All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
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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.

4 08, 2018

CollectA Dimorphodon Model Wins Award

By | August 4th, 2018|Dinosaur Fans, Everything Dinosaur Products, Main Page, Photos of Everything Dinosaur Products|0 Comments

Award Winning CollectA Deluxe Dimorphodon

The CollectA Supreme Deluxe Dimorphodon model has been voted by readers of Prehistoric Times magazine the best non-dinosaur prehistoric animal toy of 2017.  This prestigious award recognises the efforts of CollectA to bring larger models to the market, the Dimorphodon measures nearly forty centimetres in length and as such, provides an accurate scale model of one of the first Pterosaurs to be scientifically described.

The Award Winning CollectA Supreme Deluxe Dimorphodon Figure

CollectA Dimorphodon pterosaur model.

The CollectA Dimorphodon model with a movable lower jaw.

Picture Credit: Everything Dinosaur

The CollectA Dimorphodon and other models in the Deluxe range can be found on Everything Dinosaur’s website here: CollectA Deluxe Prehistoric Life Models

Early Jurassic Flying Reptile

Dimorphodon was the first Pterosaur fossil from the British Isles to be scientifically described, the first specimen was discovered by the world-famous, amateur fossil hunter Mary Anning.  The fossil, which was missing the skull, was found on the Dorset coast in 1828.  Prior to the scientific description of Dimorphodon, only two species of Pterosaur had been studied, both of which came from the Solnhofen limestone deposits of southern Germany.  When first described, this flying reptile was named Pterodactylus macronyx.  Pterodactylus was the first flying reptile genus to be erected.  It was later discovered that the Dorset specimens had very different shaped heads compared to those fossils associated with the Pterodactylus genus, a new genus name for the fossil was proposed by the English anatomist Richard Owen (1858).

A Scale Drawing of D. macronyx

Dimorphodon scale drawing.

A scale drawing of Dimorphodon macronyx.

Picture Credit: Everything Dinosaur

Long Claws on the Forelimbs

The species name “macronyx” refers to the large claws on the forelimbs.  It has been suggested that this flying reptile favoured inland habitats and it lived in woodland, the long claws would have helped it to scramble up trees.   The long stiff tail may have been involved in flight stability.  The wingspan of D. macronyx was approximately 1.4 metres, about the same size as the wings of today’s Raven (Corvus corax).

The CollectA Supreme Deluxe Dimorphodon Model

CollectA catalogue 2017.

The CollectA 2017 catalogue featured the Dimorphodon model on the front cover.

Picture Credit: Everything Dinosaur

A spokesperson from Everything Dinosaur commented:

“We are so pleased for all the team at CollectA.  It is great to hear that their Deluxe Dimorphodon figure has been awarded this accolade.  We look forward to hearing news about what plans the company has for prehistoric animal figures in the future.”

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.

2 08, 2018

A “Spikyosaurus”

By | August 2nd, 2018|General Teaching, Key Stage 1/2|Comments Off on A “Spikyosaurus”

A Colourful Dinosaur Drawing

Our thanks to young dinosaur fan Neve, who after attending one of our family friendly dinosaur and fossil workshops, was inspired to send in to us a drawing of their very own design for a dinosaur.  Neve even gave this prehistoric animal a name, this very colourful dinosaur is called “Spikyosaurus”.

A Very Bright, Colourful and Spiky Dinosaur Drawing

A very spiky dinosaur drawing.

Say hello to “Spikyosaurus”, a dinosaur designed and drawn by Neve.

Picture Credit: Everything Dinosaur

Armoured Dinosaurs

Palaeontologists are aware that there were lots of armoured dinosaurs.  The first armoured dinosaurs evolved in the Early Jurassic.  These plant-eaters were distinguished by the presence of bony scales on their backs and flanks.  These dinosaurs evolved from the Ornithischian line (bird-hipped dinosaurs).  Armour probably evolved in herbivorous dinosaurs to provide protection against the rapidly evolving carnivorous dinosaurs.  The last of the armoured dinosaurs died out at the very end of the Cretaceous.

Can your children or class name animals alive today that have armour?

Our thanks to Neve for sending in such a colourful and well-described dinosaur drawing.

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.

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