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/Palaeontological articles

Articles, features and information which have slightly more scientific content with an emphasis on palaeontology, such as updates on academic papers, published papers etc.

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.

25 03, 2019

Scientists Collaborate to Explore the Morrison Formation

By | March 25th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Manchester University, the Morrison Formation and the “Jurassic Mile”

Scientists at Manchester University have joined forces with a major American Museum and European partners to map and explore an extraordinary Jurassic dinosaur site in the Badlands of Wyoming (USA).  The University of Manchester will act as the academic leaders on this newly announced £20 million ($27.5 USD) research project to examine and eventually exhibit fossils excavated from a recently discovered palaeontological site nicknamed the “Jurassic Mile”.

Working in Collaboration with the Children’s Museum of Indianapolis

The University of Manchester’s Professor Phil Manning and Dr. Victoria Egerton will be collaborating with scientists from the Children’s Museum of Indianapolis.  Also involved are researchers from the Natural History Museum in London and the Naturalis Biodiversity Centre in Leiden (Netherlands).  In total, more than a hundred scientists and academics from three countries will join forces to work at a dig site representing Upper Jurassic strata from the Morrison Formation of Wyoming.  They hope to uncover new data to help explain the extraordinary diversity of the dinosaur biota known from this part of Laurasia in the Late Jurassic.

Life in the Late Jurassic – An Illustration of Morrison Formation Biota

Morrison Formation biota.

Life in the Late Jurassic (Morrison Formation biota).  An illustration of life in the Late Jurassic (Morrison Formation) by Julius Csotonyi.  A mother Stegosaurus defends her family from a marauding Allosaurus whilst a pair of diplodocids browse in the background.

Picture Credit: Julius Csotonyi

The “Jurassic Mile”

Professor Manning, Dr. Egerton and the team are calling the fossil-rich, mile-square plot of land, “The Jurassic Mile.”  There are four main quarries within the multi-level, 640-acre site that offer a diverse assemblage of Morrison Formation articulated and semi-articulated dinosaurs that has also yielded associated animals and fossil plants.  In addition, trace fossils in the form of dinosaur trackways have been identified, such tracks are rare in this part of the world.

Commenting on the significance of this collaborative field work, Professor Manning stated:

“It is splendid that such an important site has been discovered at just the right time, as the science of palaeontology is adapting existing and new imaging techniques to unpick the fossil remains of extinct life.  The imaging work that we undertake at Manchester is already world-leading and this is a great opportunity to develop this research with other world-class institutions.”

A Remarkable Fossil Assemblage

Nearly six hundred specimens, weighing more than six tons, have already been collected from this site over the past two years, despite the fact that only a fraction of the area has been explored.  Fossil bones found to date include the remains of an 20-metre plus Brachiosaur and a 27-metre-long diplodocid.  Giant Sauropods had giant bones, one of the recent discoveries is a 2-metre-long Brachiosaur scapula (shoulder bone), numerous plaster-coated burlap jackets containing articulated bones are the reward for the researchers after a successful field season..

At a press conference, held today, the discovery of an extremely well-preserved 1.5-metre-long Sauropod femur (thigh bone), was announced.

Professor Phil Manning (The University of Manchester) with the Sauropod Femur

Professor Phil Manning and the diplodocid femur.

Professor Phil Manning (The University of Manchester), poses next to the diplodocid femur.

Picture Credit: The University of Manchester

Dr. Jeffrey H. Patchen, President and CEO of The Children’s Museum of Indianapolis commented:

“We are bringing together an extraordinary international team for the first time that will critically analyse portions of the Morrison Formation in new ways.  This project reflects a natural synergy between three world-renowned museums, their research scientists and highly-respected research universities, each providing unique elements to complete one of the most interesting chapters in the evolution of Earth.”

Prehistoric Flora as well as Fauna

Dr. Egerton from the Department of Earth and Environmental Science (Manchester University), explained:

“The preservation quality and sheer amount of plants at the Jurassic Mile is extraordinary.  During this period, there were no flowering plants and this site provides significant insight to what these giant animals ate and how they may have grown to be so large.”

The Jurassic Mile project is already utilising cutting-edge science from the international team.  The University of Manchester scientists will employ the Stanford Synchrotron particle accelerator along with some of the most powerful computers on the planet, to help resurrect the Jurassic and unearth the lost world and forgotten lives of some of the most remarkable terrestrial animals that have ever lived.

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

24 03, 2019

Alligator Study Provides Insight into Dinosaur Hearing

By | March 24th, 2019|Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Alligator Hearing Study Provides Insight into Dinosaur Hearing

New research published in the “Journal of Neuroscience” identifies that living Archosaurs – birds and crocodiles make a mental map of sounds in the same way.  This suggests that this auditory strategy existed in their common ancestor which has implications for dinosaur research.

Animal brains determine where a sound is coming from, by analysing the minute difference in time it takes audio waves to reach each ear—a cue known as interaural time difference.  What happens to the cue once the signals get to the brain depends on what kind of animal is doing the hearing.

An American Alligator – New Research Suggests that Birds and Crocodilians Hear in the Same Way

An American alligator (Alligator mississippiensis).

A photograph of an American alligator.

Picture Credit: Ruth Elsey Louisiana Department of Wildlife and Fisheries

Scientists have known that birds are exceptionally good at creating neural maps to chart the location of sounds, and that the strategy differs in mammals.  Little was known, however, about how alligators process interaural time difference.

A new study of American alligators (Alligator mississippiensis), found that the reptiles form neural maps of sound in the same way birds do.  The research by Catherine Carr, a Distinguished University Professor of Biology at the University of Maryland and her colleague Lutz Kettler from the Technische Universität München, was published this week in the “Journal of Neuroscience”.

Most research into how animals analyse interaural time difference has focused on physical features such as skull size and shape, but Carr and Kettler believed it was important to look at evolutionary relationships.

Birds have very small head sizes compared with alligators, but the two groups share a common ancestor, as both Aves (birds) and crocodilians are members of the Archosauria.   Archosaurs began to emerge around 246 million years ago and split into two lineages; one that led to alligators and one that led to dinosaurs (and birds).  Although most dinosaurs died out during the mass extinction event 66 million years ago, some types of dinosaur survived and we see their descendants all around us today, these are the modern birds.

Carr and Kettler’s findings indicate that the hearing strategy birds and alligators share may have less to do with head size and more to do with common ancestry.

Carr commented:

“Our research strongly suggests that this particular hearing strategy first evolved in their common ancestor.  The other option, that they independently evolved the same complex strategy, seems very unlikely.”

Sedated American Alligators were Fitted with Earphones

An American alligator.

A photograph of an American alligator.

Picture Credit:  Ruth Elsey Louisiana Department of Wildlife and Fisheries

To study how alligators identify where sound comes from, the researchers anesthetised forty American Alligators and fitted them with earphones.  They played tones for the sleepy reptiles and measured the response of a structure in their brain stems called the nucleus laminaris.  This structure is the seat of auditory signal processing.  Their results showed that alligators create neural maps very similar to those previously measured in barn owls and chickens.  The same maps have not been recorded in the equivalent structure in mammal brains.

The Distinguished Professor added:

“We know so little about dinosaurs.  Comparative studies such as this one, which identify common traits extending back through evolutionary time add to our understanding of their biology.”

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

The scientific paper: “Neural Maps of Interaural Time Difference in the American Alligator: A Stable Feature in Modern Archosaurs” by Lutz Kettler and Catherine Carr and published in the Journal of Neuroscience.

17 03, 2019

New Study “Cracks” Dinosaur Egg Mystery

By | March 17th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Dinosaurs Innovated When it Came to Egg Production

Many museums include the fossilised remains of dinosaur eggs amongst their natural history collections and palaeontologists are aware that reptiles were laying eggs on land long before the dinosaurs evolved, but what we know about the evolution of reptile eggs (amniotic eggs in general), is largely based on inference and conjecture.  The problem is, for the first 100 million years or so of amniote evolution, there is very little fossil data related to reptile reproduction to study.  What we do know, is based on Middle Jurassic to Late Cretaceous fossils.  Although, dinosaur eggs are rare, the examples we do have, such as those associated with Asian oviraptorids demonstrate that dinosaur eggs had thick, hardened shells.  However, a new study suggests that it was not always like this and that the three main Sub-orders of the Dinosauria probably evolved thick, tough eggs independently.

Examples of Eggs from Different Archosaurs (Avian and Non-avian Dinosaurs)

Examples of fossil Archosaur eggs.

Examples of whole or partial fossilised eggs.

Picture Credit: Royal Society Open Science

Studying Some of the World’s Oldest Dinosaur Eggs Reveals New Information

Writing in the on-line, open access journal “Scientific Reports”, a team of scientists, including Robert Reisz (University of Toronto Mississauga) and Koen Stein (Royal Belgian Institute of Natural Sciences, Brussels), have examined some of the oldest examples of dinosaur eggs known and revealed new information about the evolution of dinosaur reproduction.  The researchers examined the eggs and eggshells of three coeval, but geographically widely distributed Early Jurassic basal Sauropodomorph dinosaurs (Sinemurian faunal stage).  These fossils came from Argentina, China and South Africa and include the eggs of Massospondylus and Lufengosaurus.  Their analysis showed that the basal Sauropodomorph eggs all had the basic structure, they had a thin calcareous layer less than 100 microns thick.  This thin shell layer contrasts strongly with the much thicker calcareous shells associated with Late Jurassic and later dinosaur eggs.

At approximately 195 million years old, they are the earliest known eggs in the fossil record, and they were all laid by similar, herbivorous dinosaurs that ranged in size from four to eight metres in length and were the most common and widely spread dinosaurs of their time.  These types of plant-eating dinosaur were the forerunners of the giant Sauropods of the Jurassic, dinosaurs such as Brontosaurus, Diplodocus and Brachiosaurus.

A Massospondylus Nesting Site (Life Reconstruction)

Massospondylus nesting site - life reconstruction.

Massospondylus (basal Sauropodomorpha) nesting site. Massospondylus fossil eggs from South Africa were used in the study.

Picture Credit: Julius Csotonyi

Putting the research into context Professor Reisz explained:

“Reptile and mammal precursors appear as skeletons in the fossil record starting 316 million years ago, yet we know nothing of their eggs and eggshells until 120 million years later.  It’s a great mystery that eggs suddenly show up at this point, but not earlier.”

The researchers concluded that these Early Jurassic eggs represented a step in the evolution of dinosaur reproduction, their shells were paper-thin and brittle, proportionately much thinner than the eggs of extant birds.  However, thicker, tougher eggshells in the Dinosauria were to evolve across all three Sub-orders later.  The much thicker eggshells associated with Sauropods, Ornithischian dinosaurs and the Theropoda must have evolved independently.

Professor Reisz added:

“We know that these early eggs had hard shells because during fossilisation they cracked and broke, but the shell pieces retained their original curvature.”

Other authors of the scientific paper include Edina Prondvai and Jean-Marc Baele.  Shell thickness was analysed along with membrane thickness, mineral content and distribution of pores, looking for clues about why these early eggs might have developed hard shells.  The scientists concluded that hard-shelled eggs evolved early in dinosaur evolution, with thickening of the calcareous layer (greater than 150 microns), occurring independently in several groups, but a few million years later other reptiles also developed hard-shelled eggs.  One possibility is that hard and eventually thicker shells may have evolved to shield dinosaur embryos and other reptiles from predators.

Professor Reisz commented:

“The hard shells would protect the embryos from invertebrates that could burrow into the buried egg nests and destroy them.”

Linked to Increased Oxygen in the Atmosphere

Advanced mineralisation of amniote eggshell including those of dinosaurs (≥150 microns in thickness), in general occurred not earlier than the Middle Jurassic and may correspond with a global trend of an increase in atmospheric oxygen.  If there were higher levels of atmospheric oxygen, then this would facilitate more efficient gaseous exchange through the porous eggshell and across the egg membranes.  More efficient diffusion would permit the evolution of thicker eggshells, which in turn would offer greater resistance to damage and more protection from predators.

A Lufengosaurus Embryo

The embryo of a Lufengosaurus

New research into 195 million-year-old baby dinosaurs and their eggs.

Picture Credit: D. Mazierski

Raising Further Questions About Mesozoic Reproduction Strategies

The study raises some intriguing questions that may well lead to further research projects.  For example, palaeontologists are aware that many types of marine reptile evolved viviparity (live birth), whilst the fossil evidence for the terrestrial Dinosauria seems to indicate that they continued to rely on egg laying.  Why didn’t the highly diverse dinosaurs evolve different reproductive strategies over their 160 million years of existence?

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

The scientific paper: “Structure and Evolutionary Implications of the Earliest (Sinemurian, Early Jurassic) Dinosaur Eggs and Eggshells” by Koen Stein, Edina Prondvai, Timothy Huang, Jean-Marc Baele, P. Martin Sander and Robert Reisz published in Scientific Reports.

11 03, 2019

New Australian Ornithopod Described

By | March 11th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Galleonosaurus dorisae – A New Aussie Dinosaur

A new type of Australian dinosaur has been described from the fossilised remains of five upper jaw bones (maxillae) found at the Flat Rocks locality in the Wonthaggi Formation in the famous Gippsland Basin of Victoria.  Five small-bodied Ornithopods are now known from the state of Victoria.  The new plant-eating dinosaur has been named Galleonosaurus dorisae.  The jaw bones are of different sizes and this has permitted palaeontologists to plot growth changes in these little dinosaurs as they matured.

Writing in the Journal of Palaeontology, the researchers which include Matthew Herne (University of New England, New South Wales) and Alistair Evans (Monash University, Melbourne), used detailed CT-scans of the fossil material to gain fresh insights into the structure and morphology of the cranial anatomy and dentition of small Australian Ornithopods.  The research leading to the establishment of this new genus has also helped to define more clearly other small Ornithopods known from the Gippsland Basin and the Otway Basin located on the opposite side of Port Phillip Bay.

A Life Reconstruction of the Newly Described Ornithopod Galleonosaurus dorisae

Galleonosaurus dorisae illustrated.

A life reconstruction of the newly described Australian Ornithopod Galleonosaurus dorisae.

Picture Credit: James Kuether

“Galleon Lizard”

When the scientists were examining the maxillae, their shape reminded them of the upturned hull of an old-fashioned sailing ship – a galleon.  It was the morphology of the jaw that inspired the genus name “Galleon Lizard”.  The species or trivial name honours Doris Seegets-Villiers for her geological, palynological, and taphonomic work on the Flat Rocks fossil vertebrate locality.

Jaw Fossils and a Tooth with a CT-scan of the Fossil Material

Galleonosaurus fossiils and a CT-scan of a jaw.

Fossil jaw bones, a single tooth and a CT-scan image of a jaw bone (Galleonosaurus dorisae).

Picture Credit: Herne et al

Niche Partitioning in Ornithopods

The plethora of vertebrate fossils at the Flat Rocks site, suggests that several more dinosaurs await discovery.  However, for the moment, the researchers are confident that Galleonosaurus shared its habitat with at least one other small, light, fast-running Ornithopod – Qantassaurus intrepidus.  The jaws of Qantassaurus are more robust and more powerful.  The researchers were able to confirm that Q. intrepidus is uniquely characterised by a deep, foreshortened dentary (lower jaw).  This suggests that the robust Q. intrepidus and the more gracile jawed G. dorisae fed on different vegetation, they did not compete directly for food, an example of niche partitioning.

Dr Herne described Galleonosaurus:

“We know it would have been a two-legged, quite agile plant-eating dinosaur.  It seems that Galleonosaurus was no doubt closely related to possibly as many as four or five other species that look a little bit similar and were similar sizes, but we can tell they’re different by the anatomy of the jaws and the teeth.”

A Lush Conifer Dominated Rift Valley with an Immense Volcanic Mountain Chain to the East

Extensive research on the Otway Formation material to the west of Port Phillip Bay in conjunction with research on the geology of the Gippsland Basin have permitted scientists to build up a picture of what life was like in this part of Australia during the Early Cretaceous.  The dinosaurs lived in an extensive rift valley that had formed as Australia began to separate from Antarctica. Conifer forests dominated and at such high latitudes, the lush environment would have been subjected to long periods of extensive daylight in the summer, but conversely the winters would have been cold with little daylight each day.  Although the Earth’s climate was much warmer than today during the Early Cretaceous, it is quite possible that these little dinosaurs would have had to endure winter temperatures close to freezing.

Gondwana in the Early Cretaceous (Barremian Faunal Stage)

Gondwana in the Early Cretaceous.

Around 125 million years ago, although Gondwana was breaking up, Australia was still linked to Antarctica with a large volcanic mountain range to the east.

Picture Credit: Herne et al

A Skeletal Reconstruction of the Skull of Galleonosaurus and the Anatomical Position of Jaw Material

Jaw fossils of Galleonosaurus dorisae.

An illustration of the skull of Galleonosaurus dorisae with fossil elements placed in the correct anatomical position.  The lower jaw shown in the image might pertain to G. dorisae based on a reassessment of other known lower jaw elements associated with Q. intrepidus and Atlascopcosaurus loadsi.

Picture Credit: Herne et al

A Phylogenetic Analysis

The scientists conclude that a highly diverse, small-bodied Ornithopod fauna flourished in the periodically disturbed, high-latitude, riverine floodplain environment of the Australian-Antarctic rift valley during the Early Cretaceous (Barremian to Early Albian faunal stage).  A phylogenetic analysis places Galleonosaurus as the earliest member of the Elasmaria, a clade of Gondwanan Ornithopods distantly related to the Hypsilophodonts.

The Five Victorian Ornithopods – Spanning 12 million years

The Lower Cretaceous rocks either side of Port Phillip Bay were laid down at different times during the Cretaceous.  The Gippsland Basin deposits close to the town of Inverloch, were laid down around 125 million years ago, however, the Otway Basin deposits (Eumeralla Formation), represent younger material laid down in the Early Albian (113 million years ago).

  1. Leaellynasaura amicagraphica – named in 1989 (Early Albian faunal stage), from the Eumeralla Formation (Otway Basin).
  2. Atlascopcosaurus loadsi – also named in 1989 from the Eumeralla Formation.
  3. Diluvicursor pickeringi – named in 2018 (Eumeralla Formation).  To read an article about the discovery of this dinosaur: Fast-running Ornithopod from Victoria.
  4. Qantassaurus intrepidus named in 1999 from the Wonthaggi Formation (Gippsland Basin) – older strata associated with the Barremian faunal stage of the Early Cretaceous.
  5. The newly described Galleonosaurus dorisae (2019), also from the Wonthaggi Formation.

Dr Herne stated:

“The interesting thing about that whole coast line is it gives us a decent age range over quite a long period.”

A spokesperson from Everything Dinosaur commented:

“It is likely that many more small dinosaurs are going to be named and described in the future.  Fossil finds from Victoria will, most likely, lead to further revisions of Gondwanan Ornithopod taxonomy.”

6 03, 2019

Twisting and Turning Tyrannosaurs Made them Top Predators

By | March 6th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

New Study Suggests Tyrannosaurids More Manoeuvrable than Other Large Theropods

Researchers at the University of Wisconsin-La Crosse and the Oklahoma State University Centre for Health Sciences have applied mathematical models to assess the manoeuvrability of predatory dinosaurs.   This research, published in the on-line journal PeerJ, involving numerous collaborators, suggests that large bodied Tyrannosaurs were more agile and able to turn more sharply than other similar sized Theropods such as Allosaurs and carcharodontosaurids.

A Large Tyrannosaur Attacks a Styracosaurus

Daspletosaurus fighting a horned dinosaur.

Tyrannosaur fighting a horned dinosaur.  A new study suggests that large bodied Tyrannosaurs may have been surprisingly agile.

Picture Credit: John Gurche

A Factor in the Evolutionary Success of Tyrannosaurs

The research involving complex mathematics, a study of animal anatomy and physics compared how rapidly meat-eating dinosaurs could turn their bodies.  In summary, the scientists concluded that Tyrannosaurs could attack smaller, faster and more dangerous prey.  It is suggested that the greater manoeuvrability of these carnivores may have been a factor in their evolutionary success.

Associate Professor at the University of Wisconsin-La Crosse, Eric Snively, in collaboration with co-author Haley O’Brien (Oklahoma State University Centre for Health Sciences) along with several other leading palaeontologists such as Professor Phil Currie (University of Alberta), demonstrated that whether a Tyrannosaur was dog-sized or a fully-grown, mature adult, it retained its agility and manoeuvrability.

Three-dimensional Computer Models Used to Test Tyrannosaurid Manoeuvrability

Assesing the agility of tyrannosaurids.

Computer models were created to examine the agility of tyrannosaurids.

Picture Credit: University of Wisconsin-La Crosse

Enhanced Agility Compared to Other Super-sized Theropods

Tyrannosaurs were assessed to be more agile as they had relatively short bodies (anteroposteriorly short thoracic regions, and cervical vertebrae that aligned into posterodorsally retracted necks).  In summary, shorter bodies meant less turning resistance and even their tiny arms helped!  In addition, long, tall ilia bones (part of the hip), provided plenty of room for huge leg muscle attachments that gave the power needed for rapid turns and pivots.

The Size of the Ilia (Hip Bones) was Used to Infer Muscle Size Along with Postulated Tail Depth

Tyrannosaur agility, mapping the position of leg locomotor muscles.

Mapping muscle groups to assess the agility of tyrannosaurids.  Tyrannosaur musculature was compared to that of an extant alligator.

Picture Credit: PeerJ

In terms of the fastest results from the Tyrannosaur family, a horse-sized juvenile T. rex turned the quickest for its size, followed by the giant T. rex “Sue”, the enormous, mature adult from the Field Museum (Chicago).

Eric Snively described the T. rex turn as something akin to a “slow-motion-ten-tonne figure skater from hell,” quite apt in a way as T. rex fossils are known from the Hell Creek Formation.

Biomechanical Model Has Implications for Large Theropod Hunting Strategies

The researchers used very accurate anatomical assessments and rigorous statistics to create three-dimensional models that could then be tested for their range of movements.  Different Theropods were examined including Dilophosaurus, Ceratosaurus, Giganotosaurus, Sinraptor as well as numerous Tyrannosaurs at different growth stages as well as smaller members of the Tyrannosauroidea Superfamily such as Raptorex.  With respect to other Theropods, tyrannosaurids were found to be increasingly agile without compromising their large body mass, such that in a pairwise comparison, tyrannosaurids were achieving the same agility performance as much smaller Theropods.  For example, a 500 kg Gorgosaurus had slightly greater agility scores than the 200 kg Eustreptospondylus, and an adult Tarbosaurus nearly twice the agility scores of the lighter Sinraptor.

The Oxford University Specimen of Eustreptospondylus Used in the Study

Eustreptospondylus dinosaur skeleton exhibit.

The fossil specimen on display (E. oxoniensis).

Picture Credit: Everything Dinosaur/Siri Scientific Press

Enhanced agility and tight manoeuvrability in tyrannosaurids suggest that T. rex et al had superior abilities when it came to pursuing and subduing prey.  This new research may have important implications when it comes to examining how large Theropods hunted.

If tyrannosaurids were more agile and able to manoeuvre faster than other large predators they may have been more adept than earlier, super-sized, apex predators when it came to catching agile prey.  It is postulated that this capability of tyrannosaurids is consistent with coprolite evidence that indicates that tyrannosaurids fed on juvenile Ornithischians.  Furthermore, it is proposed that healed Tyrannosaur bite marks on fossilised remains of adult horned dinosaurs and Hadrosaurs indicate an ability to outmanoeuvre quadrupedal prey.

A spokesperson from Everything Dinosaur commented:

“Whilst this is a fascinating piece of research, it is important that we don’t entirely discount observations of modern-day predator/prey interactions.  Often an apex predator will select a weakened, or sick animal within a herd to attack.  In addition, young animals are particularly vulnerable as they are smaller and less experienced in avoiding predators compared to adult animals.”

The largest non-tyrannosaurids, including Giganotosaurus, often lived in habitats alongside Sauropod dinosaurs.  These associations may suggest that allosauroids may have preferred less agile prey than did tyrannosaurids.  It is also possible that stability conferred by high rotational inertia, as when holding onto giant prey, was more important for allosauroids than turning quickly.

The researchers intend to undertake research to assess the manoeuvrability of ceratopsids and other prey such as duck-billed dinosaurs before applying the same techniques to examine Tyrannosaur bite forces.

3 03, 2019

Late Triassic Frogs of North America

By | March 3rd, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

The Earliest Equatorial Record of Frogs

Researchers including palaeontologists from the Department of Geosciences at Virginia Tech, have identified tiny fossil fragments collected from Upper Triassic deposits in Arizona that provide evidence of the oldest known frogs from North America.  Although, no new genus has been erected, the scientists are confident that further study of the microfossils at the location may yield skull and jaw bones which will result in the naming of new species.

A Little Chinle Frog Has a Close Encounter with a Phytosaur

A suggested encounter between a frog and a phytosaur.

A Chinle frog encounters a phytosaur. It is likely that phytosaurs would have fed on amphibians.

Picture Credit: Andrey Atuchin

The fossils are composed of several tiny pieces of hip bone, (from the ilium), they were collected last May from three separate locations within the famous Chinle Formation and they have been dated to between 223 and 213 million years ago.  The bones represent the earliest equatorial record of the Salientia, the group that includes stem and crown-frogs.  These tiny amphibians, little more than two centimetres in length, are not direct ancestors of modern frogs (Anura).

One of the authors of the scientific paper, published in the journal Biology Letters, Assistant Professor Michelle Stocker, stated that these fossils underscore the importance of microfossil collection, analysis and study as it helps palaeontologists to build up a more comprehensive picture of an ancient ecosystem.

Assistant Professor Stocker explained:

“This new find highlights just how much there is still to learn about the Late Triassic ecosystem and how much we can find when we just look a little closer.  We are familiar with the charismatic Archosaurs from the Chinle Formation, but we know that based on other ecosystems, they should make up a small percentage of the animals that lived together.  With this new focus, we are able to fill in a lot of those missing smaller components with new discoveries.”

Time-calibrated Stratigraphic and the Geographical Distribution Across Pangaea of Triassic and Jurassic Anurans

The stratigraphic and biogeographic distribution of Triassic and Jurassic fossil frogs.

Time-calibrated stratigraphic and biogeographic distribution of Triassic and Jurassic Period anuran specimens.

Picture Credit: Biology Letters

The image above shows (a) the stratigraphic sequence indicating the three fossil examples of Chinle frogs and their relationship to the Early Jurassic Prosalirus (MNA 291) from the Kayenta Formation (Arizona), whilst (b) shows the biogeographic distribution of fossil anurans from the Jurassic and Triassic.  Note, the proximity of the Late Triassic Chinle frogs to the equator.  Photograph (c) shows an eyelash sized fossil ilium whilst (d) and (e) are computerised scans of the same fossil material shown in lateral and medial views.  Scale bars equal 1 millimetre.

Long and Hollow Hip Bones

The fossil material gathered from extensive sieving  and screen washing of sediments in order to obtain microvertebrate fossils, consists of long, hollow hip bones with the hip socket offset rather than centred, anatomical traits that are characteristic of frogs and that help to support their hoping style of locomotion.  Stocker and her collaborators include fellow scientists from Virginia Tech, Arizona’s Petrified Forest National Park, and the University of Florida’s Museum of Natural History.

The Chinle frogs share more features with living frogs and Prosalirus, a genus of Early Jurassic frog found in sediments from the present-day Navajo Nation (Arizona), than to Triadobatrachus, an Early Triassic frog discovered in Madagascar.

Stocker added:

“These are the oldest frogs from near the equator.  The oldest frogs overall are roughly 250 million years old from Poland [Czatkobatrachus] and Madagascar, but those specimens are from higher latitudes and are not equatorial.”

Comparing the Ilia of Stem Anurans

Comparing fossilised hip bones from stem anurans (frogs).

Comparing the ilia of stem anurans and those of extant frogs (Ascaphus, Leiopelma, Alytes and Barbourula) scale bar = 1 mm.

Picture Credit: Biology Letters

Co-author Sterling Nesbitt (Virginia Tech), commented:

“Now we know that tiny frogs were present approximately 215 million years ago from North America, we may be able to find other members of the modern vertebrate communities in the Triassic Period.”

This is the first time that frog fossils have been found in sediments associated with phytosaurs and early members of the Dinosauria.

The research team hope that further work screening and washing sediments from the Chinle Formation sites, will yield more information about the tiny animals that lived alongside some of the first dinosaurs in North America.

A spokesperson from Everything Dinosaur stated:

“The sieving and screen washing methodology employed to discover the tiny hip bones and fossil material associated with Late Triassic frogs could also be used to help identify other small animals that lived in this ecosystem, animals such as salamanders, early squamates and even small mammals.”

Everything Dinosaur acknowledges the assistance of a press release from the Virginia Tech College of Science in the compilation of this article.

The scientific paper: “The Earliest Equatorial Record of Frogs from the Late Triassic of Arizona” by Michelle R. Stocker, Sterling J. Nesbitt, Ben T. Kligman, Daniel J. Paluh, Adam D. Marsh, David C. Blackburn and William G. Parker published in Biology Letters.

26 02, 2019

Middle Cambrian Worm – Amiskwia Finds a Home

By | February 26th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Weird Prehistoric Worm Finally Gets Classified

Ever since Charles Doolittle Walcott, discovered the now famous Burgess Shale deposits of Cambrian-aged fossils in British Columbia, palaeontologists have marvelled at the amazing snapshot of ancient marine life the fossils represent.  One of the enduring mysteries surrounding many of the preserved remains is how to classify the more than 500-million-year-old-fossil specimens.  One such Burgess Shale creature, a prehistoric worm with jaws – Amiskwia sagittiformis and its equally ancient cousin A. sinica from the roughly contemporaneous Maotianshan shales of Yunnan Province, China have finally found a home on the Tree of Life.

A Fossil of Amiskwia sagittiformis (Burgess Shale)

Amiskwia sagittiformis from the Burgess Shale.

The fossil, Amiskwia sagittiformis from the Burgess Shale (508 million years old), preserving bilateral jaw elements inside its head.

Picture Credit: Luke Alexander Parry/University of Bristol – Yale University

Analysis of Fossils from the Smithsonian Institute

Researchers from Bristol University in collaboration with a former colleague now based at the University of Yale, have identified that this soft-bodied creature is a stem lineage to arrow worms that possesses the jaw apparatus seen in microscopic gnathiferan worms.  This new analysis of ancient fossils helps to link recent DNA studies on the bristle-jawed arrow worms (Chaetognatha), indicating that these worms are related to the Gnathifera, tiny, unsegmented worms with primitive jaws that like the chaetognaths, are found in marine environments.

The scientists conclude that the soft-bodied taxon Amiskwia possesses characters intermediate between chaetognaths and gnathiferans.

A Close View of the Head of an Extant Arrow Worm

A photograph of the head of an arrow worm.

The head of the arrow worm, Parasagitta elegans.  This group of animals (Chaetognatha), are the closest living relatives to the Amiskwia genus.

Picture Credit: Rafael Martin Ledo/Consejería de Educación de Cantabría

Originally Described by Walcott

Like many of the Burgess Shale animals, an original description of Amiskwia was published by Walcott (1911).  Walcott made the connection with extant arrow worms (chaetognaths).  These unsegmented worms are predators and they use the spines on their head for catching prey.  Despite the remarkable degree of preservation of Burgess Shale specimens, fossils of Amiskwia are very rare when compared to other Burgess Shale Middle Cambrian biota.  Fossils of Amiskwia sinica are also very rare in the Chinese Maotianshan shales.  These types of creatures may have comprised a scarce component of the Middle Cambrian marine fauna, or perhaps, there is a fossil preservation bias.

With few fossils to study, there was widespread debate amongst scientists with regards to Walcott’s conclusions regarding the taxonomy of Amiskwia.  The renowned American palaeontologist, Stephen Jay Gould (1941-2002), re-ignited the controversy by speculating that these little, soft-bodied, squished fossils represented an organism that had no modern relatives.  Gould proposed that Amiskwia was an experiment in evolution that ultimately failed leaving an extinct lineage and no modern-day descendants.

The problem with Walcott’s idea that Amiskwia was related to arrow worms was that scientists were unable to find evidence of any grasping spines at the anterior end of the animal in any of the fossils.  Instead, many researchers proposed that Amiskwia was a representative of another group of worms the ribbon worms (Nemertea).

When Dr Jakob Vinther from the University of Bristol’s Schools of Earth Sciences and Biological Sciences and Luke Parry (Yale University), studied specimens of Amiskwia, kept at the Smithsonian Institute, they found something that had been overlooked by the previous researchers.

Dr Vinther explained:

“I coated the specimen with ammonium chloride smoke to make the relief of the fossil stand out and then I could see that in the head was a pair of robust elements.”

A Set of Jaws

Interpreting these structures as a set of jaws, their resemblance led the scientists to the conclusion that there was a link between these fossils and the Gnathifera.  In essence, the Amiskwia fossil material represents a sort of half-way stage between two important groups of invertebrates.  Amiskwia had the jaw apparatus of a gnathiferan, but the body plan of an arrow worm.

A Microscopic Member of the Gnathifera – the gnathostomulid Rastrognathia macrostoma

The gnathostomulid Rastrognathia macrostoma.

The gnathostomulid Rastrognathia macrostoma, these microscopic animals have a jaw apparatus similar to Amiskwia, which scientists now propose are amongst the closest living relatives of living arrow worms.

Picture Credit: Martin Vinther Sørensen/SNM Denmark

This study in conjunction with the recent DNA analysis, confirms that Amiskwia is the fossil link between the Gnathifera and arrow worms, the Chaetognatha.  This research was originally conducted some years, ago but was not published as the paper’s conclusions lacked supporting evidence from other studies.

Dr Vinther added:

“The bizarre combination of anatomy seemed altogether alien back in 2012.  Some people have proposed that there could be a relationship between arrow worms and gnathiferans based on their shared possession of a jaw apparatus, both made of a substance called chitin.  However, there was little other evidence to suggest a relationship, such as evidence from phylogenetic analyses of DNA.”

Co-author of the scientific paper, Luke Parry stated:

“It altogether seemed like heresy to propose that gnathiferans and arrow worms may be related back then so we held off publishing our intriguing results out of fear of criticism from our peers.  However, new DNA studies have since emerged that found arrow worms to be more and more closely affiliated to the Gnathifera in the Tree of Life.  In particular, some researchers found that arrow worms share a duplication of the important Hox genes with a gnathiferan, the rotifers.  We suddenly felt no more in a deadlock situation.”

Now the authors have published their findings in the journal Current Biology. The study follows a new phylogenetic study, which finds robust support for arrow worms forming an evolutionary group with gnathiferans.

The Inferred Phylogeny of Amiskwia and its Position in Relation to the Gnathifera and the Chaetognatha

Amiskwia inferred phylogeny.

Inferred phylogeny. Thumbnails at the bottom of the figure show reconstructions of relevant extant and extinct gnathiferan and chaetognath taxa.

Picture Credit: Current Biology

Scientists have pieced together a little bit of the enigmatic Burgess Shale and the Chinese Maotianshan biotas and linked them to modern organisms.  Amiskwia has been found a place on the Tree of Life.  It is a stem lineage to arrow worms that possess the jaw apparatus seen in gnathiferan worms.

This jaw evolved into the fearsome grasping spines in living arrow worms, which play an important role in  marine ecosystems.

The scientific paper: “Bilateral Jaw Elements in Amiskwia sagittiformis Bridge the Morphological Gap between Gnathiferans and Chaetognaths” by Jakob Vinther and Luke A. Parry published in Current Biology.

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

22 02, 2019

Fleet-footed Tyrannosaur Leaps 70-million-year Gap

By | February 22nd, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

The Diminutive Tyrannosaur Moros intrepidus

A small, but speedy dinosaur is the newest member of the Superfamily Tyrannosauroidea, a distant relative of the most famous dinosaur of all Tyrannosaurus rexT. rex et al might have a reputation for being giant, bone-crunching apex predators, but for much of their evolutionary history, the Tyrannosaurs have been rather over-shadowed by other super-sized dinosaur carnivores.  Indeed, it was only in the last few million years of the Cretaceous that these types of Theropod emerged as the apex predators of northern latitudes.  The new dinosaur, named Moros intrepidus, at approximately 78 kilograms (data range 53 to 85 kilograms), around the same bodyweight as a South American Jaguar (Panthera onca), is about ninety times lighter than its famous top-of-the-food-chain relative.

Ironically, contrary to public opinion, M. intrepidus might just be more typical of the Tyrannosauroidea bauplan than its more famous relatives – Gorgosaurus, Albertosaurus and T. rex.

The Newly Described Moros intrepidus from the Late Cretaceous of Central Utah

Life reconstruction Moros intrepidus.

Moros intrepidus from the Late Cretaceous of central Utah.

Picture Credit: Jorge Gonzalez

Teeth and a Hind Limb from a New Theropod

The fossilised remains of a partial right leg consisting of a femur, a tibia, metatarsal bones and some toe bones from the fourth toe were discovered in sediments representing the lower Mussentuchit Member of the Cedar Mountain Formation located in Emery County (Utah).  These fossils, in conjunction with isolated teeth from the front portion of the upper jaw (premaxilla) found nearby provide the basis for this new taxon.  The deposits represent a terrestrial environment, a large delta and they date from approximately 96 million years ago (Cenomanian faunal stage of the Late Cretaceous).

Moros intrepidus represents the oldest known Cretaceous-aged tyrannosauroid discovered to date in North America. It extends the definitive fossil record for these types of dinosaurs by around 15 million years.

The Temporal Relationships and Phylogeny of the Tyrannosauroidea

Moros intrepidus fills a 15-million-year evolutionary gap.

Phylogenetic and temporal relationships between tyrannosauroids and an examination of faunal turnover.  The Allosaurs/Megaraptor apex predator niche was gradually taken over by Tyrannosaurs.

Picture Credit: Nature Communications Biology

In the diagram (above), the section on the left (a), shows the fossil record gap between Late Jurassic tyrannosauroids and much larger Late Cretaceous members of the Tyrannosauridae family such as Lythronax (L. argestes).  Section (b) demonstrates the temporal range of these Theropods and the change in bauplan, whilst (c) demonstrates key evolutionary anatomical changes.  The blue and pink coloured shapes in (d) reflect the transition from Allosaur/Megaraptoran dominated ecosystems to Tyrannosaur dominated palaeoenvironments.

A Changing of the Guard When it Comes to Apex Predators

Palaeontologists know that the Tyrannosaur lineage dates back a long way.  For example, basal tyrannosaurids such as Stokesosaurus (S. clevelandi) are known from Upper Jurassic deposits of Utah.  By the Late Cretaceous (Campanian faunal stage), Tyrannosaurs were large and had become the iconic apex predators beloved by dinosaur fans and film directors.  The fossil record for North American Tyrannosaurs was essentially blank, giving palaeontologists a T. rex skull-sized headache when it came to piecing together how these Theropods changed over time.

The discovery of Moros helps to narrow a 70-million-year-gap in the fossil record of tyrant lizards in North America.

Lead-author of the study, published in “Nature Communications” Lindsay Zanno of the North Carolina Museum of Natural Sciences explained:

“When and how quickly Tyrannosaurs went from wallflower to prom king has been vexing palaeontologists for a long time.  The only way to attack this problem was to get out there and find more data on these rare animals.”

A Silhouette of M. intrepidus Showing the Anatomical Position of the Known Fossil Material

Moros intrepidus silhouette showing placement of known fossil elements.

Silhouette of M. intrepidus showing known fossil elements.  Key = (g) femur, (h) tibia, (i) fourth metatarsal, (j) second metatarsal, and (k) pedal phalanges of the fourth digit.   Scale bar (c) 1 m, (g–k) 5 mm.  Note the tooth (views d-f) are not to scale.

Picture Credit: Nature Communications Biology

Living in the Shadow of Siats meekerorum

In 2013, two of the authors of the Moros intrepidus paper, Lindsay Zanno and Peter Makovicky (Field Museum, Chicago), published a study on a large allosauroid from similar-aged sediments.  The dinosaur, named Siats meekerorum is estimated to have measured around 12 metres in length, dwarfing the contemporary Moros, which had a hip height of around 1.2 metres.  The researchers conclude that within a palaeoenvironment dominated by giant, allosauroid Theropods, Tyrannosaurs such as M. intrepidus relied on their speed and small size and would have kept out of the way of the larger predators.

A spokesperson from Everything Dinosaur commented:

“During the Cenomanian, tyrannosauroids like Moros intrepidus were secondary predators within an ecosystem dominated by apex predators from a completely different part of the Theropod family tree.  For the greater part of the Tyrannosaur evolutionary history, these types of dinosaurs were marginal predators, living in the shadow of much bigger carnivorous dinosaurs.”

A Life Reconstruction of Siats meekerorum with two Tyrannosauroids shown in the Foreground

Siats meekerorum .

Siats meekerorum has nothing to fear from these two Tyrannosaurs.  Moros intrepidus may have scavenged the kills of larger Theropods but these types of tyrannosauroid were very much the secondary predators.

Picture Credit: Julio Laceardo

To read Everything Dinosaur’s article on the discovery of Siats meekerorumUnravelling the Apex Predators of the Cretaceous Before Tyrannosaurs

Phylogeny Points at Asian Ancestry

A study of the longer limb bones indicates that the individual was around six to seven years of age when it died.  It was likely to have reached its adult size.  A phylogenetic assessment indicates an affinity with Asian Tyrannosaur taxa, in essence, the ancestors of famous North American dinosaurs such as Gorgosaurus and Tyrannosaurus rex migrated into North America from Asia.

Assistant Research Professor Zanno stated:

“T. rex and its famous contemporaries such as Triceratops may be among our most beloved cultural icons, but we owe their existence to their intrepid ancestors who migrated here from Asia at least 30 million years prior.  Moros signals the establishment of the iconic Late Cretaceous ecosystems of North America.”

Views of the Lower Leg Bones from the Right Leg of M. intrepidus

Views of the lower leg bones of Moros intrepidus.

Right tibia (a–f) and right fourth metatarsal (g–l) of M. intrepidus (NCSM 33392).

Picture Credit: Nature Communications Biology

What’s In a Name?

The etymology of this new tyrannosauroid reflects the later faunal turnover that led to the apex predator roles in North America being dominated by Tyrannosaurs.  The genus name is from the Greek “Moros”, the embodiment of impending doom, for the descendants of this fast-running dinosaur were to evolve into some of the largest and most formidable terrestrial predators known to science.  The species name is from the Latin “intrepidus”, a reference to these intrepid dinosaurs making the migration from Asia into North America and their subsequent dispersal.

Size is Not Everything

Although around ninety times lighter than Tyrannosaurus rex, Lindsay warns against underestimating the predatory abilities of Moros.

She added:

“Moros was lightweight and exceptionally fast.  These adaptations, together with advanced sensory capabilities, are the mark of a formidable predator.  It could easily have run down prey, while avoiding confrontation with the top predators of the day.  Although the earliest Cretaceous Tyrannosaurs were small, their predatory specialisations meant that they were primed to take advantage of new opportunities when warming temperatures, rising sea-level and shrinking ranges restructured ecosystems at the beginning of the Late Cretaceous.  We now know it took them less than 15 million years to rise to power.”

The scientific paper: “Diminutive fleet-footed tyrannosauroid narrows the 70-million-year gap in the North American fossil record” by Lindsay E. Zanno, Ryan T. Tucker, Aurore Canoville, Haviv M. Avrahami, Terry A. Gates and Peter J. Makovicky published in Nature Communications Biology.

19 02, 2019

“The Dinosaurs Rediscovered” – New Book About Dinosaurs

By | February 19th, 2019|Book Reviews, Dinosaur Fans, Main Page, Palaeontological articles, Press Releases|0 Comments

“The Dinosaurs Rediscovered” – New Book About Dinosaurs

Everything Dinosaur has received an uncorrected proof of the eagerly awaited new dinosaur book by Professor Michael Benton.  Team members are looking forward to reading about how research into the Dinosauria has been revolutionised over the last two decades or so.  Professor Benton is one of the leading lights in vertebrate palaeontology and has written over fifty books covering a wide range of prehistoric animals and events from deep time.  As the head of the world-renowned Palaeobiology Research Group at the University of Bristol, Professor Benton has been involved in and led some of the most insightful and ground-breaking studies into the dinosaurs, helping to re-write scientific understanding.

“The Dinosaurs Rediscovered” – Exploring the Revolution in Dinosaur Research

A new dinosaur book "The Dinosaurs Rediscovered".

“The Dinosaurs Rediscovered” by Professor Mike Benton.

Picture Credit: Thames & Hudson/Everything Dinosaur

The Changing Story of the Dinosaurs

The book runs to 336 pages with 163 illustrations (23 in colour), it explores the changing story of the dinosaurs, highlighting how the application of 21st Century technologies have revealed new information about these remarkable reptiles, information that had been locked deep inside their fossilised bones and teeth.  Trace fossils are also explored in detail and Professor Benton demonstrates how biomechanical engineering combines with computer modelling and digital dinosaurs to calculate how fast Theropod dinosaurs could run.  The work of the famous Bristol Dinosaur Project is covered and naturally, Bristol’s very own dinosaur Thecodontosaurus (T. antiquus) is included, but Professor Benton does not just feature dinosaurs from the south-west of England, this impressive publication provides a global perspective on the Dinosauria.  This beautifully written book includes chapters on feathered dinosaurs and even explores whether dinosaur DNA could be used to resurrect the Dinosauria.

The Book includes Chapters on Feathered Dinosaurs and Explores Whether Dinosaur DNA could be Found Preserved in Amber

Feathered dinosaur illustration.

An illustration of the feathered dinosaur, about to become stuck in amber.  Professor Mike Benton introduces the reader to some amazing recent dinosaur discoveries.

Picture Credit: Cheung Chung-Tat

An Engaging Account

This is an engaging account of the evolution of the “terrible lizards” and is aimed at readers with a general interest in life in the past as well as academics and students.  Fans of prehistoric animals and dinosaur devotees don’t have to wait too long before this book is published.  The hardback is due out on April 25th (published by Thames and Hudson).

The Front Cover of Professor Benton’s New Book

"The Dinosaurs Rediscovered".

The jacket cover of the new book about dinosaurs “The Dinosaurs Rediscovered”.

Picture Credit: Thames & Hudson

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