All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
Articles, features and information which have slightly more scientific content with an emphasis on palaeontology, such as updates on academic papers, published papers etc.
The discovery of a fossil sturgeon scute demonstrates that these “royal fish” were present in North Africa during the Late Cretaceous. The single, fossil scute is the first ever sturgeon fossil to have been found in Africa. The scute is a bony plate embedded into the sturgeon’s skin. Scutes provided a form of dermal armour that evolved to help protect these very ancient fish.
A digital photo of the sturgeon scute (also called buckler) specimen. Picture credit: University of Portsmouth.
A Significant Fossil Discovery
The sturgeon (there are more than two dozen extant species), belongs to the Acipenseriformes Order, which probably originated in the Late Triassic. Sturgeon fossils which are very similar to extant species, are known from Upper Cretaceous strata. Historically, they are associated with cooler waters of the Northern Hemisphere. The specimen was discovered by Professor David Martill (University of Portsmouth). It proves that these magnificent fish were present in Africa.
Sturgeons were more widespread in the Cretaceous than previously thought.
An extant European sturgeon. Picture credit: University of Portsmouth.
Professor Martill was exploring a well-known Moroccan fossil site during a field trip last November. He spotted a row of bony plates (bucklers) on a piece of rock and instinctively recognised the fossils represented the scutes from a sturgeon.
Discussing this significant fossil find, the Professor commented:
“It was a surprising discovery because all sturgeon species have been exclusively found in the Northern Hemisphere in the past. They’ve been located in North America, Europe, Russian Asia, Chinese Asia, but never in South America, Australia, Africa or India, which are the land masses that made up Gondwana, a supercontinent that existed around 336 million years ago and began breaking up around 150 million years ago.”
A drawing showing an extant sturgeon in lateral view. The different scutes are highlighted. Picture credit: University of Portsmouth.
A “Royal Fish”
The sturgeon has long been prized for its meat and for its roe (eggs). The roe is commonly referred to as caviar. King Edward II of England declared that all sturgeon from the waters of Wales and England belong to the monarch. This declaration was made in the early 14th century. Since then, these fish have been regarded as “royal fish”.
Sadly, due to overfishing and pollution, many species of extant sturgeon are close to extinction.
Commenting on his African fossil discovery Professor Martill stated:
“Russian beluga caviar is one of the most expensive in the world. Little did we know that at one time an extremely rare African sturgeon could have been a source of this delicacy!”
A digital photo of the dorsal surface of the fossil. Note the scale bar of 20 mm. Picture credit: University of Portsmouth.
Fossil Sturgeon Scute
Sturgeon are thought of as being “living fossils”, for they seem to have remained relatively unchanged since the time of Tyrannosaurus rex and Triceratops. Records from the 18th and 19th centuries indicate specimens reaching more than seven metres in length and weighing over 1.5 tonnes, but fish of this size are exceedingly rare today.
Professor Martill added:
“The very first sturgeons appear in the fossil record in the Late Triassic period in China. But the oldest true sturgeon ever discovered is probably a specimen in the Steve Etches collection from Dorset’s Jurassic Coast in England, which is mentioned in a book Steve and I wrote about fossils in the Kimmeridge Clay Formation.”
The discovery of a sturgeon fossil in Morocco complicates models of the geographical distribution of these fish during the Late Cretaceous.
A map of the continents at the end of the Cretaceous (66 million years ago). Sturgeon fossil localities are marked by solid black circles. Picture credit: University of Portsmouth
The fossil specimen is now in the collection of the University King Hassan II, Casablanca.
Everything Dinosaur acknowledges the assistance of a media release from the University of Portsmouth in the compilation of this article.
The scientific paper: “A sturgeon (Actinopterygii, Acipenseriformes) from the Upper Cretaceous of Africa” by David M. Martill published in Cretaceous Research.
Whilst the Dinosauria dominated terrestrial environments during the Mesozoic the seas and oceans of the world were home to a diverse assemblage of marine reptiles. Many different types of marine reptile evolved, and the diverse swimming techniques employed by these ancient animals have been revealed in a recently published scientific paper.
The swimming secrets of Mesozoic marine reptiles have been decoded thanks to a research team from the University of Bristol.
A replica of the ichthyosaur Eurhinosaurus (PNSO). During the Mesozoic, many different types of marine reptile evolved. Scientists from the University of Bristol have unlocked the swimming secrets of ancient marine reptiles.
The image (above) shows a replica of an Eurhinosaurus. An ichthyosaur (Leptonectidae family) that lived during the Early Jurassic (approximately 180 million years ago).
During the Mesozoic, which lasted from approximately 252 million years ago to the end-Cretaceous mass extinction event around 66 million years ago, many different types of marine reptile evolved. There were placodonts, turtles, the first ichthyosaurs and nothosaurs during the Triassic and these were replaced by marine crocodiles, derived ichthyosaurs, long-necked plesiosaurs and pliosaurs. During the Cretaceous the mosasaurs evolved.
In the new paper, published in the academic journal “Palaeontology”, the research team report on the use of cutting-edge statistical methods used to undertake a substantial quantitative study. This research, the first of its kind, provides a fresh perspective on the locomotion of Mesozoic marine reptiles.
Examining 125 Skeletons
In total, 125 marine reptile skeletons were studied. The research team mapped the changes in swimming styles within the different lineages over time. There was no explosive radiation at the beginning of the Triassic, but a gradual diversification of swimming styles. This diversity peaked during the Cretaceous.
Marine reptiles from the Mesozoic Era evolved a great diversity of body forms and sizes. Changes in their body and limb anatomy throughout evolution are associated with swimming adaptations. The variety of locomotory modes in Mesozoic marine reptiles is illustrated by (bottom-to-top) an early mosasauroid, a placodont, a plesiosaur and a fish-shaped ichthyosaur. Picture credit: Dr Susana Gutarra.
Dr Susana Gutarra (School of Earth Sciences at the University of Bristol), lead author of the paper commented:
“Changes in anatomy in land-to-sea transitions are intimately linked to the evolution of swimming. For example, sea lions’ flippers have relatively short forearm and large hands, very different from the walking legs of their ancestors. The rich fossil record of Mesozoic marine reptiles provided great opportunity to study these transitions at a large scale.”
The End-Permian Mass Extinction Event
At the end of the Permian, the Earth experienced a catastrophic mass extinction event. Life on Earth was devastated. It has been estimated that 50% of all marine families and over 80% of all marine genera died out (Raup and Sepkoski).
Remarkably, marine environments recovered relatively quickly. Various groups of reptiles became aquatic hunters.
To read an article from 2010 that documents a remarkable fossil site in China that provides evidence of how marine food webs recovered from the end-Permian mass extinction event: Ancient Ecosystem Revealed.
To test the validity of the statistical analysis, measurements from extant aquatic animals were included in the study.
Co-author Beatrice Heighton (University of Bristol), explained:
“We included measurements from living aquatic animals, such as otters, seals and turtles, of which we know their swimming behaviour. This is very important to provide a functional reference for the ancient species, with unknown swimming modes.”
Palaeobiologist Dr Susana Gutarra taking measurements from a very complete specimen of Liopleurodon, a pliosaur from the Middle-Late Jurassic of Germany (Museum of Palaeontology in Tübingen). Picture credit: Dr Susana Gutarra.
A Gradual Diversity of Swimming Styles
Co-author Dr Tom Stubbs (University of Bristol) added:
After this devastating event, there was a gradual diversification of locomotory modes, which contrasts with the rapid radiation described previously for feeding strategies. This is fascinating because it suggests a ‘head-first’ pattern of evolution in certain lineages.”
The scientific paper sheds light into the swimming styles of specific groups of marine reptile.
Dr Ben Moon (University of Bristol) explained the significance of this study, stating:
“Ichthyosaurs were highly specialised for aquatic locomotion from very early in their evolution. This includes their close relatives, the hupehsuchians, which had a morphology unlike any other known aquatic tetrapod. Further, we see overlap between mosasaurs and ichthyosaurs, which is indicative that mosasaurs evolved a swimming mode by oscillating flukes, different from the eel-like body undulation suggested in the past.”
An almost 8m-long specimen of Temnodontosaurus, an ichthyosaur from the Early Jurassic of Germany (State Museum of Natural History of Stuttgart, Germany), is one of the fossils included in this study. Picture credit: Dr Susana Gutarra.
Dr Moon of Bristol University’s School of Earth Science went onto add:
“In contrast, we don’t find evidence of convergence between ichthyosaurs and metriorhynchids (the highly aquatic crocodyliform thalattosuchians). This group retained quite primitive-looking hindlimbs, which seems incompatible with swimming by fluke oscillation.”
Examining the Evolution of Size
This comprehensive study also examined the evolution of size, a feature related to locomotion, animal physiology and ocean productivity.
The University of Bristol’s Professor Mike Benton, a co-author of the research paper commented:
“We know that transition to life in water is usually accompanied by an increase in body mass, as seen in cetaceans, and one of our previous studies shows that large sizes benefit aquatic animals in reducing the mass-specific costs of drag. Thus, it was essential to explore this trait in the wider ensemble of Mesozoic marine reptiles.”
Dr Gutarra explained that body mass follows a similar trend to the diversification of locomotory modes. The widest spread of body size also occurred in the Cretaceous. This confirms a strong correlation between the evolution of diverse swimming styles and changes in body mass.
Dr Gutarra added:
“The rate of increase and the maximum limits to body size seems to vary a lot between groups. This is a fascinating observation. We need to explore further what factors influence and limit the increase in body mass in each group.”
Everything Dinosaur acknowledges the assistance of a media release from the University of Bristol in the compilation of this article.
The scientific paper: “The locomotor ecomorphology of Mesozoic marine reptiles” by Susana Gutarra, Thomas L. Stubbs, Benjamin C. Moon, Beatrice H. Heighton and Michael J. Benton published in Palaeontology.
A virtually complete titanosaur skull has been found in Queensland. The fossil discovery is Australia’s most complete sauropod skull found to date. It supports the hypothesis that Australian sauropods originated in South America. The titanosaur skull has been assigned to Diamantinasaurus matildae.
A view of the Diamantinasaurus skull bones in approximate life position: Picture credit: Australian Age of Dinosaurs.
Diamantinasaurus matildae
Australian Age of Dinosaurs Museum researchers in collaboration with Curtin University (Perth) despatched a media release announcing the discovery of the stunning sauropod skull. The fossil specimen, nicknamed “Ann” was excavated in 2018 at a dig site located at Elderslie Station, near Winton (Queensland).
Field team members working at the “Ann” dig site. Picture credit: Australian Age of Dinosaurs.
The fossil specimen is believed to be between 98-95 million years old (Cenomanian faunal stage of the Late Cretaceous). It is the fourth specimen of Diamantinasaurus matildae to have been discovered by Australian Age of Dinosaurs Museum staff.
Studying the Skull
Research on the titanosaur skull was led by Museum Research Associate Dr Stephen Poropat, a Postdoctoral Research Fellow at Curtin University.
Dr Poropat stated:
“This skull gives us a rare glimpse into the anatomy of this enormous sauropod that lived in northeast Australia almost 100 million years ago.”
Dr Stephen Poropat (left) and right, Dr Phil Mannion (University College London) examining the “Ann” site fossil material including the Diamantinasaurus skull bones, the Oliver scapula and vertebra two. Picture credit: Australian Age of Dinosaurs.
Implications for Titanosaur Evolution
The researchers identified similarities between “Ann” and the skull of another titanosaur Sarmientosaurus musacchioi. S. musacchioi fossils come from southern Argentina, from rocks which are roughly contemporaneous with the Winton Formation strata. The braincases of these two titanosaurs were similar, along with the dentition (teeth). Similar anatomical characteristics were also identified in the quadratojugal (a bone from the back of the skull near the posterior of the lower jaw).
Dr Poropat commented that their findings support previous theories that sauropods were using Antarctica as a migratory pathway between South America and Australia between 100 and 95 million years ago.
The doctor added:
“Our research suggests that Diamantinasaurus was one of the most ‘primitive’ titanosaurs. Gaining a better understanding of this species might explain why titanosaurs were so successful, across so much of the world, right until the end of the Age of Dinosaurs.”
A life reconstruction of the titanosaur Diamantinasaurus. Picture credit: Australian Age of Dinosaurs.
Titanosaur Skull Links Australian Dinosaurs to Antarctica and South America
At the beginning of the Late Cretaceous (100 to 95 million years ago), the Earth was much warmer than it is today. Antarctica which was located approximately where it is today, was ice free. Australia was much further south and closely associated with the Antarctic landmass. The huge conifer forests of Antarctica might have been an attractive habitat for migratory sauropods. The similarities between “Ann” and Sarmientosaurus skull matieral lends weight to the theory that titanosaurs used Antarctica as a pathway to Australia.
The Diamantinasaurus skull fossils are currently on display at the Australian Age of Dinosaurs Museum.
Everything Dinosaur acknowledges the assistance of a media release from the Australian Age of Dinosaurs Museum in the compilation of this article.
The scientific paper: “A nearly complete skull of the sauropod dinosaur Diamantinasaurus matildae from the Upper Cretaceous Winton Formation of Australia and implications for the early evolution of titanosaurs” by Stephen F. Poropat, Philip D. Mannion, Samantha L. Rigby, Ruairidh J. Duncan, Adele H. Pentland, Joseph J. Bevitt, Trish Sloan and David A. Elliott published by Royal Society Open Science.
A new study suggests that the key to the evolutionary success of the early mammals, was to stay small, eat insects and to reduce the number of bones in their skull. The reduction of mammalian skull bones led to a more efficient absorption of bite forces and this adaptation helped mammals to diversify and to ultimately dominate modern ecosystems.
The study, published in the academic journal “Communications Biology” contrasts the skulls of other vertebrates and mammalian ancestors with mammals known from the Jurassic and Cretaceous. In many vertebrate groups such as reptiles and fishes, the skull and lower jaw are composed of numerous bones. This configuration was also seen in the earliest ancestors of modern mammals that lived over 300 million years ago (Cynodontia). However, during evolution the number of bones in the skull was reduced.
Digital skull model of the small-sized Jurassic mammal ancestor Hadrocodium wui with coin providing scale. Picture credit: Dr Stephan Lautenschlager, University of Birmingham.
A Reduction in Mammalian Skull Bones
Computer simulations based on three-dimensional skull models permitted the research team to examine bite forces and skull stresses. Their research demonstrates that reducing the number of skull bones did not lead to higher bite forces or increased skull strength as postulated previously.
Instead, the researchers, found that the skull shape of these early mammals redirected stresses during feeding in a more efficient way.
Lead author for the study, Dr Stephan Lautenschlager, Senior Lecturer for Palaeobiology (University of Birmingham) explained:
“Reducing the number of bones led to a redistribution of stresses in the skull of early mammals. Stress was redirected from the part of the skull housing the brain to the margins of the skull during feeding, which may have allowed for an increase in brain size.”
Switching Diets
The study, which also involved scientists from the University of Hull, Bristol University, the University of Chicago and the London Natural History Museum, demonstrated that alongside the reduction of skull bones, early mammals also became a lot smaller. Some Mammaliaformes for example, had skulls around 1 cm in length.
This miniaturisation considerably restricted the available food sources and early mammals adapted to feeding mostly on insects.
Dr Lautenschlager added:
“Changes to skull structure combined with mammals becoming smaller are linked with a dietary switch to consuming insects – allowing the subsequent diversification of mammals which led to development of the wide-range of creatures that we see around us today.”
Life reconstruction of Hadrocodium wui. This Jurassic mammal is depicted hunting insects, illustrating how the adoption of an insectivorous diet and miniaturisation played a significant role in mammal evolution. Picture credit: Dr Stephan Lautenschlager, University of Birmingham.
Hadrocodium wui
One of the mammaliaforms used in the study, is Hadrocodium wui fossils of which are known from the Early Jurassic (Sinemurian faunal stage) of China. At around ten centimetres long, this tiny animal was a very small and inconsequential member of the Lufeng Formation biota, which was dominated by dinosaurs such as Lufengosaurus.
An illustration of Lufengosaurus. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
The image (above) is a drawing of the Early Jurassic sauropodomorph Lufengosaurus.
The research team concludes that miniaturisation and staying small, combined with a reduction in skull bones and a switch to an insectivorous diet allowed the ancestors of modern mammals to thrive in the shadows of the Dinosauria. Having nocturnal habits may also have permitted these animals to carve out their own ecological niches in dinosaur dominated ecosystems.
It was not until dinosaurs became extinct at the end of the Cretaceous, some 66 million years ago, that mammals had a chance to further diversify and reach the large range of body sizes seen in many extant mammals today.
Everything Dinosaur acknowledges the assistance of a media release from the University of Birmingham in the compilation of this article.
The scientific paper: “Functional reorganisation of the cranial skeleton during the cynodont–mammaliaform transition” by Stephan Lautenschlager, Michael J. Fagan, Zhe-Xi Luo, Charlotte M. Bird, Pamela Gill and Emily J. Rayfield published in Communications Biology.
Everything Dinosaur team members have produced numerous blog posts documenting fossil discoveries and research into human evolution. Scientists are gradually gaining a better understanding of the evolution of our own species (Homo sapiens). Readers may have noticed a change in the use of the terms that describe members of the Homo genus, related genera and their ancestors.
For example, the terms “hominid” and “hominin”. In the past, these terms were interchangeable. Both hominid and hominin referred to the group of apes consisting of modern humans, extinct humans and all our immediate ancestors. The definition of these terms has changed. This change can lead to confusion, so, Everything Dinosaur thought it might be helpful to explain what “hominid” and “hominin” now refer to.
Hominid (Hominidae Family)
The term “hominid” has been given a wider definition, encompassing all the Great Apes. It now encompasses all modern and extinct Great Apes (humans, chimpanzees, including the bonobos, gorillas, orangutans and their immediate ancestors.
The Great Apes – extant and extinct (humans, gorillas, orangutans, chimpanzees, bonobos and all their immediate ancestors) – defining hominids (Hominidae Family).
Hominin Defined
The term “hominin” now refers to a narrower group. This group consists of modern humans, extinct human species and all our immediate ancestors (including members of the genera Homo, Australopithecus, Paranthropus and Ardipithecus).
The term hominin defined: modern humans, extinct human species and all our immediate ancestors (including members of the genera Homo, Australopithecus, Ardipithecus and Paranthropus).
Hominid or Hominin?
The change in definition has occurred as palaeoanthropologists have altered the way that apes are classified. In the previous taxonomy, humans were distinct and separate from all other apes. They were placed into their own, unique family the Hominidae or hominids, one of three families classifying the apes.
Scientists have revised their classifications to develop more up-to-date evolutionary trees. The revision has reduced the number of families recognised to just two. All the Great Apes (including humans) are placed into the same family, the Hominidae or hominids. The next branching of this evolutionary tree divides the orangutans into one subfamily and all the remaining Great Apes into another subfamily. Then at the tribe level, gorillas, chimpanzees and humans separate onto different branches of the evolutionary tree with humans in the Hominini or hominin branch.
Visitors to the Berlin Naturkundemuseum (Germany) will be able to see an amazing Triceratops skull on display as part of an exhibition entitled “Dinosaurs! Age of the Giant Lizards”.
The impressive cranium, complete with horns and an imposing head shield measures two metres long and it was found in Lance Creek Formation deposits (Wyoming, USA) back in 2020. The fossil was discovered by an amateur fossil hunter and after preparation in Canada, the current owner Lars Fjeldsoe-Nielsen has lent the stunning specimen to the Museum für Naturkunde in Berlin.
The magnificent Triceratops skull on display in the “Dinosaurs! Age of the Giant Lizards” gallery at the Berlin Naturkundemuseum. Picture credit: Lukasz Papierak.
Horned Dinosaur Skull
The Triceratops specimen has been nick-named “Amalie” after the daughter of the owner. It is not known whether the skull fossil is from a female or male Triceratops. Both males and females sported neck frills and horns.
Numerous ornithischian dinosaurs are known from the Lance (Creek) Formation. The strata were deposited during the Maastrichtian faunal stage of the Late Cretaceous (69-66 million years ago). The fossils found in these rocks represent a diverse dinosaur dominated terrestrial fauna that thrived prior to the mass extinction event that saw the demise of the non-avian dinosaurs, including ceratopsians like Triceratops.
The new for 2022 PNSO Doyle the Triceratops 1:35 scale model comes complete with a scale model of a Triceratops skull.
The picture above shows a Triceratops model and skull, which is part of the PNSO Age of Dinosaurs series.
A spokesperson from Everything Dinosaur commented that they were unsure as to the Triceratops species that “Amalie” represented. They explained that both Triceratops horridus and an as yet, not fully described Triceratops species are associated with the Lance Formation.
Johannes Vogel, Director General of the Museum für Naturkunde Berlin thanked the owner for lending this wonderful specimen and stated:
“The Museum für Naturkunde Berlin would like to express its sincere thanks to Mr Fjeldsoe-Nielsen for this further generous loan. This will enable research museums like ours to get visitors excited about nature and explore the objects.”
The exhibition “Dinosaurs! Age of the Giant Lizards” is due to run until the end of the year.
Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde Berlin in the compilation of this article.
Everything Dinosaur team members were sent a question by a young dinosaur fan who wanted to know how big was the brain of T. rex? We put our own brains trust to work on this intriguing question.
Having a large brain does not necessarily indicate intelligence, how that organ is configured, and its complexity can provide neuroscientists with an insight into the intelligence of organisms.
Ironically, a controversial study published earlier this year, postulated that Tyrannosaurus rex might have been as smart as a primate, it may have possessed a comparable number of brain cells to that of a monkey.
An endocast of the brain of T. rex derived from internal moulds of the brain case. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
How Big was the Brain of T. rex?
CAT scans of theropod skulls have enabled palaeontologists to trace nerve pathways and to build up a picture of what some brains of dinosaurs might have looked like. The Tyrannosaurus rex fossil material known as Stan (BHI3033), has provided researchers with a detailed understanding of T. rex brain function. For example, fifty percent of the brain volume was dedicated to analysing smells. Hence the assertion that the sense of smell was extremely important to this carnivore.
As for brain size, estimates vary, but a recent paper published in the Journal of Comparative Neurology estimated the T. rex brain to have weighed around 350 grammes, and endowed this predator with considerable intelligence, putting the “King of the Tyrant Lizards” on a par with extant monkeys.
To read an article from 2013 that looks at research that indicated that dinosaurs had complex brains and postulated that they were capable of sophisticated behaviours similar to modern birds and mammals: Scientists Create a Detailed Map of a Dinosaur’s Brain.
Capable of Tool Use?
Author of the recently published paper, Dr Suzana Herculano-Houzel from the Department of Psychology at Vanderbilt University (Tennessee), postulates that Tyrannosaurus rex had approximately 3 billion cerebral neurons, a greater number than found in baboons.
The image of the Beasts of the Mesozoic Tyrannosaurus rex model in 1:18 scale that features on the back of the product packaging. A recent research paper has suggested T. rex was as clever as a monkey. Picture credit: Everything Dinosaur.
The picture (above) shows an image of an articulated Tyrannosaurus rex from the Beasts of the Mesozoic range. To view this range of prehistoric animal figures: Beasts of the Mesozoic Models and Figures.
Using data on living birds and reptiles, Dr Herculano-Houzel inferred the number of neurons extinct creatures had based on calculations of brain mass, including many theropods such as Allosaurus, Archaeopteryx and T. rex.
Writing in the “Journal of Comparative Neurology”, a publication edited by Dr Herculano-Houzel, the doctor extrapolated how many brain cells T. rex possessed in its cerebrum (telencephalon), the most highly advanced part of the brain associated with higher cognitive functions.
Dr Herculano-Houzel postulates that Tyrannosaurus rex would have matured rapidly, lived to about forty years of age and was smart enough to use tools and to pass on acquired knowledge to offspring.
Controversial Ideas
Summarising her research, the doctor concludes:
“That theropods such as Tyrannosaurus and Allosaurus were endotherms with baboon and monkey-like numbers of telencephalic neurons, respectively, which would make these animals not only giant but also long-lived and endowed with flexible cognition, and thus even more magnificent predators than previously thought.”
T. rex brain endocast. Was T. rex really smart? Picture credit: Everything Dinosaur.
As Clever as a Primate!
The paper has attracted scepticism from palaeontologists and other researchers. Gaining an understanding of the neuronal composition of the brains of dinosaurs would provide fundamental insights into their behavioural and cognitive capabilities.
However, brain tissue is rarely fossilised and to achieve her calculations Dr Herculano-Houzel assumed that the entire volume of the braincase was filled by brain tissue. This may not have been so. Perhaps, less than fifty percent of the braincase of T. rex was filled with brain tissue. Dinosaur brains could have been considerably smaller than the size postulated in the scientific paper.
In addition, how the brain is configured, its composition, if you like how it is “wired”, will have a significant impact on an organism’s intelligence.
Claiming that theropods such as Tyrannosaurus and Allosaurus were “the primates of their times”, is exceptionally difficult to substantiate in the absence of a living animal to study.
To read an article from October 2016 about the remarkable discovery of a preserved partial iguanodontid brain: Dinosaur Brain from Southern England.
Bird Brains
Assessing intelligence is challenging, even in living creatures. Pigeons for example, would perhaps not be regarded by many people as being particularly smart, but these avian dinosaurs are capable of remarkable feats of navigation. Many birds demonstrate advanced cognitive abilities such as corvids (crows and their relatives) using tools. Crows have much smaller brains than most monkeys, they have far fewer cerebral neurons but they can outperform some primates when it comes to cognitive assessment tasks.
Dr Herculano-Houzel argues that estimating neuron counts from brain mass is a method that has been applied to hundreds of mammal, bird, and non-avian dinosaur species, the methodology is robust.
However, claiming that T. rex was a smart as a monkey is quite a leap.
The Dinosaur Renaissance
A spokesperson from Everything Dinosaur commented:
“The research paper is free to access, so readers can make up their own minds. Whilst it is extremely challenging to try to work out how intelligent an extinct animal was, the days of regarding dinosaurs as creatures so stupid that they were an evolutionary dead end are long gone.”
The spokesperson added:
“Since the 1960s and the work of palaeontologist John Ostrom, the view of the Dinosauria has fundamentally changed. These animals were perfectly adapted to their environments and they were capable of complex behaviours just like mammals and their close relatives the birds. Just how smart T. rex was is difficult to quantify and validate with scientific evidence. Along with other theropods such as the dromaeosaurids and the oviraptorids these predators might have demonstrated very complex behaviours derived from their cognitive abilities.”
Unfortunately, as we are unlikely to ever observe a living non-avian dinosaur, assessments regarding dinosaur intelligence remain speculative.
How Big was the Brain of T. rex? Something to Ponder
However, the idea of a smart, 7 tonne carnivore measuring in excess of 12 metres long, it makes you think…
The scientific paper: “Theropod dinosaurs had primate-like numbers of telencephalic neurons” by Suzana Herculano-Houzel published in the Journal of Comparative Neurology.
Large, predatory theropod dinosaurs are often portrayed as fierce-looking monsters, with huge and highly visible teeth. These teeth are visible over the jaw line when the meat-eating dinosaur’s mouth is closed. This is reminiscent of the appearance of modern crocodilians, which after all, are closely related to fellow archosaurs such as the theropod members of the Dinosauria. However, a new study suggests predatory dinosaurs had scaly, lizard-like lips. Even Tyrannosaurus rex had lips according to a new paper published in the academic journal Science.
A juvenile Edmontosaurus disappears into the enormous, lipped mouth of Tyrannosaurus. Picture credit: Mark Witton.
Tyrannosaurus rex Had Lips
The researchers including Dr Mark Witton (University of Portsmouth) and the study lead author Assistant Professor Thomas M. Cullen (Auburn University, Alabama) suggest that carnivores such as Tyrannosaurus rex did not have permanently exposed teeth. Films such as “Jurassic Park”, many palaeoartists and numerous model manufacturers have got it wrong. Instead, these dinosaurs had scaly lips, covering and sealing their mouths.
The debate as to whether theropod dinosaurs such as Giganotosaurus, Velociraptor, T. rex and Allosaurus had lips has gone on for some time. Did these dinosaurs have perpetually visible upper teeth that hung over their lower jaws and were therefore exposed and on view even with the jaw closed? The researchers suggest that dinosaurs such as Tyrannosaurus rex did not have a smile like a crocodile. Theropods possessed lips similar to those of lizards and the ancient reptile Tuatara, the only extant member of the Rhynchocephalia.
Detailed Study
In the most detailed study concerning the presence or otherwise of extraoral tissue in the Theropoda conducted to date, the researchers examined the tooth structure, wear patterns and jaw morphology of lipped and lipless reptile groups and found that theropod mouth anatomy and functionality resembles that of lizards more than the mouths of crocodilians.
T. rex skull and head reconstructions. Picture credit: Mark Witton.
These lips were probably not muscular, like those of mammals. Most reptile lips cover their teeth but cannot be moved independently, a reptile can’t curl its lips back and snarl like a dog. They could not make the sort of movements that we might associate with our faces or that of other mammals.
Derek Larson, Collections Manager and Researcher in Palaeontology at the Royal BC Museum in Canada and a co-author of the study stated:
“Palaeontologists often like to compare extinct animals to their closest living relatives, but in the case of dinosaurs, their closest relatives have been evolutionarily distinct for hundreds of millions of years and today are incredibly specialised.”
The research team concluded that theropod teeth were extremely similar to the teeth of monitor lizards (varanids). The teeth are thought to have functioned in the same way, so perhaps monitor lizards such as the Komodo dragon (Varanus komodoensis) can be favourably compared to extinct animals such as theropod dinosaurs, even though the Varanidae as members of the Squamata, are only very distantly related to the Dinosauria.
Upending Popular Theropod Depictions
Co-author Dr Mark Witton (University of Portsmouth) explained:
“Dinosaur artists have gone back and forth on lips since we started restoring dinosaurs during the 19th century, but lipless dinosaurs became more prominent in the 1980s and 1990s. They were then deeply rooted in popular culture through films and documentaries — Jurassic Park and its sequels, Walking with Dinosaurs and so on. Curiously, there was never a dedicated study or discovery instigating this change and, to a large extent, it probably reflected preference for a new, ferocious-looking aesthetic rather than a shift in scientific thinking. We’re upending this popular depiction by covering their teeth with lizard-like lips. This means a lot of our favourite dinosaur depictions are incorrect, including the iconic Jurassic Park T. rex.”
The Implications of “Tyrannosaurus rex Had Lips”
The results of the study, found that tooth wear in lipless animals was markedly different from that seen in carnivorous dinosaurs and that dinosaur teeth were no larger, relative to skull size, than those of modern lizards, implying they were not too big to cover with lips.
Furthermore, the distribution of small holes around the jaws, which supply nerves and blood to the gums and tissues around the mouth, were more lizard-like in dinosaurs than crocodile-like. In addition, modelling mouth closure of lipless theropod jaws showed that the lower jaw either had to crush jaw-supporting bones or disarticulate the jaw joint to seal the mouth.
Tyrannosaurus rex bellowing with its mouth shut, like a vocalising alligator. Picture credit: Mark Witton
Kirstin Brink (Assistant Professor of Palaeontology at the University of Manitoba, Canada) and fellow co-author of the scientific paper commented:
“As any dentist will tell you, saliva is important for maintaining the health of your teeth. Teeth that are not covered by lips risk drying out and can be subject to more damage during feeding or fighting, as we see in crocodiles, but not in dinosaurs.”
Assistant Professor Brink added:
“Dinosaur teeth have very thin enamel and mammal teeth have thick enamel (with some exceptions). Crocodile enamel is a bit thicker than dinosaur enamel, but not as thick as mammalian enamel. There are some mammal groups that do have exposed enamel, but their enamel is modified to withstand exposure.”
Theropod Teeth are Not Oversized
Previously, it had been suggested that the teeth of predatory dinosaurs were just too big to be covered by lips. This study challenges that view and suggests that theropod teeth were not atypically large. Even the huge, banana-shaped teeth of tyrannosaurs are proportionally similar in size to living predatory lizards when the actual skull size is considered. Therefore, the researchers reject the hypothesis that theropod teeth were too large to be covered by lips.
Model makers and figure manufacturers have created figures that reflect the current scientific debate about the presence or otherwise of lips in theropod dinosaurs. For example, Rebor recently introduced two new Tyrannosaurus rex figures “Kiss” being a lipped model, whereas the counterpart figure “Tusk” was lipless.
Some model manufacturers have reflected the current scientific debate by producing replicas with lips as well as lipless forms such as the recent Rebor “Kiss” and “Tusk” figures.
To view the range of Rebor figures and replicas in stock at Everything Dinosaur: Rebor Models and Figures.
Important Implications with Regards to Reconstructing Theropod Dinosaurs
This new study provides a new perspective on the “lips” versus “lipless” debate. It provides new insights into how scientists, artists and model makers reconstruct the soft tissues of dinosaurs and other prehistoric animals. This research provides information on how theropod dinosaurs fed, how they maintained their dental health as well as broader issues such as dinosaur ecology and evolution.
Dr Witton summarised the study stating:
“Some take the view that we’re clueless about the appearance of dinosaurs beyond basic features like the number of fingers and toes. But our study, and others like it, show that we have an increasingly good handle on many aspects of dinosaur appearance. Far from being clueless, we’re now at a point where we can say ‘oh, that doesn’t have lips? Or a certain type of scale or feather?’ Then that’s as realistic a depiction of that species as a tiger without stripes.”
The research team stress that their study does not say that no extinct animals had exposed teeth — some, like sabre-toothed carnivorous mammals, or marine reptiles and flying reptiles with extremely long, interlocking teeth, almost certainly did.
Everything Dinosaur acknowledges the assistance of a media release in the compilation of this article.
The scientific paper: “Theropod dinosaur facial reconstruction and the importance of soft tissues in paleobiology” by Thomas M. Cullen, Derek W. Larson, Mark P. Witton, Diane Scott, Tea Maho, Kirstin S. Brink, David C. Evans and Robert Reisz published in the journal Science.
The earliest ichthyosaur fossil specimen discovered to date has been found on the Arctic island of Spitsbergen. The fossil represents a marine reptile that lived around 252 million years ago. The bones indicate that this animal was not a transitional form, but a fully adapted marine reptile.
Reconstruction of the earliest ichthyosaur and the 250-million-year-old ecosystem found on Spitsbergen. Picture credit: Esther van Hulsen.
Picture credit: Esther van Hulsen
Ichthyosaur Evolution
The evolutionary history of the ichthyosaurs remains contentious. No transitional forms representing land-dwelling tetrapods adapting to a marine habit have been found. However, small, basal ichthyosauriforms are known from the Lower Triassic of China, and the fossils of at least one, primitive Early Triassic, dolphin-shaped member of the Ichthyopterygia has already been described from Spitsbergen (Grippia longirostris).
Thanks to the work of a joint team of Swedish and Norwegian palaeontologists a fresh perspective on the origins of the “fish lizards” is provided by these newly described fossil bones.
An Ichthyosaurus model, typical of the dolphin-like, streamlined forms that existed during the Early Jurassic. Picture credit: Everything Dinosaur.
Ichthyosaurs were a highly successful, globally distributed group of marine reptiles. The evolved, a “dolphin-like” streamlined body and were active, nektonic predators surviving into the Late Cretaceous.
The first marine reptiles, such as the mesosaurs evolved during the Early Permian. The end-Permian mass extinction event devasted both terrestrial and marine faunas. The cataclysmic event was thought to have led to an evolutionary reset which permitted animals such as the Ichthyosauria to evolve, exploiting niches vacated after the extinction event.
Tetrapods (land-based vertebrates), invaded shallow coastal environments to take advantage of marine predator niches that were left vacant after the mass extinction event. Over millions of years, these early amphibious reptiles became more efficient at swimming and eventually modified their limbs into flippers, developed a ” dolphin-like” body plan, and started giving birth to live young (viviparity). With the evolution of viviparity, there was no need to come ashore in order to lay eggs, so the last ties these creatures had with a terrestrial existence was lost.
The newly described fossil material from Spitsbergen is helping to revise and re-write this previous hypothesis.
Fossil-bearing rocks on Spitsbergen that produced the earliest ichthyosaur remains. Picture credit: Benjamin Kear.
Picture credit: Benjamin Kear
Flower’s Valley Fossils
On western Spitsbergen a valley (Flower’s Valley), cuts deep into the surrounding mountains and provides access to Lower Triassic marine sediments, approximately 250 million years old. The rocks represent mud deposited at the bottom of an ancient sea and snow melt has gradually eroded the mudstone exposing rounded limestone boulders known as concretions. These objects are formed from limey sediments that coalesced around decomposing animal remains, subsequently preserving them in amazing, three-dimensional detail.
In 2014, the field team removed a number of concretions from the Flower’s Valley site. The rocks were taken back to the Natural History Museum at the University of Oslo for further study.
Scientists from The Museum of Evolution at Uppsala University have identified bony fish remains and bizarre “crocodile-like” amphibian bones, together with 11 articulated caudal vertebrae from an ichthyosaur.
Found in Rocks Thought to be Too Old for Ichthyosaur Fossils
Surprisingly, these tail bones occurred within rocks that were supposedly too old for ichthyosaurs. Also, the fossil bones do not represent a transitional form, but they show characteristics associated with geologically younger ichthyosaurs.
The vertebrae are identical to those of geologically much younger, larger-bodied ichthyosaurs, and even preserve internal bone microstructure showing adaptive hallmarks of fast growth, elevated metabolism and a fully oceanic lifestyle.
Computed tomography image and cross-section showing internal bone structure of vertebrae from the earliest ichthyosaur. Picture credit: Øyvind Hammer and Jørn Hurum.
Picture credit: Øyvind Hammer and Jørn Hurum
Dating the Surrounding Rock (Geochemical Testing)
Geochemical testing of the surrounding matrix dated the age of the fossils at approximately two million years after the end-Permian mass extinction. When the estimated timescale of marine reptile evolution is considered, this suggests the origins and early diversification of the Ichthyosauria took place during the Permian and prior to the Mesozoic Era.
These fossils suggest that the popular hypothesis of ichthyosaurs evolving to exploit niches vacated as a result of the end-Permian mass extinction is incorrect. Ichthyosaurs were present prior to the end of the Permian.
The discovery of the oldest ichthyosaur rewrites the popular vision of Age of Dinosaurs (Mesozoic Era), as the emergence timeframe of major reptile lineages. It now seems that at least some groups predated this landmark interval, with fossils of their most ancient ancestors still awaiting discovery in even older rocks on Spitsbergen and elsewhere in the world.
Everything Dinosaur acknowledges the assistance of a media release from the Uppsala University in the compilation of this article.
The scientific paper: “Earliest Triassic ichthyosaur fossils push back oceanic reptile origins” by Kear, B.P., Engelschiøn, V.S., Hammer, Ø., Roberts, A.J. and Hurum, J.H. published in Current Biology.
The Silurian is a relatively short geological time period when compared to the other periods outlined in the geological time scale. The Silurian lasted around twenty-five million years (444 million years ago to approximately 419 million years ago). Although it was brief, in relative terms, during the Silurian the first land plants evolved and many invertebrate forms began to make the transition to a terrestrial habit. Life in the seas still dominated the Earth’s biota. One of the apex, marine predators was the straight-shelled nautiloid. Some of these orthocones evolved into giants.
Everything Dinosaur and the straight-shelled nautiloid Orthoceras which was introduced into the CollectA range in 2020. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Straight-shelled Nautiloid
During the Silurian most of the nautiloid cephalopods had straight or slightly curved shells. The planispiral forms had yet to become common. The last straight-shelled forms (Orthocerida), probably died out during the Mesozoic. Most straight-shelled nautiloids became extinct at the end of the Triassic, but one fossil specimen collected in the Caucasus (Zhuravlevia insperata), indicates that one species persisted into the Early Cretaceous.
An early scale drawing design for the Orthoceras/Orthocone fact sheet. Picture credit: Everything Dinosaur.
Picture credit: Everything Dinosaur
Zhuravlevia insperata
Described in 1994 by Larisa Doguzhaeva of the Swedish Museum of Natural History, based on a fragmentary orthocerid fossil, Zhuravlevia insperata is the geologically youngest straight-shelled orthocone known to science. The tiny fossil, just 1.3 cm long, with four chambers preserved, was found when Aptian-aged concretions from the Hokodz River Basin in the north-western Caucasus (Russia), were being split.
The orthocone fragment would be around 120 million years old.
CollectA introduced an Orthocone replica in 2020. The figure was added to the Age of Dinosaurs Popular range.
