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

14 08, 2018

Toothy, Pterosaur Terror from the Saints and Sinners Quarry

By | August 14th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Caelestiventus hanseni – Rare Pterosaur Fossil Sheds Light on Triassic Pterosaur Diversity

A team of scientists have published a paper in the journal “Nature Ecology & Evolution”, detailing the discovery of a new type of Triassic pterosaur.  The exquisitely preserved fossils, including skull and jaw material excavated from strata laid down at a desert oasis that existed around 210 million years ago, has got vertebrate palaeontologists in a flap.  Firstly, only around thirty fossils of Triassic pterosaurs are known, most of these from only fragmentary remains and secondly, as this flying reptile fossil is associated with a desert environment, it suggests that by the Late Triassic the Pterosauria were very specious and had already adapted to a variety of different habitats.  If all this wasn’t enough to get scientists excited, the exceptional state of preservation has revealed anatomical features previously obscured in other early pterosaurs and shows that this new flying reptile from Utah, was closely related to Dimorphodon macronyx which is known from Lower Jurassic rocks from Dorset (southern England).

The flying reptile was large, very large for a Triassic Pterosaur, it had an estimated wingspan of 1.5 metres.  It has been named Caelestiventus hanseni (pronounced Sel-less-tees-vent-us han-son-eye).

A Life Restoration of the Newly Described Late Triassic Pterosaur Caelestiventus hanseni

Caelestiventus hanseni illustration.

Caelestiventus hanseni illustration. Study of the fossil bones suggests the presence of a throat pouch.

Picture Credit: Michael Skrepnick

From Saints and Sinners Quarry (Utah)

The fossils come from a vertebrate bone bed located in the Saints and Sinners Quarry, within sandstone deposits in north-eastern Utah.  Numerous vertebrate fossils have been associated with this locality including Crocodylomorphs and Theropod dinosaur material.  The bones come from silty, fine-grained sandstones laid down in near-shore waters of an oasis, that was surrounded by arid desert.  More than 18,000 individual bones representing a total of nine Tetrapod taxa (including two Theropod dinosaurs), have been found.  The flying reptile bones described in the scientific paper are the only ones known from this deposit and Caelestiventus hanseni is the first Triassic pterosaur from the western hemisphere from outside Greenland.  Whether this flying reptile was a resident of the oasis is unclear, but it is possible that this individual was an occasional visitor, to what would have been, an isolated oasis surrounded by extensive dune fields.

One of the Delicate Skull and Jaw Fossils Held by Professor Brooks Britt (Brigham Young University)

Holding fossils of Caelestiventus hanseni.

Professor Brooks Britt (Brigham Young University) holds one of the pterosaur fossils (jaw and skull fossils). His finger is pointing to roughly where the eye socket would have been.

Picture Credit: Brigham Young University

The picture above, shows a prepared piece of the fossilised skull of C. hanseni (maxilla and other elements from the jaws and skull), the specimen is held by Professor Brooks Britt of Brigham Young University and the lead author of the scientific paper.  It is not possible to remove the delicate, three-dimensional fossils from the matrix, the fossils would collapse under their own weight, but CT scans in conjunction with computer modelling enabled the production of precise plastic replicas of the fossil pieces, that gave the researchers the opportunity to reconstruct the skull.

Related to Dimorphodon (D. macronyx)

The beautiful state of preservation enabled the research team to gain fresh insights into the morphology of skull and jaws of Late Triassic pterosaurs.  The reconstructed brain case reveals that those parts of the brain responsible for processing vision were particularly well-developed, reinforcing the theory that flying reptiles had very keen eyesight.

A phylogenetic analysis undertaken by the researchers reveals that Caelestiventus is a sister taxon of Dimorphodon macronyx, which is known from Lower Jurassic rocks from Dorset.

A Three-Dimensionally Printed Skull of Caelestiventus hanseni

Line drawings and three dimensional model.

C. hanseni model skull and line drawing comparisons between C. hanseni and D. macronyx.

Picture Credit: Brigham Young University with additional annotation by Everything Dinosaur

The use of CT scans and computer software to digitally remove the fossils from their matrix without damaging them has enabled the scientists to produce extremely accurate three-dimensional images of the specimen, these data files can then be shared with other vertebrate specialists across the world.

A spokesperson from Everything Dinosaur commented:

“The scans permitted the production of finely detailed and extremely accurate three-dimensional models of the individual bones.  When these were fitted together this gave the scientists the opportunity to study the entire skull and to share this information very easily with other palaeontologists.  The use of technology is now helping scientists to gain much easier access to important fossil finds.”

The Geographical Significance of Caelestiventus hanseni

Not only is Caelestiventus hanseni the first record of a Triassic pterosaur from North America, the discovery suggests that by the Late Triassic, flying reptiles were not only quite large but also that they may have already adapted to a wide variety of habitats.  Similarly aged fossils from Greenland and Europe indicate pterosaurs living in forested areas and coastal environments on the super- continent of Pangaea.  This fossil discovery demonstrates that early pterosaurs were geographically widely distributed and ecologically diverse, even living in harsh desert environments.  C. hanseni is the only record of a desert-dwelling, non-pterodactyloid pterosaur and predates all known desert living pterosaurs by more than sixty-five million years.

The Geographical Significance of the Utah Pterosaur Fossil Discovery

The geographical location of the pterosaur find.

The location of the Triassic pterosaur find from Utah plotted against a map of Pangaea during the Late Triassic and other pterosaur fossil discoveries from Triassic strata.

Picture Credit: Brigham Young University

The picture above shows (top left), the location of Utah in the United States and (insert), the geological formations associated with north-western Utah.  The world map shows the location of Triassic pterosaur fossil discoveries superimposed on an illustration of Pangaea with a colour key to indicate different habitats.  Caelestiventus is the first Triassic pterosaur identified from a desert environment.

The genus name is from the Latin for “heavenly wind”, in recognition of the volant capabilities of this reptile.  The trivial name honours geologist Robin L. Hanson of the Bureau of Land Management, who has played a crucial role in the excavation of the Saints and Sinners Quarry material.

Photographs Showing Some of the Fossil Material Associated with the Caelestiventus Genus

Caelestiventus hanseni fossil material.

Views of the Pterosaur fossil material – Caelestiventus hanseni.

Picture Credit: Brigham Young University

To read Everything Dinosaur’s 2015 article that first broke the news of this Pterosaur fossil discovery: Fearsomely-fanged Triassic Pterosaur from Utah

13 08, 2018

Rare Silurian Fossil “Worm” from a Herefordshire Hotspot

By | August 13th, 2018|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A New Species of Lobopodian from Herefordshire

A team of international researchers including scientists from the Oxford University Natural History Museum, Imperial College London, Manchester and Leicester Universities and the Yale Peabody Museum of Natural History, have identified a new species of lobopodian, a bizarre segmented worm-like creature, in 430 million-year-old rocks in Herefordshire (England).  Digital technology has been utilised to reconstruct a three-dimensional model of this exceptional fossil, an ancient ancestor of the modern, enigmatic Velvet worm.

The Research Team Produced Three-dimensional Images of the Fossil Lobopodian

Thanahita distos - digital reconstruction.

Three-dimensional digital images of the fossil lobopodian from Herefordshire.

Picture Credit: University of Leicester

Soft-bodied, Worm-like Creatures with Legs

Lead author of the study, Derek Siveter, (Professor Emeritus of Earth Sciences at Oxford University and Honorary Research Associate at Oxford University Museum of Natural History), commented:

“Lobopodians are extremely rare in the fossil record, except in the Cambrian Period.  Worm-like creatures with legs, they are an ancestral marine relative of modern-day velvet worms, or onychophorans – predators that live in vegetation, mainly in southern latitudes.”

The Velvet Worm (Peripatus Genus)

Velvet worm - Peripatus.

Peripatus a genus within the  Onychophora – creatures like this may have been the first to walk on land.

Picture Credit: BBC

The Evolution of the Arthropods

Palaeontologists have puzzled for decades over the evolution of groups of modern animals such as the Arthropoda, the largest phylum of animals which includes the trilobites, insects, crustaceans, spiders, scorpions, mites and so forth.  Studies of the exotic Ediacaran and Cambrian biota has helped scientists to better understand the evolutionary relationships between living groups of animals today and their ancient invertebrate ancestors, but many soft-bodied groups are severely underrepresented in the fossil record.  It is still extremely difficult to pin down which type of organism preserved within the remarkable Cambrian-aged Burgess Shale deposits for example, is an ancestor of modern groups of animals alive today.  This newly described fossil specimen, named Thanahita distos represents an example of a member of the Lobopodia, an extremely ancient group of invertebrates that might be a basal member of the Panarthropods – a clade that includes today’s Arthropods, as well as Velvet Worms (Onychophora) and the Water Bears (Tardigrades).

The Silurian-aged deposits in Herefordshire, consist of finely grained volcanic ash layers that settled on a seabed some 430 to 425 million years ago.  These sediments have preserved in exquisite detail many of the marine organisms that roamed across the sea floor.  Writing in the Royal Society Open Science journal, the researchers describe T. distos and note that it is the first lobopodian to be formally described from rocks from the Silurian and it is one of only eight known three-dimensionally preserved lobopodian or onychophoran fossil specimens known to science.

Professor Siveter explained how the team were able to build up a picture of the ancient sea creature:

“We have been able to digitally reconstruct the creature using a technique called physical-optical tomography.  This involves taking images of the fossil at a fraction of a millimetre apart, then “stitching” together the images to form a “virtual fossil” that can be investigated on screen.”

Herefordshire Lagerstätte

The Herefordshire Lagerstätte has provided scientists with numerous exceptionally preserved invertebrate fossils.   Everything Dinosaur has reported on several of these, very significant fossil discoveries on this blog, including one Herefordshire fossil which was named in honour of Sir David Attenborough:

Silurian Fossil Discovery Honours Sir David Attenborough

Professor Siveter outlined how delicate creatures like Thanahita distos became preserved, he stated:

“Thanahita distos and the other animals that became fossilised here likely lived 100 to 200 metres down, possibly below the depth to which much light penetrates.  We deduce this because we found no vestiges of photosynthetic algae, which are common in contemporaneous rocks laid down at shallower points on the seafloor to the east.  Some special circumstances allowed for their remarkable preservation.  The first was the immediate precipitation of clay minerals around the dead organisms, which decayed over time, leaving empty spaces behind.  The mineral calcite – a form of calcium carbonate – then filled these natural moulds, replicating the shape of the animals.  Almost at the same time, hard concretions began to form, being cemented by calcite.  Thanks to the early hardening of these Silurian time capsules in this way, the fossils were not squashed as the ash layer slowly compacted.”

Related to the Enigmatic Hallucigenia

A phylogenetic analysis undertaken by the researchers placed T. distos, together with all the described Hallucigenia species, in a sister-clade to crown-group the Panarthropods.  Its placement in a redefined Hallucigeniidae, an iconic Cambrian clade, indicates the survival of these types of creatures into Silurian times.

The Newly Described Thanahita distos is Placed Within the Enigmatic Hallucigeniidae

An illustration of Hallucigenia.

Scientists have classified the newly described T. distos as a relative of the bizarre Cambrian Hallucigenia from the Burgess Shale of British Columbia.

Picture Credit: Danielle Dufault

The professor added:

“Some lobopodians lie in a position on the tree of life which foreshadows that of the terrestrial velvet worms, while others are precursors of the arthropods: the “king crabs”, spiders, crustaceans and related forms.  Since its discovery, the Herefordshire Lagerstätte has yielded a diversity of arthropods that have contributed much to our understanding of the palaeobiology and early history of this very important invertebrate group.  The lobopodian Thanahita distos belongs to an extended, Panarthropod grouping.”

The discovery of the Herefordshire specimen and its subsequent phylogenetic analysis indicates that the lobopodian group, which is associated with Late Cambrian strata, persisted into the Silurian, thus demonstrating that these creatures survived for at least 100 million years.

A Fossil of Hallucigenia Specimen from the Late Cambrian Rocks of British Columbia

A Hallucigenia specimen (Burgess Shale).

A Hallucigenia specimen (Royal Ontario Museum) from the Late Cambrian deposits of British Columbia.  The red arrow is highlighting a droplet-like structure, once thought to represent the head but now regarded as probable gut contents.

Picture Credit: Royal Ontario Museum/Dr Jean Bernard Caron

The scientific paper: “A Three-dimensionally Preserved Lobopodian from the Herefordshire (Silurian) Lagerstätte, UK” by Derek J. Siveter, Derek E. G. Briggs, David J. Siveter, Mark D. Sutton and David Legg published by the Royal Society Open Science

12 08, 2018

In Praise of “Meg”

By | August 12th, 2018|Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Everything Dinosaur Products, Everything Dinosaur videos, Main Page, Movie Reviews and Movie News, Photos of Everything Dinosaur Products|0 Comments

Megalodon Makes it to the Big Screen

This weekend sees the opening of the summer blockbuster “Meg”, a prehistoric shark-based action movie featuring Jason Statham and a twenty-five-metre-long representation of Carcharocles megalodon – Megalodon, an extinct species of prehistoric shark, so famous that it is just known by its specific or trivial name.  With the film likely to make in excess of £30 million in box office receipts on just its opening weekend in the USA, the movie, which incidentally is the most expensive shark film ever made (estimated budget of around $130 million USD), is likely to be a runaway box office success.  However, this iconic marine monster is well and truly extinct, it really is “safe to enter the water” to borrow a strapline from perhaps, the best-known and best-loved shark movie of them all, the 1975 “Jaws”.

Warner Bros and director Jon Turteltaub may have resurrected Megalodon, but most palaeontologists will confidently tell you that, what was probably the largest carnivorous shark to have existed, died out around 2.6 million years ago.

When those talented people as Safari Ltd introduced a “Megalodon” model back in 2014, Everything Dinosaur put together a short video introduction to the model.

Everything Dinosaur’s Video Review of the Wild Safari Dinos Megalodon Model

Video Credit: Everything Dinosaur

We may have lacked the budget of the movie and unfortunately, we were unable to afford the services of Jason Statham, but our six minute video review set out to explain a little more about the science behind this prehistoric shark and to provide a guide to the Wild Safari Prehistoric World Megalodon model.

Carcharocles megalodon

Many marine biologists had believed that Carcharocles megalodon was closely related to the modern Great White Shark – Carcharodon carcharias (hence Everything Dinosaur’s original research into finding a suitable Megalodon model).  However, recent studies suggest that it was actually a member of another sub-branch of the Lamniformes Order and that Megalodon was a member of the Otodontidae family and not a member of the Lamnidae family as previously thought.  It may have had a similar lifestyle and habit to the Great White Shark and it was much bigger and heavier, but it was unlikely to have been around twenty-five metres in length, the size of Megalodon in the movie.

A Still from the Motion Picture “Meg”

Meglaodon from the movie "Meg".

A still from the 2018 summer blockbuster “Meg”.

Picture Credit: Warner Bros

A spokesperson from Everything Dinosaur commented:

“If these giant, prehistoric sharks were still around today, then, as we suspect they were shallow water specialists living in the top two hundred metres of water, the upper portions of the epipelagic zone of the ocean, then they certainly would have been spotted by now.  The “Meg” is very much extinct and we are sure that the film will provide plenty of thrills and spills for cinema goers.  Perhaps, it will also raise awareness amongst its audience about the plight of many shark species today.  Over fishing, habitat loss and pollution are having a devastating effect on global shark populations.  It has been estimated that some 100 million sharks die each year, with luck this movie will raise awareness about shark species conservation.”

The Jaws of Megalodon

Megalodon jaws.

Reconstructed jaws of a Megalodon shark (human gives scale).

Picture Credit: Rex Features

Safari Ltd have produced an excellent replica of this prehistoric shark, to view the model and the rest of the amazing figures in the Wild Safari Dinos Prehistoric World collection: Safari Ltd. Wild Safari Prehistoric World

The Wild Safari Prehistoric World Megalodon Figure 

Wild Safari Prehistoric World Megalodon model.

Fearsome C. megalodon

Picture Credit: Everything Dinosaur

8 08, 2018

Did Alaskan Therizinosaurs and Hadrosaurs Live Together?

By | August 8th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Scientists Describe Therizinosaur and Hadrosaur Tracks from Alaska

A team of international scientists have published a report on a series of dinosaur trackways found in Upper Cretaceous rocks located in Denali National Park, Alaska.  The tracks show the presence of duck-billed dinosaurs (Hadrosaurs) and bizarre herbivorous Theropods (Therizinosaurs), in the same location at potentially the same time.  If this is the case, then it could be speculated that these very different dinosaurs benefited from an association, just as some animals today congregate together for mutual benefit.

The Hadrosaur and Therizinosaur trackways represent the first report from North America of co-occurrence between these very different dinosaurs and the trace fossils support the idea that the dinosaur population in Alaska in the Late Cretaceous was similar in composition to that associated with Asia (Nemegt Formation).  Alaska could have been a “highway” linking the dinosaur faunas of Asia with the North American continent.

Did Therizinosaurs and Hadrosaurs Live Side by Side?

Hadrosaur and Therizinosaur Tracks Found Together

A series of Hadrosaur and Therizinosaur tracks have been discovered together in the Denali National Park of Alaska.

Picture Credit: Masato Hattori

It Started with a Single Footprint

The lower Cantwell Formation represents a series of sedimentary deposits laid down in a terrestrial environment and fossil pollen analysis suggests a Late Campanian to early Maastrichtian temporal setting (73-71 million years ago).  Numerous vertebrate and plant fossils are associated with this strata, vertebrates including fishes, pterosaurs and numerous dinosaurs.  Lead author of the paper, published in the journal “Scientific Reports”, Anthony Fiorillo, (Perot Museum of Nature and Science, Dallas, Texas), had previously described a single four-toed print found in the area back in 2012.  This track was identified as having been made by a Therizinosaur and was the first evidence found of these strange Theropods living at such high latitudes.

To read more about the 2012 fossil discovery: Potential Therizinosaur Track Discovered in Alaska

The discovery of a single fossil leaf, resembling that of a waterlily from the same site as the Therizinosaur and Hadrosaur trackways suggest the prints were made by dinosaurs as they crossed a shallow body of water away from the main river channels.  During the Late Cretaceous this part of North America was a vast wetland habitat.

A Photograph and Line Drawing of the Waterlily Fossil

Photograph (a) and line drawing (b) of nymphaceous leaf found in study area. This plant is indicative of standing water.

A fossil of a waterlily leaf found in Upper Cretaceous rocks of Alaska.  Photograph (a) and line drawing (b) of nymphaceous leaf found in study area.  This plant is indicative of a body of standing water.

Picture Credit: Scientific Reports

A More Detailed and Thorough Mapping of the Area

A field team returned to this location in 2013 and 2014 an mapped a series of dinosaur tracks, unearthing dozens more four-toed tracks that were identified as Therizinosaur prints.  The researchers were surprised to discover that the Therizinosaur tracks seem to co-occur with lots of tracks indicating herds of Hadrosaurs.

Commenting on the significance of these trace fossils, Dr Fiorillo stated:

“Hadrosaurs are very common and found all over Denali National Park.  Previously, they had not been found alongside Therizinosaurs in Denali.  In Mongolia, where Therizinosaurs are best known, though no footprints have been found in association, skeletons of Hadrosaurs and Therizinosaurs have been found to co-occur from a single rock unit so this was a highly unusual find in Alaska and it prompted my interest.”

A Photograph and Accompanying Diagram Showing Some of the Associated Trace Fossils

The co-occurrence of Therizinosaur and Hadrosaur tracks (Alaska).

A photograph of a large block within the study area showing the co-occurrence of Hadrosaur and Therizinosaur tracks.

Picture Credit: Scientific Reports

The picture above (a) shows a large block of stone representing a single bedding plane with two distinctive trackways highlighted (note the geology hammer, closest to the uppermost yellow circle that provides scale).  Diagram (b) illustrates the two types of trackway found, yellow prints and circles indicate Therizinosaur, whilst blue prints and circles indicate trace fossils made by Hadrosaurs.

The scientists deduced that from the range of sizes of the Hadrosaur tracks (pes prints), these trace fossils represented groups of duck-billed dinosaurs of different ages, with younger animals associating with larger, fully-grown adults.

A Highway Linking North America to Alaska – A Dinosaur Driveway

The scientists state that this co-occurrence of Therizinosaurs and hadrosaurids at this single locality within the lower Cantwell Formation has not been documented elsewhere in North America.  This dinosaur co-occurrence is more characteristic of dinosaur biota associated with contemporaneous rocks found in central Asia.  The team speculate that the Alaska of the Late Cretaceous represented a gateway for faunal exchange between the two continental landmasses.  The existence of a Cretaceous Beringian land bridge prompted this mixing of faunas, which was encouraged as similar habitats were present within continental North America and Asia.

Co-author of the scientific paper, Dr Yoshitsugu Kobayashi (Hokkaido University Museum, Japan), reaffirmed the team’s conclusion stating:

“This study helps support the idea that Alaska was the gateway for dinosaurs as they migrated between Asia and North America.”

A Fondness for Marshland?

A report from Asia has commented on the presence of both Therizinosaurs and hadrosaurids at the same location.  Fossils of both these types of dinosaur being found in the same strata, in a sequence of sediments that indicate the palaeoenvironment was very wet at the time, relative to the sequence of rocks deposited above and below the fossil layer.  The authors of this newly published study, suggest that Therizinosaurs and Hadrosaurs liked to live in wetter locations, such as marshland.

Did Therizinosaurs and Hadrosaurs Co-exist?

It is possible the tracks were made at different times and the these two different types of herbivorous dinosaur did not interact.  However, given the similarity of track preservation, the research team conclude that it is likely that these two taxa occupied the same environment at the same time, but why would two dinosaurs want to hang out together?

There are probably a number of reasons for this co-existence with one group of dinosaurs at least tolerating the presence of another megaherbivore, two possibilities are speculated upon within the scientific paper and summarised below:

  1. Not competing with each other for food – the teeth and jaws of hadrosaurids and Therizinosaurs are very different.  The two herbivores probably fed on different types of plant food and therefore they were not in direct competition with each other for food.
  2. Mutual protection/spotting predators – studies have suggested that Therizinosaurs had excellent hearing and a well-developed sense of smell, their long necks gave them an excellent field of view.  Although, an excellent sense of smell has been proposed for at least some duck-billed dinosaurs (Lambeosaurinae), re-evaluation of the nasal cavities of some Hadrosaurs has suggest that their sense of smell was not that remarkable.  It is tempting to consider the differences in sensory adaptations and capabilities in these taxa that might have served a role as a mutually beneficial predatory avoidance mechanism for the more inclusive herd.  Zebras and ostriches are often found feeding together, the sharp, colour vision of the ostrich compliments the zebra’s better developed sense of smell, helping to detect the approach of predators, thus benefiting all the grazing animals.

Examples of Mutual Association (Extinct and Extant)

Mutual association in herbivores.

Zebras and ostriches benefit from the presence of each other when it comes to sensing predators.  Perhaps, duck-billed dinosaurs and Therizinosaurs had a similar mutually beneficial relationship.

Picture Credit: Everything Dinosaur

Although the scientists speculate on the reasons why these plant-eaters might have associated, they suggest it is more likely that Therizinosaurs and Hadrosaurs gathered together simply because they preferred the same habitat.

6 08, 2018

What Did the Long-necked Plesiosaurs Use Their Necks For?

By | August 6th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Nichollssaura borealis – Shaking its Neck from Side to Side

The long-necked Plesiosaurs (Plesiosauroidea), are characterised (unsurprisingly), by their long necks, which in the case of the elasmosaurids were taken to extremes with some Late Cretaceous species having necks around seven metres in length, comprising 76 cervical vertebrae, but how did these marine reptiles use their necks?  What degree of movement did these long necks have?  These are questions that have been debated by palaeontologists for nearly two hundred years.

New research, published this week by the Royal Society, sheds light on the flexibility and neck movement in one Plesiosaur, the Early Cretaceous leptocleidid Nichollssaura borealis.

The Fossilised Skeleton of Nichollssaura borealis (TMP 1994.122.0001)

Nichollssaura borealis type specimen.

Superbly preserved Plesiosaurus fossil – the type specimen of Nichollssaura borealis in dorsal view.

Picture Credit: Everything Dinosaur/Royal Tyrrell Museum (Drumheller))

Defining the Plesiosauria Clade

The Plesiosauria clade was very successful, originating in the Triassic and persisting until the very end of the Cretaceous.  This clade is split into three distinct groups, although palaeontologists debate the phylogeny between the Plesiosauria clade members.

  1. The Plesiosauroidea – the long-necked marine reptiles, epitomised by short tails, broad bodies, four flippers, a small head and an elongated neck.
  2. The Pliosauridae – the short-necked Plesiosaurs, with large heads, broad bodies, four flippers and much shorter necks than the Plesiosauroidea.
  3. The Rhomaleosauridae – a sort of half-way house between the other two, typically possessing longer necks and smaller heads relative to the Pliosauridae, but have shorter necks and larger heads when compared to members of the Plesiosauridae.  Most known rhomaleosaurids are confined to the Early to Middle Jurassic of Europe, with most specimens assigned to this group having been found in England.

The Three Groups Within the Plesiosauria

The Plesiosauroidea illustrated

The three groups that make up the Plesiosauroidea.  The long-necked Plesiosauroidea, the short-necked Pliosauridae and the Rhomaleosauridae.

Picture Credit: Everything Dinosaur

Studying One Member of the Plesiosauroidea – Nichollssaura borealis

The researchers from the Royal Tyrrell Museum and the University of Calgary, focused their study upon one specimen, a member of the Plesiosauroidea called Nichollssaura borealis.  This specimen was chosen as it represents a very nearly complete individual and the fossil is not distorted or crushed to any degree which might have comprised any research into neck flexibility.  There were two further, more practical reasons why N. borealis was selected.  Firstly, the specimen is housed at the Royal Tyrrell Museum and since one of the researchers involved in the study was Donald Henderson, a curator at the museum, accessing the specimen was not a problem.  In addition, with a total length of 2.6 metres Nichollssaura could squeeze into the medical CT scanner that was being used to create accurate three-dimensional images of the bones.

Once the specimen had been CT scanned, the subsequent three-dimensional models that were produced could be examined so as to conclude the range of movement afforded by the 24 bones in the neck of this Plesiosaur (24 cervical vertebrae).

The Research Team Tested the Range of Neck Movement Using Three-Dimensional Models

The range of neck movement in Examining the range of motion of Nichollssaura borealis.

Examining the range of motion of Nichollssaura.

Picture Credit: Royal Society Open Science

Sideways Movement of the Neck

When the three dimensional models of the Nichollssaura borealis neck were examined the scientists discovered that the neck of this Plesiosaur was indeed very mobile, but their results suggest a preference for lateral (sideways) movements of the neck in this species.  This supports the idea that these marine reptiles fed in or along the seafloor, using their small heads and long necks to probe into the sediment to find invertebrates and fish.  Unfortunately, no gut contents indicating potential prey have been preserved in association with the single fossil specimen of Nichollssaura, however, other researchers have found prey gut contents in other plesiosaurids that supports the idea that these animals fed by disturbing and catching animals that live on the sea floor (epifaunal).

To test the validity of the three-dimensional computer models, the scientists studied the range of neck movement in a extant species of monitor lizard, Dumeril’s monitor, a species from south-east Asia (Varanus dumerilii).  This species was chosen as it has a relatively long neck for a monitor lizard and a preserved specimen was available for study.

The researchers conclude that if this species of plesiosaurid (N. borealis) had a neck that was adapted to rapid sideways movements then this probably evolved in relation to feeding method and prey capture.  Different types of Plesiosauroidea with their different neck lengths very likely had different ecological roles within the ecosystem.  This study also demonstrates that three-dimensional modelling is an effective tool for assessing function morphology for structures where no good, living analogue for comparison exists.

5 08, 2018

Dorset Dinosaur Tracks Discovered

By | August 5th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Sauropod Trackways Discovered in Dorset

Scientists have been measuring and mapping a set of dinosaur tracks found in a quarry in Dorset.  The saucer-shaped tracks were made by a herd of long-necked Sauropod dinosaurs that crossed a stretch of a tidal lagoon back in the Early Cretaceous.  The quarry is located close to the village of Worth Matravers, around three-and-a half-miles east of the coastal town of Swanage, on the Isle of Purbeck.

A View (Dorsal) of a Dinosaur Footprint (Sauropoda)

Sauropod fossil footprint (Dorset).

Dorsal view of one of the dinosaur footprints (Sauropoda).

Picture Credit: Bournemouth University

Giant Dinosaur Footprints

The group of large dinosaurs were walking slowly in a herd, leaving a series of parallel trackways.  They have been described as “giant saucer-shaped depressions just a few millimetres deep”, according to geologist Matthew Bennett from Bournemouth University who has been called in to study and map the fossilised tracks.

The quarry is the property of Lewis Quarries, one of a number in the area that provide valuable limestone blocks for the construction industry.

An Aerial View of the Dinosaur Tracks

Dorset Dinosaur Footprint Quarry Site (Sauropoda).

An aerial view of the Dorset dinosaur footprint site.

Picture Credit: Bournemouth University

The footprints were made between 139 and 145 million years ago (Early Cretaceous), the tracks were infilled by lime rich muds, creating trace fossils.

David Moodie, a spokesperson for Lewis Quarries explained:

“It became apparent that we had come across something of historical interest, so working closely with the National Trust and Professor Matthew Bennett of Bournemouth University, we were able to move forward in the best way without stopping progress in the quarry itself.”

National Trust Lead Ranger Jonathan Kershaw added:

“The group of dinosaurs that made these tracks may be the same ones whose footprints can still be seen in situ just nearby at Keates Quarry just off the Priest’s Way bridleway.  It’s exciting to think that giant Sauropods once roamed where today there are dry stone walls, skylarks and nesting seabirds.”

An Illustration of the Sauropods Crossing the Shallow Lagoon

Sauropod illustration.

Sauropod illustration – Sauropods crossing a shallow lagoon.

Picture Credit: Bournemouth University

In 2015, Everything Dinosaur reported on the discovery of a series of Sauropod footprints and tracks on the Isle of Skye.  These tracks were made in similar circumstances as the Purbeck limestone prints, a group of Sauropods crossed a shallow lagoon, however, the Isle of Skye prints are around thirty million years older and date from the Middle Jurassic.

To read more about the Sauropod prints from the Isle of Skye: Isle of Skye Sauropods and their Watery World

DigTrace Maps the Fossil Footprints

Using a process of photogrammetry and special freeware developed at Bournemouth University called DigTrace, Professor Bennett carefully documented the tracks in three dimensions.  The DigTrace technology was developed with a government grant and help from the Home Office and National Crime Agency.  Its principle aim is to forensically examine footprints and other tracks related to crime scenes, however, it is ideal for plotting the movements of extinct dinosaurs too.

Professor Bennett commented:

“This technology is now being used by the police to help track criminals via their footprints, but we can also use it to record and preserve rare footprints like these.  The beauty of capturing the tracks in 3D is that they can be analysed digitally and even printed in the future, no need to hold up the quarrying for long.”

Drawing Up a Conservation Plan for the Dinosaur Tracks

With the co-operation of Lewis Quarries and in collaboration with the National Trust and researchers at Bournemouth University, a conservation plan is being prepared.  It is hoped that the tracks will be lifted from their setting and put on public display once all the appropriate scientific steps (pardon the pun), have been taken.

The trackway surface is also exposed in nearby Keates Quarry where the National Trust maintains a small conservation area of similar tracks.

Professor Bennett concluded:

“What is remarkable, is that the tracks at both adjacent quarries were probably made by the same animals moving along the coast.  The dip of the beds, folded when the European Alps were pushed up, means that the tracks are closer to the ground in Keates Quarry and can be preserved but are much deeper at Lewis Quarries where in situ preservation is not possible.”

The Dig Site at the Dorset Quarry

The Dorset Sauropod dinosaur trackway.

The Sauropod trackway site (Purbeck limestone).

Picture Credit: Everything Dinosaur

Everything Dinosaur acknowledges the assistance of the media centre at Bournemouth University for the compilation of this article.

3 08, 2018

Modern Shark Diversity Strongly Influenced by Cretaceous Extinction Event

By | August 3rd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Study Suggests Shift from Lamniform to Carcharhiniform Dominated Shark Populations

The Cretaceous mass extinction event saw the demise of the non-avian dinosaurs on land, but in the seas there was a massive faunal turnover too.  For example, many of the marine reptiles became extinct.  However, sharks seem to have come through the K-Pg extinction event largely unscathed, but a new study, published in the journal “Current Biology” suggests a subtle change in the diversity of shark species, a change that is reflected in extant shark species today.

The researchers, which include scientists from Uppsala University (Sweden) and the University of New England (Australia), examined hundreds of fossilised shark teeth across the Cretaceous through to the Palaeogene and their study concludes that modern shark biodiversity was triggered by the mass extinction event that took place approximately 66 million years ago.

A Late Cretaceous (Maastrichtian) Marine Faunal Assemblage

A Maastrichtian marine faunal assemblage.

A Late Cretaceous sea scene.

Picture Credit: Julius Csotonyi

Hell’s Aquarium

The Upper Cretaceous marine deposits of Kansas have provided palaeontologists with an insight into the number of large predators that inhabited the sea during the last few million years of the Mesozoic.  There were numerous types of Mosasaur, such as Hainosaurus which was as long as Tyrannosaurus rex.  In addition, you had enormous marine turtles as well as the elasmosaurids, giant Plesiosaurs that measured up to fifteen metres in length.  Then you have the fish, brutes like Xiphactinus (zie-fak-tin-us) with a mouth lined with needle-sharp teeth and the sharks, lots of species, some of which were apex predators, such as Squalicorax and Cretoxyrhina.

Hell’s Aquarium – Many Different Types of Predator in Late Cretaceous Seas

Western Interior Seaway.

Typical Western Interior Seaway marine life.

Picture Credit: Everything Dinosaur

Carcharhiniformes and Lamniformes – Two Different Types of Shark

Today, there are two major groups of predatory sharks.  Firstly, there are the Carcharhiniformes, otherwise called “ground sharks”, typically represented by species such as the dangerous bull and tiger sharks, as well as the enigmatic hammerhead shark and closer to home, the lesser spotted dogfish (Scyliorhinus canicula) which is resident in British waters.  There are around 270 extant species within this clade.

Secondly, there are the  Lamniformes, or the “mackerel sharks” which has around fifteen species and includes the great white, mako and another resident of British waters, the Porbeagle shark (Lamna nasus).  Back in the Cretaceous, things were very different, the Lamniform sharks, in particular, a diverse group of great-white-like sharks, members of the family Anacoracidae, were much more numerous.  The fearsome Squalicorax was an anacoracid and therefore along with Cretoxyrhina, members of the Lamniformes clade.

Lead author of the study, PhD student at Uppsala University, Mohamad Bazzi stated:

“Our study found that the shift from Lamniform to Carcharhiniform-dominated assemblages may well have been the result of the end-Cretaceous mass extinction.  Unlike other vertebrates, the cartilaginous skeletons of sharks do not easily fossilise and so our knowledge of these fishes is largely limited to the thousands of isolated teeth they shed throughout their lives.  Fortunately, shark teeth can tell us a lot about their biology, including information about diet, which can shed light on the mechanisms behind their extinction and survival.”

Fossil Shark Teeth

fossilised shark teeth.

A successful fossil hunt.  Shark teeth study reveals shift from Lamniform to Carcharhiniform dominated shark populations.

Picture Credit: Everything Dinosaur

Cutting-edge Analytical Techniques

The researchers used state-of-the-art analytical techniques to explore the variation of tooth shape in Carcharhiniformes and Lamniformes and measured diversity by calculating the range of morphological variation, also called disparity.

Dr Nicolás Campione, (University of New England), a co-author of the study added:

“Going into this study, we knew that sharks underwent important losses in species richness across the extinction.  But to our surprise, we found virtually no change in disparity across this major transition.  This suggests to us that species richness and disparity may have been decoupled across this interval.”

A More Complex Picture

Despite this seemingly stable pattern, the study found that extinction and survival patterns were substantially more complex.  Morphologically, there were differential responses to extinction between Lamniform and Carcharhiniform sharks, with evidence for a selective extinction of Lamniformes and a subsequent proliferation of Carcharhiniformes in the immediate aftermath of the extinction.

Student Bazzi explained:

“Carcharhiniforms are the most common shark group today and it would seem that the initial steps towards this dominance started approximately 66 million years ago.”

Although the reasons for the shift in shark species are not that clear, the researchers hypothesise that the extinction of various types of prey such as the marine reptiles and ammonites may have played a significant role.  In addition, it is likely that the loss of apex predators (such as Lamniformes and marine reptiles) benefited secondary predator sharks, a role fulfilled by many Carcharhiniforms.

Dr. Campione concluded:

“By studying their teeth, we are able to get a glimpse at the lives of sharks and by understanding the mechanisms that have shaped their evolution in the past, perhaps we can provide some insights into how to mitigate further losses in current ecosystems.”

2 08, 2018

Do It Yourself Taphonomy

By | August 2nd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Scientists Learn to Make Fossils in 24-hours

Fossils help us to learn about life in the past and palaeontologists study fossils.  Fossils can form in a variety of conditions, but scientists have discovered a new way to mimic key fossilisation processes in the laboratory.  What might have taken tens of thousands, or even millions of years can be replicated in around twenty-four hours.  Taphonomy is the branch of palaeontology that deals with the fossilisation process.  Taphonomy involves studying how organisms become fossilised.  Scientists have been  able to build up a better picture about how the fossilisation process works.  Perhaps, more importantly, this new research paints a picture about what kinds of materials can become fossils, from feathers and scales to tiny molecules like proteins and which materials can’t.

Writing in the journal of the Palaeontological Association “Palaeontology”, the researchers, which include scientists from the Field Museum of Chicago and Bristol University, found a way to improve simulations of the fossilisation process with modern-day animal and plant specimens.

The Scientists Mimicked the Fossilisation Process

A "baked" lizard foot fossil produced in a laboratory.

A laboratory made fossil of a lizard’s foot.

Picture Credit: The Field Museum (Chicago)

Lead author, Evan Saitta, a PhD student at the Field Museum, explained:

“Palaeontologists study fossils.  We interpret them to learn about the evolution and biology of extinct animals,  but the fossil record yields data that can be hard to interpret.  For us to answer our questions, we need to understand how fossils form.  The approach we use to simulate fossilisation saves us from having to run a seventy-million-year-long experiment.”

Working Backwards

Palaeontologists can learn about the fossilisation process by finding fossils and then chemically analysing them.  However, these researchers worked backwards, finding a way to simulate the fossilisation process and then studying the materials that survived the heat and pressure used to create the fossil in the first place.

Bird feathers, lizard limbs and leaves were put into a hydraulic press to pack them into clay tablets, just a few millimetres in diameter.  These tablets were baked in a sealed metal tube inside a laboratory oven heated to over 400 degrees Fahrenheit and at 3,500 psi pressure.  After a day, the tablets were examined and they produced specimens that are reminiscent of fossils that take millennia to make.

Student, Evan Saitta stated:

“We kept arguing over who would get to split open the tablets to reveal the specimens.  They looked like real fossils, there were dark films of skin and scales, the bones became browned.  Even by eye, they looked right.”

At the Start of the Fossilisation Process

Death of the dinosaurs.

By learning more about the fossilisation process, scientists can learn more about fossils.

Picture Credit: Mark Garlick/Science Photo Library

Easy Bake Fossils

The laboratory-made “fossils” were examined under a scanning electron microscope.  The researchers could identify exposed melanosomes, the structures that contain the biomolecule melanin that gives feathers and skin their colour.  Less stable materials such as proteins and fatty tissues did not show up in the laboratory specimens, these materials are usually absent from fossils found in the field too.

Evan Saitta added:

“Our experimental method is like a cheat sheet.  If we use this to find out what kinds of biomolecules can withstand the pressure and heat of fossilisation, then we know what to look for in real fossils.”

This is not the first attempt to mimic the fossilisation process under artificial conditions, but as one of the authors of the scientific paper explained “I think we are the first ones to get it pretty darn close”.

Previous experimental attempts to cook up fossils in sealed tubes didn’t work because the unstable biomolecules that naturally break down, leak out, and disappear during fossilisation, but in these experiments, these materials stayed trapped.  With this new method, the breakdown products remain entombed within the artificial sediment.

The Implications for the Study of Dinosaurs

The researchers are excited by the possibilities that their new experimental method unlocks.  Exceptional dinosaur fossils don’t just contain hard materials like bones and teeth, soft tissues can be preserved too.  These often carbonaceous films provide important data, so it is important to understand how these materials are preserved.

Learning How to Simulate Fossil Production Can Improve Our Understanding of Taphonomy

Melanosome fossils study.

This new study can help with interpreting soft tissue preservation in feathered dinosaur fossils.

Picture Credit: Li et al

Everything Dinosaur recognises the contribution of a press release from the Field Museum (Chicago) in the compilation of this article.

1 08, 2018

How Did We Get Our Bones?

By | August 1st, 2018|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Tracing the Origins of the Vertebrate Skeleton

Our skeleton is very special, the evolution of a rigid internal skeleton (bones), was an extremely significant development in the history of life on Earth.  However, how hard, internal skeletons evolved has been the subject of much debate amongst palaeontologists.  However, thanks to research undertaken by scientists at Manchester and Bristol Universities in collaboration with the technicians at a synchrotron light source based in Switzerland, we might have a better understanding of how we came to be.

All living vertebrates have skeletons built from four different tissue types: bone and cartilage (the main tissues that human skeletons are made from), and dentine and enamel (the tissues from which our teeth are constructed).  These tissues are unique because they become mineralised as they develop, giving the skeleton strength and rigidity.

Primitive fish were the first to develop a mineralised skeleton and one group of early fishes, the Heterostracans, has attracted a lot of interest from scientists as they try to work out the evolutionary processes that took place.  The Heterostracans, were a group of heavily armoured, jawless fishes that evolved during the Early Silurian.  These fish, which are mostly associated with marine and estuarine deposits, had two plates, one on the top of the body and one underneath, they served to help protect the animal from attack and might have had a secondary function to help keep the body stiffened.  These fish also had large scales on their bodies too.

A “Swimming Table Tennis Paddle” –  A Life Restoration of Drepanaspis – An Early Devonian Heterostracan

Drepanaspis life reconstruction.

A life reconstruction of Drepanaspis a typical Heterostracan fish.

Picture Credit: Everything Dinosaur

The Primitive Bone-like Tissue Aspidin

Earlier research had identified that the surface scales and broad plates of these primitive fishes had enamel-like tops over a core of dentine, essentially the same material that forms our teeth.  Supporting these structures was a layer of sponge-like material called aspidin.  Aspidin is bone in its earliest mineralised form.  It is thought that the very first basal, internal skeleton provided an anchor to support the armour that was on the outside of the body.  In this new study, the scientists used synchrotron X-ray tomographic microscopy to reveal the nature of aspidin.

Lead author of the paper, published in the journal “Nature Ecology & Evolution”, Dr Joseph Keating (Manchester University), explained:

“Heterostracan skeletons are made of a really strange tissue called “aspidin”.  It is crisscrossed by tiny tubes and does not closely resemble any of the tissues found in vertebrates today.  For 160 years, scientists have wondered if aspidin is a transitional stage in the evolution of mineralised tissues.”

Errivaspis – A Member of the Heterostraci from the Early Devonian

Errivaspis - primitive fish.

Errivaspis – anterior portion of fossil, from the Early Devonian.

Picture Credit: Keating et al

Ruling Out Other Theories

Scientists had been aware of the spongy nature of aspidin.  However, they were unable to work out what might have filled the pores and spaces in the material, using traditional methods of study.  Knowing what filled these unmineralised spaces would provide the information needed to help demonstrate the role that aspidin played in the evolution of back-boned animals.

Four theories regarding what filled these spaces had been put forward:

  1. The spaces housed cells, like the osteoblasts and osteocytes that are found in living bones.
  2. The spaces were filled with fibres made from proteins such as collagen.
  3. The spaces were filled with dentine.
  4. The spaces were filled with a mixture of dentine and bone.

The team showed that these “gaps” in the aspidin represented the location of bundles of collagen (2).  These “gaps” housed the same sort of protein that is found in our skin and bones (in fact collagen is the most abundant type of protein found in our bodies).

These findings enabled Dr Keating to rule out all but one theory for the tissue’s identity, proving that aspidin is the earliest evidence of bone in the fossil record.

Co-author of the study, Professor Phil Donoghue (University of Bristol), who has done much to reveal the true anatomical nature of the Heterostracans, stated:

“These findings change our view on the evolution of the skeleton.  Aspidin was once thought to be the precursor of vertebrate mineralised tissues.  We show that it is, in fact, a type of bone, and that all these tissues must have evolved millions of years earlier.”

The team suggest that the collagen bundles form a scaffold which permits minerals to be deposited.  Aspidin is acellular dermal bone, so one question is answered but it gives rise to a host of others.  For example, if all the skeletal tissue types associated with vertebrates were present in the Heterostracans, then these structures and materials must have evolved earlier than expected.

The scientific paper: “The Nature of Aspidin and the Evolutionary Origin of Bone” by J. Keating, C. Marquart and P. Donoghue published in Nature Ecology & Evolution.

29 07, 2018

Gharial Evolution – A Fishy Business

By | July 29th, 2018|Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

Convergent Evolution Thoracosaurs and Gharials

Crocodylians are a very ancient group of reptiles, sometimes these animals are referred to as living dinosaurs, that’s a mistake, they may be Archosaurs, the same as the Dinosauria, but they represent a different branch of the “ruling reptiles” clade.  However, just as with the dinosaurs, the ancient lineage of the crocodylians is full of intriguing taxonomic mysteries.  Back in 2017, Everything Dinosaur reported upon a new scientific paper that fundamentally re-wrote the dinosaur family tree, in recent weeks, a new scientific study has thrown light on the evolution of the gharials, specialist fish-eating crocodylians.  This new research into the gharials may not result in such a seismic shift that we saw with the 2017 dinosaur family tree, but it does help to explain an inconsistency that has puzzled palaeontologists for decades.

A Gharial (Gavialis gangeticus)

A Gharial.

An extant Gharial, note the long thin jaw lined with conical teeth, ideal for catching fish.

Picture Credit: Everything Dinosaur

The Thoracosaur Mystery

Late Cretaceous, long-snouted, fish-eating crocodiles known as Thoracosaurs had been thought to be closely related to modern-day gharials (Gavialis lineage).  However, fossils of these crocodylians are found in Upper Cretaceous/Lower Palaeocene strata, but analysis of the genome of the modern Indian gharial suggests that these crocodiles only evolved some forty million years ago.  In a new study, led by Flinders University (South Australia), it is concluded that the Thoracosaurus is not closely related to the Gavialidae, it just happens to look very similar and to share the same adaptations for life as a piscivore.

A Life Reconstruction of the Late Cretaceous Crocodylian Thoracosaurus

Thoracosaurus life reconstruction.

A life reconstruction of the fish-eating Thoracosaurus.

Picture Credit: Jacob Baardse

The Four-metre-long Thoracosaurus

Two species of Thoracosaurus have been described, one from North America with a second species known from Europe.  This freshwater crocodile could have grown to a length of four metres or more.  Writing in the journal “Proceedings of the Royal Society Biology”, a team of international scientists propose that the uncanny resemblance between the modern gharial and the ancient Thoracosaurus is due to convergent evolution, the process whereby two unrelated organisms end up looking similar as they adapt to similar environments and ecological niches.

The study shows that the prehistoric Thoracosaurs, that were around at the same time as the last of the dinosaurs, were not closely related to modern gharials at all.  They represent a separate and distinct group of reptiles that adopted a similar fish-eating habit, evolving long, narrow jaws with needle-like teeth, anatomical traits they share with gharials.  Therefore, as borne out by the DNA of modern-day gharials, members of the Gavialidae are relatively newcomers when it comes to crocodylian evolutionary history.  Gharials did not exist in the Mesozoic.

The Fossilised Skull and Upper Jaw of Thoracosaurus (Cast)

The skull of Thoracosaurus.

A cast of the fossilised skull and upper jaw of Thoracosaurus.

Picture Credit: Michael Lee (Flinders University and South Australia Museum

Confusion Over the Indian Gharial and the False Gharial

The False gharial of south-east Asia (Tomistoma schlegelii), has a similar long snout to the Indian gharial, however, as it is broader at the base it was thought that this species was not closely related to the true gharial.  However, genomic studies have revealed that it is the sister taxon and consequently, very closely related to Gavialis gangeticus. Many biologists now classify this species as a member of the Gavialidae.

Lead author of the study, Professor Michael Lee (Flinders University), commented:

“The DNA of living gharials indicates they are a young group, which evolved well after the dinosaurs, but then why are there gharial-like fossils older than T. rex?  Either the DNA evidence is wrong, or we’ve misinterpreted these ancient Thoracosaurs.  Our work suggests we have got the fossils wrong, after being misled by convergent evolution.”

The scientific paper:
“Tip Dating and Homoplasy: Reconciling the Shallow Molecular Divergences of Modern Gharials with their Long Fossil Record” by MSY Lee and AM Yates and published in Proceedings: Biological Sciences:

Everything Dinosaur’s article on the reassessment of the Dinosauria: Root and Branch Reform for the Dinosaur Family Tree

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