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

18 08, 2019

Prehistoric Predator with a Mouth Like a Slice of Pineapple

By | August 18th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

The Predatory Cambroraster falcatus from the Burgess Shale

Palaeontologists at the Royal Ontario Museum and the University of Toronto have announced the discovery of a new 500-million-year-old predator, adding to the diversity associated with the Cambrian-aged Burgess Shale biota.  The animal, a distant relative of today’s spiders, insects and crustaceans, has been named Cambroraster falcatus.  At around thirty centimetres in length C. falcatus was one of the biggest animals around in the Late Cambrian and it was a distant relative of the formidable Anomalocaris, the apex predator on Earth during this time in our planet’s history.

A Life Reconstruction of Cambroraster falcatus

Illustrating the newly described Cambroraster from the Burgess Shale biota.

Cambroraster life reconstruction (dorsal view) and top, a view of the animal’s underside.

Picture Credit: Royal Ontario Museum

Providing New Information About the Diversity of Early Arthropods

Fossils of this newly described species were found in the Kootenay National Park in the Canadian Rockies.  Cambroraster has rake-like claws and a pineapple-slice-shaped mouth at the front of an extremely large head, it probably used its rake-like claws to sift through sediment and trap prey.

Lead author of the scientific paper published in the Proceedings of the Royal Society B (Biology), Joe Moysiuk, based at the Royal Ontario Museum stated:

“Its size would have been even more impressive at the time it was alive, as most animals living during the Cambrian Period were smaller than your little finger.  Cambroraster was a distant cousin of the iconic Anomalocaris, the top predator living in the seas at that time, but it seems to have been feeding in a radically different way.”

Revealing a Fossil of a Cambroraster at the Kootenay National Park Field Site

Cambroraster fossil excavation.

Excavating a Cambroraster fossil from the Burgess Shale. Although flattened, enough detail has been preserved in the fine sediments for paleaontologists to reconstruct the animal.

Image Credit: Royal Ontario Museum

Remarkable Claws and the Millennium Falcon

The name Cambroraster refers to the remarkable claws of this animal, which bear a parallel series of outgrowths, looking like forward-directed rakes.   With the space between the spines on the claws at typically less than a millimetre, this would have enabled Cambroraster to feed on very small organisms, although larger prey could also likely be captured, and ingested into the circular tooth-lined mouth.  It is this specialised radial mouth that links Cambroraster to the Radiodonta, a clade of stem arthropods that were geographically widespread during the Cambrian, with many genera evolving into large nektonic predators.  The species or trivial name “falcatus”, is in honour of another of this marine animal’s distinctive features – the large, shield-like carapace covering the anterior part of the body.  This shield reminded the scientists of the iconic spaceship the Millennium Falcon from the Star Wars movie.

Graduate student Moysiuk added:

“With its broad head carapace with deep notches accommodating the upward facing eyes, Cambroraster resembles modern living bottom-dwelling animals like horseshoe crabs.  This represents a remarkable case of evolutionary convergence in these radiodonts.”

The researchers conclude that such convergence is likely reflective of a similar environment and mode of life, like modern horseshoe crabs, Cambroraster may have used its carapace to plough through sediment as it fed.

A Large Number of Specimens Found

Co-author of the paper, Dr Caron, an Assistant Professor at the University of Toronto commented:

“The sheer abundance of this animal is extraordinary.  Over the past few summers we found hundreds of specimens, sometimes with dozens of individuals covering single rock slabs.”

Based on over a hundred exceptionally well-preserved fossils now housed at the Royal Ontario Museum, the researchers were able to reconstruct Cambroraster in unprecedented detail, revealing characteristics that had not been seen before in related species.

Dr Caron added:

“The radiodont fossil record is very sparse, typically, we only find scattered bits and pieces.  The large number of parts and unusually complete fossils preserved at the same place are a real coup, as they help us to better understand what these animals looked like and how they lived.  We are really excited about this discovery.  Cambroraster clearly illustrates that predation was a big deal at that time with many kinds of surprising morphological adaptations.”

A View of the Underside of Cambroraster with a Close-up View of the Radial Mouth

Cambroraster Life Reconstruction

A life reconstruction of Cambroraster showing the underside (ventral view) and the unusual mouth parts with the pair of raking appendages.

Picture Credit: Royal Ontario Museum

The Significance of the Burgess Shale

The fossils from the Burgess Shale of British Columbia document a remarkable time during the evolution of life on Earth.  There was a huge increase in biodiversity and food chains became much more complex as most of the major Phyla of animals that are around today evolved.  The Cambroraster fossil material comes from several locations in the Marble Canyon area of Kootenay National Park.  These locations and others like them are being explored and mapped by field teams from the Royal Ontario Museum.  These sites are about 25 miles (40 km) away from the original Burgess Shale fossil site in Yoho National Park that was discovered in 1909.  Scientists are confident that more new species will be discovery in this area of Kootenay National Park

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

The scientific paper: “A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources” by J. Moysiuk and J.B. Caron published in the Proceedings of the Royal Society B.

13 08, 2019

Monster Penguin from the Palaeocene of New Zealand

By | August 13th, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Crossvallia waiparensis – Monster Penguin from New Zealand

Sixty-six million years ago, the non-avian dinosaurs became extinct.  The end-Cretaceous mass extinction event also resulted in the extinction of the majority of the marine reptiles, the mosasaurs and the plesiosaurs.  Nature abhors a vacuum and in some parts of the world, the apex piscivore niche became occupied by man-sized penguins.  This idea of prehistoric penguin super-predators has been boosted with the naming and scientific description of a “monster penguin” from Palaeocene-aged deposits on New Zealand’s South Island.  Weighing in at an estimated eighty kilograms, and standing around 1.6 metres tall, Crossvallia waiparensis is one of the largest penguins known to science.

The Newly Described Crossvallia waiparensis Compared to an Average-height Woman

Crossvallia waiparensis compared to a human.

Crossvallia waiparensis compared to an average-height woman.

Picture Credit: Canterbury Museum

One of the World’s Oldest Species of Penguin

Writing in the scientific journal “Alcheringa: An Australasian Journal of Palaeontology”, researchers Dr Paul Scofield and Dr Vanesa De Pietri (Canterbury Museum), in collaboration with their colleague Dr Gerald Mayr (Senckenberg Natural History Museum in Frankfurt, Germany), describe C. waiparensis based on leg bones representing an individual animal and tentatively referred partial humeri (upper arm bones).  The fossils were found by amateur palaeontologist Leigh Love last year, during field work at the Waipara Greensand fossil site located north of Canterbury.

The sediments were laid down in the Palaeocene Epoch (66 to 56 million years ago), making C. waiparensis is one of the world’s oldest known penguin species.  The discovery also reinforces the idea that penguins (Sphenisciformes), attained large size early in their evolutionary history.  The biggest extant penguin is the Emperor Penguin (Aptenodytes forsteri), which can weigh more than twenty kilograms and stands around 1.2 metres high.

Overview of the Leg Bones of C. waiparensis

Fossils of Crossvallia waiparensis.

Fossils of Crossvallia waiparensis a giant penguin from the Palaeocene of New Zealand.

Picture Credit: Mayr et al

The photograph (above), shows an overview of the leg bones of Crossvallia waiparensis (A-L), along with views of the tentatively referred proximal end of a left humerus (M-O), scale bar = 5 centimetres.

The team have concluded that the closest known relative of C. waiparensis is a fellow Palaeocene species Crossvallia unienwillia, which was identified from a fossilised partial skeleton found in the Cross Valley in Antarctica.  This newly described “monster penguin” is not the first giant penguin to have been discovered.  For example, the Eocene taxa Anthropornis and Palaeeudyptes were comparable in size, if not bigger and this suggests that giant penguins evolved several times in the evolutionary history of the penguin family.

To read a related article from Everything Dinosaur: Gigantism in Penguins

The scientific paper: “Leg bones of a new penguin species from the Waipara Greensand add to the diversity of very large-sized Sphenisciformes in the Paleocene of New Zealand” by Gerald Mayr, Vanesa L. De Pietri, Leigh Love, Al Mannering and R. Paul Scofield published in Alcheringa; An Australasian Journal of Palaeontology.

4 08, 2019

New Study Confirms Ichthyosaurs Had Tough Lives

By | August 4th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

The Hard, Tough Lives of Ichthyosaurs

A trio of scientists have published a study looking at signs of injury and disease in a range of ichthyosaur genera.  Such studies have been undertaken before, indeed the authors of this new paper, published by the Royal Society Open Science, Judith M. Pardo-Pérez, Erin Maxwell (Staatliches Museum für Naturkunde, Stuttgart, Germany) and Benjamin Kear (Uppsala University, Sweden) have examined pathologies in the giant ichthyosaur Temnodontosaurus as recently as 2018, but this study takes a different approach.  The researchers looked in detail at one specific ancient ecosystem, analysing injuries and disease recorded in several different types of  ichthyosaur and found some surprising results.

A Scale Drawing Illustrating the Size of the Superpredator Temnodontosaurus

Scale drawing of Temnodontosaurus.

Temnodontosaurus scale drawing.  In this illustration the marine reptile is giving birth (these vertebrates were viviparous).  A study was published in 2018 which examined pathologies associated with the skeleton of this apex predator.

Picture Credit: Everything Dinosaur

Back in 2018, these scientists published a paper detailing the injuries and disease lesions (pathology), associated the ichthyosaur superpredator Temnodontosaurus.  They found that despite its size, growing up to ten metres in length, these predators led quite tough lives, given the healed wounds, evidence of trauma and signs of disease preserved in their fossils.

In this new paper, published last week, the scientists examined the fossils of five different ichthyosaurs known from a single fossil deposit (Posidonienschiefer Formation).  These fossils from southern Germany, date from the Early Jurassic (Toarcian faunal stage) and represent a marine fauna that suffered a minor extinction event resulting in a significant faunal turnover amongst the vertebrates.

The five genera of ichthyosaur (Posidonienschiefer Formation) from the study in order of maximum size:

1).  Hauffiopteryx (2.5 m long) – a relatively short-snouted genus that probably fed on small fish and squid.
2).  Stenopterygius (3.5 m long) – feeding on small fish and squid.
3).  Suevoleviathan (4 m long)- a primitive member of the Neoichthyosuria clade that with a short-snout that indicates a generalist feeding habit.
4).  Eurhinosaurus (7 m long) – its elongated upper snout suggests a specialist position in the food chain, perhaps feeding on small fish or probing the seabed to feed on invertebrates.
5).  Temnodontosaurus (up to 10 metres long) – the top predator in the ecosystem, attacking and eating other marine reptiles including ichthyosaurs.

Not Just Damaged Ribs

Damaged ribs are quite commonly found on ichthyosaur fossils, but in this study, a detailed examination of the entire fossilised remains of individual animals was carried out.  The team examined the influence of taxa (which species demonstrated the greatest signs of trauma and disease), as well as which parts of the body were damaged the most, the influence of ontogeny and the impact of environmental change (early Toarcian Oceanic Anoxic Event).

Examples of Pathologies in Ichthyosaurs from the Posidonienschiefer Formation

Ichthyosaur pathologies.

Examples of ichthyosaur pathologies from the Posidonienschiefer Formation.  In picture (a) a fused (ankylosed) femur and fibula is indicated by the two black arrows, the species is Stenopterygius uniter.  In picture (b) fused neural spines (ankylosis) is indicated by the single black arrow.   The species is Stenopterygius quadriscissus.

Picture Credit: Royal Society Open Science

Small-bodied Genera Do Best

Following the review of the skeletal material, the researchers found that the incidence of pathologies is dependent on the type of taxon being examined.  Small-bodied genera such as Stenopterygius had fewer injuries, signs of disease and trauma when compared to larger-bodied ichthyosaurs.  Within the Stenopterygius genus, the scientists discovered that more pathologies were identified in large adults when compared to smaller sized individuals.  Stratigraphic horizon, a proxy for evidence of change within the ancient marine ecosystem did not influence the incidence of pathology associated with Stenopterygius.

The Research Team Carefully Examined an Extensive Portion of the Posidonienschiefer Formation Ichthyosaur Biota

Ichthyoaur pathology.

Evidence of pathologies found in ichthyosaur fossils.  Photograph (C) shows a fractured and healed gastralia rib (belly rib) of a Hauffiopteryx (H. typicus).  The black arrow indicates the break and the resulting callus.  Photograph (D) shows a healed fractured rib from a Stenopterygius, the arrow indicating the break and showing the callus.

Picture Credit: Royal Society Open Science

Skull and Forelimb Injuries

When all the data from the examined taxa was added together, it was no surprise that the rib area was identified as that part of an ichthyosaur’s body most likely to show signs of pathology.  Around 8% of the specimens examined showed rib trauma.  However, approximately 6% of skulls and 4% of forelimbs also showed pathologies.  In contrast, those areas of the body showing the least signs of injury were the vertebrae and the hind limb.

The researchers concluded that within the fauna studied, ichthyosaurs appear to be similar to living vertebrates in which pathologies accumulate in the oldest/largest members of a population, and larger taxa experience proportionately more frequent skeletal traumas.

The scientific paper: “Palaeoepidemiology in extinct vertebrate populations: factors influencing skeletal health in Jurassic marine reptiles” by Judith M. Pardo-Pérez , Benjamin Kear and Erin E. Maxwell published in Royal Society Open Science.

1 08, 2019

Cute and Cuddly Marsupial Had a Fearsome Fossil Relative

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

Sparassocynus – A Pliocene Predator

Scientists, including a researcher from the University of Salford (Manchester), writing in the academic publication the “Journal of Mammalian Evolution”, have shed further light on a predatory prehistoric marsupial from the Pliocene of South America.  Sparassocynus might be related to living short-tailed opossums, but unlike its extant relatives, Sparassocynus was not insectivorous, most likely, other small mammals were on the menu.

A Life Reconstruction of Sparassocynus

Sparassocynus life reconstruction.

A life reconstruction of Sparassocynus feeding on a small rodent.

Picture Credit: Velizar Simeonovski

Living short-tailed opossums are cute and most are not much bigger than a squirrel, but these natives of South America had a bigger and ferocious fossil relative.  The joint British and Argentinian research team have shown that Sparassocynus, is an extinct carnivorous relative of today’s cute and cuddly short-tailed opossums.  The Sparassocynus genus has been known to science for over a hundred years, but its evolutionary position within the Didelphimorphia, that great clade of marsupials that includes the specious opossums and their relatives has been uncertain.  However, Dr Robin Beck, a mammal systematist at the University of Salford, in collaboration with Matías Taglioretti (Museo Municipal de Ciencias Naturales “Lorenzo Scaglia”, Argentina), have clarified its taxonomic position.

The pair of scientists focused their attention on a 4-million-year-old skull of Sparassocynus (Sparassocynus derivatus), that provided vital new information about this genus.  The skull was found in 2012 by Taglioretti and colleagues in a fossil deposit in cliffs along the Atlantic coast of Argentina, near the city of Mar del Plata (Playa Las Palomas).

Commenting on the significance of the skull fossil find Dr Beck stated:

“As soon as Matías showed me the skull, I knew it was really important.  It’s almost perfectly preserved, and it’s not fully grown [it still has its baby teeth], so it preserves a lot of features that are not visible in other specimens.”

The Juvenile Sparassocynus Skull Fossil (Lateral View)

Sparassocynus fossil skull.

Four-million-year-old skull of a Sparassocynus (S. derivatus) juvenile from the Chapadmalal Formation near Mar del Plata, Argentina.  Note scale bar = 1 cm.

Picture Credit: Dr Robin Beck (University of Salford)

By comparing over a hundred different anatomical characteristics, and incorporating DNA evidence from living species, Beck and Taglioretti showed that Sparassocynus is an extinct member of the opossum family and is most closely related to the much more cute and cuddly, insect-eating short-tailed opossums.

Dr Beck added:

“This might seem surprising because Sparassocynus was clearly a carnivore that would probably have eaten rodents and other small vertebrates, whereas short-tailed opossums are about five times smaller and mainly eat insects, but they share some unusual features that indicate a close relationship.”

Sparassocynus survived in South America until about 2.5 million years ago, when it may have been driven extinct by the arrival of weasels from North America in what is known as the “Great American Biotic Interchange”, the land masses of North America and South America were finally united when the Panama land bridge became complete.  There are over a hundred species of opossum still alive today in South America, of which, twenty-four are short-tailed opossums.  Thankfully, none of these extant species are quite as ferocious as Sparassocynus would have been.

The scientific paper:

“A nearly complete juvenile skull of the marsupial Sparassocynus derivatus from the Pliocene of Argentina, the affinities of “sparassocynids” and the diversification of opossums (Marsupialia; Didelphimorphia; Didelphidae)” by RMD Beck and ML Taglioretti published in the Journal of Mammalian Evolution.

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

24 07, 2019

Mammaliaforms Could Swallow Just Like Us

By | July 24th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Microdocodon gracilis – Hyoid Bones

A team of international researchers have announced the discovery of a tiny, Middle Jurassic mammaliaform that was not much longer than a pencil and had thigh bones no thicker than a matchstick.  The little critter, named Microdocodon gracilis comes from strata estimated to be around 164-million-years old, it measured under fifteen centimetres in length, most of which was tail.  It was very probably scansorial (capable of climbing), very likely arboreal and this lithe early mammal hunted insects.

A Life Reconstruction of the Newly Described M. gracilis

Life reconstruction Microdocodon.

A life reconstruction of Microdocodon gracilis.

Picture Credit: April I. Neander

Important Hyoid Bone Fossil Find

The researchers, which included scientists from the Shenyang Normal University in China’s Liaoning Province, Yale University, the University of Chicago (United States), as well as colleagues from the Institute of Geosciences, Rheinische Friedrich-Wilhelms-Universitat (Bonn, Germany) report in the academic journal “Science”, on the discovery of the earliest example of hyoid bones in the mammalian fossil record.  Hyoid bones link the back of the mouth (pharynx), to the openings of the larynx and the oesophagus.  They are arranged in a “U-shape” and suspended by jointed segments from the skull.  These bones permit mammals, including us, to chew food and then swallow it efficiently.  Reptiles such as crocodilians can only gulp down food, there is very little processing undertaken in the mouth.

Lead author of the scientific paper Zhou Chang-Fu explained that the hyoid bone is not closely connected to other bones such as the jaws, so it is easy for it to be lost as a body decomposes.  Zhou also added that the hyoid bone measures just a few millimetres in length and has mobile joints arranged in a saddle-shaped configuration, which are fundamentally different from the simple hyoid rods associated with nonmammaliaform cynodonts.

The Evolution of Hyoid Bones in the Mammalian Lineage

Hyoid bone evolution in mammals.

The evolution of hyoid bones in mammals.

Picture Credit: April I. Neander/University of Chicago

Commenting on the significance of the fossil discovery, Zhe-Xi Luo (University of Chicago) stated:

“Mammals have become so diverse today through the evolution of diverse ways to chew their food, whether it is insects, worms, meat or plants.  But no matter how differently mammals can chew, they all have to swallow in the same way.  Essentially, the specialised way for mammals to chew and then swallow is all made possible by the agile hyoid bones at the back of the throat.”

The scientific paper: “New Jurassic mammaliaform sheds light on early evolution of mammal-like hyoid bones.” by Chang-Fu Zhou et al and published in the journal Science.

23 07, 2019

Defining Allometric Growth

By | July 23rd, 2019|Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Defining Allometric Growth

Everything Dinosaur received an email from a dinosaur model collector the other day enquiring about the concept of allometric growth.  She had read in one of our blog articles about the growth rates of tyrannosaurids and wanted to enquire how we define allometric growth and what this might mean when looking at the lives of theropods.

Put simply, allometric growth occurs when different parts of an organism grow and develop at different rates.  The appearance of an organism undergoing allometric growth changes radically as the organism grows and matures.

Gorgosaurus libratus – One of the Most Extensively Studied Tyrannosaurs

Gorgosaurus libratus illustrated.

Faster and slightly more nimble when compared to contemporaneous tyrannosaurids and the extensive fossil record representing juveniles as well as adults has enabled palaeontologists to plot body plan changes.

Picture Credit: Everything Dinosaur

Gorgosaurus libratus

The Late Cretaceous tyrannosaurid Gorgosaurus (G. libratus) provides palaeontologists with the most extensive fossil record of any member of the Tyrannosauridae.  It is known from numerous fossil specimens, including adults and juveniles, most of these fossils having come from the famous Dinosaur Park Formation of southern Alberta (Canada).  Leg bone proportions changed as these predators grew and matured.  For example, the femur (thigh bone), in adults  and sub-adults was slightly longer than or equal in length to the lower leg bones (tibia and fibula).  In the very largest specimens, the femur is more than a metre in length.  In many juveniles, it is the tibia that is longer than the femur.  The body proportions of these dinosaurs changed as they grew, so they are demonstrating allometric growth.

A Juvenile Gorgosaurus Feeding on the Carcase of a Centrosaurus

A speculative illustration of a young Gorgosaurus feeding on the carcass of a juvenile Centrosaurus.

A young Tyrannosaur (Gorgosaurus) scavenging the carcass of the juvenile Centrosaurus.  As Gorgosaurus grew and matured its body proportions changed.

Picture Credit: Marie-Hélène Trudel-Aubry/PeerJ

As the body proportions of Gorgosaurus changed as the animal grew and matured, this has implications for its behaviour.  For instance, young immature animals were very probably much faster runners than adult animals, they may have specialised in hunting and catching much smaller prey.  If these dinosaurs were pack hunters, then juveniles may have had a specific role in hunting, perhaps pursuing prey and driving it towards the adult members of the pack.

Isometric Growth

Organisms that have parts that grow at the same rate and therefore retain a consistent body plan as they grow are deemed to demonstrate isometric growth.  Many types of amphibian demonstrate isometric growth.  Once a frog has metamorphosised from the tadpole stage, its body proportions hardly change as it grows.

 

13 07, 2019

Microraptor Ate Lizards

By | July 13th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Stomach Contents Reveal New Species of Early Cretaceous Lizard

Scientists writing in the academic journal “Current Biology”, have described a new specimen of Microraptor (M. zhaoianus) from Liaoning Province (north-eastern China), that preserves the remains of a small lizard in its body cavity.  The remains of the lizard, inside what would have been the stomach of this little feathered dinosaur, are largely intact and articulated.  This indicates that the unfortunate lizard was swallowed head first, a feeding behaviour seen in extant carnivorous birds and many small reptiles.  The fossilised bones of the lizard represent a new species, it has been named Indrasaurus wangi.

Microraptor is now known to have fed on a variety of small vertebrates, supporting the interpretation that it was an opportunistic predator.

Microraptor About to Swallow the Unfortunate Indrasaurus

Microraptor feeds on Indrasaurus.

A life reconstruction of a Microraptor consuming the lizard Indrasaurus.  The position of the lizard’s remains inside the body cavity of Microraptor indicate that the lizard was swallowed head first.

Picture Credit: Doyle Trankina

Direct Evidence of Predator-Prey Interactions from the Jehol Biota

Direct evidence of diet and predator-prey relationships are extremely rare in the fossil record.  However, the exceptional preservation conditions associated with the Liaoning deposits have resulted in four examples of stomach contents in Microraptor specimens having been identified.  Microraptor is now known to have been a generalist, eating a variety of small vertebrates including  mammals, birds, fish, and with this new discovery, lizards.

Photograph of the Microraptor Specimen (STM5-32) Preserving the Lizard Indrasaurus wangi in the Body Cavity

Microraptor ate lizards.

The Microraptor fossil specimen (STM5-32) the white box indicates location of lizard remains.

Picture Credit: O’Connor et al (Current Biology)

The white lines in the photograph indicate the body cavity area of the Microraptor and show the location of the lizard fossil remains.  The genus name Indrasaurus comes from Hindu scriptures in which the deity Indra was swallowed by the dragon Vritra during their battle.  The species (trivial name), honours Yuan Wang, for his extensive work on the Jehol Biota and his assistance in helping to promote Chinese fossils through museum events and exhibitions.

An Interpretative Line Drawing Showing the Remains of Indrasaurus (I. wangi) in the Abdominal Cavity

The remains of the lizard inside the Microraptor.

A line drawing showing the remains of the lizard Indrasaurus wangi within the stomach cavity of a Microraptor (M. zhaoianus).

Picture Credit: O’Connor et al (Current Biology)

The interpretative drawing (above), shows the contents within the white box outlined in the specimen (STM5-32).  Analysis of the lizard’s bones indicate that it was probably a sub-adult when it met its doom.  Ironically, the Microraptor itself died shortly after eating the lizard, although this would probably have not been much comfort to Indrasaurus had it known this at the time.

Most scientists believe that Microraptor could fly, it is not known whether this little lizard was caught in a tree or captured on the ground after a terrestrial pursuit.  Perhaps Microraptor swooped down onto its prey from a lofty vantage point, a tactic common to many carnivorous birds today.  The probable troodontid Anchiornis from the older Late Jurassic Yanliao Biota is roughly the same size as Microraptor and fossils of Anchiornis reveal that this dinosaur ate lizards too.  However, comparison of the fossilised remains of prey suggests that dromaeosaurids such as Microraptor ingested prey that were fully digested, whereas, Anchiornis may have regurgitated undigested body parts, bringing up a pellet as demonstrated in many bird species alive today.  This feeding behaviour supports a closer relationship between true birds and Anchiornis and suggests that powered flight did not precipitate the evolution of pellet regurgitation (egestion), in these reptiles.

The scientific paper: “Microraptor with Ingested Lizard Suggests Non-specialized Digestive Function by Microraptor with Ingested Lizard Suggests Non-specialized Digestive Function” by Jingmai O’Connor, Xiaoting Zheng, Liping Dong, Yan Wang, Xiaomei Zhang and Zhonghe Zhou published in the journal “Current Biology”.

12 07, 2019

New Theropod Dinosaur from the Late Triassic of Switzerland

By | July 12th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Notatesseraeraptor frickensis – A Mixture of Coelophysid and Dilophosaurid Characteristics

A new European theropod dinosaur from the Late Triassic of Switzerland has been named and described this week.  This is big news, as very little is known about Late Triassic theropods that roamed Europe more than 200 million years ago, only a handful have been described to date, just four species.  The dinosaur has been named Notatesseraeraptor frickensis (No-tah-tess-er-ray-rap-tor frick-ensis), the genus name derives from the Latin “nota” meaning feature and “tesserae”, a Latin term to describe tiles used to create a mosaic, a reference to the mixture of anatomical features (dilophosaurid and coelophysoid) identified in the fossil bones. The trivial name honours the Swiss town of Frick, where the fossils were found.

The Body Plan, Known Fossil Material and a Skeletal Reconstruction of N. frickensis

Skeletal anatomy of Notatesseraeraptor frickensis

The silhouette shows the body plan of Notatesseraeraptor, known fossil material and pictures of the blocks that make up the holotype specimen.

Picture Credit: Nature: Ecology and Evolution

Lizard-eating Dinosaur

The partially articulated specimen was collected in 2006 from the famous Gruhalde clay pit in the town of Frick (Aargau Canton, northern Switzerland).  This clay pit has yielded large numbers of Plateosaurus fossils, although Notatesseraeraptor layer is located above the classic Plateosaurus bone beds.  The strata are from the middle part of the Gruhalde Member of the Klettgau Formation and represents Late Triassic (end-Norian) sediments.  The fossils associated with N. frickensis include a nearly complete skull, articulated forelimbs, vertebrae, hip bones and ribs.  The body cavity revealed the remains of a Clevosaurus, a lizard-like rhynchocephalian, distantly related to the extant Tuatara of New Zealand.  It is likely that the Clevosaurus remains represent this dinosaur’s last meal.

The Skull of Notatesseraeraptor frickensis

Notatesseraeraptor frickensis cranial material.

A view of the skull and upper jaw (Notatesseraeraptor frickensis).  Around 90% of the cranial fossil material was recovered.

A Carnivorous Dinosaur Reported from Switzerland

Around 90% of the skull material was excavated, giving Notatesseraeraptor one of the most complete carnivorous dinosaur skulls known from before the Late Jurassic.   Although, our knowledge of early theropod dinosaurs has improved greatly since the turn of the century, thanks mainly to fossil discoveries from North and South America, very little is known about the evolution and radiation of Late Triassic/Early Jurassic European theropods, their fossil record is notably sparse.  This new theropod species is the first meat-eating dinosaur to be described from Switzerland.

Notatesseraeraptor displays a mix of characteristics typically seen either in coelophysids or in dilophosaurids.  A phylogenetic analysis suggests that it is a member of the Neotheropoda clade with affinities to Dilophosaurus of the Early Jurassic and that Notatesseraeraptor is a basal member of that line of theropods that led to the Averostra (a group, of carnivorous dinosaurs that includes the Ceratosaurs).

The Late Triassic/Early Jurassic European Theropods

The nearly complete skull will help palaeontologists to better understand the evolutionary relationships between different types of Late Triassic/Early Jurassic theropod dinosaur.  The fossil specimen suggests a sub-adult with a length of between 2.6 to 3 metres, but this is speculation based on comparative analysis with dinosaurs such as Coelophysis and Tawa as the length of the tail of Notatesseraeraptor is not known.

A Life Reconstruction of a Typical Coelophysid Dinosaur (Coelophysis bauri)

Coelophysis model.

A life reconstruction of Coelophysis bauri.

Picture Credit: Everything Dinosaur

The three previously described species of Late Triassic European theropod are:

  • Liliensternus liliensterni – named in 1934 (von Huene) from the Middle and Late Norian of Germany
  • Procompsognathus triassicus – named in 1913 (Fraas) also from the Middle to Late Norian of Germany
  • Lophostropheus airelensis named in 1993 known from slightly younger rocks (Late Rhetian to Hettangian – Late Triassic to possibly Early Jurassic)

With the exception of a few scraps of bone associated with Liliensternus skull material and the recently described  Dracoraptor hanigani from south-Wales, no other skull material has been found relating to a neotheropod dinosaur from the Late Triassic/Early Jurassic  in the whole of Europe.

11 07, 2019

Terrestrial Bird-like Dinosaur Oldest Known from North America

By | July 11th, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Hesperornithoides miessleri – Helping to Map Out the Bird Family Tree

A joint team of British and American palaeontologists have announced the discovery of a new species of dinosaur that roamed the Late Jurassic of Wyoming.  The specimen consisting of both cranial and postcranial material lived around 150 million years ago and it has been tentatively placed within the troodontid branch of the Paraves part of the Theropoda.  It could help scientists to better understand the evolutionary relationships between feathered dinosaurs and true birds and it raises intriguing questions as to when powered flight evolved within the Dinosauria.

The little dinosaur, estimated to have measured less than a metre in length (single known specimen is either an adult or a sub-adult), has been named Hesperornithoides miessleri.

A Life Reconstruction of the Newly Described Dinosaur H. miessleri

Hesperornithoides miessleri - life reconstruction.

A life reconstruction of Hesperornithoides miessleri.

Picture Credit: Gabriel Ugueto

An Inhabitant of Wetlands

Writing in the academic journal PeerJ, the authors which include scientists from the University of Manchester, report the taphonomy of the fossil material suggests that this dinosaur was an inhabitant of wetland environments for at least a portion of its life history.  The fossil material was actually discovered back in 2001, whilst excavation work was being carried out on the fossil material associated with Supersaurus.  The fossil comes from Converse County (Wyoming), from strata making up the middle portion of the famous Morrison Formation.  The fossil-bearing strata from the “Jimbo Quarry” has been variously dated to the Oxfordian and Tithonian ages of the Jurassic.

Full Skeleton of Hesperornithoides miessleri

Known fossil material associated with Hesperornithoides miessleri.

Hesperornithoides fossil material “left” (A) and “right” (B) sides of the blocks after final preparation (B).  Scale bar = one cm.

Picture Credit: Levi Shinkle

A Resident of the Famous Morrison Formation

The Morrison Formation is famous for its vertebrate fossils, including many examples of dinosaurs, such as Allosaurus, Ceratosaurus, Diplodocus, Brontosaurus and Camarasaurus.  The carnivorous Hesperornithoides is the smallest dinosaur described to date from Wyoming.

Palaeontologist Bill Wahl  (Wyoming Dinosaur Centre), a co-author of the scientific paper, recalled how excited the field team were when they uncovered the block containing the partially articulated bones.

He stated:

“We were removing a ledge of overburden rock and found, unfortunately with a shovel, some tiny, delicate bones poking out.  We immediately stopped, collected as much of the bones as possible and spent the next few days frantically searching for more.  Only after some of the bones were cleaned did we realise that we had found something spectacular.”

In 2005, the fossil specimen was donated to the Big Horn Basin Foundation, a research and education-based not-for-profit organisation that was merged with the Wyoming Dinosaur Centre back in 2016.  This is how Hesperornithoides miessleri came into the Wyoming Dinosaur Centre’s fossil collection.  The fossil, now known as WYDICE-DML-001, was nicknamed “Lori”  and was examined by Dean Lomax (University of Manchester) and co-author of the study back in 2008, a successful crowdfunding campaign permitted extensive research to be undertaken.

Dean commented:

“I remember the first time I laid my eyes on this little dinosaur.  Even back then, I knew it was a significant discovery.  But, it wasn’t until 2015 when our dino team formed and we began to study ‘Lori’ in much more detail than ever before.”

Reconstructed Quarry Map of “Lori” (Hesperornithoides miessleri)

A quarry map of the fossil material asociated with Hesperornithoides.

Association of skeletal elements assembled from 3-D scans of specimen blocks prior to final mechanical preparation.

Picture Credit: PeerJ

Found on Private Land

The specimen was found on private land owned by the Miessler family.  The trivial name honours their help, support and assistance in bringing this little theropod to the attention of the scientific community.  The genus name is a combination of “Hesper”, referring to its discovery in the American West and “ornis” a nod to its very bird-like anatomy.

A Reconstruction of the Skeleton of Hesperornithoides miessleri

Hesperornithoides miessleri skeleton reconstruction.

Skeletal Reconstruction Hesperornithoides miessleri (scale bar = 25 cm).

Picture Credit: Scott Hartmann

A Key Conclusion of the Study

A key conclusion of the scientific paper relates to the origin of powered flight within the Dinosauria.  Hesperornithoides was very probably entirely terrestrial.  It could not fly, but it has a very bird-like body, suggesting that many features associated with an avian anatomy evolved in dinosaurs that lived out their lives on the ground.  It is the oldest dinosaur of this type, known from more than just teeth fossils from North America.  The terrestrial and flightless lifestyle is consistent with the base of Paraves, and with the base of paravian subclades, suggesting that avian flight evolved within the Avialae, most likely in the Late Jurassic or Early Cretaceous.

Lead author of the paper and PhD student at the University of Wisconsin-Madison, Scott Hartman stated:

“We wanted to expand the dataset used to test dinosaur-bird relationships, so we added hundreds of new species and tens of thousands of new characters.  We found that Lori is a primitive member of a group of dinosaurs that includes Troodon, but perhaps more importantly we discovered that the smaller details of the family tree of bird-like dinosaurs isn’t quite as resolved as some researchers would claim.”

Scott Hartman continued:

“For example, it only takes a few changes in the dataset for Hesperornithoides to be found as a closer relative of Velociraptor than of Troodon.  One robust finding we did come up with is that even as the interrelationships changed, the primitive members of all these groups were non-flying ground dwelling dinosaurs.  That means that some small relatives of Velociraptor such as Microraptor that looks like it could have glided evolved this separately from the modern bird family.”

Hesperornithoides Cranial Material

Fossil material and accompanying line drawings Hesperornithoides.

Hesperornithoides cranial material and interpretative line drawings.

Picture Credit: Levi Shinkle

The scientific paper: “A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight” by Hartman, S., Mortimer, M., Wahl, W. R., Lomax, D. R., Lippincott, J. and Lovelace, D. M and published in PeerJ.

Everything Dinosaur acknowledges the help of a media release from the University of Manchester in the compilation of this article.

5 07, 2019

Repeated Evolution of Herbivorous Crocodyliforms

By | July 5th, 2019|Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Fossil Teeth Suggests Lots of Different Types of Mesozoic Crocodiles

Researchers from the University of Utah have studied the teeth of extinct crocodyliforms and concluded that crocodiles occupied a large range of different ecological niches during the Age of Dinosaurs.  Furthermore, these geographically widespread and speciose reptiles adapted to a variety of diets and that herbivorous crocodyliforms evolved at least three times independently.  This suggests that plant-eating was a beneficial dietary strategy and not a unique occurrence.  Many of these crocodyliforms lived alongside omnivorous or herbivorous synapsids, illustrating an ecological partition that is not found today.

The Diets of Extinct Crocodyliforms were Diverse with Many Examples of Herbivory Identified

Extinct crocodyliforms had different shaped teeth.

Life reconstructions of extinct crocodyliforms. Differences in tooth shape are related to differences in diets.

Picture Credit: Jorge Gonzalez

Writing in the academic paper “Current Biology”, the researchers Keegan Melstrom and Randall Irmis at the Natural History Museum of Utah at the University of Utah, discovered that multiple ancient groups of crocodyliforms (the group including living and extinct relatives of crocodiles and alligators), were not all carnivorous.  Research has been conducted before on the various potential dietary niches of ancient crocodiles, but this new study proposes that vegetarianism arose at least three times within this group.

Commenting on the significance of this new study, doctoral student Keegan Melstrom stated:

“The most interesting thing we discovered was how frequently it seems extinct crocodyliforms ate plants.  Our study indicates that complexly shaped teeth, which we infer to indicate herbivory, appear in the extinct relatives of crocodiles at least three times and maybe as many as six.”

Teeth Variation within Crocodyliforms (Extinct and Extant)

Heterodonty in Crocodyliforms.

False colour 3-D images showing the range in shape of crocodyliform teeth.  Carnivores (left), such as the living Caiman, have simple teeth, whereas herbivores (right) have much more complex teeth.

Picture Credit: Keegan Melstrom (The Natural History Museum of Utah)

The Tip of the Crocodyliform Iceberg

The twenty plus species of crocodylians alive today possess a similar general body shape and ecology.  They are mainly generalist hypercarnivores and semi-aquatic, confined to lower latitudes.  Although, consuming fruit and vegetable matter has been observed in several extant species.  In 2013, Everything Dinosaur wrote an article about fruit consumption (frugivory), in crocodiles.

To read the article: New Study Suggests a Number of Different Types of Crocodylian Consume Fruit.

The crocodiles alive today, all have similar, simple conical teeth but the fossil record shows that extinct crocodyliforms were much more diverse.  Today’s crocodiles are just the remnants from a once much richer and more specious group of reptiles, consider the living crocodylians as the “tip of the crocodyliform iceberg”.

Living Crocodiles are Generalist Ambush Predators (Hypercarnivores)

Saltwater crocodile (Estuarine crocodile).

A Saltwater crocodile (Crocodylus porosus), the largest living reptile which is an apex predator (hypercarnivore).

The researchers identified different teeth morphologies (heterodonty) and this suggests that in the past crocodile-like creatures had a variety of diets.

Melstrom added:

“Carnivores possess simple teeth whereas herbivores have much more complex teeth.  Omnivores, organisms that eat both plant and animal material, fall somewhere in between.  Part of my earlier research showed that this pattern holds in living reptiles that have teeth, such as crocodylians and lizards.  So, these results told us that the basic pattern between diet and teeth is found in both mammals and reptiles, despite very different tooth shapes, and is applicable to extinct reptiles.”

Keegan Melstrom (The Natural History Museum of Utah) with Some of the Casts Used in the Study

Examing three-dimensional prints of fossil jaws.

Keegan Melstrom, the study’s lead author, with the fossil jaw of Brachychampsa and 3-D prints of other extinct crocodyliforms (blue).

Picture Credit: The Natural History Museum of Utah

Comparing Tooth Complexity – Extinct versus Extant

To deduce what long dead crocodyliforms most likely consumed, Melstrom with the assistance of his graduate advisor ( Randall B. Irmis), compared the tooth complexity of extinct crocodyliforms to those of living animals using a research methodology originally designed to study mammalian heterodonty.  In total, 146 teeth from 16 different species of extinct crocodyliforms were incorporated into the study.

Using a combination of quantitative dental measurements and an assessment morphological features, the scientists reconstructed the diets of those extinct animals.  The results indicate that these animals had a wider range of dental complexities and presumed dietary ecologies than had been appreciated previously.  Quantitative analyses also revealed that some species with complex dentition were likely to be herbivorous.

The researchers conclude that plant-eating crocodyliforms appeared early in the group, perhaps shortly after the end-Triassic mass extinction event and herbivory persisted until the end of the Age of Dinosaurs.  The analysis suggests that herbivory arose independently a minimum of three times, and possibly six times, in Mesozoic crocodyliforms.

Melstrom stated:

“Our work demonstrates that extinct crocodyliforms had an incredibly varied diet.  Some were similar to living crocodylians and were primarily carnivorous, others were omnivores and still others likely specialised in eating plants.  The herbivores lived on different continents at different times, some alongside mammals and mammal relatives, and others did not.  This suggests that herbivorous crocodyliforms were successful in a variety of environments!”

As many of these herbivorous crocodyliforms co-existed with plant-eating synapsids including Mammaliaformes, some of which were the ancestors of today’s mammals, this was an ecological partition that is no longer found on our planet.

The scientific paper: “Repeated Evolution of Herbivorous Crocodyliforms during the Age of Dinosaurs” by Keegan M. Melstrom and Randall B. Irmis published in Current Biology.

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

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