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.

25 07, 2022

New Research Identifies Earliest Known Animal Predator

By |2024-03-09T14:34:55+00:00July 25th, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Scientists have announced the discovery of what might possibly be the earliest known animal predator. The fossils discovered in Charnwood Forest (Leicester, England), are estimated to be around 560 million years old and the animal has been named Auroralumina attenboroughii in honour of Sir David Attenborough.

A life reconstruction of Auroralumina attenboroughii
A life reconstruction of Auroralumina attenboroughii superimposed on the fossil material. Picture credit: BGS @ UKRI.

Attenborough’s Dawn Lantern

As a boy, Sir David Attenborough used to collect fossils from various locations close to his Leicestershire home. However, he never went to Charnwood Forest to hunt for fossils as the rocks exposed in that area were thought to be too old to contain signs of life.

In the late 1950s, another young boy, Roger Mason found a strange frond-like impression in a rock. Researchers identified this as the fossilised remains of a bizarre organism, later named Charnia masoni, which forms part of an ancient ecosystem that existed prior to the Cambrian.

This newly described organism Auroralumina attenboroughii honours Sir David Attenborough. The first part of its name is Latin for “dawn lantern”, in recognition of its great age and the organism’s resemblance to a burning torch.

Auroralumina attenboroughii fossil.
Auroralumina attenboroughii fossil imprint preserved in the rock. Picture credit: BGS @ UKRI.

Related to Corals, Jellyfish and Anemones

The geological period known as the Ediacaran precedes the Cambrian. The Ediacaran spans an immense amount of deep time, from approximately 635 million years ago, to the beginning of the Cambrian around 540 million years ago. In some parts of the world, notably the Mistaken Point Ecological Reserve on the south-eastern coast of Newfoundland, Namibia, Guizhou Province (China), Charnwood Forest and the Flinders Ranges of South Australia, ancient sedimentary rocks preserve the remains of the oldest, complex multi-cellular organisms known to science.

Most of the Ediacaran biota bears little resemblance to fossils associated with younger Cambrian-aged strata, A. attenboroughii is an exception, the research team postulate that the fossils represent an ancestor of today’s corals, jellyfish and anemones – the Cnidaria phylum.

Auroralumina attenboroughii line drawing.
The fossil imprint of the newly described Auroralumina attenboroughii with a line drawing on the matrix to show features. Picture credit: BGS @ UKRI.

“Truly Delighted”

Naturalist, campaigner and broadcaster Sir David Attenborough stated that he was “truly delighted” with his ancient namesake.

He added:

“When I was at school in Leicester, I was an ardent fossil hunter. The rocks in which Auroralumina has now been discovered were then considered to be so ancient that they dated from long before life began on the planet. So, I never looked for fossils there.

A few years later a boy from my school found one [Roger Mason] and proved the experts wrong. He was rewarded by his name being given to his discovery. Now I have – almost – caught up with him and I am truly delighted.”

The scientific paper has been published in the journal “Nature Ecology & Evolution”. This discovery challenges perceptions as to when modern groups of animals, or their direct ancestors first evolved.

Commenting on the significance of this fossil find, one of the authors of the paper, Dr Phil Wilby (palaeontology leader at the British Geological Survey), explained:

“It’s generally held that modern animal groups like jellyfish appeared 540 million years ago in the Cambrian explosion. But this predator predates that by 20 million years. It’s the earliest creature we know of to have a skeleton. So far we’ve only found one, but it’s massively exciting to know there must be others out there, holding the key to when complex life began on Earth.”

A Geological Spring Clean

In 2007, Dr Wilby and his colleagues spent over a week carefully cleaning a 100 square metres of a rock surface exposed in the Forest. A variety of tools including pressure hoses and toothbrushes were used to spring clean deposits that were laid down at the bottom of a deep sea more than half a billion years ago.

A rubber mould of the whole surface was then taken, capturing the preserved impressions of more than a thousand fossils.

Geologists at work.
Geologists cleaning and mapping the rockface in the Charnwood Forest (Leicester, England). Picture credit: BGS @ UKRI.

One Fossil Specimen Stood Out

Co-author of the scientific paper, Dr Frankie Dunn (Oxford University Museum of Natural History), explained that one fossil impression stood out from the rest, commenting that it looked very different from the other Ediacaran fossils (Charnia masoni and Bradgatia linfordensis) preserved on the same bedding plane.

Dr Dunn commented that Auroralumina:

“Is very different to the other fossils in Charnwood Forest and around the world. Most other fossils from this time have extinct body plans and it’s not clear how they are related to living animals. This one clearly has a skeleton, with densely-packed tentacles that would have waved around in the water capturing passing food, much like corals and sea anemones do today. It’s nothing like anything else we’ve found in the fossil record at the time.”

Dr Wilby scans the fossil.
Palaeontologist Dr Phil Wilby using a 3D laser scanner to create a detailed record of the fossil. Picture credit: BGS @ UKRI.

A Lonely Fossil

Dr Dunn calls the single Auroralumina specimen a “lonely little fossil” and suggest it probably inhabited much shallower marine environments compared to rest of the Charnwood Forest biota.

She added:

“The ancient rocks in Charnwood closely resemble ones deposited in the deep ocean on the flanks of volcanic islands, much like at the base of Montserrat in the Caribbean today. All of the fossils on the cleaned rock surface were anchored to the seafloor and were knocked over in the same direction by a deluge of volcanic ash sweeping down the submerged foot of the volcano, except one, A. attenboroughii. It lies at an odd angle and has lost its base, so appears to have been swept down the slope in the deluge.”

Zircon minerals associated with the volcanic deposits permitted the researchers to accurately age the fossil based on radioactive decay measurements relating to uranium/lead ratios.

Potentially the Earliest Known Animal Predator

Dr Frankie Dunn said:

“The Cambrian Explosion was remarkable. It’s known as the time when the anatomy of living animal groups was fixed for the next half a billion years. Our discovery shows that the body plan of the cnidarians was fixed at least 20 million years before this, so it’s hugely exciting and raises many more questions.”

Nonagenarian Sir David Attenborough has been honoured on numerous occasions by having newly described extinct creatures named after him. However, arguably the lonely, little Auroralumina attenboroughii may represent the most significant, as it challenges existing perceptions about when animal body plans still found today, first evolved.

Everything Dinosaur acknowledges the assistance of a media release received via email on 26th July in the compilation of this article.

Visit Everything Dinosaur’s website: Everything Dinosaur.

The scientific paper: “A crown-group cnidarian from the Ediacaran of Charnwood Forest, UK” by F. S. Dunn, C. G. Kenchington, L. A. Parry, J. W. Clark, R. S. Kendall and P. R. Wilby published in Nature Ecology & Evolution.

22 07, 2022

Australia’s First Vulture – Hiding in Plain Sight

By |2023-02-07T12:55:44+00:00July 22nd, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Today, Australia has no vultures, but in the Pleistocene Epoch it did. Researchers have reclassified fossil remains and identified Australia’s first fossil vulture. The bird, which probably stood around one metre tall, has been named Cryptogyps lacertosus. The scientific name translates as “powerful hidden vulture”, reflecting the fact that its fossils had been hiding in plain sight for more than a hundred years.

Vulture Cryptogyps compared to Aquila audax.
A silhouette of the newly described Australian vulture Cryptogyps lacertosus which lived in Australia until around 50,000 years ago. C. lacertosus (right) is compared to Aquila audax, the Wedge-tailed eagle which is Australia’s largest extant bird of prey. Wedge-tailed eagles often scavenge carcasses and are frequently observed feeding on kangaroo corpses and other animals killed in roadside collisions. The Wedge-tailed eagle is filling the ecological niche once filled by the extinct C. lacertosus. Picture credit: Ellen Mather, Flinders University Palaeontology Lab with additional annotation by Everything Dinosaur.

Fossil Vulture Hiding in Plain Sight

Researchers from Flinders University and the South Australian Museum writing in the academic journal “Zootaxa” have reassessed fossil material first described by the English ornithologist Charles Walter de Vis in 1905 and named as “Taphaetus lacertosus”. The ornithologist thought the partial humerus and fragmentary skull bones found in north-eastern South Australia represented an ancient eagle and he named the bird “powerful grave eagle”.

The scientists were able to study fossils from the Wellington Caves of New South Wales and material recovered from the Nullarbor Plain of Western Australia including a lower leg bone (tarsometatarsus), which when compared to the lower leg bones of living birds of prey, it became clear that the fossil tarsometatarsus did not support the musculature required to despatch prey.

Eagle lower leg bone compared to fossil vulture.
Comparisons of the tarsometatarsi of wedge-tailed eagle (lower right) and Cryptogyps (lower left), with position of tarsometatarsi shown in the leg (centre, based on illustration by Jollie, 1977). Picture credit: Dr Ellen Mather (Flinders University Palaeontology Lab.

Lead author of the paper, Dr Ellen Mather (Flinders University) commented:

“We compared the fossil material to birds of prey from around the world, and it became clear right away that this bird was not adapted to being a hunter, and so it was not a hawk or an eagle.”

A Phylogenetic Analysis

A phylogenetic analysis placed C. lacertosus within the subfamily Aegypiinae, making it an Old World Vulture related to extant birds found in Africa, Asia and Europe. The identification of Cryptogyps lacertosus as an Old World Vulture significantly expands the palaeogeographical range of the Old World vultures, previously unknown in Australia and indeed, there are no vultures in Australia today.

Given the megafauna that existed on the continent until very recently, giant kangaroos, flightless thunder birds, huge wombats such as Diprotodon and the enormous monitor lizard Megalania, the presence of vultures in the Pleistocene ecosystem had been predicted.

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

The scientific paper: “A new look at an old Australian raptor places “Taphaetus” lacertosus de Vis 1905 in the Old World vultures (Accipitridae: Aegypiinae)” by Ellen K. Mather, Michael S. Y. Lee and Trevor H. Worthy published in Zootaxa.

18 07, 2022

The Eotyrannus Monograph – A New Scientific Paper

By |2024-04-13T08:05:18+01:00July 18th, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A new scientific paper on the Early Cretaceous tyrannosauroid Eotyrannus lengi has been published. It is confirmed as a valid genus and the phylogenetic assessment places the enigmatic Megaraptora clade within the Tyrannosauroidea superfamily.

First named and scientifically described back in 2001 (Hutt et al), Eotyrannus is helping to provide significant insights into the early evolution of tyrannosauroids as well as potentially redefining how enigmatic “megaraptors” such as Australovenator, Megaraptor and the recently described Maip macrothorax fit within the Theropoda.

Eotyrannus scale drawing.
Isle of Wight tyrannosauroid (E. lengi). The recently published monograph (Naish and Cau) supports the earlier hypothesis that this dinosaur had proportionately long arms and a rectangular snout. The holotype specimen (IWCMS: 1997.550) indicates an animal around 4.5 metres in length. However, these fossils represent a sub-adult and the fully-grown, adult size of this Early Cretaceous predator remains undetermined.

The Carnivorous Dinosaurs of the Wessex Formation

Since the first fossils of Eotyrannus were found (1997), this theropod has attracted a lot of scientific interest. It is one of numerous carnivorous dinosaurs associated with the Wessex Formation (part of the Wealden Supergroup), indeed, back in 2021 we blogged about two new members of the Baryonychinae named and described from fossil remains found on the Isle of Wight (Wessex Formation). Last month, we wrote about an even bigger predator, an as yet, unnamed spinosaurid known as the “White Rock spinosaurid”.

For the article on the recently described baryonychids Ceratosuchops inferodios and Riparovenator milnerae: Two New Spinosaurids from the Isle of Wight.

To read about the Isle of Wight “White Rock spinosaurid”: Super-sized Isle of Wight Carnivorous Dinosaur.

The newly published paper provides further information on Eotyrannus autapomorphies (characteristic traits) that help to distinguish it from the often, fragmentary remains of other theropods associated with the Wessex Formation.

Eotyrannus teeth.
Isolated Eotyrannus teeth from the Wessex Formation.

Deciphering the Fossil Evidence

Many of the fossil bones associated with the Eotyrannus genus remain entombed in their concrete-like matrix. Anatomical traits helping to define and classify this dinosaur are only beginning to emerge and there is a substantial amount of further preparation work required to permit a comprehensive analysis.

However, by combining all the new data since the formal description, the authors (Darren Naish and Andrea Cau) were able to produce a new skeletal reconstruction. The maxilla is confirmed as being quite rectangular in shape. Eotyrannus did not have the long, narrow snout (longirostrine) as seen in other early tyrannosauroids such as Dilong and Xiongguanlong from the Early Cretaceous of China. This suggests that longirostry evolved several times within the Tyrannosauroidea, perhaps in response to adaptations to permit these theropods to exploit a particular predatory niche.

Longirostry in Early Members of the Superfamily Tyrannosauroidea
Longirostry (having a long, narrow snout) in early members of the Tyrannosauroidea. Eotyrannus is confirmed as not exhibiting longirostry.

Where do the Megaraptora Fit?

The scientific paper also incorporated a revised phylogenetic analysis of Eotyrannus. No significant support was found for Eotyrannus having a close evolutionary relationship to Juratyrant (J. langhami), known from the Late Jurassic of Dorset or indeed to the Late Jurassic early tyrannosauroid Stokesosaurus (S. clevelandi) from the western United States.

Instead, it is grouped with gracile, mid-sized tyrannosauroids that represent a more derived state than proceratosaurids, stokesosaurs and Juratyrant.

If megaraptoran dinosaurs are tyrannosauroids and therefore coelurosaurs, then this challenges long-held views on Theropoda classification and suggests that after the Early Cretaceous most of the hypercarnivore niches within dinosaur dominated ecosystems were increasingly occupied by coelurosaurs. It also suggests that tyrannosauroids were much more diverse and widespread during the Cretaceous than previously thought.

Eotyrannus remains a fascinating dinosaur, a genus that has led to new insights into the evolution and radiation of the Theropoda. It offers a tantalising glimpse into the ecology represented by the Wessex Formation deposits and how a mid-sized theropod co-existed with other, larger members of the ever-widening collection of Wessex Formation meat-eating dinosaurs.

Everything Dinosaur Helping to Fund Research

The authors wanted to make their paper available to everyone. To do this they set up a GoFundMe campaign to cover publishing costs. Everything Dinosaur assisted with the funding.

A spokesperson from Everything Dinosaur stated:

“We were happy to support this excellent paper and we helped to make such studies possible. Your purchases from Everything Dinosaur genuinely help science”.

Everything Dinosaur helping to fund research.
Team members at Everything Dinosaur were happy to assist with funding a newly published paper on the early tyrannosauroid Eotyrannus lengi.

The scientific paper: “The osteology and affinities of Eotyrannus lengi, a tyrannosauroid theropod from the Wealden Supergroup of southern England” by Darren Naish and Andrea Cau published in PeerJ.

17 07, 2022

A Consequence of Extreme Heat – Landslides

By |2022-10-20T12:34:10+01:00July 17th, 2022|Categories: Geology, Main Page, Palaeontological articles, Photos, Press Releases|0 Comments

Hot weather can increase the risk of landslides and rockfalls, visitors to the seaside trying to avoid the extreme heat are advised to stay away from the cliffs.

For many parts of England, Monday and Tuesday (18th and 19th of July 2022), red extreme heat warnings have been issued. Such alerts have never been issued for the UK before. Temperatures could reach as high as 40 degrees Celsius (104 Fahrenheit), although this system of alerts was only introduced last year (2021). The risk of a landslide can increase in hot weather, visitors to the beach should take care to avoid areas where there are cliffs.

Rock fall at Stonebarrow Hill (Dorset).
A significant rock fall at Stonebarrow Hill (Dorset). Extreme heat can cause cliffs to become unstable and collapse. Visitors to the seaside in search of relief from the hot weather are advised to avoid cliffs due to the increased risk of landslides and rock falls. Picture credit: Brandon Lennon.

Rock Fall and Landslide Risk

In very hot weather, the risk of landslides and rock falls increases. The heating up and then cooling of rocks can increase the instability of the rock face and this can lead to a collapse. The risk of landslides after heavy rain has been widely documented. Saturated, unstable ground can collapse, however, extreme daytime temperatures can also increase the risk of landslides and rock falls.

A spokesperson from Everything Dinosaur commented:

“We do advise visitors to places such as the “Jurassic Coast” and the north coast of Yorkshire to heed the warnings about unstable cliffs. The very hot weather is likely to lead to packed beaches and we urge everyone to stay away from dangerous areas.”

Landslides are common around some parts of the British coastline. Tragically, some incidents cause fatalities. In 2012, a woman was killed when she was caught in a massive landslide at Bridport (Dorset).

We urge seaside visitors to follow local advice and to avoid straying too close to the cliffs and the cliff edge when walking above the beach area.

13 07, 2022

A Scottish Stem Salamander Revealed by New Research

By |2024-05-07T13:50:19+01:00July 13th, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos|0 Comments

The fossils of an ancient amphibian found on the Isle of Skye (Scotland), are helping scientists to better understand the evolutionary development of salamanders. Writing in the academic journal “The Proceedings of the National Academy of Sciences” (PNAS), the researchers suggest that the fossils represent the oldest salamander fossil found to date in Europe.

A Scottish Stem Salamander

A skeletal reconstruction of the stem salamander Marmorerpeton wakei.
A skeletal reconstruction of the stem salamander Marmorerpeton wakei (dorsal view). Picture credit: Jones et al.

Marmorerpeton wakei

The stem Salamander genus Marmorerpeton was named and described in 1988, but detailed analysis of the Isle of Skye fossil material, including CT scans demonstrated that this was a new species, which has been named Marmorerpeton wakei. The species name honours the late Professor David Wake, who was a world-renowned authority on early salamander evolution.

Lead author of the study, Dr Marc Jones (University College London, Cell and Developmental Biology), commented:

“The fossil is definitely a salamander but unlike anything alive today. It highlights the importance of the fossil record for preserving combinations of anatomical features that do not exist in any living animal.”

The anatomical features of the new Scottish fossils of Marmorerpeton wakei were only revealed thanks to the detailed CT scans and subsequent computer-generated models. This scanning technology provides a powerful and non-destructive tool for revealing fine details on fossil bones. One specimen, collected in 2016, was found to be part of a specimen collected in 1971 but left undescribed until now.

Marmorerpeton wakei skull reconstruction.
A three-dimensional image showing the skull bones of Marmorerpeton wakei. Following detailed CT scans of the fossil material a computer programme was used to interpret the data and reconstruct the skull. Picture credit: Jones et al.

Middle Jurassic Salamander

The fossils are thought to be around 166 million years old (Middle Jurassic) and although the Marmorerpeton genus was first described over 30 years ago, the material analysed in this new paper has permitted the researchers to build up a more complete picture of this 20-centimetre-long amphibian.

Marmorerpeton wakei had a wide but shallow frog-like head with powerful jaws and distinctive, prominent, bony projections behind its eyes. The skull roof bones show that it was ornamented like that of a crocodile or a temnospondyl, distinguishing it from extant salamanders. The limb bones and deep tail of Marmorerpeton wakei suggest this animal was aquatic, perhaps using its wide jaws to catch prey by suction feeding, similar to the lifestyle seen in the modern Hellbender salamander (Cryptobranchus alleganiensis) of North America.

The bony bumps behind the orbit are unusual and Dr Jones commented:

“The big bony projections behind the eye were a bit unexpected but smaller projections do exist in fossil salamanders from slightly younger rocks. Their purpose remains unknown.”

The early evolution of salamanders is poorly understood, their small and delicate bones are rarely preserved as fossils. This research also included a detailed survey of modern salamander anatomy which informed the subsequent analyses.

The Karaurus Genus

Several previous studies of Mesozoic salamanders have relied on fossils from the Late Jurassic, found in Kazakhstan, assigned to the genus Karaurus. As the Marmorerpeton fossils are older, they help to provide an improved understanding of how early salamanders evolved.

Daohugou salamander
Even the fine gills have been preserved, a delicate salamander fossil from China. Picture credit: Chinese Academy of Sciences/Journal of Vertebrate Palaeontology.

Senior-author Professor Susan Evans (University College London Cell and Developmental Biology), who first described Marmorerpeton in 1988 explained:

“The origin and early history of modern amphibian groups remains mysterious and new fossils like this one are key to developing a better understanding of amphibian evolution. In theory, the Skye salamander should give us a clue as to what the ancestors of modern salamanders looked like. However, it could be that they are a highly specialised off-shoot.”

To read an article from 2008 about a transitional fossil from the Early Permian that helped to define the evolutionary origins of modern amphibians: Amphibian Ancestry a Little Clearer Thanks to New Discovery.

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

Visit Everything Dinosaur’s award-winning website: Everything Dinosaur.

The scientific paper: “Middle Jurassic fossils document an early stage in salamander evolution” by Marc E. H. Jones, Roger B. J. Benson, Pavel Skutschas, Lucy Hill, Elsa Panciroli, Armin D. Schmitt, Stig A. Walsh and Susan E. Evans published in The Proceedings of the National Academy of Sciences (PNAS).

For models and replicas of prehistoric animals: Models and Replicas of Prehistoric Animals.

8 07, 2022

Meraxes gigas – New Giant Carcharodontosaurid from Argentina

By |2022-10-20T12:45:06+01:00July 8th, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A new giant, Late Cretaceous predatory dinosaur has been named based on fossils found in Argentina. The dinosaur, assigned to the Carcharodontosauridae has been named Meraxes gigas and its fossilised remains represent the most complete carcharodontosaurid specimen found to date in the Southern Hemisphere.

The giant, South American predatory dinosaur Giganotosaurus which featured in the latest instalment of the “Jurassic Park/Jurassic World” movie franchise is just one of a poorly known group of theropod dinosaurs that were the apex predators in many terrestrial environments during the Cretaceous. Although, most dinosaur fans can name many carcharodontosaurids, these meat-eaters remain enigmatic and most genera have been described based on fragmentary remains. All that has changed with the publication of a scientific paper describing Meraxes gigas from the Upper Cretaceous Huincul Formation of northern Patagonia (Argentina).

Meraxes gigas life reconstruction.
A life reconstruction of the giant carcharodontosaurid from Patagonia Meraxes gigas. Picture credit: Carlos Papolio.

A Giant Predator with Short Arms

Writing in the scientific journal “Current Biology” the researchers who include Juan Canale (Universidad Nacional de Río Negro, Argentina), suggest that M. gigas was around eleven metres long and weighed around four tonnes (estimated 4.26 tonnes). The skull bones, which represent one of the most complete large theropod skulls ever found, indicate a skull length of 1.27 metres, but its arms were disproportionately small. Like other Cretaceous apex predators, the tyrannosaurs and the abelisaurids, this dinosaur had very short arms. Arms so short that they could not reach its own mouth.

Lead author Juan Canale commented:

“I’m convinced that those proportionally tiny arms had some sort of function. The skeleton shows large muscle insertions and fully developed pectoral girdles, so the arm had strong muscles. They may have used the arms for reproductive behaviour such as holding the female during mating or support themselves to stand back up after a break or a fall.”

Meraxes gigas fossil bones and skeleton.
Meraxes gigas MMCh-PV 65 and skeleton reconstruction. The white materials represent known bones. Meraxes is the most complete carcharodontosaurid yet from the Southern Hemisphere. Picture credit: Canale et al.

The fossils found in Huincul Formation exposures (late Cenomanian to Turonian) in Las Campanas Canyon some 14 miles southwest of Villa El Chocón, (Neuquén Province, Argentina), also include an almost complete right arm (j, in the image above). This limb, one of the most complete of any derived carcharodontosaurid described to date, is comparatively short and provides evidence to support the idea that many carcharodontosaurids had reduced forelimbs similar to those observed in abelisaurids such as Carnotaurus and most famously in Tyrannosaurus rex.

The researchers propose that forelimb reduction among three lineages of large-bodied predators is an example of convergent evolution, whereby not closely related organisms evolve the same traits. The fossils of Meraxes gigas show a remarkable degree of parallelism between latest-diverging tyrannosaurids and carcharodontosaurids.

Meraxes gigas limb bones.
Articulated right arm in medial view (I to III, hand digits first to third) top right and left foot in medial view (I to IV, pedal digits first to fourth) bottom Scale bars = 10 cm. Picture credit: Canale et al.

Helping to Define the Size of Giganotosaurus (G. carolinii)

Meraxes has the most complete cranium of any Carcharodontosaurinae, with a total skull length estimated at 1.27 metres which is comparable to the most complete specimen of Acrocanthosaurus (A. atokensis) with a skull size of 1.23 metres. Giganotosaurus has the next most complete skull among carcharodontosaurids, but it is missing part of the maxilla and several other bones, so estimating its total length has been problematical. Although the head of Meraxes was not as wide as the head of Giganotosaurus, the cranium of Meraxes is sufficiently similar to G. carolinii to permit an estimate for the length of the Giganotosaurus skull to be made. Based on this comparison, the skull of the largest Giganotosaurus specimen would have been around 1.62 metres long, making it one of the longest theropod skulls known to science.

Meraxes gigas Timeline
Cladogram depicting the temporal and geographical distribution of the Carcharodontosauridae family of theropod dinosaurs. At the time of their extinction these meat-eating dinosaurs seem to have been at their peak diversity. Picture credit: Canale et al.

The discovery of yet another super-sized carcharodontosaurid from Argentina demonstrates the high diversity of these theropods shortly before their extinction. Parallels can be drawn between the diversity of South American carcharodontosaurids and tyrannosaurs known from the Campanian faunal stage in western North America.

There are no reliable records of carcharodontosaurids in South America beyond the end of the Turonian stage of the Late Cretaceous, this great clade of theropods are believed to have become extinct around 90 million years ago.

To read a related article about another South American theropod with reduced forelimbs and fingers like a T. rex: Gualicho Sticks Two Fingers up at T. rex.

What’s in a Name

The genus name (Meraxes) is named after a female dragon from the Song of Ice and Fire series of books by George R. R. Martin, upon which the hugely successful television series “Game of Thrones” was based. The species name (gigas) comes from the Greek meaning giant.

The scientific paper: “New giant carnivorous dinosaur reveals convergent evolutionary trends in theropod arm reduction” by Juan I. Canale, Sebastián Apesteguía, Pablo A. Gallina, Jonathan Mitchell, Nathan D. Smith, Thomas M. Cullen, Akiko Shinya, Alejandro Haluza, Federico A. Gianechini and Peter J. Makovicky published in Current Biology.

6 07, 2022

Cold Climate Allowed the Dinosaurs and Pterosaurs to Thrive

By |2023-02-07T09:46:59+00:00July 6th, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Palaeontological articles|0 Comments

Scientists propose that cold snaps killed off the competitors of the dinosaurs and pterosaurs at the end of the Triassic opening the door for a dinosaur dominated Jurassic. The researchers propose that dinosaurs and pterosaurs with their integumentary coverings including primitive feathers, were insulated from the cold, whereas many other types of reptile co-existing with them just had scales. It was the body coverings that permitted the Dinosauria and the Pterosauria to thrive in cold conditions, whereas many of the other reptiles became extinct.

Compsognathus illustration by Chuang Zhao.
A beautiful feathered Compsognathus catches its lunch (artwork by Chuang Zhao). Fossil evidence suggests that many types of dinosaur were feathered, there is also growing evidence to suggest that pterosaurs too had insulating coats. A new theory proposes that these insulating coverings helped the Dinosauria and the Pterosauria to endure cold climates the onset of which led to a mass extinction event.

Ice-rafted Debris Discovered in Lakebed Deposits

The research team which included Paul Olsen, lead author of the study (Lamont-Doherty Earth Observatory at Columbia University), examined sandstone and siltstone formations formed in lakebeds in China’s Junggar Basin. These deposits are Upper Triassic in age and at this time this part of China had a palaeolatitude of around 71 degrees north. It was well above the Arctic Circle. Footprints found by the researchers indicate the presence of dinosaurs. In addition, the lake sediments contained abundant small pebbles, and it was concluded that these pebbles represent ice-rafted debris deposits.

Late Triassic Pangaea and location of known dinosaur fossils.
Map of Pangaea in the Late Triassic. The Junggar Basin is highlighted in red. Silhouettes show location and type of dinosaur known. Most dinosaurs were confined to higher latitudes and f signifies the presence of dinosaur tracks indicating their presence in the palaeoenvironment of the Junggar Basin. Picture credit: Olsen et al.

The Small Pebbles are Significant

The numerous small pebbles found amongst the fine siltstones and sandstones were probably deposited by melting blocks of ice. The research team, who included scientists from the Chinese Academy of Sciences, suggest that in the winter when the lake waters froze over, pebbles were picked up by the ice from the rocky lake shores. As the warm weather returned, the ice sheets would melt and chunks of ice would float away over the lake, gradually melting and as they did, they would drop the pebbles and other material.

Survival of the Fluffiest

The ice-rafted debris suggest freezing winters endured by dinosaurs. Around 201.6 million years ago, extensive volcanism which ejected millions of tonnes of debris into the Earth’s atmosphere lowered light levels and led to global climate change. Our planet endured a prolonged period of cold.

The cold decimated all medium-to large-sized non-dinosaurian, non-insulated continental reptiles. As they were adapted to cold climates, the Dinosauria and their cousins the Pterosauria were well placed to dominate terrestrial habitats as world temperatures plummeted.

Dinosaurs and pterosaurs had an advantage in the End-Triassic extinction event.
The scientists concluded that many large reptiles that lacked thermal insulation that would have been provided by an integumentary covering died out during the End-Triassic extinction event. In contrast, pterosaurs and dinosaurs with their insulating coats were able to cope much better and survived this extinction event. The unoccupied niches in the ecosystem were soon filled as these archosaurs diversified in the Early Jurassic. Picture credit: Olsen et al.

Cold Climate

Lead author of the study Paul Olsen commented:

“They were [dinosaurs and pterosaurs] fundamentally cold-adapted animals. When it got cold everywhere, they were ready, and other animals were not.”

To read an article about integumentary coverings in the Pterosauria: Branching Feathers and Melanosomes Identified in a Pterosaur Fossil.

The scientific paper: “Arctic ice and the ecological rise of the dinosaurs” by Paul Olsen, Jingeng Sha, Yanan Fang, Clara Chang, Jessica H. Whiteside, Sean Kinney, Hans-Dieter Sues, Dennis Kent, Morgan Schaller and Vivi Vajda published in Science Advances.

3 07, 2022

Robust Roo from Papua New Guinea

By |2023-04-25T06:39:05+01:00July 3rd, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Scientists have described a new genus of robust kangaroo from fossils found in late Pleistocene deposits in Papua New Guinea. Analysis suggests that it was not closely related to kangaroos found today in Australia.

Protemnodon nombe

Researchers from Flinders University examined two partial dentaries (lower jaw bones) that had been previously assigned to the Protemnodon genus and named P. nombe. They identified unique characteristics in the teeth and the shape of the bones that led them to conclude that the fossils were sufficiently different from other Protemnodon material to be assigned their own genus. The ancient kangaroo has been named Nombe nombe honouring the Nombe Rockshelter where the fossils were discovered.

Nombe nombe life reconstruction.
A life reconstruction of the prehistoric kangaroo Nombe nombe. Standing around 1.5 metres tall and weighing up to 60 kilograms, the thick dentary and strong teeth indicate Nombe evolved to eat tough leaves in the dense jungle landscape. Picture credit: Peter Schouten.

A New Guinea/Australia Land Bridge

During the Miocene Epoch, around 5-8 million years ago, lower global sea levels permitted a land bridge between Australia and Papua New Guinea to form. This led to a faunal interchange between the two regions. An ancient form of Australian kangaroo migrated northwards and entered the territory now known as Papua New Guinea. When sea levels rose and the Torres Strait was formed, these ancient kangaroos were able to evolve in isolation away from their Australian ancestors.

Nombe nombe dentaries.
Nombe nombe lower jaw bones. Holotype and referred specimen of Nombe nombe: holotype (PNG/82/40/23) partial right dentary in (a) buccal/lateral view, (b) lingual/medial view and (c) lower dentition in occlusal/dorsal view; (d) referred specimen (PM/82/40/19) partial left dentary in buccal/lateral view. Picture credit: Kerr and Prideaux.

A Robust Kangaroo

Co-author of the scientific paper published in the Transactions of the Royal Society of South Australia, PhD student Isaac Kerr commented:

“The New Guinean fauna is fascinating, but very few Australians have much of an idea of what’s actually there.”

Co-author of the paper, Professor Gavin Prideaux (Flinders University), explained that excavations at the Nombe Rockshelter and elsewhere in central Papua New Guinea are providing palaeontologists with evidence of a unique ecosystem on the island, a biota dominated by prehistoric marsupials that were adapted to their mountainous, tropical environment. Flinders University hopes to be able to undertake more extensive fieldwork over the next three years and they are confident that these excavations will unearth new species.

Prehistoric Papua New Guinea
Life in the late Pleistocene on Papua New Guinea. The megafauna was dominated by extinct species of kangaroo and giant four-legged marsupials called diprotodontids, which in turn were hunted by Thylacines. Picture credit: Peter Schouten.

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

The scientific paper: “A new genus of fossil kangaroo from late Pleistocene New Guinea” by Isaac A. R. Kerr and Gavin J. Prideaux published in the Transactions of the Royal Society of South Australia.

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2 07, 2022

A New Book “Travels with Trilobites” by Andy Secher

By |2024-04-13T08:07:04+01:00July 2nd, 2022|Categories: Adobe CS5, Book Reviews, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

We got sent a copy of the amazing “Travels with Trilobites” by world-renowned expert on the Trilobita Andy Secher. What a fantastic book! Trilobites are regarded by many scientists as being one of the most successful animals to have ever existed and their fossils are absolutely fascinating as well as stunningly beautiful. We can’t wait to read and then review this superbly illustrated guide to all things Trilobita!

Holding the "Travels with Trilobites" book.
Very excited to receive a copy of “Travels with Trilobites” by Andy Secher (field associate in palaeontology at the American Museum of Natural History – New York).

Published by Columbia University Press

Published by Columbia University Press the book includes forewards by Mark Norell, Kirk Johnson and Niles Eldredge. There are over 25,000 described species of trilobites and although entirely marine (as far as we know), they evolved into a myriad of forms. Many of the beautiful, full-colour photographs in the book show fossils from the author’s own extensive collection.

Front cover of "Travels with Trilobites".
The front cover of the beautifully illustrated “Travels with Trilobites” by Andy Secher published by Columbia University Press. It is an adventure in Palaeozoic marine fauna.

Andy Secher is a field associate in palaeontology at the prestigious American Museum of Natural History (New York). His own private collection comprises more than 4,000 trilobite specimens. The book provides the opportunity to explore one of the most enigmatic marine creatures of the Palaeozoic Era.

Team members at Everything Dinosaur are going to enjoy reading and then reviewing this wonderful book.

To purchase “Travels with Trilobites” by Andy Secher, visit the Columbia University Press website and search for Andy Secher: Visit Columbia University Website.

30 06, 2022

Tetrapodophis Revised – It’s Not a Snake

By |2025-01-07T20:23:55+00:00June 30th, 2022|Categories: Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

The Early Cretaceous Tetrapodophis amplectus, once thought to represent an early limbed snake, was not a snake after all, but a member of the Dolichosauridae. The fossil is not a missing link between lizards and snakes but an aquatic lizard. That was the conclusion in a paper published late last year (2021) and today we take a look at this remarkable and highly controversial fossil specimen.

Tetrapodophis life reconstruction.

A life reconstruction of Tetrapodophis amplectus gliding through cover as it stalks fish close to the shore. New research suggests that this Early Cretaceous reptile is not a transitional form between a lizard and a snake, but instead it is a dolichosaurid. Picture credit: Julius Csotonyi.

Picture credit: Julius Csotonyi

A Transitional Fossil

Palaeontologists had long hoped to find a transitional fossil showing a lizard-like animal with vestigial limbs, an evolutionary link in the evolution of snakes from a limbed ancestor. Tetrapodophis was named in 2015, when a scientific paper was published describing a remarkable fossil from Brazil that had been spotted quite by chance by scientists on a visit to a German museum.

To read Everything Dinosaur’s 2015 article about the T. amplectus scientific paper: Fossil Snake with Four Limbs Described.

Had Tetrapodophis been revealed to be an ancestral snake then this would have had very significant implications for our understanding of the evolution of the Squamata. However, in November 2021 a scientific paper was published in the “Journal of Systematic Palaeontology” which concluded that the fossil had been misidentified. The research team from the University of Alberta, Harvard University, Flinders University (South Australia), the University of Toronto, Midwestern University and the Universidad Maimónides (Buenos Aires, Argentina), examined the counter slab and concluded that the fossil skull impression did not demonstrate characteristics typically seen in snake skulls.

Tetrapodophis fossil.

A beautifully preserved specimen once thought to represent an early, limbed snake but now thought to be a marine lizard related to snakes and modern lizards. Picture credit: Dr Dave Martill/University of Portsmouth with additional annotation by Everything Dinosaur.

Picture credit: Dr Dave Martill/University of Portsmouth with additional annotation by Everything Dinosaur

University of Alberta palaeontologist Michael Caldwell, who led the study commented:

“When the rock containing the specimen was split and it was discovered, the skeleton and skull ended up on opposite sides of the slab, with a natural mould preserving the shape of each on the opposite side. The original study only described the skull and overlooked the natural mould, which preserved several features that make it clear that Tetrapodophis did not have the skull of a snake — not even of a primitive one.”

Tetrapodophis Illustrated

In the original 2015 scientific description, Tetrapodophis was thought to be an ancestral snake. The tiny limbs were thought to have been used to hold prey. Scientists were uncertain whether this animal was a burrower or adapted to a marine environment. It has now been assigned to the Dolichosauridae. Picture credit: Julius Csotonyi.

Picture credit: Julius Csotonyi

Squamata Evolution Remains Ambiguous

The evolution of the Order Squamata remains ambiguous. It is thought that the first, basal squamates evolved during the Middle Triassic, but when the first true snakes evolved is uncertain. The 2021 paper examining the skull impression in the counter slab confirmed that Tetrapodophis lacked typical snake skull characteristics. The spine was also shown to lack typical snake-like anatomical traits.

The fossil record for the Squamata is particularly sparse. Primitive snake and lizard skeletons are usually small with delicate bones that are easily dispersed post-mortem. Palaeontologists hope that more fossils will be found that help to clarify the evolutionary origins of snakes.

A Controversial Fossil

Tetrapodophis amplectus may not represent a snake with four legs, transitional fossils remain elusive, it still has immense scientific value. Co-author of the 2021 paper, Tiago Simões (Harvard University) explained:

“One of the greatest challenges of studying Tetrapodophis is that it is one of the smallest fossil squamates ever found. It is comparable to the smallest squamates alive today that also have reduced limbs.”

The fossil specimen remains controversial. The fossil, originally from Brazil may have been exported without the appropriate permits. It was part of a private collection and the authorities in Brazil only became aware of the fossil’s existence when the 2015 paper was published.

Tetrapodophis

To read an article about the legal dispute: Fossil Slithers into Legal Dispute.

Everything Dinosaur acknowledges the assistance of media releases from Flinders University and the University of Alberta in the compilation of this article.

The scientific paper: “Tetrapodophis amplectus is not a snake: Reassessment of the osteology, phylogeny and functional morphology of an Early Cretaceous dolichosaurid lizard” by M. W. Caldwell, T. R. Simões, A. Palcid, F. F. Garberoglio, R. R. Reisz, M. S. Y. Lee and R. L. Nydam published in the Journal of Systematic Palaeontology (November 2021).

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