowstone encasing the fossil was made.  However, the flowstones were later infills in voids created by the collapse that had broken and displaced parts of the skeleton.  The data gave a more recent date for the fossil, “little foot” was actually much older, having lived during the Zanclean stage of the Pliocene Epoch.

Professor Ron Clarke Demonstrates the Use of an Airscribe

Professor Ron Clarke demonstrates the use of an airscribe.

Professor Ron Clarke showing how an airscribe was used to remove the surrounding matrix.

Picture Credit: PAST/Paul Myburgh

Commenting on the earlier attempts to date the skeleton, Professor Clarke stated:

“The flowstones do not date the skeleton.  In 2015, cosmogenic isochron dates using 26Al and 10Be were published in Nature, showing that the age of the actual breccia containing the skeleton dates back ca 3.67 million years.  This is consistent with the original age estimates of around 3.5 million years that were proposed based on the low stratigraphic position of the deposit within the cave.”

Helping to Reassess the Australopithecus Genus

Study of the anatomical features of “little foot” suggests that the skeleton is most similar to the Australopithecine known as A. prometheus, which was proposed as a species in 1948 by the famous anthropologist Raymond Dart.  The phylogeny of the Australopithecines and related genera is controversial.  It is hoped that the virtually complete skeleton, so painstakingly excavated, will shed new light on taxonomic relationships, helping to fill in a number of evolutionary gaps.

Professor Ron Clarke and the Skull of “Little Foot”

The skull of "little foot" with Professor Ron Clarke

Professor Ron Clarke with the skull and left humerus of “little foot”.

Picture Credit: PAST/Paul Myburgh

Everything Dinosaur acknowledges the assistance of a press release from the University of Witwatersrand and supporting materials in the compilation of this article.

23 12, 2018

Evidence That Sharks Fed on Pterosaurs

By | December 23rd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Cretoxyrhina Tooth Embedded in the Neck of a Pteranodon

There has been quite a lot of media coverage this week, following the publication of a scientific paper that described the interaction between a shark from the Western Interior Seaway (Cretoxyrhina mantelli) and a pterosaur (Pteranodon).  A single tooth from the shark, was discovered wedged against the fourth cervical vertebra (fourth bone in the neck), of the flying reptile.  The association of the tooth and its proximity to the vertebra suggests that the preservation of bone and tooth together was more than mere coincidence.  The specimen is evidence of a Cretoxyrhina shark biting a Pteranodon.

Evidence for a Shark Bite on the Neck of a Pterosaur

Shark tooth found in association with pterosaur cervical vertebrae.

Evidence of a shark bite on the neck of a pterosaur.  The red arrow indicates the location of the shark tooth and its association with cervical vertebra IV.  Scale bar = 5 cm approximately.

Picture Credit: (A) Stephanie Abramowicz, courtesy Dinosaur Institute, Natural History Museum of Los Angeles County, (B) David Hone

The Pteranodon specimen is housed in a glass case at the Los Angeles Museum of Natural History, so the researchers, David Hone (University of London), Mark Witton (Portsmouth University) and Michael Habib (University of Southern California), had difficulty in obtaining direct access to the fossils.  However, undeterred they made measurements of the embedded fossil tooth and it is estimated to be 24 mm high (root plus crown) and its morphology suggests that it came from a well-known lamniform shark from the Western Interior Seaway – C. mantelli. 

Based on the tooth dimensions, the shark is estimated to have been around 2.5 metres long, big, but not as large as some Cretoxyrhina mantelli specimens, this species of Late Cretaceous shark is believed to have reached lengths of around seven metres, making it larger than the extant Great White (C. carcharias).

Identifying the Attacker

Teeth associated with lamniform sharks are particularly common in marine deposits associated with the Western Interior Seaway.  The morphology of the tooth suggests that this tooth came from Cretoxyrhina mantelli and this fossil specimen (LACM 50926), is the first documented occurrence of this large shark interacting with any type of flying reptile.

Typical Teeth Morphologies Associated with C. mantelli

Examples of Cretoxyrhina mantelli teeth from the front portion of the jaws.

Tracing of Cretoxyrhina mantelli anterior teeth.  The root of each tooth is shaded pale gray, whilst the crown is dark gray.  Tooth (a) is position 3 in the jaw, (b) represents a tooth from position 4, whilst (c) is a representation of the fossil tooth found in close association with the Pteranodon cervical vertebra.

Picture Credit: David Hone

Evidence of Cretoxyrhina biting Pteranodon

It is not possible to state categorically, whether the fossil specimen (LACM 50926), is evidence of predation or whether the shark took a bite out of a Pteranodon carcase.  Several examples of Cretoxyrhina spp. feeding traces are known on the fossilised remains of other vertebrates from the Western Interior Seaway.  In addition, there is evidence to suggest other types of fish, including sharks, consumed Pteranodon.  This is the first example of an interaction between Cretoxyrhina and “toothless wing”.

A Close-up View of the Neck Bone and the Shark Tooth

Cretoxyrhina tooth embedded in a pterosaur bone.

Shark tooth embedded in a Pteranodon neck bone.  Two views (a and b) of the tooth in association with the pterosaur vertebra and accompanying line drawings.

Picture Credit: David Hone

Spectacular Palaeoart

One of the co-authors of the paper, Mark Witton, is a highly respected palaeoartist, as well as an authority on the Pterosauria.  He has produced a stunning illustration of a Cretoxyrhina shark leaping out of the water as it bites the neck of a Pteranodon.

A Large Pteranodon Meets Its End in the Jaws of a Cretoxyrhina Shark

Cretoxyrhina shark attacks a flying reptile (Pteranodon).

A Cretoxyrhina shark leaps from the water as it attacks a Pteranodon.

Picture Credit: Mark Witton

Pteranodon is widely believed to have foraged for small fish and other aquatic prey by alighting on the water and dip-feeding.  Once on the surface of the sea, it would have been within the reach of predatory sharks, although whether the breaching Cretoxyrhina portrayed by Mark Witton accurately depicts an attack by the shark on a pterosaur is open to speculation.  However, the image is visually stunning and as marine seabirds today are actively predated by sharks, an example being Tiger sharks attacking fledgling albatross chicks, such a dramatic scene could have taken place on the waters of the Western Interior Seaway.  However, the tooth in association with the cervical vertebra could have resulted from the scavenging of a pterosaur carcase.

Not All That It Seems

The Pteranodon fossil in the display case is not all that it seems.  Like many museum specimens, it is a composite, it is made up of bones from several animals to help make the skeleton more complete.  Furthermore, part of the fossil display is genuine, but numerous elements have been reconstructed to replace absent parts.  The authors note that the preservation quality and size of the vertebrae correspond well to the other elements (including the forelimb bones) and this implies that LACM 50926 may represent much of a skeleton.  However, the absence of both anteriormost and posterior cervical vertebrae means no anatomical continuity links the 50926 vertebrae with the rest of the material and subsequently, their association to the rest of the skeleton cannot be stated confidently.

With all this said, LACM 50926 is the first palaeoecological link between a feeding Cretoxyrhina mantelli and a Pteranodon.  Such evidence of interactions like this are very rare in the fossil record.  Pteranodon seems to have been a relatively common flying reptile, it makes up some 97% of the Niobrara Formation pterosaur fossil finds.  Sharks feeding on large pterosaurs such as Pteranodon may have been a more frequent occurrence, but the hollow bones of these flying reptiles may have broken quite easily when subjected to the biteforce of a shark and so the likelihood of any fossil evidence being preserved would be diminished.  Chances are the evidence of such interactions just got consumed.

The scientific paper: “Evidence for the Cretaceous Shark Cretoxyrhina mantelli feeding on the pterosaur Pteranodon from the Niobrara Formation” by David W. E. Hone, Mark P. Witton and Michael B. Habib and published in the open access journal PeerJ.

22 12, 2018

New Giant Early Jurassic Predator from Italy

By | December 22nd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Saltriovenator zanellai – One Tonne Giant and Oldest Ceratosaurian Described to Date

Scientists from Natural History Museum of Milan and the Geological Museum of Bologna (Museu di Storia Naturale di Milano and the Museo Geologico), have published a scientific paper on a new predatory dinosaur from the Lombardy region of northern Italy.  This new species was a giant, weighing around a tonne and measuring approximately 7.5 metres in length.  It lived some 25 million years before other known big predatory dinosaurs evolved and examination of the fossilised bones suggest that this dinosaur was still growing when it died.  The dinosaur has been named Saltriovenator zanellai and it is the largest Theropod described to date from the Early Jurassic (Sinemurian faunal stage).

A Life Reconstruction of the Newly Described Ceratosaurian Theropod Saltriovenator zanellai

Saltriovenator zanellai life reconstruction.

A life reconstruction of Saltriovenator from the Early Jurassic of Italy.

Picture Credit: Davide Bonadonna

A Chance Discovery

Saltriovenator was discovered by chance in the summer of 1996 by amateur fossil collector Angelo Zanella, whilst exploring fossil rich limestone layers associated with a marble quarry near the town of Saltrio (Varese Province, Lombardy).  The strata containing the fossilised remains represent marine deposits and explosives used in the quarrying process had broken up the fossil bearing layer into hundreds of pieces.  In total, 132 fossil pieces were excavated from the site, the remains of a single animal.

The bones show feeding traces from fish and borings from marine invertebrates.  The palaeontologists writing in the on-line academic journal “PeerJ” suggest that the carcase was washed out sea and stayed on the seabed for some time, permitting the scavenging to take place.

Fossil Elements Used to Confirm Ceratosaurian Affinity with a Skeletal Drawing

Fossil elements used to identify Saltriovenator as a Ceratosaur.

Selected fossils of Saltriovenator and a skeletal reconstruction. Sections coloured red indicate fossil material.

Picture Credit: G. Bindellini, C. Dal Sasso and M. Zilioli and M. Auditore

The picture above shows key fossils that helped to classify Saltriovenator as a member of the Ceratosauria clade, it is the oldest Ceratosaur described to date.

Key

A, B, C = views of the right humerus.

D = left scapula.

E = right scapular glenoid and coracoid.

F = furcula (wishbone).

G = single tooth from the anterior portion of the lower jaw.

I = partial left humerus, the circular depressions represent borings made by marine invertebrates feeding on the carcase.

J, L, N = views of the right second metacarpal (finger bone).

K, M, O, = views of the right second digit.

P-T = views of the right third digit.

U = distal tarsal IV.

V, X = third right metatarsal views.

W, Y = second right metatarsal views.

Z = reconstructed skeleton of Saltriovenator with identified fossil elements shaded red.

Scale bars: 10 cm in (A)–(E), (I), and (U)–(Y); two cm in (F), and (J)–(T); one cm in (G).

A Skeletal Reconstruction of Saltriovenator zanellai 

A reconstruction of the skeleton of Saltriovenator.

Saltriovenator skeletal reconstruction.  Colour key – right bones in red; counterlateral copies of the left bones in light red; bones from the medial side of the lower jaw in orange.  Note scale bar equals one metre.

Picture Credit: M. Auditore

The First Jurassic Dinosaur From Italy

Saltriovenator is the first dinosaur to be described from fossils found in the Italian Alps.  It is the first dinosaur from the Jurassic Period to have been found in Italy and the country’s second Theropod, the first being Scipionyx samniticus which lived during the Early Cretaceous and at just over two metres in length, was considerably smaller than S. zanellai.  A study of growth rings found in a cross-sectional analysis of the fossil bones indicates that the dinosaur was around twenty-four years of age when it died.  It was still growing, albeit slowly, so the maximum size of this predator is not known, although at an estimated 7.5 metres long, it was considerably bigger than any other Theropod from the Early Jurassic described to date.

A Mosaic of Basal and More Advanced Theropod Features

Saltriovenator exhibits a mosaic of features seen in four-fingered Theropods and basal Tetanuran dinosaurs.  The fossilised finger bones indicate that this dinosaur had a fully functioning four-fingered hand, well-adapted for grasping and coping with struggling prey.  Later Ceratosaurs had only three fingers on each hand.  Study of the finger bones will help scientists to understand better the evolutionary relationships between the four-fingered Dilophosaurs, Ceratosaurs and later types of Theropod such as the Allosaurs with their atrophied hands.

Views of the Pectoral Girdle and the Right Hand of Saltriovenator zanellai

Saltriovenator right hand and forelimb.

Saltriovenator pectoral girdle and forelimb with a line drawing of the right hand showing four fingers.  Preserved elements in white, reconstructed bone in light grey, exposed inner bone in grey, hidden bone in dotted lines.  Scale bar equals 10 cm in (A) and (B), five cm in (C).

Picture Credit: M. Auditore

Commenting on the importance of this fossil discovery, one of the authors of the scientific paper, Dr Andrea Cau (Museo Geologico), stated:

“The grasping hand of Saltriovenator zanellai fills a key gap in the Theropod evolutionary tree: predatory dinosaurs progressively lost the pinkie and ring fingers and acquired the three-fingered hand which is the precursor of the avian wing.”

A spokesperson from Everything Dinosaur commented:

“The evolution of large, powerful predatory dinosaurs at the very beginning of the Jurassic, may have been a factor in the evolution of bigger and bigger herbivorous dinosaurs such as the Sauropods.  Think of it as an evolutionary arms race as carnivores got bigger, selection pressure was put on herbivores to become bigger and stronger themselves in order to avoid predation.”

21 12, 2018

The First Flowering Plants Originated in the Early Jurassic

By | December 21st, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Nanjinganthus dendrostyla – Putting Back Flowering Plants by 50 Million Years

When did flowering plants (Angiosperms) evolve?  That has been a puzzling question, one that has taxed the minds of leading scientists for more than 200 years.  Genetic studies indicate that the diverse and widespread Angiosperms have an ancient lineage, but the fossil record does not support this idea.  Fossils of delicate flowers are very rare and the oldest known, date from the Early Cretaceous.  Time for the fossil record to catch up with the announcement of the discovery of a plant that produced flowers some 174 million years ago, during the late Early Jurassic (Toarcian stage).

Specimens of the Newly Described Early Jurassic Flowering Plant Nanjinganthus dendrostyla

Nanjinganthus, a flowering plant from the Early Jurassic.

Views of individual specimens of Nanjinganthus, a flowering plant from the Early Jurassic.

Picture Credit: (NIGPAS)

The newly described plant has been named Nanjinganthus dendrostyla and it comes from the South Xiangshan Formation (Nanjing, eastern China), which has been studied extensively since the turn of the century and is famous for its abundant plant fossils, which up until now had consisted of cycads, ferns, ginkgoes and horsetails.  Researchers from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), have been able to identify the earliest known examples of a flowering plant, one that predates most of the Angiosperm fossil material by around 50 million years.

Catching Up with the Molecular Clock

Analysis of the genetic data contained in living plant taxa indicates that plants probably evolved earlier than previously thought.  In a study published in February, researchers from the Chinese Academy of Sciences as well as Bristol University, mapped the genetic make-up of 644 types of plant and concluded, based on molecular dating, flowering plants (Angiosperms), probably evolved sometime between the Late Permian and the Late Jurassic.

To read Everything Dinosaur’s article summarising this research: When Did Flowers Evolve?

Lots of Fossil Specimens to Study

The researchers studied a total of 264 specimens representing 198 individual flowers preserved on 34 slabs of stone.  The scientists had the luxury of working on so many examples of the same fossil organism.  They produced numerous high resolution images of the flowers allowing the features of N. dendrostyla to be revealed in great detail.  With so many fossil specimens, the scientists were able to exclude other plant types and confirm that the fossils do indeed represent an Angiosperm.

A Life Reconstruction of the Earliest Flowering Plant Described to Date

A life illustration of Nanjinganthus dendrostyla.

A life reconstruction of the flowering plant Nanjinganthus dendrostyla from the Early Jurassic of China.

Picture Credit: (NIGPAS)

Commenting on the significance of the study, one of the researchers Wang Xin (NIGPAS), stated:

“The origin of Angiosperms has long been an academic headache for many botanists.  Our discovery has moved the botany field forward and will allow a better understanding of Angiosperms.”

Identifying a Key Feature of Angiosperms

The scientists were able to identify the presence of fully enclosed ovules in the fossilised flowers.  These are the precursors of seeds before pollination.  The reconstructed flower was found to have a cup-form receptacle and ovarian roof that together enclosed the ovules/seeds.  This botanical feature confirms that Nanjinganthus dendrostyla is definitely an Angiosperm.

Numerous Examples of N. dendrostyla Preserved in Siltstone

A block containing evidence of the flowering plant Nanjinganthus.

One of the fossil blocks containing examples of Nanjinganthus (South Xiangshan Formation, China).

Picture Credit: (NIGPAS)

Discoveries of Angiosperm-like fossils have been reported from Jurassic rocks before.  In January (2018), Everything Dinosaur published an article on the remarkable discovery of fossilised wing scales from butterflies and moths that lived during the Late Triassic.  This discovery challenged the theory of co-evolution between flowering plants and pollinating insects such as members of the Lepidoptera.

To read Everything Dinosaur’s article about this: Ancient Butterflies Flutter By

The morphological features of Nanjinganthus distinguish it from other specimens and suggest that it is a new Angiosperm genus.

The scientists hope to determine whether Angiosperms are monophyletic (all flowering plants share a common ancestor).  If this is the case and Nanjinganthus is one of the earliest of all the flowering plants, then these fossils represent a stem group giving rise to all later species.  Angiosperms could also be polyphyletic, (a group descended from more than one common ancestor), meaning Nanjinganthus represents an evolutionary dead end and subsequently, it did not give rise to later types of flowering plant.

20 12, 2018

Russian Scientists Announce Dinosaur Discovery

By | December 20th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Volgatitan simbirskiensis – Early Cretaceous Leviathan

A team of palaeontologists from Russia have announced the discovery a new genus of Titanosaur from fossil bones found on the western bank of the River Volga close to the village of Slantsevy Rudnik in Ulyanovsk Oblast (western Russia).  The dinosaur has been named Volgatitan simbirskiensis, it is one of a trio of Sauropods recently described from Russian deposits, the others being Tengrisaurus starkovi and Sibirotitan astrosacralis, both of these herbivorous, long-necked dinosaurs were named and described in 2017.

V. simbirskiensis has been named based on the study of seven tail bones (caudal vertebrae), the first of which were discovered following a rock fall on the Volga River back in 1982.

A Scale Drawing of Volgatitan simbirskiensis Showing the Anatomical Position of the Known Fossil Material

Volgatitan fossil tail bones shown in situ and scale drawing.

A reconstruction of Volgatitan simbirskiensis with a human being shown for scale.

Picture Credit: St Petersburg State University

Tell Tale Tail Bones

Fortunately, for the Sauropoda, vertebrae can be quite diagnostic when it comes to ascribing new genera.  Titanosaurs for example, have distinctive shaped caudal vertebrae, especially towards the base of the tail (proximal end close to the hips).  The proximal tail bones of Titanosaurs are procoelous (pronounced pro-see-lus), that is, the front face of the bone is concave and the opposite face, the bit that points in the direction of the tail, is bulbous (convex).

Views of the Holotype Caudal Vertebra of V. simbirskiensis

Volgatitan caudal vertebra (holotype).

Views of a Volgatitan caudal vertebra.

Picture Credit: Alexander Averianov and Vladimir Efimov

The photograph (above) shows the holotype caudal vertebra of Volgatitan simbirskiensis in right lateral (A), anterior (B), left lateral (C), posterior (D), dorsal (E) and ventral (F) views.

Nomenclature

The dinosaur’s genus honours the Volga River, whilst the trivial name is in honour of the old name for the city of Ulyanovsk (Simbirsk), after all, the fossils were found just three miles to the north of the city.  Aleksandr Averianov, one of the authors of a scientific paper describing this new Titanosaur, published in the journal “Biological Communications”, explained that the description of dinosaur taxa in recent years has become possible due to the progress in understanding the anatomy and phylogeny of the Dinosauria.  Furthermore, the recent Russian Sauropod discoveries have allowed scientists to learn more about how these species of lizard-hipped reptiles had lived and developed.

Based on comparisons with the fossilised bones of more complete Titanosaurs, Volgatitan is estimated to have been around 16 metres long.  Fully fused neural arches on the centrum from the most proximal of the caudal vertebrae indicate that the bones came from a fully, mature adult animal.

It had been thought that Titanosaurs evolved in the southern hemisphere, specifically South America, with some taxa migrating into North America, Asia and Europe later in the Cretaceous.  However, the formal description of Volgatitan coming so soon after the naming of Tengrisaurus from the Early Cretaceous of Transbaikal Region, suggests that Early Cretaceous Titanosaurs were more widely distributed.  It is possible to postulate that important stages in the evolution of this group of long-necked dinosaurs may have taken place in eastern Europe and Asia.

For an article published in 2017 about the discovery of a new species of African Titanosaur: Shingopana songwensis from south-western Tanzania

To read about an Australian Titanosaur discovery made in 2017: Titanosaur “Judy” from the Outback

19 12, 2018

Dozens of Dinosaur Footprints Exposed at Hastings

By | December 19th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Dinosaur Footprints Exposed by Cliff Erosion

The seaside town of Hastings in East Sussex is steeped in history.  It is synonymous with the battle that began the Norman conquest back in 1066 but scientists have been aware for many years that the cliffs to the east of the town contain evidence of much older inhabitants – dinosaurs.  Researchers from the Department of Earth Sciences at Cambridge University have published a paper this week documenting dozens of Early Cretaceous dinosaur tracks and footprints that represent at least seven different kinds of dinosaur.

Two Iguanodontian Prints from the Lee Ness Sandstone (Ashdown Formation) Exposed at Hastings

Two iguanodontian footprints from the Lee Ness Sandstone.

Examples of two iguanodontian footprints from the Lee Ness Sandstone (Ashdown Formation).

Picture Credit: Neil Davies/University of Cambridge

A Rich and Diverse Dinosaur Fauna

The footprints and trackways were identified and mapped by a team of researchers from Cambridge University between 2014 and 2018, following periods of extensive coastal erosion along the cliffs to the east of Hastings.  The footprints range in size from 2 cm wide to over 60 cm across.   These prints and tracks record a rich and diverse dinosaur fauna from the Lower Cretaceous – Lee Ness Sandstones (Ashdown Formation), which date from approximately 140 million years ago (Berriasian faunal stage of the Cretaceous).

The exact age of the Lee Ness Sandstone strata is unknown, however, the Ashdown Formation is estimated to be around 145-133 million years old, based on relative dating of ostracod fossils.

The researchers, writing in the academic journal ” Palaeogeography, Palaeoclimatology, Palaeoecology”, report on more than 85 exceptionally well-preserved dinosaur footprints, comprising prints from at least seven different types of dinosaur (ichnogenera).  They document the trace fossils eroding out of cliffs and their work records the greatest diversity of dinosaurs in a single location in Cretaceous-aged rocks found in the UK.  In particular, a variety of armoured dinosaurs (Thyreophora) are represented.

One of the Many Different Types of Armoured Dinosaur Print Found

Armoured dinosaur footprint - Ashdown Formation (Hastings).

A footprint ascribed to an armoured dinosaur (Thyreophora) from the Lee Ness Sandstone (Ashdown Formation).  The print has been assigned to the Tetrapodosaurus ichnogenus.

Picture Credit: Neil Davies/University of Cambridge

Details of Skin, Scales and Claws are Visible

The trace fossils are preserved in remarkable detail.  Impressions of skin, scales and even toe claw impressions have been preserved.

A Close View of an Iguanodontian Print Showing a Distinct Claw Impression

Preserved iguanodontian claw impression.

A close view of an iguanodontian claw impression preserved within one of the dinosaur footprints.

Picture Credit: Neil Davies/University of Cambridge

An Iguanodontian Footprint with Preserved Skin Impressions

Iguanodontian footprint showing skin impressions.

Some of the tracks from recent rock falls show skin impressions.  This is the skin impression from the underside of an iguanodontian footprint.

Picture Credit: Neil Davies/University of Cambridge

The best preserved prints come from large blocks of stone that are mapped and photographed after recently falling from the cliff.  The tracks are quickly eroded with prolonged exposure to the elements and from damage caused by further rock falls.  When dealing with a rapidly eroding cliff, it is essential that any fresh rock falls are examined and any fossils contained within the blocks are mapped and measured.

Two Photographs (February 2017 and February 2016) Showing the Extent of the Trace Fossil Erosion

Weathering of the dinosaur tracks at Hastings.

The effect of weathering on the trace fossils.  Over 12 months the tracks are heavily eroded.

Picture Credit: Neil Davies/University of Cambridge

Wealden Group Trace Fossils

The Ashdown Formation is part of the Wealden Group of rock formations, the most important sequence of dinosaur fossil bearing strata in England.  Numerous fossilised footprints are associated with the Wealden Group and the first report of tracks was made in 1846 by the Reverend Tagart, who described a series of three-toed prints, which he thought had been made by giant birds.  Never before has such a diverse footprint assemblage been mapped and documented in the British Isles.

A Table Showing the Different Types of Dinosaur Footprint (Morphotypes) Mapped at the Location

Lee Ness Sandstone dinosaur footprint analysis.

A table showing the number and characteristics of the Hastings dinosaur footprint fossils.

Table Credit: Palaeogeography, Palaeoclimatology, Palaeoecology with additional notation from Everything Dinosaur

One of the authors of the scientific paper, Anthony Shillito, a PhD student in Cambridge’s Department of Earth Sciences commented:

“Whole body fossils of dinosaurs are incredibly rare.  Usually you only get small pieces, which don’t tell you a lot about how that dinosaur may have lived.  A collection of footprints like this helps you fill in some of the gaps and infer things about which dinosaurs were living in the same place at the same time.”

Different Kinds of Theropod Dinosaurs

The footprints along with the various plant fossils and invertebrate trace fossils (burrows), are helping the scientists to put together a picture of life in this part of the world in the Early Cretaceous.  Dinosaurs dominated the biota, with several different types of meat-eating dinosaur (Theropods) identified, including a potential dromaeosaurid-like dinosaur, as two-toed prints (didactyl) have been found.

Different Types of Theropod Track Have Been Found

Different types of Theropod footprint. Scale bars = 5 cm.

Examples of different types of Theropod footprint (Lee Ness Sandstone – Ashdown Formation).

Picture Credit: Neil Davies/University of Cambridge

The picture above shows four different types of Theropod footprint identified at the Hastings site.  Picture (A) shows a large tridactyl (three-toed) cast with a long digit III and a faint heel impression.  The footprint in (B), is also large but the toes are narrower and elongated, maintaining a consistent width for their whole length.  The cast has no heel pad impression.  The Theropod morphotype (C), represents a much smaller animal with digit III being much longer than digits II and IV.  Intriguingly, the researchers have also logged potential two-toed prints (D), this suggests that this floodplain, braided environment might have been home to dromaeosaurid-like dinosaurs.

PhD student Shillito added,

“You can get some idea about which dinosaurs made them from the shape of the footprints, comparing them with what we know about dinosaur feet from other fossils lets you identify the important similarities.  When you also look at footprints from other locations you can start to piece together which species were the key players.”

Although, the majority of the footprints have been ascribed to Ornithopods, and several are referred to as iguanodontian, none of these prints were made by a member of the Iguanodon genus.  Iguanodon (I. bernissartensis), lived many millions of years after these prints were formed.  There have been many different types of iguanodont described, it is possible that the larger prints were made by an animal such as Barilium dawsoni.  The slightly smaller prints could have been created by the iguanodontid Hypselospinus (H. fittoni).

The Three-toed Tracks of a Small Ornithopod Dinosaur

Small Ornithopod trackway (Ashdown Formation).

Trackway assigned to a small, Ornithopod dinosaur.

Picture Credit: Neil Davies/University of Cambridge

Dinosaurs Helping to Shape the Environment

Anthony Shillito is focusing on the role played by dinosaurs in terms of shaping their environment, how dinosaurs behave as zoogeomorphic agents.  Large animals today, such as elephants and hippos can alter their habitats as they interact with their environment.  Hippos for example, can create river channels and divert the course of water flow.  Dinosaurs very probably did the same, with larger dinosaurs having a bigger impact than smaller dinosaurs.

The student commented:

“Given the sheer size of many dinosaurs, it’s highly likely that they affected rivers in a similar way, but it’s difficult to find a ‘smoking gun’, since most footprints would have just washed away.  However, we do see some smaller-scale evidence of their impact; in some of the deeper footprints you can see thickets of plants that were growing.  We also found evidence of footprints along the banks of river channels, so it’s possible that dinosaurs played a role in creating those channels.”

Evidence of Sauropods?

Footprint evidence indicating the largest dinosaurs of all, the presence of Sauropods is virtually absent from the site.  Three poorly preserved trace fossils have been tentatively ascribed to the Sauropoda, although they are very indistinct and could represent under traces representing the tracks of other ichnogenera.

It is very likely that there are many more dinosaur footprints hidden within the eroding sandstone cliffs of East Sussex, but the construction of sea defences in the area to slow or prevent the process of coastal erosion may mean that they remain locked away within the rocks.

The scientific paper: “Dinosaur-landscape Interactions at a Diverse Early Cretaceous Tracksite (Lee Ness Sandstone, Ashdown Formation, southern England)” by Anthony P. Shillito and Neil S. Davies published in Palaeogeography, Palaeoclimatology, Palaeoecology.

18 12, 2018

Zuul Goes on Display at the Royal Ontario Museum

By | December 18th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Amazing Armoured Dinosaur Zuul Goes on Display

The ankylosaurid named Zuul (Z. crurivastator), is the centrepiece of a new exhibition that opened this week at the Royal Ontario Museum, (Canada).  The exhibition is entitled “ZUUL: Life of an Armoured Dinosaur” and it tells the tale of how this beautifully-preserved dinosaur fossil was discovered and what it can tell us about life in the Late Cretaceous some 76 million years ago.

Zuul – Destroyer of Shins

Zuul crurivastator exhibit opens at the Royal Ontario Museum.

A life reconstruction of the giant armoured dinosaur from Montana Zuul crurivastator.

Picture Credit: Royal Ontario Museum

Commenting on this new addition to the Museum’s galleries, Royal Ontario Museum Director and CEO Josh Basseches stated:

“We are thrilled to be introducing Toronto and the world to an extraordinary new dinosaur.  The acquisition of Zuul represents a significant new addition to our globally renowned collection of dinosaurs and fauna.  With the generous support of presenting sponsor Sinking Ship Entertainment, and our team of renowned palaeontologists and exhibition developers, we look forward to presenting a truly unique exhibition that will inspire and delight visitors of all ages.”

Cutting Edge Technology to Showcase Ancient Armoured Giant

The exhibition uses a combination of engaging video games, digital images and animations along with full-sized murals that recreates northern Montana/southern Alberta during the Campanian faunal stage of the Late Cretaceous.

This is the first time that the fossilised remains of Zuul have been put on display anywhere in the world.  Touchscreens will let visitors rotate 3-D views of Zuul’s original fossil pieces, while life-size touchable bronze models of Zuul’s skull, armour, skin, and tail club will permit visitors to feel what it would have been like to touch the living dinosaur.  An animal named after a monster from the 1984 film “Ghostbusters” , Zuul was named in honour of the horned, demi-god Zuul, the Gatekeeper of Gozer from the movie.

A Replica of the Zuul Fossil Material Being Attacked by a Gorgosaurus

Zuul being attacked by a Gorgosaurus.

A replica of the Zuul fossil material being attacked by a tyrannosaurid (Gorgosaurus).

Picture Credit: Royal Ontario Museum

Dr David Evans, the exhibition’s lead curator and one of the palaeontologists that formally named and described this Ankylosaur, commented:

“In this multi-faceted exhibition, visitors will see the breath-taking Zuul fossil up close and through a treasure trove of incredible fossils found alongside the skeleton, learn more about Zuul’s diverse ancient world.  Zuul: Life of an Armoured Dinosaur will spark curiosity about our distant past and the evolution of life over time.”

To read Everything Dinosaur’s article on the discovery of this remarkably complete (95% of the skeleton has been preserved), armoured dinosaur: Zuul – The Destroyer of Shins

The Beautiful and Fantastically-well Preserved Skull of Zuul crurivastator will be on Display as Part of the Exhibit

The very nearly complete skul of Zuul crurivastator.

The beautifully-preserved skull of Zuul crurivastator will be on display as part of the exhibit.

Picture Credit: Royal Ontario Museum

From the Judith River Formation of Montana

Heralding from the famous Judith River Formation, Zuul crurivastator is one of the most complete Ankylosaur fossils ever found.  It has a complete skull and tail club as well as preserved skin and other soft tissues that will provide a rare and exciting opportunity for new, cutting-edge scientific research.  Zuul was acquired by the ROM in 2016 through the generous support of the Louise Hawley Stone Charitable Trust.

Everything Dinosaur acknowledges the assistance of a press release from the Royal Ontario Museum in the compilation of this article.

17 12, 2018

Are the Feathers About to Fly in the Pterosauria?

By | December 17th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Study Finds Four Types of Feather-like Structures in Pterosaur Fossils

Most palaeontologists have accepted that it is likely that pterosaurs (flying reptiles), were covered in a sort of hairy fuzz, technically referred to as pycnofibres, that helped insulate their bodies and keep them warm.  However, an international team of scientists from Hong Kong University, Nanjing University (China), University College Cork, University College Dublin (Ireland), the Foundation for Scientific Advancement, (Arizona, USA), the Chinese Academy of Sciences and Bristol University (UK) have published a scientific paper that describes four kinds of feather-like structures associated with the fossilised remains pterosaurs.  If these structures are feathers, then this suggests that either the Pterosauria evolved feathers as a form of convergent evolution, or, that feathers evolved many millions of years earlier than previously thought – in a common ancestor of the Dinosauria and the Pterosauria.

A Life Reconstruction of the Chinese Anurognathid Pterosaur

A life reconstruction of a "feathered" anurognathid pterosaur.

Daohugou pterosaur life reconstruction.  Fossil evidence indicates that pterosaurs may have had at least four types of feathers.

Picture Credit: Yuan Zhang

Two Anurognathid Pterosaur Specimens Studied

Writing in the academic journal “Nature Ecology and Evolution”, the scientists report how high-resolution microscopy revealed evidence of different kinds of pycnofibres on two pterosaur fossils  (representing anurognathids), from the Daohugou Formation in Inner Mongolia.  Although, when the rocks that make up the Daohugou Formation were deposited has been debated and the relative dating of these sediments in relation to other Chinese Jurassic/Early Cretaceous formations has proved controversial, it is suggested that the pterosaurs, one of which represents a new species, lived approximately 160 million years ago.

Four feather-like structures were identified:

  • simple filaments (hairs)
  • bundles of filaments
  • filaments with a tuft halfway down the shaft
  • down feathers

The Scientists Identified Four Types of Feather-like Structures in the Fossils

Different types of filaments associated with pterosaur fossils.

Close-up views of different types of feather-like filaments identified in pterosaur fossils.

Picture Credit: Yang, Jiang, McNamara et al

An Amazing Discovery

One of the paper’s authors, Dr Maria McNamara (University College Cork), stated that some critics have suggested that there is only one simple hair-like type of pycnofibre, but this study shows different structures that we also see in dinosaurs, in essence real feathers.  Furthermore, the team identified melanosomes that indicate that some flying reptiles may have been coloured a sort of reddish brown.

Dr McNamara explained:

“We focused on areas where the feathers did not overlap and where we could see their structure more clearly.  They even show fine details of pigment granules, which may have given the fluffy feathers a ginger colour.  This discovery has amazing implications for our understanding of the origin of feathers, but also for a major time of revolution of life on land.  When feathers arose, about 250 million years ago, life was recovering from the devastating end-Permian mass extinction.”

The Enigmatic Anurognathidae

Only a handful of anurognathid fossils are known and only a few species have been assigned to this pterosaur family.  Although, the first anurognathids were described from Upper Jurassic deposits of Bavaria (Solnhofen limestone), the best preserved and most complete specimens came from the Daohugou Beds of Inner Mongolia.  Since these types of small, short-faced flying reptiles are known from Europe, South Korea, China and potentially North America, they seem to have been geographically widespread.  Although very rare, the Daohugou Bed fossil specimens have some soft tissue and muscle outline preservation and have provided palaeontologists with a lot of information on pterosaur anatomy.

An Anurognathid Pterosaur from the Daohugou Beds – Jeholopterus ninchengensis 

Jeholopterus pterosaur fossil.

Pterosaur material from the Daohugou Beds.  This is a fossil specimen of the anurognathid pterosaur Jeholopterus ninchengensis.

Picture Credit: Chinese Academy of Sciences/Journal of Vertebrate Palaeontology

Re-writing the History of the Evolution of Feathers

Feathers are essentially highly modified scales; this new research could potentially re-write the evolutionary history of feathers.  One of the authors, Professor Mike Benton (Bristol University), explained:

“We ran some evolutionary analyses and they showed clearly that the pterosaur pycnofibres are feathers, just like those seen in modern birds and across various dinosaur groups.  Despite careful searching, we couldn’t find any anatomical evidence that the four pycnofibre types are in any way different from the feathers of birds and dinosaurs.  Therefore, because they are the same, they must share an evolutionary origin, and that was about 250 million years ago, long before the origin of birds.”

Birds have two types of advanced feathers used in flight and for body smoothing, the contour feathers with a hollow quill and barbs down both sides.  These types of feathers are found only in birds and the Theropod dinosaurs close to the evolutionary origins of the Aves (birds).  However, the other feather types of modern birds include monofilaments and down feathers, and these are seen much more widely across dinosaurs and pterosaurs.

The armoured dinosaurs and the giant Sauropods probably did not have feathers, but they were likely suppressed, meaning they were prevented from growing, at least in the adults, just as hair is suppressed in large-bodied animals today such as cetaceans, hippos and elephants.

High Resolution Microscopy Revealed Different Types of Feather-like Structures

High resolution microscopy identified different types of integumentary filamentous structures in pterosaur fossils.

Different types of integumentary filamentous structures identified in specimen number CAGS-Z070.

Picture Credit: Yang, Jiang, McNamara et al

Professor Benton added:

“This discovery has amazing implications for our understanding of the origin of feathers, but also for a major time of revolution of life on land.  When feathers arose, about 250 million years ago, life was recovering from the devasting end-Permian mass extinction.  Independent evidence shows that land vertebrates, including the ancestors of mammals and dinosaurs, had switched gait from sprawling to upright, had acquired different degrees of warm-bloodedness, and were generally living life at a faster pace.  The mammal ancestors by then had hair, so likely the pterosaurs, dinosaurs and relatives had also acquired feathers to help insulate them.  The hunt for feathers in fossils is heating up and finding their functions in such early forms is imperative.  It can rewrite our understanding of a major revolution in life on Earth during the Triassic, and also our understanding of the genomic regulation of feathers, scales, and hairs in the skin.”

Different Kinds of Pycnofibres – Different Functions?

Pterosaurs were the first back-boned animals to evolve powered flight.  However, following their extinction at the end of the Cretaceous, they left no living close relatives, nor indeed any near related analogues for scientists to study.  Whilst the presence of pycnofibres on the bodies of these flying reptiles is quite well accepted by the scientific community, their functions are not fully understood.  If different types of feather-like structures have been identified in two anurognathid pterosaur specimens, it is likely that other types of pterosaur had them too.

These different feather-like structures probably served a variety of functions, perhaps the first “pterosaur fuzz” evolved to provide insulation and then other types evolved perhaps to aid tactile sensing, visual communication and to assist with flight.

The scientific paper: “Pterosaur Integumentary Structures with Complex Feather-like Branching” by Z. Yang, B. Jiang, M. McNamara, S. Kearns, M. Pittman, T. Kaye, P. Orr, X. Xu and M. Benton and published in Nature Ecology and Evolution.

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

14 12, 2018

A New Horned Dinosaur Species from Late Cretaceous Arizona

By | December 14th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Crittendenceratops krzyzanowskii – A New Horned Dinosaur from Arizona

Many scientists and observers have described the last two decades as the “Golden Age” of dinosaur discoveries.  Since the turn of the century, there have been some astonishing fossil finds and many new species of dinosaur have been discovered and described.  None more so than with the horned dinosaurs and their relatives (Marginocephalia).  Over the last few years, we have reported on numerous new types of Ceratopsian, many of these new horned dinosaurs having been discovered in strata laid down in the United States, for example, Medusaceratops, Aquilops, Kosmoceratops and Utahceratops.  Surprisingly, there had been no new horned dinosaurs named in 2018, that is no longer the case with a scientific paper published describing a new Centrosaurine dinosaur from the Late Cretaceous of Arizona – Crittendenceratops krzyzanowskii.

A Life Reconstruction of the Newly Described Ceratopsian Crittendenceratops krzyzanowskii

Crittendenceratops krzyzanowskii illustrated.

A life reconstruction of the newly described Ceratopsian Crittendenceratops (2018).

Picture Credit: Sergey Krasovskiy

Only a Few Dinosaurs Named from Arizona

Writing in the New Mexico Museum of Natural History and Science Bulletin, the researchers, Sebastian G. Dalman and Asher Lichtig, both Research Associates at the New Mexico Museum of Natural History and Science, in collaboration with John-Paul Hodnett from the Maryland-National Capital Parks Commission and Spencer G. Lucas (a curator at the New Mexico Museum of Natural History and Science), describe Crittendenceratops and assign it the Centrosaurinae subfamily of horned dinosaurs and specifically to the Nasutoceratopsini tribe.

There have been so many new horned dinosaurs from North America named and described in the last twenty years or so, that this has led to a revision of Ceratopsian taxonomy.  For example, the Nasutoceratopsini was erected recently (2016).

To read an article that summarises this revision: Redefining the Horned Dinosaurs

Despite the wealth of dinosaur fossil material associated with the western United States, Crittendenceratops is one of only a handful of dinosaurs named from Arizona.

A Reconstruction of the Parietosquamosal Frill of C. krzyzanowskii

A reconstruction of the parietal frill of Crittendenceratops krzyzanowskii.

A line drawing showing a reconstruction of the parietosquamosal frill of Crittendenceratops krzyzanowskii.

Picture Credit: New Mexico Museum of Natural History and Science

From the Fort Crittenden Formation

This new herbivore has been described from fragmentary fossil material, including skull elements from the shale member of the Fort Crittenden Formation.  Two individual animals are represented by the fossils.  Crittendenceratops is estimated to have been around 3.5 metres in length and would have weighed about 750 kilograms.  It lived 73 million years ago (Campanian stage of the Cretaceous) and the rocks that yielded the bones were deposited along the margins of a large lake that was present in an area southeast of Tucson, Arizona.

The Nearly Complete Left Squamosal (Skull Bone) of Crittendenceratops

Near complete left squamosal bone of Crittendenceratops (NMMNH P-34906) dorsal view.

Left squamosal bone of Crittendenceratops (NMMNH P-34906) dorsal view.

Picture Credit: New Mexico Museum of Natural History and Science

Honouring Stan Krzyzanowski

The new species was named by Sebastian G. Dalman, John-Paul Hodnett, Asher Lichtig and Spencer G. Lucas.  The genus name reflects the rock formation where the fossils were found (Fort Crittenden Formation), whereas the trivial name honours the late Stan Krzyzanowski, a Research Associate from the New Mexico Museum of Natural History and Science, who discovered the first bones to be ascribed to this new dinosaur in the Adobe Canyon area eighteen years ago.  Crittendenceratops can be distinguished from other members of the Centrosaurinae subfamily by the unique shape of the bones in its frill.

The scientific paper: “A New Ceratopsid Dinosaur (Centrosaurinae Nasutoceratopsini) from the Fort Crittenden Formation Upper Cretaceous (Campanian) of Arizona” by Spencer G. Lucas, Sebastian Dalman, Asher Lichtig and John-Paul Michael Hodnett published in the New Mexico Museum of Natural History and Science Bulletin.

Everything Dinosaur acknowledges the assistance of a press release from the New Mexico Museum of Natural History and Science in the compilation of this article.

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