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/Geology

Articles, features and stories with an emphasis on geology.

1 04, 2019

Amazing Fossils Depict End Cretaceous Mass Extinction Event

By | April 1st, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Fossil Discovery Offers Detailed View Minutes After Chicxulub Impact

A paper published in the PNAS (Proceedings of the National Academy of Sciences – USA), provides a detailed snapshot of a terrible natural disaster linked to the Chicxulub bolide impact event.  A site (Tanis), in North Dakota’s Upper Cretaceous Hell Creek Formation, records the devastation caused by a massive surge of water which occurred as seismic shockwaves reverberated around the Earth as a result of the huge extra-terrestrial impact in what is now the Gulf of Mexico.

Examining Rock Layers Looking for Evidence

Exploring sediments, looking for fossils.

Identifying the K-T boundary at the margins of  Upper Cretaceous sediments.

Picture Credit: Robert DePalma (University of Kansas)

A team of palaeontologists, including researchers from the University of Kansas, the Black Hills Institute and Manchester University, in collaboration with a number of other academic institutions report on what has been described as a “motherlode of exquisitely-preserved plant, animal and fish fossils”, the remains of a river ecosystem which flowed into the Western Interior Seaway, which was wrecked within minutes of the extra-terrestrial impact event.

The site is described as a “rapidly emplaced high-energy onshore surge deposit” along the KT boundary that contains associated ejecta and iridium impactite associated with the End Cretaceous extinction event that resulted in the loss of many groups of terrestrial vertebrates including the pterosaurs and the dinosaurs as well as the extinction of a wide variety of marine organisms.

Lead author of the scientific paper, Robert DePalma (University of Kansas), described the site as:

“A tangle mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures was all packed into this layer by the inland-directed surge”.

One of the Plaster Jackets from the Site Reveals the Devastation

The Tanis Konservat-Lagerstätte

The Tanis Konservat-Lagerstätte.  Plaster field jacket  (A) with partially prepared (freshwater) Acipenseriform fish next to a fragment from an ammonite shell (inset).

Picture Credit: PNAS

The doctoral student went onto add:

“Timing of the incoming ejecta spherules matched the calculated arrival times of seismic waves from the impact, suggesting that the impact could very well have triggered the surge.”

Devastation Occurred Within Minutes of the Impact

The researchers conclude that the fossil site does not record a tsunami.  Tanis is more than 2,000 miles from the bolide impact site in the Gulf of Mexico, a tsunami would have taken at least seventeen hours to reach North Dakota, but seismic waves and a subsequent water surge would have occurred within minutes of the collision.

DePalma and his colleagues describe the rushing wave that shattered the Tanis site as a “seiche.”

What is a Seiche?

A seiche (pronounced “saysh”), relates to a standing wave in an enclosed or part-enclosed body of water.  This term was first used widely by the Swiss scientist François-Alphonse Forel (1841-1912), who pioneered the study of inland water ecosystems.  It is believed the etymology derives from the Swiss/French dialect meaning “swaying back and forth”, a reference to observations of water level changes in alpine lakes.  This phenomenon can have many causes, but seismic activity is known to lead to water surges.

DePalma explained:

“As the 2011 Tohoku earthquake in Japan showed us, seismic shaking can cause surges far from the epicentre.  In the Tohoku example, surges were triggered nearly 5,000 miles away in Norway just 30 minutes after impact.  So, the KT impact could have caused similar surges in the right-sized bodies of water worldwide, giving the first rapid “bloody nose” to those areas before any other form of aftermath could have reached them.”

According to Kansas University researchers, even before the surge arrived, Acipenseriform fish (sturgeon) found at the site already had inhaled tiny spherules ejected from the Chicxulub impact.

Fish Fossils Show Evidence of Microtektites Embedded in Their Gills

Microtektites from the Chicxulub impact recorded in fossil fish.

Fish Fossils show evidence of microtektites embedded in their gills.

Picture Credit: PNAS

The picture above shows Acipenseriform fish with ejecta clustered in the gill region.  Image (A) an X-ray of a fossil sturgeon head (outlined, pointing left; FAU.DGS.ND.161.115.T).  Magnified image (B) of the X-ray in (A) showing numerous ejecta spherules clustered within the gill region (arrows).  Images C and D are micro-CT images of another fish specimen (paddlefish), with microtektites embedded between the gill rakers in the same fashion.

Co-author David Burnham (Kansas University) stated:

“The fish were buried quickly, but not so quickly they didn’t have time to breathe the ejecta that was raining down to the river.  These fish weren’t bottom feeders, they breathed these in while swimming in the water column.  We’re finding little pieces of ejecta in the gill rakers of these fish, the bony supports for the gills.  We don’t know if some were killed by breathing this ejecta, too.”

One of the co-authors of the paper is Californian geologist Walter Alvarez, who, along with is his father Luis, postulated the theory of an impact event playing a role in the End Cretaceous extinction (1980).  They identified a layer of sediment in the strata marking the Cretaceous/Palaeogene boundary (KPg), that was enriched with the rare Earth element iridium and they concluded that an extra-terrestrial object must have collided with the Earth.

The Approaching Bolide About to Strike Planet Earth

Asteroid strikes the Earth.

An extra-terrestrial impact event.  Moments before the impact event, now scientists have fossil evidence providing data on what happened minutes after the collision.

Picture Credit: Deposit Photos/Paul Paladin

Described as a Lagerstätte of the KT Event

The number and quality of preservation of the fossils at Tanis are such that Burnham dubs it the “lagerstätte” of the KT event.  A lagerstätte, comes from the German “storage place”, it describes a sedimentary deposit that contains a large number of very well preserved fossils.  For example, the Tanis site preserves numerous Acipenseriform fish, which are cartilaginous and not bony and therefore less likely to become fossils.

David Burnham added:

“The sedimentation happened so quickly everything is preserved in three dimensions, they’re not crushed.  It’s like an avalanche that collapses almost like a liquid, then sets like concrete.  They were killed pretty suddenly because of the violence of that water.  We have one fish that hit a tree and was broken in half.”

Indeed, the Tanis location contains many hundreds of articulated ancient fossil fish killed by the Chicxulub impact’s consequences and is remarkable for the biodiversity it reveals alone.

Mapping the Direction of the Surge and Examining the Fish Fossils

Carcasses orientated by flow and mass mortality deposit.

A site map (left) showing the flow of water indicated by the orientation of the material and a mass deposit of fish from the site.

Picture Credit: PNAS

Several New Species

The scientists conclude that there are likely to be several new species of fish named as a result of this discovery.  In addition, some specimens are the best known examples of their genus found to date.  It was quickly realised that the surrounding matrix was deposited by a sudden, violent rush of water, a surge that was directed inland away from the Western Interior Seaway.  Impact debris including shocked minerals and ejecta spherules were found in the sediment and a compact layer of KT boundary clay overlies the deposit.

Tanis provides a post impact “snapshot,” including ejecta accretion and faunal mass death, advancing our understanding of the immediate effects of the Chicxulub impact.

According to Burnham, this site will advance our understanding of the Chicxulub impact significantly, describing Tanis as “smoking-gun evidence” of the aftermath.

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

The scientific paper: “A Seismically Induced Onshore Surge Deposit at the KPg Boundary, North Dakota” by Robert A. DePalma, Jan Smit, David A. Burnham, Klaudia Kuiper, Phillip L. Manning, Anton Oleinik, Peter Larson, Florentin J. Maurrasse, Johan Vellekoop, Mark A. Richards, Loren Gurche, and Walter Alvarez published in the PNAS.

28 02, 2019

Rare Fossils of a North Lincolnshire Pliosaur Go on Display

By | February 28th, 2019|Dinosaur and Prehistoric Animal News Stories, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

The “Scunthorpe Pliosaur”

This week has seen the formal unveiling of the fossilised remains of a pliosaur at North Lincolnshire Museum in Scunthorpe.  The fossils, consisting of a single tooth, a series of vertebrae, elements from the ribs, the tip of the snout and a single humerus, suggest an animal of around eight metres in length.  It would have been one of the apex predators of the Late Jurassic marine environment.

The “Scunthorpe Pliosaur” on Display

Rose Nicholson, Richard Forrest and Darren Withers with the Scunthorpe Pliosaur.

Rose Nicholson (North Lincolnshire Museum), palaeontologist Richard Forrest and Darren Withers (Stamford and District Geological Society), showing where the fossil bones are located on a pliosaur skeleton.

Picture Credit: North Lincolnshire Museum

A Memorable Geology Field Trip

The first evidence of the remains of a marine reptile, were discovered by Darren Withers of the Stamford and District Geological Society during a field trip to a north Lincolnshire quarry in October 2017.  The Society had visited the quarry previously and were aware that the Kimmeridge Clay deposits (dating from 157 to 152 million years ago), contained numerous fossils, but marine reptile bones, especially several pieces from an individual skeleton are exceptionally rare.

After spending some time looking at the quarry floor, Darren decided to investigate some of the stepped banks in the quarry side.  He followed a trail of small Rasenia cymodoce ammonites until they petered out after about thirty metres, but he decided to explore further and then a surprising discovery was made:

Darren commented:

“I’m so glad I did [explore a little further] because the next thing I was looking down at was a large vertebra.”

CEMEX, the quarry owners, granted further access to the site and over the next twelve months or so more of the pliosaur remains were found.  In total, the haul consists of twenty-eight vertebrae, a single tooth, fourteen rib elements, a bone from the upper arm (humerus) and some fragments from the front portion of the upper jaw (premaxilla).  It has been estimated that the specimen is around 155 million-years-old.

Excavating the Pliosaur Specimen

Extracting the fossilised remains of a pliosaur.

Extracting fossils at the north Lincolnshire quarry (CEMEX).

Picture Credit: North Lincolnshire Museum

Pliosaurs were marine reptiles, part of the Plesiosauria Order, specifically, the short-necked plesiosaurs, the Suborder Pliosauroidea.  They were the apex predators in most Late Jurassic marine ecosystems.  Pliosaurs had an enormously powerful bite, perhaps the most powerful bite of any vertebrate, a complex system of sensory organs in their snouts, superb eyesight and the ability to taste water as they swam to help them locate prey.

A Model of a Typical Pliosaur

Martin Garratt's customised CollectA Deluxe Pliosaurus.

The customised CollectA Deluxe Pliosaurus model.  The model helps to portray what the “Scunthorpe Pliosaur” might have looked like.

Picture Credit: Martin Garratt/Everything Dinosaur

Explaining the significance of the “Scunthorpe Pliosaur”, Richard Forrest, a vertebrate palaeontologist with an extensive knowledge of the Plesiosauria stated:

“Although the specimen is not complete it tells a fascinating story of how the carcase was broken down by scavenging and decay in the ancient Kimmeridge Clay seas.  Because top predators are much less common than their prey, this is indeed a rare find.  We have hundreds of specimens of other marine reptiles, but only a handful of Pliosaurs.”

The “Scunthorpe Pliosaur” Goes on Display

The fossils will be on display at the North Lincolnshire Museum in a temporary exhibit, however, there are plans to give this exceptionally rare fossil find from eastern England a permanent home at the Museum.

Richard Forrest Examines the Pliosaur Vertebrae

Richard Forrest (vertebrate palaeontologist) examines a Pliosaur vertebra.

Richard Forrest laying out one of the vertebrae in the correct anatomical position.

Picture Credit: North Lincolnshire Museum

Councillor Elaine Marper, responsible for the North Lincolnshire Museum added:

“We are over the moon to be able to have this prehistoric sea monster on display at North Lincolnshire Museum.  This is a rare find and to have the fossilised remains stay in North Lincolnshire and go on display for the public is a real feat.  Thank you to CEMEX for making this possible.”

Richard Forrest at the Quarry Holding the Pliosaur Tooth Discovered at the Site

The pliosaur tooth examined by Richard Forrest.

Richard Forrest holding a pliosaur tooth.

Picture Credit: North Lincolnshire Museum

Everything Dinosaur acknowledges the assistance of a press release from North Lincolnshire Council in the compilation of this article.

24 02, 2019

Mini Marsupial Lived Amongst Arctic Dinosaurs

By | February 24th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page|0 Comments

Unnuakomys hutchisoni – Late Cretaceous of Alaska

Researchers have discovered a new species of ancient marsupial that lived deep in the Arctic Circle approximately 69 million years ago (lower Maastrichtian faunal stage).  The new mammal has been named Unnuakomys hutchisoni, not much bigger than a house mouse (Mus musculus), it is likely that this little creature was nocturnal and may have retreated to burrows to protect itself from periods of extreme cold.  Known from more than sixty fossil specimens, the vast majority being tiny teeth but two dentaries (lower jaw bones ) were found along with a fragment of upper jaw (maxilla), this little mammal helps to flesh out the rich, diverse and unique Late Cretaceous biota of Alaska.

Little Mammals Such as the Marsupial  Unnuakomys hutchisoni Lived in the Shadow of Dinosaurs

Alaska in the Late Cretaceous (inset shows tiny mammal).

Hadrosaurs (Ugrunaaluk kuukpikensis) under the northern lights in the Late Cretaceous of Alaska – inset shows tiny mammal.  See note at the bottom of this article.

Picture Credit: James Havens

Fossils from the Pediomys Point Locality 

For several years now, researchers have been exploring the Upper Cretaceous strata that is exposed along the steep banks of the Colville River.  The researchers, which include lead author of the paper on Unnuakomys hutchisoni, Jaelyn Eberle (University of Colorado) and her collaborator Patrick Druckenmiller (University of Fairbanks Alaska), have uncovered evidence of a unique assemblage of dinosaurs and the discovery of this little marsupial represents the most northern of this type of mammal known to science.  The climate during the Late Cretaceous in this part of the world was not as severe as it is today, but the animals living this far north would have had to endure around four months of complete darkness each year and the temperatures would frequently drop below freezing.  The fossil material representing U. hutchisoni was collected during the sieving of sediments from the Pediomys Point Locality of the Prince Creek Formation exposed along the Colville River on the North Slope of Alaska.

Field Team Members Pose Next to Buckets of Sediment Ready for Sieving

Researchers pose next to buckets of sediments that will be sieved for microfossils.

Field team members pose for a photograph next to buckets of sediment that they will sift through to search for tiny mammalian teeth.

Picture Credit: Jaelyn Eberle

A Diverse Faunal Assemblage

This part of Alaska was some 80 degrees north around 69 million years ago.  It was once thought that these high latitudes were virtually devoid of life, but that view has gradually changed as more fossil discoveries have been made.  Teeth of U. hutchisoni greatly outnumber those recovered from other mammals at Pediomys Point, this could be down to sampling, or it could have arisen due to a preservation bias, perhaps the remains of this tiny mammal were more likely to be preserved than other mammal bones and teeth, although this is unlikely.  The abundance of Unnuakomys fossils in relation to other mammals could indicate that this tiny animal thrived in an environment well above the Arctic Circle whose climatic extremes may have acted as a biogeographical barrier preventing the encroachment of other types of Late Cretaceous mammal.

Field Team Members Working on a Steeply Sloping Riverbank

Unnuakomys hutchisoni - looking for fossils on a steep Alaskan riverbank.

Looking for fossils on a steep riverbank.

Picture Credit: Patrick Druckenmiller

Patrick Druckenmiller stated:

“Northern Alaska was not only inhabited by a wide variety of dinosaurs, but in fact we’re finding there were also new species of mammals that helped to fill out the ecology.  With every new species, we paint a new picture of this ancient polar landscape.”

“Night Mouse”

In a reflection of the likely ecology of this miniature marsupial, that of an animal well-adapted to living in the dark, Eberle and her colleagues gave the new mammal the genus name Unnuakomys, a mixture of Greek and the indigenous Iñupiaq language that means “night mouse.”  The trivial name honours the palaeontologist J. Howard Hutchison, who was the first person to identify and explore this fossil assemblage.

The research team, whose project was funded with a National Science Foundation grant, identified the new marsupial using a painstaking process.  With the help of numerous graduate and undergraduate students, they collected, washed and screened ancient river sediment collected on the North Slope and then carefully inspected it under a microscope.  Over many years, they were able to locate numerous fossilised teeth, most of which were no bigger than a grain of sand.

Co-author of the paper, Gregory Erickson (Florida State University), explained:

“I liken it to searching for proverbial needles in haystacks, more rocks than fossils.”

Find the Teeth – Identify the Mammal

By far the most durable part of most mammal skeletons are the teeth, thanks to their coating of hard enamel.  It is the shape of the teeth and their wear pattern, particularly the shape of the molars that allow palaeontologists to identify the type of mammal they have found simply by examining the teeth.  Mammalian teeth have unique cusps on the crown that differ from species to species and they, as a result, are highly diagnostic.  The triangular cusps on the teeth of U. hutchisoni are reminiscent of the triangular blades associated with pinking shears and are typical of an insectivore.

A Computer Generated Image Showing the Lower Jaw (Dentary) of Unnuakomys hutchisoni

Unnuakomys hutchisoni dentary.

Unnuakomys hutchisoni lower jaw bone with teeth.

Picture Credit: University of Colorado Boulder

Other co-authors of the Journal of Systematic Palaeontology paper include William Clemens (University of California), Paul McCarthy (University of Alaska Fairbanks) and Anthony Fiorillo of the Perot Museum of Nature and Science.

Recycling a Scientific Illustration

In 2015, Everything Dinosaur reported upon the discovery of a unique species of Alaskan Hadrosaur (Ugrunaaluk kuukpikensis), James Havens produced an exquisite piece of art showing a herd of these duck-billed dinosaurs moving through the Late Cretaceous, Alaskan landscape.  To illustrate the likely position of U. hutchisoni in this ecosystem, the original artwork was carefully photoshopped to permit the inclusion of the little mammal (see inset above).  As our understanding of the fauna and flora of Late Cretaceous Alaska evolves, the artwork may have to be altered again, in the meantime, we have an excuse to show the original illustration once more.

The Original Ugrunaaluk kuukpikensis Life Reconstruction (2015)

Ugrunaalik life reconstruction.

The original Ugrunaaluk illustration without the inclusion of a little marsupial.

Picture Credit: James Havens

To read our article about U. kuukpikensisLatest Dinosaur Discovery from Alaska

The scientific paper: “Northernmost record of the Metatheria: A New Late Cretaceous Pediomyid from the North Slope of Alaska” by Jaelyn J. Eberle, William A. Clemens, Paul J. McCarthy, Anthony R. Fiorillo, Gregory M. Erickson and Patrick S. Druckenmiller published in the Journal of Systematic Palaeontology

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

12 02, 2019

Reflecting on the Eyes of Cretaceous Spiders

By | February 12th, 2019|Dinosaur and Prehistoric Animal News Stories, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

Early Cretaceous Spiders Reveal Reflective Eyes

A team of scientists, including a researcher from the University of Kansas, writing in an academic journal (Journal of Systematic Palaeontology), have described spiders from the Early Cretaceous that had reflective eyes, an adaptation to permit these tiny predators to hunt at night.  The remarkable fossils were discovered in black shale beds from South Korea which form part of the Jinju Formation (Albian faunal stage) and the flattened fossils preserve the remains of spiders that lived between 113 and 110 million years ago.

The Light Reflective Properties of the Crescent-shaped Tapetum

UV light reveals the ancient tapetum of spiders.

The two tapetum can be seen as crescent-shaped objects on the anterior portion of the head.

Picture Credit: Paul Selden/University of Kansas

Two of the fossils from the extinct spider family Lagonomegopidae feature reflective eyes.  The fossils represent the first non-amber Lagonomegopidae to be described, with the first preservation of a spider eye tapetum recorded in the fossil record.

C0-author of the scientific paper, Paul Selden, Gulf-Hedberg Distinguished Professor of Geology and the Director of the Palaeontological Institute at Kansas University’s Biodiversity Institute and Natural History Museum, explained:

“Because these spiders were preserved in strange slivery flecks on dark rock, what was immediately obvious was their rather large eyes brightly marked with crescentic features.  I realised this must have been the tapetum — that’s a reflective structure in an inverted eye where light comes in and is reverted back into retina cells.  This is unlike a straightforward eye where light goes through and doesn’t have a reflective characteristic.”

Selden said that some contemporary spiders feature eyes with a tapetum, but the new paper is the first to describe the anatomical feature in a fossilised spider.  The research team said the discovery provides evidence for lagonomegopid enlarged eyes being posterior medians.

“In spiders, the ones you see with really big eyes are jumping spiders, but their eyes are regular eyes — whereas wolf spiders at night time, you see their eyes reflected in light like cats.  So, night-hunting predators tend to use this different kind of eye.  This was the first time a tapetum had been in found in fossil.  This tapetum was canoe-shaped — it looks a bit like a Canadian canoe.  That will help us place this group of spiders among other families.”

Selden’s collaborators were Tae-Yoon Park of the Korea Polar Research Institute and amateur fossil hunter Kye-Soo Nam of the Daejeon Science High School for the Gifted, who found the fossils preserved in the shale.

The description of the fossils increases the number of known spiders from the Jinju Formation from a single specimen to eleven.

Commenting on their remarkable state of preservation, Paul added:

“This is so rare because they’re very soft — they don’t have hard shells so they very easily decay.  It has to be a very special situation where they were washed into a body of water.  Normally, they’d float.  But here, they sank, and that kept them away from decaying bacteria, it may have been a low-oxygen condition.  These rocks also are covered in little crustaceans and fish, so there maybe was some catastrophic event like an algal bloom that trapped them in a mucus mat and sunk them, but that’s conjecture.  We don’t really know what caused this, but something killed off a lot of animals around the lake at one time or on an annual basis.”

According to Selden, the shale preserved the spider fossils in a manner that highlighted the reflectivity of the tapetum, a feature that may have been missed had the spiders been preserved in amber instead, as is more typical.

Preserved in the Black Shale an Almost Perfect Impression of an Early Cretaceous Spider

Fossilised remains of an Early Cretaceous spider with reflective eyes.

The black shale preserved perfect impressions of the ancient spiders.

Picture Credit: Paul Selden/University of Kansas

The discovery of these spiders will help researchers to piece together a better understanding of the environment that existed in South Korea during the Early Cretaceous.

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

31 01, 2019

A Newly Described Archosauromorph from Antarctica

By | January 31st, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

Antarctanax shackletoni – Rise of the Archosaurs

A team of researchers, including scientists from the Field Museum (Chicago, USA), the University of Witwatersrand (South Africa) and the Burke Museum (University of Washington, USA), have published a scientific paper announcing the discovery of an archosauriform archosauromorph, that roamed Antarctica in the Early Triassic.  The fossil discovery suggests that early Archosaurs were more geographically widespread than previously thought and demonstrates that the biota of Antarctica may have been very different from other parts of the super-continent Pangaea as the planet recovered from the End-Permian mass extinction event.

A Diverse Fauna in Antarctica During the Early Triassic

Antarctica around 250 million years ago (Antarctanax shackletoni is in the left foreground).

A typical scene in Antarctica during the Early Triassic.   Antarctanax is in the left foreground.

Picture Credit: Adrienne Stroup (Field Museum, Chicago)

The illustration above depicts a typical ecosystem that existed in Antarctica approximately 250 million years ago.

Along the banks of a river, three Archosaur inhabitants of the dense Voltzia conifer forest cross paths, Antarctanax shackletoni attempts to sneak up on an early titanopetran insect, an archosauromorph Prolacerta rests on a log, and an enigmatic large Archosaur pursues two unsuspecting Dicynodonts, (Lystrosaurus maccaigi).

“Antarctic King”

Commenting on the significance of the discovery of the iguana-sized animal, co-author of the scientific paper Brandon Peecook (Field Museum) stated:

“This new animal was an Archosaur, an early relative of crocodiles and dinosaurs.  On its own, it just looks a little like a lizard, but evolutionarily, it’s one of the first members of that big group.  It tells us how dinosaurs and their closest relatives evolved and spread.”

The fossil skeleton is far from complete.  The material was collected from a site representing Lower Fremouw Formation deposits in the central Transantarctic Mountains.  The fossils consist of cervical and dorsal vertebrae, a single humerus and foot bones.  The reptile has been named Antarctanax shackletoni.  The genus name means “Antarctic King”, although this ancient, basal member of the group of reptiles that was to give rise to the dinosaurs, pterosaurs, crocodiles and birds, was probably not an apex predator.  This cannot be stated with certainty, after all, only one fossil specimen has been found, but Antarctanax shackletoni co-existed with a number of other vertebrates including amphibians, synapsids and at least one large archosauriform, which may have been the top predator.

The species name honours the polar explorer Ernest Shackleton.  It is suggested that Antarctanax hunted insects as well as smaller vertebrates.

Antarctanax – Where it Lived and When

Brandon Peecook, a member of the Integrative Research Centre, at the Field Museum explained that this fossil find (made in the 2010/11 field season), is significant because it demonstrates that the ecosystem in Antarctica bounced back relatively quickly after the End-Permian mass extinction event and that  archosauriforms were quite widespread at this time.

He stated:

“The more we find out about prehistoric Antarctica, the weirder it is.  We thought that Antarctic animals would be similar to the ones that were living in southern Africa, [Karoo Basin biota] since those landmasses were joined back then, but we’re finding that Antarctica’s wildlife is surprisingly unique.”

The fauna of the Lower Fremouw Formation traditionally has been considered to represent a subset of the Lystrosaurus Assemblage Zone of the Karoo Basin of southern Africa, with discrepancies largely a result of pronounced differences in sampling intensity.  However, a review of recent changes to the fauna, as well as a reassessment of occurrences based on older literature, indicates that significant discrepancies, including the co-occurrences of taxa known from both earlier and later in time and the presence of endemic forms in Antarctica, exist between the faunas of the Lystrosaurus Assemblage Zone and Lower Fremouw Formation.  In essence, Antarctica 250 million years ago had a different ecosystem to that associated with the contemporaneous Karoo Basin deposits.

A Slab of Rock Containing Exposed Post-cranial Material Attributed to Antarctanax shackletoni

Antarctanax shackletoni fossils

Antarctanax shackletoni fossil material.

Picture Credit: Brandon Peecook, Field Museum

As life on Earth recovered in the Early Triassic, so the Archosaurs rapidly diversified and laid the foundation for the evolution of the Dinosauria, Pterosauria, crocodiles and those other Archosaurs still very much with us today – the Aves (birds).

Post-doctoral Fellow Peecook, went on to state:

“Before the mass extinction, Archosaurs were only found around the Equator, but after it, they were everywhere.   Antarctica had a combination of these brand-new animals and stragglers of animals that were already extinct in most places, what palaeontologists call ‘dead clades walking.’  You’ve got tomorrow’s animals and yesterday’s animals, co-habiting in a cool place.”

The fact that scientists have found Antarctanax helps bolster the idea that Antarctica was a place of rapid evolution and diversification after the mass extinction.

A spokesperson from Everything Dinosaur commented:

“Antarctica is an extremely difficult part of the world to prospect for fossils.  However, as more of the frozen continent is mapped and explored, so more fossil discoveries are going to occur.  Antarctanax shows that there was a diverse faunal assemblage on this part of Pangaea during the Early Triassic and this discovery will help palaeontologists to plot the evolution and distribution of Archosaurs.”

Everything Dinosaur acknowledges the assistance of a press release from the Field Museum (Chicago), in the compilation of this article.

The scientific paper: “A Novel Archosauromorph from Antarctica and an Updated Review of a High-latitude Vertebrate Assemblage in the Wake of the End-Permian Mass Extinction” by Brandon R. Peecook, Roger M. H. Smith and Christian A. Sidor published in the Journal of Paleontology.

11 01, 2019

On the Trail of the “Hand Beast”

By | January 11th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Everything Dinosaur Products, Geology, Main Page, Photos of Everything Dinosaur Products, Press Releases|0 Comments

New “Hand Beast” Chirotherium Exhibition

The county of Cheshire in north-west England has some fascinating geology, but from a palaeontological point of view, fossils are few and far between.  However, there are some notable exceptions, the sandstone quarries that once operated around the picturesque village of Lymm have provided evidence that before the dinosaurs evolved, this part of rural Cheshire was stalked by a powerful, three-metre-long predator – Chirotherium.

A new exhibition at the Lymm Heritage Centre, tells the story of Chirotherium and highlights the scientific importance of the trackways that revealed its existence.  Visitors will be able to get up close to this distant relative of today’s crocodiles, meeting “Kerry”, Lymm Heritage Centre’s resident Archosaur (ruling reptile) as well as embarking on the trail of the “Hand Beast”.

On the Trail of the “Hand Beast” – Chirotherium

Lymm Heritage Centre - Chirotherium leaflet.

On the trail of the “Hand Beast” – Chirotherium (Lymm Heritage Centre).

Picture Credit: Lymm Heritage Centre/Everything Dinosaur

Triassic Lymm – Deserts, Dunes and Salt Lakes

Strange, five-fingered tracks had been discovered in Triassic sandstones in Germany in the early 1830’s.  More tracks were uncovered at Storeton on the Wirral in 1836.  As the demand for building materials grew, a number of sandstone quarries in the Lymm area were opened up and more footprints were found.  These trace fossils are preserved in the Tarporley Siltstones Formation, which was deposited in the early Middle Triassic.  Lymm was located on the super-continent of Pangaea and the rocks deposited in this region portray a dry, arid Triassic landscape, dominated by sand dunes and salt lakes which were close to the sea.  In areas, where freshwater was present, such as river valleys and oases, there was abundant life, but the animals and plants would have been very unfamiliar to us. The land was ruled by reptiles and one of the biggest and most dangerous was Chirotherium.

Tracks Assigned to the Ichnogenus Chirotherium on Display at Oxford University Natural History Museum

A Chirotheriuim trackway.

Chirotherium tracks on display at the Oxford University Museum of Natural History.  Note the five-fingered tracks (pentadactyle).

Picture Credit: Everything Dinosaur

Face to Face with Chirotherium

This new exhibition at the Lymm Heritage Centre brings you face to face with the “Hand Beast” and the hard-working, dedicated team behind this informative, interactive exhibition have created lots of family-orientated activities to support learning.  You can go on your own fossil hunt, make prehistoric footprints and follow Lymm’s bespoke geology trail.

Further information about this new attraction, which officially opens tomorrow (January 12th), can be found here: On the Trail of the “Hand Beast”.

The exhibition is open from from 12 noon until 4pm Thursday to Sunday.

Everything Dinosaur team members have been involved in this project, many of the fossils have been supplied by our team members and visitors will be able to pick up a model of a Prestosuchus, a prehistoric animal that closely resembles the Chirotherium ichnogenus.

The Prestosuchus Model is Available at the Trail of the “Hand Beast” Exhibition at Lymm Heritage Centre

Prestosuchus prehistoric animal model.

The Prestosuchus model takes an interest in the trail of the “Hand Beast” leaflet.

Picture Credit: Everything Dinosaur

9 01, 2019

When Did Life on Land First Evolve?

By | January 9th, 2019|Dinosaur and Prehistoric Animal News Stories, Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Was There Life on Land During the Ediacaran?

The transition of vertebrates from fully aquatic to partially terrestrial animals has been well documented.  Transitional vertebrates such as the remarkable Tiktaalik roseae* provide evidence of the anatomical adaptations undertaken by back-boned animals as they conquered the land.  However, invertebrates got there first and before them the land was home to other organisms such as multi-cellular, photosynthesisng mats of algae.  When complex organisms, rather than members of the Plantae Kingdom or bacteria established themselves on land is somewhat controversial, but new clues might be emerging from fossils found in some of the oldest known soils on Earth.  Could land-dwelling organisms have been present during the Ediacaran?

An Ediacaran Fossil Affected by Wind-drift Deposition

Evidence of wind-drift deposition in ancient Ediacaran sediments.

A portion of a quilted Ediacaran fossil is partly covered by ancient wind deposition – source Namibia.

Picture Credit: Greg Retallack (Oregon University)

Not Marine Fossils But Fossils from a Fluvial Environment

Multi-cellular, terrestrial animals may have existed during the Ediacaran, that is the conclusion of Greg Retallack, fossil collections director at the University of Oregon’s Museum of Natural and Cultural History, writing in the journal Sedimentary Geology.  The evidence for such a conclusion emerged from fossil assemblages, previously considered to represent ocean organisms, found in thin layers of silt and sand located between thicker sandstone beds from Ediacaran-aged fossil localities of Nilpena, South Australia and in similarly aged rocks from Namibia.

The Ediacaran is the last geological period of the Precambrian (Neoproterozoic Era), it lasted from 635 million years ago to 542 million years ago and this period in Earth’s history was named after the Ediacara Hills, located north of Adelaide (South Australia), in which, geologist Reginald Sprigg discovered a remarkable collection of fossils representing bizarre, soft-bodied organisms.

Commenting on his new research Greg Retallack stated:

“These Ediacaran organisms are one of the enduring mysteris of the fossil record.  Were they worms, sea jellies, sea pens, amoebae, algae?  They are notoriously difficult to classify, but conventional wisdom has long held that they were marine organisms.”

Studying Interflag Sandstone Laminae

An in-depth, microscopic analysis of the sediments and their geochemical properties has led to a reassessment of the environmental conditions that led to their deposition.  The grains that make up the sediments, reveal telltale marks of ancient wind erosion, the sediments suggest wind-drift deposition between flood beds.  This indicates a terrestrial origin for them and not deposition in a marine environment, after all, wind (aeolian forces), hardly affect sand grains on the seabed.

These thin, silty to sandy layers that are “sandwiched” between thicker sandstone beds are referred to as interflag sandstone laminae, they are sometimes called “shims” or “microbial mat sandwiches”.  In the research paper, Greg Retallack found similar structures in modern river deposits as well as more ancient interflag sandstone laminae in Pennsylvanian (Upper Carboniferous), and Eocene fluvial levee facies.

Thin, Silty to Sandy Layers Deposited Between Thicker Layers of Sandstone

Interflag Sandstone Laminae

How interflag sandstone laminae form – wind deposition alternates with flood deposition – a phenomenon observed in modern fluvial environments.

Picture Credit: Greg Retallack (Oregon University)

Professor Retallack confirmed his diagnosis of an aeolian factor in the deposition by stating:

“Such wind-drifted layers are widespread on river levees and sandbars today.  They are present throughout the Flinders Ranges of South Australia and also in Ediacaran rocks of southern Namibia.”

If the sediments are affected by aeolian forces, then it follows that they were deposited in terrestrial environments and therefore the fossil assemblage associated with these deposits are very likely to represent a terrestrial biota.  The organisms that left these fossils would have been multicellular and quite complex, visible to the naked eye.  Such life would have preceded the emergence of the first land plants by many tens of millions of years.

Unearthing Important Clues

The Ediacaran biota remains extremely difficult to classify, only impressions have been preserved so the internal structure of most of these bizarre organisms is entirely unknown.  They could represent a “dead-end” in the evolution of complex life, or some of them might be ancestral to extant groups of animals.  The fauna of the Ediacaran might remain enigmatic, when it comes to learning what the fossils actually represent, but this new study offers some intriguing new evidence about the palaeoenvironment.

The Professor concluded:

“The investigation points to a terrestrial habitat for some of these organisms, and combined with growing evidence from studies of fossil soils and biological soil crust features, it suggests that they may have been land creatures such as lichens.”

*To read an article about Tiktaalik roseaeScientists Get to Grips with Tiktaalik’s Rear End

Life in the Ediacaran (Marine Biota)

Ediacaran marine life.

Life in the Ediacaran.  Up until now, most if not all of the life reconstructions have focused on a marine ecosystem scenario.

Picture Credit: John Sibbick

The scientific paper: “Interflag Sandstone Laminae, A Novel Sedimentary Structure, with Implications for Ediacaran Paleoenvironments” by Gregory J. Retallack published in Sedimentary Geology.

Everything Dinosaur acknowledges the help of a press release from the Univesity of Oregon in the compilation of this article.

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|2 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.

9 12, 2018

“A Guide to Fossil Collecting on the West Dorset Coast”

By | December 9th, 2018|Book Reviews, Dinosaur Fans, Geology, Main Page, Photos/Pictures of Fossils, Press Releases|0 Comments

“A Guide to Fossil Collecting on the West Dorset Coast” – Book Review

At a conference in a rather chilly Helsinki held seventeen years ago this week, delegates of the World Heritage Committee of the United Nations Educational, Scientific and Cultural Organisation (UNESCO), confirmed that World Heritage Site status would be conferred upon a 95-mile stretch of the coastline of southern England covering the east Devon and Dorset coast.

In the minutes of the conference, the reason for this award was recorded:

“The Dorset and East Devon Coast provides an almost continuous sequence of Triassic, Jurassic and Cretaceous rock formations spanning the Mesozoic Era, documenting approximately 185 million years of Earth history.  It also includes a range of internationally important fossil localities – vertebrate and invertebrate, marine and terrestrial – which have produced well-preserved and diverse evidence of life during Mesozoic times.”

However, this description does not convey the true majesty of this location, nor does it provide a sense of awe that this part of the British Isles inspires in so many people.  Neither does it do justice to the simple pleasure of finding a fossil, gazing at it and realising that you are the first living creature in 180 million years to set eyes upon the petrified remains of what was once another inhabitant of our planet.

Then a book is published, a book that provides a sense of the stunning natural landscape, a book that transports the reader back in time, a book that conveys the sense of excitement and achievement associated with fossil collecting – “A Guide to Fossil Collecting on the West Dorset Coast” – does all this and more.

The Front Cover of “A Guide To Fossil Collecting on the West Dorset Coast”

"A Guide to Fossil Collecting on the West Dorset Coast" published by Siri Scientific Press

A beautifully illustrated guide to fossil hunting on the West Dorset coast.  RRP of £18.95 – highly recommended.

Picture Credit: Siri Scientific Press

Conveying a Sense of Beauty, Conveying a Sense of Wonder

Authors Craig Chivers and Steve Snowball focus on one part of the “Jurassic Coast”, that beautiful coastline that runs east from Lyme Regis to the foreboding cliffs of Burton Bradstock.  First the scene is set.  There is a brief description of the geological setting and an outline of the contribution to science of arguably Dorset’s most famous former resident, Mary Anning, and then the reader is taken in Mary’s footsteps through a series of guided walks travelling eastwards along the coast and forwards in time to explore the geology and remarkable fossil heritage of this unique sequence of sedimentary strata.

The Book is Filled with Stunning Photographs of Fossil Discoveries

Prepared specimen of Becheiceras gallicum.

A Lower Jurassic ammonite (Becheiceras gallicum) from the Green Ammonite Member (Seatown, Dorset).

Picture Credit: Siri Scientific Press (fossil found and prepared by Lizzie Hingley)

A Reference for All Collectors and Fossil Enthusiasts

Drawing on their detailed knowledge of fossil collecting, Craig and Steve describe what to look for and where to find an array of fossil specimens along this part of the “Jurassic Coast”.  The landscape is vividly portrayed and the book provides a handy, rucksack-sized reference for fossil collectors, whether seasoned professionals or first time visitors to Dorset.  We commend the authors for including copious amounts of helpful information on responsible fossil collecting and for publishing in full the West Dorset Fossil Collecting Code.

Breath-taking Views of the Natural Beauty of the Coastline

Fossil hunting around Seatown.

Golden Cap – excursions around Seatown.  Majestic views of the “Jurassic Coast”.

Picture Credit: Siri Scientific Press

Recreating Ancient Environments

Talented palaeoartist Andreas Kurpisz provides readers with digital reconstructions of ancient environments and brings to life the fossil specimens, showing them as living creatures interacting with other prehistoric animals in a series of Jurassic landscapes and seascapes.  These reconstructions help to document the changing environments that are now preserved within the imposing cliffs of this remarkable part of the British coastline.

Crinoids (Sea Lilies) from the West Dorset Coast

Crinoids from the "Jurassic Coast".

The book contains stunning photographs of fossils from the “Jurassic Coast”.

Picture Credit: Siri Scientific Press

Spokesperson for Everything Dinosaur, Mike Walley commented:

“This guide manages to capture the beauty and the fascination of this part of the “Jurassic Coast”.  It is a “must have” for all fossil collectors and if ever the delegates at that UNESCO conference needed to reaffirm their decision to grant this stunning part of the British coastline World Heritage Site status, this book provides ample evidence to justify their original decision.”

For further information and to order this exquisite guide book: Order “A Guide to Fossil Collecting on the West Dorset Coast”

8 12, 2018

Animantarx Fact Sheet

By | December 8th, 2018|Dinosaur Fans, Everything Dinosaur Products, Geology, Main Page, Photos of Everything Dinosaur Products, Press Releases|0 Comments

Preparing a Fact Sheet for the Schleich Animantarx Model

Team members at Everything Dinosaur have been busy preparing for the arrival of the first batch of new for 2019 Schleich prehistoric animal figures.  In this first set of models from the German-based manufacturer, there is a replica of the armoured dinosaur called Animantarx (Animantarx ramaljonesi), a fact sheet providing information about this nodosaurid is being compiled, so that customers of Everything Dinosaur can learn about this enigmatic member of the Thyreophora (shield-bearers).

New for 2019 the Schleich Animantarx Dinosaur Model

The new for 2019 Schleich Animantarx dinosaur model.

The Schleich Animantarx dinosaur model (new for 2019).

Picture Credit: Everything Dinosaur

Using Ankylosaurs for Biostratigraphical Dating of the Cedar Mountain Formation

The disarticulated and fragmentary fossils representing a single, individual animal were described in 1999 (Carpenter, Kirkland, Burge and Bird) and Animantarx is one of numerous Ankylosaurs known from the Cedar Mountain Formation of the western United States.  The Cedar Mountain Formation has the highest concentration of ankylosaurid species of any Lower Cretaceous formation, it is hoped that further field work will help palaeontologists to build up a better picture of their evolution and subsequent radiation.

The list of armoured dinosaurs is quite long for example:

  • Sauropelta – Poison Strip Sandstone
  • Cedarpelta – Mussentuchit Member
  • Animantarx – Mussentuchit Member
  • Peloroplites – Mussentuchit Member
  • Gastonia – Yellow Cat Member

It has been suggested that given the numbers of armoured dinosaurs present in the strata, ankylosaurids can be used to help with relative dating of rock layers (biostratigraphy).

A Scale Drawing of Animantarx

Animantarx Scale Drawing.

A scale drawing of the armoured dinosaur from Utah – Animantarx ramaljonesi.

Picture Credit: Everything Dinosaur

Distinct Cretaceous Dinosaur Faunas

Recent research has identified three distinct dinosaur-based faunas represented by the vertebrate fossils from the Cedar Mountain Formation.  Ankylosaurs are the most common dinosaur of the upper part of the Yellowcat Member and Poison Strip Sandstone of the Cedar Mountain Formation but are rare in other members.  This scarcity may be due to insufficient collecting in the middle and upper parts of the Cedar Mountain.  Nevertheless, Ankylosaur dinosaurs indicate a three-fold division of the Cedar Mountain dinosaur faunas.  Intriguingly, Animantarx is known from the youngest member of the Cedar Mountain Formation (Mussentuchit Member).  These rocks hold a mixture of Early and Late Cretaceous dinosaur fossils – tyrannosaurids, ceratopsids, iguanodonts, ankylosaurids etc.  The strata might document a migration event whereby Asian dinosaurs moved into North America via an Alaskan land bridge.  This migration may have contributed to the extinction of several types of endemic North American members of the Dinosauria.

To view the range of Schleich prehistoric animal figures available from Everything Dinosaur: Schleich Dinosaurs and Prehistoric Animal Models

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