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

27 01, 2021

Ancient Placoderm Could Turn Vertebrate Evolution on its Head

By | January 27th, 2021|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Cutting-edge Technology Provides New Insights into Ancient Fish

Sophisticated, cutting-edge MicroCT scanning employed to look inside the fossilised skull of a prehistoric fish from the Early Devonian of New South Wales (Australia), has provided scientists with new insights into early vertebrate evolution and challenged the current view regarding the phylogeny and taxonomy of the bony, armoured prehistoric fishes known collectively as placoderms.

The research team, which included scientists from the University of Birmingham, the Chinese Academy of Sciences and colleagues based in Australia and Sweden, used MicroCT scanning to view the internal structures of the skull of a 400 million-year-old Brindabellaspis (Brindabellaspis stensioi) specimen.  A fish nicknamed the “platypus fish” due to its elongated snout.

Computer software was used to create a digital reconstruction of brain cavity and the inner ear.  The team discovered that Brindabellaspis possessed an inner ear that was surprisingly compact with closely connected components resembling the inner ear of modern jawed vertebrates such as sharks and bony fishes.  Some features of the inner ear from this ancient fish are remarkably similar to the structure of our own inner ear.

A Digital Model Showing the Skull and its Constituent Parts (Brindabellaspis stensioi)

A digital model of the skull of Brindabellaspis stensioi.

The skull of Brindabellaspis stensioi digitally recreated after MicroCT scan analysis.

Picture Credit: Institute of Vertebrate Palaeontology and Palaeoanthropology

Important Implications for the Placodermi

Brindabellaspis is a member of the Placodermi, a diverse, geographically and temporally widespread class of armoured fish which thrived during the Devonian between 420 and 360 million years ago.  Most placoderms have less complex inner ear structures, with a large sac, called a vestibule, placed in the centre and separating all the other components.  The remarkably well-preserved and three-dimensional nature of the specimens from New South Wales provided the research team with an opportunity to examine the brain cavity and inner ear of Brindabellaspis for the first time.

Their findings could change the way in which the tree of life representing early vertebrates is constructed.

Life Reconstruction of Devonian fishes including Brindabellaspis with a Modern Shark and Diver for Scale

Life reconstruction of Devonian fishes with a Great White shark and a diver for scale.

Artistic rendering of Brindabellaspis (foreground) with a range of other Devonian fossil fishes.  The Great White shark and human diver in the upper right corner represent modern jawed vertebrates and provide scale.  Brindabellaspis is the large grey fish with its snout pointing to the bottom of the picture.

Picture Credit: YANG Hongyu and ZHENG Qiuyang

Re-writing the Evolutionary History of Early Vertebrates

Previous studies had suggested that prehistoric fish such as Brindabellaspis were closely related to primitive, jawless fish (agnathans), that first evolved around 500 million years ago.  This study challenges the assumption that placoderms are a distinct group, as considerable variation has been identified in the brain cavities and inner ears of “placoderms”.

Furthermore, this research suggests the possibility that these types of fish may be the ancestors of modern jawed vertebrates (the Gnathostomata).

Co-author of the scientific paper, published in the journal Current Biology, Dr Sam Giles (University of Birmingham), stated:

“The inner ear structure is so delicate and fragile that it is rarely preserved in fossils, so being able to use these new techniques to re-examine specimens and discover this wealth of new information is very exciting.  This fossil has revealed a really intriguing mosaic of primitive features and a surprisingly modern inner ear.  We don’t yet know for certain what this means in terms of our understanding of how modern jawed vertebrates evolved, but it’s likely that virtual anatomy techniques are going to be a critical tool for piecing together this fascinating jigsaw puzzle.”

An earlier research paper suggested that the snout of Brindabellaspis was sensitive and may have played a role in locating food or avoiding predators.  To read Everything Dinosaur’s article from 2018 about this study: A Primitive Placoderm Platypus Fish from Australia.

Everything Dinosaur acknowledges the assistance of a media release from the University of Birmingham in the compilation of this article.

The scientific paper: “Endocast and Bony Labyrinth of a Devonian “Placoderm” Challenges Stem Gnathostome Phylogeny” by You-an Zhu, Sam Giles, Gavin C. Young, Yuzhi Hu, Mohamed Bazzi, Per E. Ahlberg, Min Zhu and Jing Lu published in Current Biology.

25 01, 2021

Baby Tyrannosaurs Born Ready to Hunt

By | January 25th, 2021|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Baby Tyrannosaurs Born Ready to Hunt

A new scientific paper published this week suggests that tyrannosaurs were able to hunt and to look after themselves soon after they hatched.  In addition, tyrannosaur hatchlings were surprisingly large, perhaps more than a metre long when they broke out of their eggs and if this the case, then tyrannosaur eggs would have been colossal, perhaps larger than any other dinosaur egg known to science.

A Life Reconstruction of a Baby Tyrannosaur

Juvenile tyrannosaur life reconstruction.

A life reconstruction of a juvenile tyrannosaur.  This illustration by the talented palaeoartist Julius Csotonyi, depicts a baby tyrannosaur covered in a coat of insulating protofeathers.

Picture Credit: Julius Csotonyi

As Big as a Collie Dog

Writing in the latest edition of the Canadian Journal of Earth Sciences, the scientists which include such eminent figures as Phil Currie, “Jack” Horner and Stephen Brusatte, have written up an on-line presentation from last October which took place at the virtual Society of Vertebrate Palaeontology Conference and they indicate that young tyrannosaurs were big babies.  With a length of in excess of 1 metre, that’s about the size of a border collie dog.

A Model of a Young Tyrannosaurus rex

A juvenile T. rex.

A young T. rex.  Research suggests that Late Cretaceous tyrannosaurs may have been around a metre in length when very young.  Rare fossil bones from perinatal tyrannosaurs from North America also suggest that these predators were highly developed and capable of hunting for themselves – precocial development – mobile and relatively fully developed when first hatched.

Picture Credit: Everything Dinosaur

Perinatal tyrannosaurid bones and teeth from the Campanian–Maastrichtian of western North America provide the first window into this critical period of the life of a tyrannosaurid.  An embryonic dentary (Daspletosaurus horneri) from the Two Medicine Formation of Montana, measuring just 3 cm in length, already exhibits distinctive tyrannosaurine characters like a “chin” and a deep Meckelian groove, and reveals the earliest stages of tooth development.  When considered together with a remarkably large embryonic claw bone (ungual) from the Horseshoe Canyon Formation of Alberta and believed to have come from an Albertosaurus sarcophagus, a minimum hatchling size for tyrannosaurids could be estimated by the research team.

Corresponding author for the paper, Gregory Funston (University of Edinburgh), stated:

“It appears that tyrannosaurs were born ready to hunt, already possessing some of the key adaptations that gave tyrannosaurs their powerful bites.  So, it’s likely that they were capable of hunting fairly quickly after birth, but we need more fossils to tell exactly how fast that was.”

Tyrannosaur Babies Bigger than Other Dinosaur Babies

The dentary and the claw bone indicate that Late Cretaceous tyrannosaurs were bigger than any other known dinosaur babies.  The researchers conclude that they must have hatched from enormous eggs, perhaps exceeding the 43 cm length of largest dinosaur eggs described to date.

The Embryonic Tyrannosaur Dentary

Daspletosaurus horneri juvenile jawbone.

The fossilised lower jawbone (dentary) of a Daspletosaurus horneri, one of the first baby tyrannosaurs ever discovered.

Picture Credit: Gregory F. Funston (University of Edinburgh)

Co-author of the paper, Mark Powers a PhD student at the University of Alberta (Canada), commented:

“Tyrannosaurs are represented by dozens of skeletons and thousands of isolated bones or partial skeletons, but despite this wealth of data for tyrannosaur biology, the smallest identifiable individuals are aged three to four years old, much larger than when they would have hatched.  No tyrannosaur eggs or embryos have been found even after 150 years of searching—until now.”

The study, focused on the two fossils representing perinatal development of tyrannosaurids.  The ungual was found near Morrin in the province of Alberta, whilst the dentary came from Montana. The ungual is approximately 71.5 million years old, and the jawbone a little older at around 75 million years old.

Comparing the Tyrannosaurid Fossil Material with Dr Funston and an Adult Albertosaurus

Comparing the juvenile tyrannosaur specimens.

This diagram compares the size of a full-grown Albertosaurus with that of palaeontologist Greg Funston and the two dinosaur embryos whose toe claw and jawbone were identified in a newly published study.

Picture Credit: Gregory F. Funston (University of Edinburgh)

Mark Powers, who completed the research as a master’s student supervised by Phil Currie added:

“The discovery of embryonic material is a huge find in our efforts to understand how some of the most popular and charismatic dinosaurs began their life and grew to immense sizes.  It provides a much-needed—and until now, missing—data point depicting the starting point for tyrannosaur growth.”

Surprising Results

The researchers were surprised to find that the small tyrannosaur teeth in the lower jaw were distinct from the teeth of older tyrannosaurids.  They had not developed true serrations running along the cutting edges.  In addition, the toe claw (specimen number UALVP 59599), came from an animal estimated to be about 1.1 metres long, whilst the tiny jawbone (MOR 268), came from a tyrannosaur around 71 cm in length.

The size estimates for perinatal tyrannosaurs based on this study reinforce the work of the late American-Canadian palaeontologist Dale Russell, who back in 1970 provided some of the first insights into tyrannosaur development and ontogeny.  This study was published in a special issue of the Canadian Journal of Earth Sciences which honours the contribution made to vertebrate palaeontology by Professor Russell.

Everything Dinosaur acknowledges the assistance of a media release from the University of Alberta in the compilation of this article.

The scientific paper: “Baby tyrannosaurid bones and teeth from the Late Cretaceous of western North America” by Gregory F. Funston, Mark J. Powers, S. Amber Whitebone, Stephen L. Brusatte, John B. Scannella, John R. Horner and Philip J. Currie published in the Canadian Journal of Earth Sciences.

22 01, 2021

Limb Bone Confirms Large Pterosaurs Across Laramida

By | January 22nd, 2021|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Single Bone Suggests Large Pterosaurs Across Both North and South Laramidia

A single bone from a large pterosaur tentatively described as an ulna found in 2016 has confirmed the presence of large flying reptiles in terrestrial ecosystems in both north and south Laramidia during the Late Cretaceous.

Writing in the on-line, academic journal “PeerJ”, Dr Andrew Farke of the Raymond M. Alf Museum of Palaeontology (Claremont, California), reports that the 36 cm long bone from a bonebed within the middle unit of the Kaiparowits Formation (Utah), extends the distribution of large pterosaurs across terrestrial environments during the Campanian of western North America.

Views of the Single Pterosaur Bone with Accompanying Line Drawings

RAM 22574 pterosaur limb bone and line drawings

Views of the pterosaur limb bone with accompanying line drawings.  Note scale bar = 10 cm.

Picture Credit: Farke (PeerJ)

The picture above shows various views of the single pterosaur limb bone (specimen number RAM 22574).  Dorsal (A), proximal (B) with anterior (C) and dorsal (D) views, whilst E and F represent ventral and posterior views.  Line drawing (G) shows an interpretation of the posterior view with missing parts shaded and line drawing H shows a posterior view of the complete and restored bone.  The large size of the bone has permitted Dr Farke to make an estimate of the wingspan of the pterosaur.  He estimates that this bone came from an individual with a wingspan between 4.3 and 5.9 metres.   This bone is the largest pterosaur fossil reported to date from the Kaiparowits Formation.

Based on these estimates, the Kaiparowits Formation specimen is roughly comparable in size to Cryodrakon boreas an azhdarchid pterosaur known from the Dinosaur Park Formation of southern Alberta, Canada which was formally named and described in 2019: The First Pterosaur Unique to Canada is Described Cryodrakon boreas.

Significant Pterosaur Fossil Finds Associated with Terrestrial Environments in Late Cretaceous North America

Late Cretaceous major pterosaur fossil finds in western North America.

Major pterosaur fossil finds from late Campanian-aged terrestrial depositional environments in western North America.

Picture Credit: Farke (PeerJ) with additional annotation from Everything Dinosaur (silhouettes based on work from Naish and Witton)

Silhouettes are scaled to maximum estimates of wingspan for individual specimens.  The silhouette for RAM 22574 shows the minimum (black) and maximum (green) size estimates for the specimen (4.3 to 5.9 metre wingspan).

The strata in southern Alberta (Dinosaur Park Formation) from which C. boreas comes from was laid down shortly after the portion of the Kaiparowits Formation associated with this single pterosaur bone.  Thus, Dr Farke concludes that relatively large pterosaurs occurred in terrestrial ecosystems in both the northern and southern parts of Laramidia (western North America), during the late Campanian.

The scientific paper: “A large pterosaur limb bone from the Kaiparowits Formation (late Campanian) of Grand Staircase-Escalante National Monument, Utah, USA” by Andrew A. Farke published in PeerJ.

17 01, 2021

Unravelling the Origins of the Earliest Animals

By | January 17th, 2021|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos|0 Comments

Unravelling the Origins of the Earliest Animals

A team of international scientists including researchers from the University of Edinburgh and Moscow State University have used some remarkable fossils of animals that lived before the Cambrian Explosion to trace the ancestry of some of the world’s earliest organisms.  The fossils, a total of 73 specimens of the primitive metazoan known as Namacalathus (N. hermanastes), were found a single bedding plane sample of rocks associated with the Upper Omkyk Member of the Nama Group of Namibia (Africa).  An in-depth analysis of the tiny three-dimensional fossils, the largest of which were around 12.3 mm in diameter, suggest that these animals are basal members of the Superphylum Lophotrochozoa which are characterised by having a feeding/food gathering structure that is surrounded by a ring of tentacles and a free-swimming, zooplankton developmental stage.  This Superphylum includes the Brachiopoda as well as molluscs, worms and other related, generally soft-bodied organisms.

Members of the Research Team at the Fossil Site (Namibia)

Field team members looking for Ediacaran fossils in Namibia.

Exploring an outcrop of the Upper Omkyk Member (Nama Group, Namibia).  The beautiful but remote fossil site.

Picture Credit: Professor Rachel Wood (University of Edinburgh)

Writing in the academic journal Science Advances, the research team report on the first known link between some of the major groups of animals that evolved during the Cambrian Explosion and their ancestral forms.

Mapping Life from 547 Million Years Ago

The close proximity of the marine deposits that contain the tiny Namacalathus fossils and an ash layer which resulted from volcanic activity permitted the researchers to accurately date the fossils to around 547 million years ago (late in the Ediacaran), the geological period that immediately precedes the Cambrian and the beginning of the Phanerozoic Eon (visible life).  It is only in the last few decades that scientists have been able to piece together a picture of life prior to the Cambrian Explosion event but the fossil record for the tiny, soft-bodied creatures that dominated early marine ecosystems is exceptionally poor.

Once thought to be an ancestor of today’s jellyfishes, Namacalathus have been described as a “pin cushion on a short, hollow stalk”.  The stalk is at its narrowest towards the strange cup-like structure at the top of the stalk where the feeding apparatus was located.

A Diagram of the Proposed Body Plan of Namacalathus (N. hermanastes)

The anatomy of Namacalathus.

A diagram showing the anatomy of Namacalathus.  Measuring just a few millimetres in diameter, the 3-dimensional preservation of the Namibian specimens has permitted researchers a glimpse into the biological affinity of some of the oldest animals known to science.

Picture Credit: Shore et al (Science Advances)

Commenting on the significance of this research, co-author of the scientific paper, Professor Rachel Wood of the School of GeoSciences at the University of Edinburgh stated:

“These are exceptional fossils, which give us a glimpse into the biological affinity of some of the oldest animals.  They help us trace the roots of the Cambrian Explosion and the origin of modern animal groups.  Such preservation opens up many new avenues of research into the history of life which was previously not possible.”

Soft Tissue Preservation and Preserved Structures

Prior to this research the exact position of Namacalathus within the Kingdom Animalia remained controversial.  It had been difficult to trace the origins of the major invertebrate groups found today, as the mainly soft-bodied Ediacaran biota left only the merest hints as to their taxonomy in the fossil record.

Using advanced and sophisticated X-ray imaging techniques, the research team were able to identify some of the animal’s soft tissues beautifully preserved inside the fossils by iron sulphide. Until this paper’s publication, scientists had only ever identified exoskeleton remains of Namacalathus.

By looking at the soft tissues that had been entombed by the iron sulphide, the research team were able to identify that Namacalathus was probably a distant ancestor of today’s worms and molluscs (a basal member of the Superphylum Lophotrochozoa).

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

The scientific paper: “Ediacaran metazoan reveals lophotrochozoan affinity and deepens root of Cambrian Explosion” by A. J. Shore, R. A. Wood, I. B. Butler, A. Yu Zhuravlev, S. McMahon, A. Curtis and F. T. Bowyer published in Science Advances.

15 01, 2021

Extensive Dinosaur Tracks Discovered in China

By | January 15th, 2021|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Over 240 Fossilised Dinosaur Prints Discovered in South-eastern China

Everything Dinosaur team members have received several media reports from Chinese news agencies about the discovery of an extensive series of dinosaur tracks in Fujian Province (south-eastern China).  The dinosaur track site was uncovered in Shanghang County and covers approximately 1,600 square metres.  The tracks and individual prints were made around 80 million years ago (Campanian faunal stage of the Late Cretaceous) and they represent the first dinosaur trace fossils to have been found in Fujian Province.

Field Team Members Examine and Map the Dinosaur Tracks

Extensive dinosaur tracks uncovered in China.

Chinese field team members examine and map the numerous dinosaur tracks and prints uncovered in Fujian Province.

Picture Credit: CFP

The Tracks of at Least Eight Different Types of Dinosaur

Extensive track sites such as this are exceptionally rare, early indications from the field team mapping the prints are that at least eight different types of dinosaur are represented.  The three-toed prints of ornithopods and the large, more rounded prints of sauropods have been identified.  The various media channels have also reported both large and small theropod prints including prints around thirty centimetres in length made by a large, bird-like member of the Deinonychosauria, a raptor that has left distinctive two-toed prints, as the second toe was raised off the ground as it possessed a large, curved sickle-like claw.

Running with Second Toe Raised Off the Ground

The second toe claw of Velociraptor.

A model showing the raised second toe held off the ground as a member of the Deinonychosauria (Velociraptor) runs.

Picture Credit: Everything Dinosaur

Xing Lida, from the China University of Geosciences and a member of the research team has stated:

“Judging from the size of the footprints, which were eight to fifty-five centimetres long, lengths of the dinosaurs range from one metre to ten metres.”

The site is under the stewardship of the local authorities in order to protect this important discovery and to deter any would-be fossil hunters who might be tempted to remove any prints for sale on the black market.  The site contains at least 240 individual dinosaur prints.

Two of the Dinosaur Prints from the Shanghang County Site

Dinosaur tracks discovered in Fujian Province.

Two dinosaur prints from the Fujian Province site.  The research team estimate that the tracks represent lakeside activity from around 80 million years ago.

Picture Credit: CFP

The tracks were made as dinosaurs visited an ancient lake, the various prints and trackways being preserved in the soft mud on the lake margins.

Senior palaeontologist and former curator at the Zigong Dinosaur Museum (Sichuan Province) Peng Guangzhao, explained that the researchers were optimistic about finding more fossils.  The team are hopeful that more tracks, bones or even dinosaur eggs could be discovered in Fujian Province in the future.

14 01, 2021

World’s Oldest Cave Art Discovered

By | January 14th, 2021|Adobe CS5, Animal News Stories, Dinosaur and Prehistoric Animal Drawings, Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

Oldest Cave Art Found in Sulawesi

Scientists have discovered the world’s oldest known animal cave painting on the island of Sulawesi (Indonesia) – a wild pig – believed to have been drawn 45,500 years ago.  The cave painting consists of a figurative depiction of a group of Sulawesi warty pigs, one male seems to be observing an interaction between two other pigs, their impressions are only partly preserved.  Painted in red ochre, the dark red impressions are approximately life size.  There are two handprints painted above the back of the pig, this evocative artwork provides the earliest evidence recorded to date of human settlement in this region.

The World’s Oldest Known Animal Cave Painting

Warty pig cave art (Sulawesi, Indonesia).

The world’s oldest known animal cave painting on Sulawesi (Indonesia).  An illustration of a warty pig believed to have been drawn 45,500 years ago.

Picture Credit: Maxime Aubert (Griffith University, Australia)

Writing in the academic journal Science Advances, the archaeologists from Griffith University, the University of Brisbane in collaboration with their Indonesian colleagues from Pusat Penelitian Arkeologi Nasional (ARKENAS), Hasanuddin University (Indonesia) and other academic bodies discovered the remarkable cave art in a limestone cave known as Leang Tedongnge on the south-western peninsula of the island of Sulawesi.  The cave painting consists of a figurative depiction of a group of Sulawesi warty pigs (Sus celebensis) that are endemic to this Indonesian island.

Commenting on the significance of their discovery, Professor Adam Brumm (Australian Research Centre for Human Evolution at Griffith University) stated:

“The Sulawesi warty pig painting we found in the limestone cave of Leang Tedongnge is now the earliest known representational work of art in the world, as far as are aware.  The cave is in a valley that’s enclosed by steep limestone cliffs and is only accessible by a narrow cave passage in the dry season, as the valley floor is completely flooded in the wet.  The isolated Bugis community living in this hidden valley claim it had never before been visited by Westerners.”

Views of the Entrance to the Leang Tedongnge Cave and a Schematic Plan of the Cave Site

Views of the Leang Tedongnge cave on Sulawesi and a schematic diagram of the cave system.

(A and B) Leang Tedongnge cave.  The cave is located at the foot of a limestone karst hill (A); the cave mouth entrance is shown in (B).  Plan (C) and section of Leang Tedongnge site.

Picture Credit: Brumm et al (Science Advances)

Dating Using Isotope Analysis of Mineral Deposits

To determine the approximate age of the cave paintings, the research team used Uranium-series isotope dating of associated calcium carbonate mineral deposits.  The oldest cave painting was estimated to be at least 45,500 years old.  A second painting from a nearby cave known as Leang Balangajia was dated to around 32,000 years ago.

A Digitally Enhanced View of the Cave Art at the Leang Tedongnge site

Computer enhanced view of the cave art with hand prints and pigs highlighted.

A stitched panorama view of the cave art enhanced using Decorrelation Stretch (DStretch) computer software.

Picture Credit: Brumm et al (Science Advances)

Professor Brumm described the artwork:

“It shows a pig with a short crest of upright hairs and a pair of horn-like facial warts in front of the eyes, a characteristic feature of adult male Sulawesi warty pigs.  Painted using red ochre pigment, the pig appears to be observing a fight or social interaction between two other warty pigs.”

Co-author of the paper PhD student Basran Burhan, an Indonesian archaeologist from southern Sulawesi ,who is currently studying at Griffith University commented:

“These pigs were the most commonly portrayed animal in the ice age rock art of the island, suggesting they have long been valued both as food and a focus of creative thinking and artistic expression.”

Recovering DNA from the Handprints

The research team are confident that they will be able to recover DNA from the two handprints located above the pig’s back.  A study of this genetic material will shed light on the origins of the people who painted this prehistoric scene.  This cave art underlines the importance of Indonesia in terms of mapping the spread of modern humans around Asia and the researchers state that even older cave art may still be awaiting discovery in the hundreds of limestone caves located on Sulawesi.

Views of the Two Sulawesi Handprints

Cave art hands.

Close-up views of the two Sulawesi handprints preserved above the red ochre illustration of the warty pig.  One looks much larger than the other and these may represent stencils made by two individuals.

Picture Credit: Maxime Aubert (Griffith University, Australia)

The scientific paper: “Oldest cave art found in Sulawesi” by Adam Brumm, Adhi Agus Oktaviana, Basran Burhan, Budianto Hakim, Rustan Lebe, Jian-xin Zhao, Priyatno Hadi Sulistyarto, Marlon Ririmasse, Shinatria Adhityatama, Iwan Sumantri and Maxime Aubert published in the journal Science Advances.

9 01, 2021

Oviraptorid Overturns Ideas on Late Stage Egg Incubation

By | January 9th, 2021|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Fossil of Dinosaur Sitting on Eggs (Late Stage Incubation)

Fossils of dinosaurs are rare, fossils of articulated dinosaur skeletons rarer still and any fossils that preserve evidence of behaviour, these are amongst the rarest of all, truly scientific treasures.  A newly published paper describes the fossilised remains of a Late Cretaceous oviraptorid from east China’s south-eastern Jiangxi Province, a specimen that ticks all these boxes.  The fossils represent the partial, articulated remains of oviraptorosaur preserved sitting on a clutch of eggs in a brooding position.  Such fossils have been found before, but uniquely these 70 million-year-old remains include fossils of baby dinosaurs preserved inside the eggs, the first time this has been recorded in the non-avian dinosaur fossil record.

The Partially Preserved Adult Oviraptorid On the Nest

Oviraptorid sitting on eggs with embryos identified.

The fossilised remains of an oviraptorid with preserved eggs that contain the remains of baby dinosaurs.  Note scale bar = 10 cm.

Picture Credit: Shundong Bi et al (Science Bulletin)

Sitting Atop a Nest

The multinational team of researchers includes Dr Shundong Bi (Indiana University of Pennsylvania) and Xing Xu (Institute of Vertebrate Palaeontology – Beijing) along with Dr Matt Lamanna (Carnegie Museum of Natural History) and scientific illustrator Andrew McAfee.

Commenting on the significance of this discovery, Dr Bi stated:

“Dinosaurs preserved on their nests are rare, and so are fossil embryos.  This is the first time a non-avian dinosaur has been found, sitting on a nest of eggs that preserve embryos, in a single spectacular specimen.”

Fossils of brooding dinosaurs have been found before, perhaps the most famous is “Big Mamma” the fossilised remains of an adult Citipati osmolskae (also an oviraptorid) on display at the American Museum of Natural History (New York).

Citipati osmolskae Fossil Sitting Atop a Nest of Eggs

Citipati osmolskae fossil.

The Citipati fossil sitting on a nest “Big Mamma”.

Picture Credit: The American Museum of Natural History

Oviraptorids – Very Bird-like Dinosaurs

The Chinese fossil material has been assigned to the Oviraptoridae, although Everything Dinosaur are not aware of any new taxon being announced.  Oviraptorid dinosaurs are mainly associated with Asia, but the closely related Caenagnathidae are also known from North America.  The bones of these dinosaurs are very bird-like and they do belong to a great linage of theropods that are related to modern birds (the Maniraptora).

The specimen represents an incomplete, articulated skeleton of a large, (presumably adult) oviraptorid crouched in a bird-like brooding posture over a clutch of at least twenty-four eggs.  The adult appears to have perished whilst brooding the clutch.  The researchers identified the preserved remains of seven unhatched dinosaurs entombed inside the eggs.  The late stage of development of the embryos suggests that, just like modern birds, oviraptorids brooded their eggs, rather than simply guarding them as observed in extant crocodilians.

A Caring Parent

Dr Lamanna explained:

“This kind of discovery, in essence, fossilised behaviour, is the rarest of the rare in dinosaurs.  Though a few adult oviraptorids have been found on nests of their eggs before, no embryos have ever been found inside those eggs.  In the new specimen, the babies were almost ready to hatch, which tells us beyond a doubt that this oviraptorid had tended its nest for quite a long time.  This dinosaur was a caring parent that ultimately gave its life while nurturing its young.”

As part of their research, the scientists conducted an oxygen isotope study that demonstrated that the eggs were incubated at high bird-like temperatures, further evidence to support the idea that the adult died whilst brooding its clutch of eggs.  Analysis of the tiny baby dinosaur bones preserved inside their eggs indicate that some babies were more fully developed than others, this suggests that the eggs might have hatched at different intervals, a hatching strategy known as asynchronous hatching.  This strategy is found in many types of birds today such as Shoebill storks and numerous species of birds of prey such as raptors and owls.

Oviraptorids – Evidence that they were Caring Parents

Communal roosting in oviraptorids.

A pair of oviraptorosaurs.  Scientists suggest that these dinosaurs incubated their eggs and that they were caring parents.

Picture Credit: Mike Skrepnick

Asynchronous hatching appears to have evolved independently in oviraptorids and modern avians.

The Evolutionary Benefits of Asynchronous Hatching

If the eggs of oviraptorids did hatch at different intervals, then this too can provide an insight into the behaviour of these Late Cretaceous dinosaurs.  Biologists have identified a number of reasons why some kinds of bird alive today have evolved asynchronous hatching.

The evolutionary benefits of asynchronous hatching:

  • To reduce the losses from predators due to the whole brood not being present in the nest at the same time.
  • The younger animals are a back-up plan in case earlier hatched animals die.
  • When food resources are scarce the adults can dedicate the bulk of these scarce resources to the older babies and let the younger siblings perish.
  • Reduces the demands on the parents as they do not have to care for all the babies at the same time.

Gastroliths Identified

The researchers also noted the presence of gastroliths (stomach stones).  A cluster of tiny pebbles had accumulated in the body cavity of the adult dinosaur.  Gastroliths are associated with many different types of dinosaur, but this is the first time that undoubted gastroliths have been found in an oviraptorid.  As such, these stones may provide new insights into the diets of these very bird-like dinosaurs.

Dr Xu concluded:

“It’s extraordinary to think how much biological information is captured in just this single fossil.  We’re going to be learning from this specimen for many years to come.”

To read a related article on dinosaur parenting skills: Doting Fathers – A Parenting Strategy Amongst the Dinosauria

Everything Dinosaur acknowledges the assistance of a press release from the Carnegie Museum of Natural History (Pennsylvania).

The scientific paper: “An oviraptorid preserved atop an embryo-bearing egg clutch sheds light on the reproductive biology of non-avialan theropod dinosaurs” by Shundong Bi, Romain Amiot, Claire Peyre de Fabrègues, Michael Pittman, Matthew C. Lamanna, Yilun Yu, Congyu Yu, Tzuruei Yang, Shukang Zhang, Qi Zhao and Xing Xu published in Science Bulletin.

8 01, 2021

How Far Might Plant-eating Dinosaurs Have Dispersed Seeds?

By | January 8th, 2021|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

How Far Might Plant-eating Dinosaurs Have Dispersed Seeds?

During the imposed lockdown due to COVID-19 lots of people have attempted to learn new skills, perhaps studying a musical instrument, mastering a new language or taking an on-line course as part of a planned career move.

For Professor George Perry of the School of the Environment at the University of Auckland, time away from his students gave him the opportunity to conduct a study into the pooping habits of plant-eating dinosaurs. This is not simply a case of an educated man with too much time on his hands but a serious examination in the role played in seed dispersal by ancient megaherbivores.

How Far Might Plant-Eating Dinosaurs Have Dispersed Seeds?

The new Mojo Fun Brachiosaurus deluxe dinosaur model.

A scientist has examined the role large, herbivorous dinosaurs may have had in the dispersal of seeds.

Picture Credit: Everything Dinosaur

Plotting Frequency of Pooping Against Walking Speed

Herbivores play and important role in seed dispersal in modern ecosystems and it has been proposed that herbivorous dinosaurs might have been important seed dispersal agents in the Mesozoic. It is likely that a proportion of the plant seeds ingested by plant-eating dinosaurs would have passed through the gut, ending up being deposited with a helpful quantity of dung to act as fertiliser.

How far dinosaurs of different body sizes might have dispersed seeds remains uncertain.

Professor Perry modelled the likely travelling speeds of various dinosaurs along with the likely frequency of defecation (both factors that can be estimated based on an assessment of body mass).

It is known that large vertebrates are capable of transporting seeds considerable distances.  For example, African elephants (Loxodonta africana africana) can deposit seeds as a far away as 36 miles (60 kilometres), from their parent plant.  Using statistical analysis to assess the spread of seeds from members of the Dinosauria, Professor Perry concluded that the simulations demonstrated that dinosaurs likely moved some seeds very long distances, comparable distances to those observed in extant megaherbivores.

It is not possible to infer from the fossil record the effect on germination on seeds having passed through the gut of a dinosaur, or indeed, whether plants evolved seed dispersal strategies to take advantage of browsing and grazing dinosaurs, but this research does suggest that dinosaurs such as Triceratops and Stegosaurus may have spread seeds around 20 miles (more than 30 kilometres) away from their parent plants.

A Champion at Seed Dispersal (Triceratops)

Triceratops dinosaur illustration.

Triceratops was one of the last dinosaurs to evolve.  It is likely that ornithischian dinosaurs played an important role in seed dispersal during the Mesozoic.

Picture Credit: Julius Csotonyi

The scientific paper: “How far might plant-eating dinosaurs have moved seeds?” by George L. W. Perry published in Biology Letters.

4 01, 2021

Early Dinosaur’s Brain Reveals New Insights into Sauropodomorpha

By | January 4th, 2021|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

The Brain of Thecodontosaurus

Analysis of the brain and inner ear of the Late Triassic basal Sauropodomorpha Thecodontosaurus (T. antiquus), reveals that it may have been bipedal, able to hold a steady gaze whilst running and possibly predatory.  These are some of the conclusions drawn by researchers from the University of Bristol and the Oxford University Museum of Natural History in a new study published in the Zoological Journal of the Linnean Society.

The Research Team Used CT-scans and 3-D Modelling to Construct the Brain and Inner Ear of Thecodontosaurus

CT-scans and computer modelling used to construct the brain of Thecodontosaurus.

Building up a picture of the brain and the inner ear based on the fossilised braincase of Thecodontosaurus antiquus.

Picture Credit: Antonio Ballell et al

Named in 1836 (it was only the fourth dinosaur to be scientifically described), Thecodontosaurus is regarded as a basal member of the lizard-hipped Sauropodomorpha, a clade of dinosaurs that includes Brontosaurus, Brachiosaurus, Diplodocus and Argentinosaurus.  Thecodontosaurus was much smaller than its illustrious Jurassic and Cretaceous descendants.  It was approximately two metres long, more than half its body length was made up by its long, thin tail and it was lightly built with most palaeontologists estimating that it weighed around 20-25 kilograms, about as heavy as a border collie.

As an early member of the lineage of long-necked dinosaurs, a study of the fossilised remains of Thecodontosaurus can provide palaeontologists with a better understanding of the evolutionary history of the Sauropodomorpha.

Bristol University has Researched the “Bristol Dinosaur” For Decades

Thecodontosaurus study.

Thecodontosaurus fossil block with life reconstruction in the background.  In the picture (above), from 2009, a researcher stands in front of a block of Thecodontosaurus bones with a life reconstruction of the dinosaur in the background.  Note that in 2009, Thecodontosaurus was thought to be quadrupedal, this new study suggests that it may have been bipedal.

Picture Credit: Simon Powell/University of Bristol

Three-dimensional Modelling Techniques

Research, led by the University of Bristol, used advanced imaging and 3-D modelling techniques to digitally rebuild the brain of Thecodontosaurus.  The scientists suggest that Thecodontosaurus could have eaten meat, although the substantial part of its diet was plant matter, its brain morphology indicates that this little dinosaur had a good sense of balance and that it was agile, traits that may have helped it supplement its vegetarian diet with the occasional meal of captured prey.

Lead author of the study, Antonio Ballell stated:

“Our analysis of Thecodontosaurus’ brain uncovered many fascinating features, some of which were quite surprising.  Whereas its later relatives moved around ponderously on all fours, our findings suggest this species may have walked on two legs and been occasionally carnivorous.”

The research team was able to deploy imaging software to extract new information from the fossils in a non-destructive manner.  Numerous three-dimensional models were generated from CT scans by digitally extracting the bone from the rock, identifying and classifying anatomical details about the brain and the inner ear which were previously unknown in this taxon.

PhD student Antonio explained the basis of the research:

“Even though the actual brain is long gone, the software allows us to recreate brain and inner ear shape via the dimensions of the cavities left behind.  The braincase of Thecodontosaurus is beautifully preserved so we compared it to other dinosaurs, identifying common features and some that are specific to Thecodontosaurus.  Its brain cast even showed the detail of the floccular lobes, located at the back of the brain, which are important for balance.  Their large size indicate it was bipedal.  This structure is also associated with the control of balance and eye and neck movements, suggesting Thecodontosaurus was relatively agile and could keep a stable gaze while moving fast.”

The Diet of Thecodontosaurus

The diet of Thecodontosaurus, nicknamed the “Bristol dinosaur” as a result of its association with the city, remains uncertain, although this new study suggests that it may have been omnivorous.

Antonio added:

“Our analysis showed parts of the brain associated with keeping the head stable and eyes and gaze steady during movement were well-developed.  This could also mean Thecodontosaurus could occasionally catch prey, although its tooth morphology suggests plants were the main component of its diet.  It’s possible it adopted omnivorous habits.”

The researchers were also able to reconstruct the inner ears, allowing them estimate how well it could hear compared to other dinosaurs.  Its hearing frequency was relatively high, potentially inferring some sort of social complexity, an ability to recognise varied squeaks and honks from different animals.

Comparing the Brain Cast of Thecodontosaurus to Other Dinosaurs

The changing shape of sauropod brains.

Structure, size and shape of the inner ear and brain examined in relation to the evolution of the Sauropodomorpha.

Picture Credit: Antonio Ballell et al with additional notation by Everything Dinosaur

Comparing Thecodontosaurus to Other Members of the Sauropodomorpha

The application of these technologies enabled the research team to compare the brain and inner ear of Thecodontosaurus to Saturnalia tupiniquim – an earlier basal sauropodomorph which roamed the southern hemisphere around twenty-five million years before Thecodontosaurus evolved.  Comparisons were also carried out between Plateosaurus, which is also known from the Late Triassic and the much later sauropod Spinophorosaurus (S. nigerensis) from the Middle Jurassic.

Professor Mike Benton, study co-author, said:

“It’s great to see how new technologies are allowing us to find out even more about how this little dinosaur lived more than 200 million years ago.”

The distinguished professor added:

“We began working on Thecodontosaurus in 1990, and it is the emblem of the Bristol Dinosaur Project.  We’re very fortunate to have so many well-preserved fossils of such an important dinosaur here in Bristol.  This has helped us understand many aspects of the biology of Thecodontosaurus, but there are still many questions about this species yet to be explored.”

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

The scientific paper: “The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquus” by A. Ballell, J. L. King, J. M. Neenan, E. J. Rayfield and M. J. Benton published in the Zoological Journal of the Linnean Society.

30 12, 2020

Serrated Teeth – Mammal Lineage Got There First!

By | December 30th, 2020|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Study Suggests Ziphodont Dentition Appeared First in Synapsids

If we ever get back into cinemas (the ravages of COVID-19 notwithstanding), if the latest instalment of the “Jurassic Park/Jurassic World” franchise ever gets released, then movie goers will be treated to lots of scenes of scary-looking meat-eating dinosaurs flashing their huge teeth in their cavernous mouths at their luckless human victims.  Huge theropod dinosaurs such as Acrocanthosaurus, Giganotosaurus and T. rex might be famous for their big teeth, with serrations running along the edges, after all, we have all heard and probably used the term “steak knives”  to describe the shape of tyrannosaur teeth, but new research published in Biology Letters suggest that it was those tetrapods that were eventually to lead to the mammalian lineage that evolved such specialised tearing and cutting teeth first.

Theropod Dinosaurs Are Famous for Their Teeth Adapted to Cutting and Tearing Flesh

PNSO A-shu the Qianzhousaurus dinosaur model has an articulated jaw.

The PNSO A-shu the Qianzhousaurus dinosaur model has an articulated jaw.  The tyrannosaurid Qianzhousaurus has the typical serrated and blade-like teeth of a carnivorous dinosaur (ziphodont dentition).

Picture Credit: Everything Dinosaur

Ziphodont Dentition

Teeth that are laterally compressed, pointed and have serrated edges are known as ziphodont teeth (ziphodont dentition).  The teeth of Theropoda, the only clade of predominantly predatory dinosaurs, are characterised by ziphodonty, the presence of serrations (denticles) on their cutting edges (carinae).  Today, such dentition is only found in monitor lizards (varanids) but the fossil record reveals that this condition was much more pervasive in the past.

A team of researchers from Harvard University (USA), in collaboration with colleagues based at the universities of Manitoba, Alberta and Ontario (Canada), examined and compared the teeth from four types of extinct prehistoric hypercarnivore (an animal that gets at least 70% of its nutrition from the consumption of the flesh of other animals).

The teeth studied were:

  • Tyrannosaurid tooth from the Dinosaur Provincial Park (Alberta, Canada) – a Late Cretaceous tyrannosaur tooth which is approximately 75 million years old.
  • Dimetrodon grandis tooth (synapsid, pelycosaur) from the Arroyo Formation Texas, USA) which is approximately 275 million years old.
  • A tooth from the Permian gorgonopsid Lycaenops ornatus from the Upper Permian Madumabisa Mudstone Formation of Zambia.  A synapsid (Therapsida) that lived approximately 265 million years ago.
  • An upper canine tooth from Smilodon fatalis a member of the Felidae (cat family).  The tooth comes from the Talara “tar pits” of Peru.  The youngest tooth in the research circa 13,000 years old.

The scientists identified the same denticles and interdental folds forming the cutting edges in the teeth of the Permian gorgonopsid (L. ornatus), as those seen in members of the Theropoda.  The researchers conclude that these tooth features, specifically adaptations to assist with the processing of meat, first appeared in the non-mammalian synapsids.  Comparisons of tooth serrations in gorgonopsians with those of earlier synapsids and hyper carnivorous mammals reveal that some gorgonopsians acquired a complex tissue arrangement that differed from other synapsids,

Plotting the Serrations in Non-mammalian Synapsids

Plotting the serrations in gorgonopsids.

The skull of the gorgonopsid Lycaenops ornatus (a), serrations on the canine (b) and (c) serrations on the incisors in the premaxilla.

Picture Credit: Whitney et al (Biology Letters)

In 2015, Everything Dinosaur published an article on research into the Theropoda that looked specifically at the interdental folds associated with their teeth.

To read this article: Research to Get Your Teeth Into.

For an article from 2014 that looked at the ziphodont teeth of members of the Dimetrodon genus: Dimetrodon with “Steak Knife” Teeth.

Convergent Evolution

This new study demonstrates that similar types of teeth evolved in different types of hypercarnivores that were not closely related.  This is an example of convergent evolution and the ziphodont teeth of the non-mammalian synapsids represent the earliest record of this adaptation and indicate that the first iteration of this morphological feature appeared long before the Dinosauria evolved.

High Magnification Images Showing the Morphology of the Carinae (Cutting Edges)

Looking at the inter-dental folds in non-mammalian synapsids.

Thin section through distal serrations of NHCC LB334 displaying both interdental folds and denticles (d).  Dashed box indicates location of high magnification images in both plain (e) and cross polarized light (f).  Both (e) and (f) highlight features of the denticles and interdental folds including the enamel spindles that cross the enamel.

Picture Credit: Whitney et al (Biology Letters)

The scientific paper: “Convergent dental adaptations in the serrations of hypercarnivorous synapsids and dinosaurs” by M. R. Whitney, A. R. H. LeBlanc, A. R. Reynolds and K. S. Brink published in Biology Letters.

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