Dinosaur Nesting Site May Have Yielded Ancient Organic Material

A dinosaur nesting site that has been dated to the Early Jurassic is providing a team of international scientists with an unprecedented insight into the growth and development of baby dinosaurs.  A scientific paper, published in the academic journal “Nature” and the cover story of this publication’s latest edition, also states that the research team may have discovered traces of organic remains.  If this is the case and the fossils have not been contaminated by more recent organic material, then this discovery marks the earliest known organic remains of a terrestrial vertebrate.

New Research into Baby Dinosaurs

New research into 190-million-year-old baby dinosaurs.

Picture credit: D Mazierski

The fossil site was discovered by Timothy Huang of the National Chung Hsing University (China) when he was exploring an area of Lower Jurassic aged strata in Yunnan Province (south-western China).  His preliminary investigations led to the discovery of a monotaxic bone bed (an extensive amount of fossil material all assigned to the same species).  The fossils consist of the remains of dinosaur embryos at various stages of development along with the remains of dinosaur egg shell.  The strata represents a dinosaur nesting site.

Fossilised Dinosaur Embryos

Fossilised dinosaur embryos are extremely rare in the fossil record.  The oldest known until the Chinese discovery, are believed to represent the Early Jurassic sauropodomorph of the genus Massospondylus, these fossils were discovered in South Africa, back in 1976.  The South African fossil material was kept in storage for many decades and detailed research into these embryos and their ontogeny (growth rates) was published in 2010.

To read the Massospondylus article: Cracking the Mysteries of the Dinosaur Egg.

The Chinese embryos represent another type of sauropodomorph.  The joint Canadian/Chinese scientific team have assigned these beautifully preserved fossil remains to the genus Lufengosaurus.  This Early Jurassic dinosaur, closely related to the European Plateosaurus of the earlier Triassic Period, is known from more than twenty fossils of individuals. All these fossils have been found in the same geological formation as the newly discovered nesting site (Lufeng Formation).  Lufengosaurus, was a herbivorous dinosaur which may have reached lengths in excess of eight metres.  It was probably one of the largest dinosaurs living in this part of the world in the Early Jurassic (190-197 million years ago).

An Illustration of an Adult Lufengosaurus

Early Jurassic sauropodomorph.

Picture credit: Everything Dinosaur

Studying Two Hundred Embryonic Fossil Bones

The initial investigation of the bone bed by Timothy, yielded more than two hundred embryonic fossil bones.  Realising the significance of his discovery he invited Dr Robert Reisz who had worked on the South African embryo fossils to investigate.  Dr Reisz and his team (University of Toronto), working with Chinese colleagues quickly identified that the fossils did not represent a single nest but a number of broods of young, with many at different stages of embryonic development.  This has permitted the team to study the growth and development of a single dinosaur species in great detail.

By comparing the femurs (thigh bones) of baby dinosaurs of different ages the team were able to suggest that these dinosaurs maintained a consistent and rapid rate of growth and development.  For example, the thigh bones of these dinosaurs more than doubled in size whilst still in the egg.  The team’s findings also indicate that sauropodomorphs  had very short incubation times – the embryos grew quickly and hatched fast.

A Stained Cross Section of Embryonic Thigh Bone with Large Pore Spaces Indicating Rapid Growth

This stained sample of a thin cross section of femur suggests rapid growth.

Picture credit: A. Leblanc

Archosaur Hatching Data

Chickens hatch in about three weeks, whereas crocodile eggs hatch after approximately one hundred days.  The largest living lizard today, the Komodo dragon (Varanus komodoensis) has a much longer incubation period – over eight months.  In addition, tiny muscle scars on the miniature bones indicate that the muscles of these herbivorous dinosaurs were well developed.  This suggests that just like modern birds, baby dinosaurs moved around a lot inside their eggs.  Highly active muscles before hatching suggests that these dinosaurs were far from helpless when they hatched.

It is not known whether these Sauropodomorphs had a precocial habit, the babies being virtually independent from their parents at birth and able to fend for themselves.  Well developed muscles would have helped these young dinosaurs to escape from the nest, to avoid many potential predators and to start to find their own food.

The presence of such large numbers of fossil bones, free from the eggs in which they were formerly contained gave the researchers the opportunity to assess the growth rates of this type of dinosaur from a clade known for its gigantism.  However, the scientists also detected traces of organic remains in the fossil material, astonishing to think that such matter could have possibly survived for 190 million years or so.

Studying Arctic Camels

Back in March, we reported on a joint Canadian and British research project which examined the fossilised remains of prehistoric camels in the High Arctic, although the bone found was extremely fragmentary and represented a tibia (lower leg bone), the research team discovered evidence of collagen present in the fossil.  By extracting a portion of the preserved organic material, scientists from Manchester University were able to prepare a “collagen fingerprint” and when this data was compared to the collagen from extant mammals it was found that the fossil specimen most closely matched the collagen found in camels.  This test helped to confirm that the 3.5 million year old tibia bone was from a prehistoric camel that once roamed high latitudes.

To read about the camel research: Camels of the Arctic.

Dr Reisz and his co-workers claim to have discovered locked deep inside the fossilised bones, evidence of collagen fibres, the main protein constituent of bone.  Organic material usually decomposes very quickly and to find potential evidence of organic material in Early Jurassic vertebrate remains is simply “astonishing” according to some commentators.

The research team hope that they may be able to collect some of this organic material.

He stated:

“We are opening a new window into the lives of dinosaurs.  This is the first time we’ve been able to track the growth of embryonic dinosaurs as they have developed.  The bones of ancient animals are transformed to rock during the fossilisation process, so to find remnants of proteins in the embryos is really remarkable.  If we can extract the collagen, then we can compare it to collagen in living organisms for further studies.  Comparisons can be very valuable in evolutionary studies.”

The potential discovery of such ancient organic material in tiny, delicate fossilised bones of embryos, especially when one considers the porosity of bone material has been described by Dr. Reisz as “mind boggling”.

A “Collagen Fingerprint”

The team hope that if they are able to extract a sample, other researchers such as the University of Manchester research team who analysed the collagen sample from the prehistoric camel, might be able to create a “collagen fingerprint”.  This would allow the prehistoric protein to be compared to the collagen of living vertebrates, perhaps once and for all cementing a link between the Dinosauria and Aves (birds).

The implications for this discovery may indeed be far reaching.  If the remnants of collagen can be found in such an unusual fossil sample, then it might be more common in the fossil record than previously thought.  If small bones could have preserved 190 million year old organic material then much more collagen could be lurking inside other fossil specimens.  This could revolutionise our understanding of the taxonomy of extinct species.

As Dr Reisz commented:

“I suspect that if we start using this methodology elsewhere, we will find it [collagen] more frequently than we think.”

To view models and replicas of prehistoric animals: Prehistoric Animals and Dinosaur Models.

Shape of Melanosomes and Hence Plumage of Dinosaurs Questioned 

Over the last couple of years or so, a number of scientific institutions have published academic papers revealing evidence of melanosomes preserved in fossil specimens.   As the shape and structure of these microscopic fossil features can provide evidence of the pigmentation and colour of an organism, the geometry of these melanin-loaded specialised elements within a cell, effectively acts as a colour chart for the animal the fossils represent.

Feathered Microraptors – Still Uncertain Regarding Colouration

New research casts doubt over previous colour claims.

Picture credit: Everything Dinosaur

The Colour of Dinosaurs

Perhaps one of the most famous fossils of all, material ascribed to the Late Jurassic transitional bird/reptile fossil known as Archaeopteryx (Archaeopteryx lithographica) has had melanosome evidence presented.  In this case, a single feather preserved in the fine grained lithographic limestone of the area suggested that the tip of the feather may have been coloured black.  The research was carried out in 2012 and undertaken by a team from Yale University, Brown University, the Carl Zeiss Laboratory (Germany) and the University of Akron (Ohio, United States).

Using extremely high-powered microscopy, the international research team identified the colour of a single fossilised feather, very likely from an Archaeopteryx.  They concluded that the feather, most probably a wing feather was black at the tip.  Their conclusions were based on the geometry (shape) of the remains of melanosome structures that they had observed.

To read more about the Archaeopteryx research: Archaeopteryx – Back in the Black

The Colour of Archaeopteryx Feathers

However, the colour of Archaeopteryx or any other animal in the fossil record with preserved evidence of melanosomes is not quite as “black and white” as it seems.  A new paper, published in the scientific journal “Biology Letters” suggests that over millions of years, the shape and structure of the melanosomes can be distorted under heat and pressure and the fossilised shape may not have much of a resemblance to the structure of these pigmentation organelles when the organism was alive, and in the case of Archaeopteryx, flapping around.

Debate Likely to Continue over the Colour of Archaeopteryx

Debate likely to continue over the colour of Archaeopteryx.

To view models and replicas of Archaeopteryx and other prehistoric animals: Wild Safari Prehistoric World Replicas.

Melanosomes Providing a Guide

The theory about melanosomes providing a guide to the colour of an extinct animal is on the surface very simple, but the trick, as with most aspects of palaeontology is the analysis of the data.  Melanosomes contain melanin and these specialised cell structures are present in skin, hair and feather cells.  The colour of the melanosome relates to a specific pigment.

Although the fossilisation process may have degraded all signs of actual colour, the ghostly shapes of the melanosomes themselves are often visible using specific lighting and optical devices such as high powered electron microscopes.  The preserved size, layout and shape can give palaeontologists some suggestions about the original colour in the organism.

Maria McNamara et al (University of Bristol), have published a study which suggests that the properties of melanosomes preserved in such fossils as the remains of dinosaur feathers, could become distorted and therefore provide scientists with misleading clues as to the original colour.  Under Professor Mike Benton (University of Bristol), some of the initial research into the colour of feathered dinosaurs was undertaken.  Professor Benton, in collaboration with Chinese colleagues provided evidence of the first colouration of a member of the Dinosauria back in 2010, when it was announced that the cursorial Chinese Theropod Sinosauropteryx may have been ginger.

To read more about the potential colouration of dinosaurs: Ginger Dinosaurs?

Simulating the Fossilisation Process

Maria and her fellow researchers mimicked the fossilisation process of feathers by simulating burial by placing modern-day bird feathers into an autoclave and then subjecting them to temperatures in excess of 250 degrees Celsius.  The chamber which held the experiment, was pressurised to 250 atmospheres, the intense heat and extreme pressures would be similar to the forces applied to strata and the fossils within them over millions of years.

When the melanosomes were studied under high magnifcation, the structure and shape of many of them had changed.  In effect, they had become distorted and withered.  This could lead to misinterpretations of fossil material if the melanosomes found preserved were taken at face value.

Black Feathers?

Ryan Carney, a research scientist based at Brown University, one of the team members who worked on the Archaeopteryx case study, black feathers and all, commented that shrinkage had been taken into account when he and his co-workers prepared their Archaeopteryx paper.  Their black feather conclusion was based on observations made using hundreds of melanosome structures that the team studied under very high magnification.  Although, the melanosomes may shrink a little during the fossilisation process, their original shape can still be determined by examining an imprint left in the matrix by the organelle (organelle – specialised area of a cell with specific functions).

Referring to the Archaeopteryx study he stated:

“We found that the length and width of melanosomes were significantly smaller compared to those of the imprints, the shrinkage was actually quite similar to that of the McNamara et al experiment”.

McNamara and her team remain confident in the validity of their data and they have provided intriguing evidence which requires careful analysis in the light of the current research.  For example, another important conclusion from this research is that melanosomes survive the heat and pressure of fossilisation even after the destruction of other non-melanin colour traces such as carotenoids (organic pigments, responsible for example for the colour of carrots and apricots).  Carotenoids can create vivid shades of orange, green, yellow, red and blue in feathers, however, in the University of Bristol experiments the multi-coloured feathers tested gave results indicating that they were just black.  This was because their non-melanin organic pigments had been destroyed and only the melanosomes survived to give the false reading of black.

With this conclusion in mind, the discovery of melanosomes in a fossilised feather such as that from a 150 million year old specimen such as Archaeopteryx might not necessarily mean that the original feathers were coloured black, reddish or brown.

McNamara commented:

“The bottom line is that until we understand how the fossilisation process affects these colour-producing chemicals and structures, and until we know how to look for evidence of these in fossils, there’s really no point in attempting to reconstruct colour of feathers based on melanosomes alone.”

Being able to determine the colour of an extinct animal would be very helpful in trying to work out its behaviour or how it reacted to its environment.  Knowing the true colour of a Velociraptor for instance, would enable palaeontologists to assess how it camouflaged itself or used visual signals to communicate with other members of its kind.  If a number of fossil specimens of different aged individuals could be studied, scientists might be able to see how the colouration changed as the animal grew, what differences there may have been between males and females etc.

Examining a Highly Magnified Image Showing Melanosome Structures

Interpretation of melanosomes.

Picture Credit: Brown University

The Archaeopteryx study also led to some conclusions related to the development of avian flight.  The melanin in the wing feathers may not only have provided colouration but also helped to increased the strength of the feather, very helpful to have strong feathers with core strength if you are trying to evolve into a more active and efficient flier.

There is still so much to learn about fossils, new techniques and new areas of research are providing some astonishing data but we still have a long way to go before we can say definitively what colour a feathered dinosaur may have been.

Study into 350 Million Year Old Echinoderms Reveals Presence of Biomolecules

America some 350  million years ago looked very different than it does today.  For starters, much of the land mass which we now know as the United States formed part of a super-continent called Laurentia, but a considerable portion of the USA was covered by a warm, shallow tropical sea.

Scientists from Ohio State University have been studying an unusual phenomena associated with crinoid fossils from strata deposited in an ancient marine environment in the American Midwest and their research reveals that complex organic molecules may have been preserved.  It had been thought that organic molecules could not survive the fossilisation process and remain present in fossil material after immense periods of time, but a number of recent studies using the most sophisticated analysis techniques ever to be employed in palaeontology are challenging  this assumption.

Ancient Crinoid Fossils

Crinoid fossils preserved in rocks from the American Midwest (specifically Indiana, Ohio and Iowa), the remains of animals that lived during the Mississippian Epoch (Carboniferous), can be preserved in different colours depending on the species.  Different species of crinoid, preserved in the same matrix, the same fossil slab, can be blueish grey, creamy white or even dark grey when observed under natural light.  Scientists had commented on this bizarre phenomenon over a hundred years ago, the fact that the crinoid fossils found in some parts of the Midwest seemed to be colour coded, but it took a team of geologists and scientists from the Ohio State University to get to the bottom of this mystery.

An Example of the Different Coloured Crinoid Fossils Used in this Study

Revealing 350 million year old organic compounds.

Picture credit: Professor William Ausich, courtesy of Ohio State University.

Crinoids are members of the ancient Phylum known as Echinodermata (Echinoderms) – starfish, brittle stars, sea urchins and crinoids (sea-lilies).  Their fossil record dates back to the Cambrian.  Crinoids are often referred to as sea-lilies, as they superficially look like plants.  The fossil record for crinoids dates back to the Early Ordovician and there are a number of genera living today, including forms with stems that live attached to the sea-bed filling an ecological niche once filled by the Carboniferous crinoids.

Crinoids Described

Most prehistoric crinoids were attached to the sea-bed by a stem or a stalk, with a root-like holdfast at the bottom.  The mouth and the digestive tract was located in an enclosed cup at the top of the stem.  A series of feathery appendages which were covered in tiny, thin plates (pinnules) acted as a food gathering mechanism.  The sea current brought particles of food which were caught by the pinnules on the arm-like appendages and these food items were than wafted into the mouth.

The hard parts of the animal were formed of calcium carbonate (calcite), extracted from the surrounding sea water.  This calcite was porous and a thin skin of living tissue covered these hard parts.  Calcite is often very well preserved in the fossil record and the calcite plates that make up the flexible stem of these sea creatures are common fossils in Palaeozoic and Mesozoic aged marine, sedimentary deposits.

Dramatic Storms

A series of dramatic storms seem to have devastated the sea-bed where vast colonies of these sea-lilies thrived.  The sea-floor became choked in finely grained mud.  Once these crinoids were buried they were no longer able to feed and vast numbers of them were wiped out.  Being rapidly buried, quickly isolated from scavengers and oxygen to speed up the degradation process the calcite skeletons were preserved in beautiful detail, many of which remain articulated.

The porous calcium carbonate elements of the animal gradually became filled with minerals and preserved as fossils, however it seems that some of the pores that once contained living tissue were sealed so completely that traces of the molecules that made up the living tissue of the organism may have been preserved.

The University based research team were able to extract organic molecules from the individual sea-lily fossils.  They discovered that different species contained different organic molecules.   Some of these ancient sea creatures, that had died during these storm events, although they lay next to other species of crinoid  and had become preserved in the same slab of sedimentary rock: the different species were preserved in different colours – the greys, creams and blue-greys.

The organic molecules, referred to as biomarkers were extracted using a gas chromatograph mass spectrometer.  Tiny samples were taken from the individual fossils, these were then dissolved into a solution.  This liquid and its contents was analysed by the gas chromatograph mass spectrometer and individual molecules were identified based on their mass and their electric charge.  A computer programme was used to sort the data and to find a match in living crinoid species for the organic molecules recovered.

To view models and replicas of iconic invertebrates from the fossil record: CollectA Age of Dinosaurs Models.

The software identified these biomarkers as being similar to quinones found in Echinodermata.  These quinones are aromatic, organic compounds that are found in a number of organisms, they are associated with pigmentation (the colour of an animal) or in the production of toxins and other unpalatable substances that deter predators from attacking.

Professor William Ausich, of the School of Earth Sciences (Ohio State University) and  a co-author of the academic paper that has just been published in the scientific journal “Geology” stated:

“There are lots of fragmented biological molecules—we call them biomarkers—scattered in the rock everywhere.  They’re the remains of ancient plant and animal life, all broken up and mixed together.  But this is the oldest example where anyone has found biomarkers inside a particular complete fossil.  We can say with confidence that these organic molecules came from the individual animals whose remains we tested.”

Christina O’Malley in conjunction with the Ohio State geochemist Yu-Ping Chin, confirmed that the quinone-like molecules occur in fossil crinoids as well as in their extant descendants.  Although different coloured fossils do contain different quinones, the research team stressed that there was no definitive evidence to suggest that the preserved molecules were directly associated with the extinct creatures colouration.

The researchers hope to be able to extract more organic material from the fossils in a bid to find out as much as they can about each individual species.

Explaining that these molecules did not represent genetic material such as DNA, Professor Ausich commented:

“We suspect that there’s some kind of biological signal there, we just need to figure out how specific it is before we can use it as a means to track different species.”

It is truly astonishing that these gregarious, benthic (living on the sea-floor), animals from the Palaeozoic can reveal traces of organic compounds when their fossilised remains are analysed.

The scientific paper: “Isolation and characterization of the earliest taxon-specific organic molecules (Mississippian, Crinoidea)” by Christina E. O’Malley; William I. Ausich and Yu-Ping Chin published in Geology.

New Research Suggests Earlier Reconstructions had the Backbones “Back to Front”

The fossils of the early tetrapod Ichthyostega, the first Devonian tetrapod to be discovered, have always puzzled scientists. This one and a half metres long transitional creature between a fish and a land-dwelling amphibian has always courted controversy and a new study suggests previous attempts to model the vertebrae may have been inaccurate.  In effect, the backbone in skeletal reconstructions of this creature may have formerly been “back to front.”

Tetrapods

Tetrapods (the name means “four feet”), are in essence, the limb-bearing vertebrates with four limbs and distinct digits.  Human beings (H.sapiens), are members of the tetrapod group.  Scientists agree that the tetrapods evolved from fish and the first of these creatures evolved during the Devonian geological period but exactly what group of fishes gave rise to the tetrapods and when remains open to some debate.

Ichthyostega had four limbs, in earlier models this animal was pictured as being well suited to life on land with its robust limbs holding the front portion of the body clear of the ground.  It is now thought that the first tetrapods were not so well adapted to a life out of the water and it is likely that if these animals did venture out onto land they would not have been capable of lifting their body weight up, most probably just dragging their bodies along rather than lifting them clear of the land surface.

An Early Interpretation of Ichthyostega

An older interpretation of Ichthyostega.

Picture credit: Everything Dinosaur

Professor Jenny Clack (University of Cambridge), a world-authority on early tetrapods in conjunction with her colleague Dr Stephanie Pierce (Royal Veterinary College (London), has published new evidence that provides a fresh insight into the Ichthyostega genus.  These distinguished scientists reaffirm that these animals may not have been that well adapted to terrestrial life after all.  It is known that Ichthyostega and its near relative Acanthostega had large teeth and that they were predators, what is unclear however, is whether these animals hunted on land or in the water.

The European Synchrotron Radiation Facility in Grenoble (France) was employed by the researchers to bombard three fossil specimens of Ichthyostega with very powerful X-rays.  These X-rays once interpreted by sophisticated computer software were able to reveal more details regarding the structure of this tetrapod’s skeleton.  The three-dimensional images of the fossil material the research team was able to produce revealed something very surprising.  It had been thought that the back bones of early tetrapods were comprised of four separate bones arranged with one at the front, one just behind the first one and a pair towards the rear of each element of the vertebrae.  The images, that the team produced showed that in the case of the Ichthyostega fossils, the bones at the back had become fused to the one at the front.  This discovery revealed that the first “anterior ” bone at the front of the four bone series was actually the posterior one (at the back).  The change in the orientation and the relationship between the bones in the spine would change the way in which this early tetrapod could move

Writing in the academic journal “Nature”, Dr Pierce explained:

 “Ichthyostega made us open our minds, stand back and reassess the anatomy of other early tetrapod fossils.  When we did this, it was obvious that the bones of their spines were also in the reverse order than what had previously been described.”

Ichthyostega

In addition, the application of new research techniques has enabled the scientists to spot evidence of a primitive sternum in this Devonian animal.  The sternum consists of a series of bones that are aligned together and run down the centre of Ichthyostega’s chest.  This suggests that the animal’s body weight was supported by the sternum and that the limbs did not hold the body clear of the ground as shown in much earlier illustrations of Ichthyostega, but instead this animal probably moved on land by dragging its body along by moving its front limbs.  This method of locomotion is seen today with the Mudskippers (fish from the family Gobiidae).  These Gobies are able to haul themselves around on land using their sturdy pectoral fins as simple, efficient forelimbs.

The Latest Interpretation of Ichthyostega

Ichthyostega interpreted dragging its body across the ground.

Picture credit: Julia Molner

The research team hope to be able to analyse the vertebrae of other Devonian tetrapods using the European Synchrotron Radiation Facility so that a more detailed understanding of the evolution of terrestrial locomotion can be obtained.

Everything Dinosaur stocks a wide range of models of early tetrapods: Models of Early Tetrapods and Prehistoric Animal Figures.

Producing Three-Dimensional Fossils Using Resin

Palaeontology may still be very much a case of using your eyes to spot fossils and such fossil prospecting is always going to be an important part of this Earth science but more and more technology is being employed to give palaeontologists an insight into the fossil specimens that they find.  The advent of affordable three-dimensional printers that can produce an object from scanned images is helping scientists to produce copies of the fossils they discover and allowing them to share their discoveries with other museums without having to go to the expense of using conventional casting techniques.

Palaeontology

Palaeontologists working at the museum of Natural History in Rio de Janeiro (Brazil), have invested in a portable CT scanner to help them determine what fossil material may be contained in an individual block of stone that they excavate.  Even locating fossils, has become much easier with ground penetrating radar providing field teams with information about the orientation of any fossil specimen in the ground.  The images this radar can produce thus guides the excavation team and helps with the safe removal of any matrix material, after all, one careless blow with a geological hammer could damage a precious and rare fossil beyond repair.

Once the location and position of a fossil has been calculated, circular saws can cut out a section of rock, the block, which may represent Cretaceous sediments from the famous Santana Formation of eastern Brazil is then subjected to a further aspect of 21st Century technology – three-dimensional CT scans.  Portable CT scans (computerised tomography), permit the block to be penetrated by powerful X-rays which can be analysed by computer to produce information about what fossils are present in the individual block.  This work is usually carried out in the safety and relative comfort of the museum’s preparation lab.

Data from Scans

This data from the 3-D scan can be analysed by one of the new three-dimensional printers and within hours a replica of the object can be printed out using resin.  The scientists can have their own fossil replica to help them study the delicate structures of any fossil that they find.

The combination of CT scans and three-dimensional printers is helping to change the study of ancient animals.  Already the Brazilian team have used this combination of technologies to gain a better understanding of a fossilised snake and a crocodile skull dating from the Late Cretaceous.

Examining the Structures of a Crocodile Skull in Three Dimensions

New technology meets Cretaceous crocodile.

Picture credit: Sergio Azevedo

Commenting on the use of these new techniques, Sergio Azevedo of the Natural History Museum of Rio de Janeiro stated:

“We are developing several research lines in palaeontology using CT and surface 3-D scanning.  These include the nervous system and biomechanics of crocodiles, dinosaurs and other vertebrate fossils.”

This is a non-destructive technique and with prices of three-dimensional printers likely to come down over the next twelve months or so, more museums, universities and even schools can gain access to this technology.  The 21st century is seeing a cross-over of technology from different scientific disciplines providing palaeontologists with the opportunity to create accurate, highly detailed replicas of the fossils they discover.

Visit Everything Dinosaur’s award-winning website: The Website of Everything Dinosaur.

Pannoniasaurus inexpectatus – The Unexpected Mosasaur

A joint team of Hungarian and Canadian scientists have unearthed a new species of mosasaur, one that as far as the known fossil record goes, was unique amongst the Mosasauridae – it lived in freshwater.  It seems that just like some species of extant cetacean (whales and dolphins), one group of mosasaurs adapted to living in a freshwater environment.  There are river dolphins that live in the Amazon and other riverine habitats such as, until recently, the Yangtze river (Yangtze river dolphin believed to be extinct).  Now scientists have the fossilised remains of several freshwater mosasaurs to study, a number of individuals, all of which have been assigned to a new species – Pannoniasaurus inexpectatus.

Freshwater Mosasaur

Mosasaurs are members of the Order Squamata (lizards and snakes), they evolved from terrestrial reptiles but they adapted to marine environments and rapidly diversified with many different genera and something approaching eighty different species being recognised.  Mosasaurs were typically streamlined, with long, narrow jaws, four paddles and possibly a fish like tail, (new evidence suggests that some mosasaurs had tail fins like those found on extinct ichthyosaurs and extant dolphins).  As vertebrates; their backbones became specially adapted to undulate in an up and down motion to aid propulsion through water.  Some of these marine lizards evolved into giant forms such as Tylosaurus and Hainosaurus which could have been as much as fifteen metres in length.

It seems that these reptiles, whose closest living relatives today are thought to be the monitor lizards (Varanus), evolved around ninety million years ago and spread throughout the world’s oceans before dying out approximately around 25 million years later.

Pannoniasaurus inexpectatus

The holotype fossil material, plus over one hundred Pannoniasaurus fossils so far collected from the location come from alluvial (floodplain and channel) deposits which form a section of the  Csehbánya Formation of Cretaceous aged strata.  The fossils which include juveniles and bones from specimens which may have exceeded six metres in length come from various exposures at the Iharkút open-pit bauxite mine in Hungary.

An Illustration of the Skeleton of P. inexpectatus

The mosasaur that lived in freshwater.

Picture credit: PLoS One/Makádi et al

It is thought that this river mosasaur had a similar body shape to other mosasaurs as well as long, narrow, crocodile-like jaws.  Palaeontologists believe that this genus represents a basal member of the Mosasauridae, it may have retained feet with clawed toes that were capable of moving the animal about on land.  However, no lower limb bones have been found to date.  The flattened skull, may have been a useful adaptation for water-level hunting and the ambushing of terrestrial animals such as small dinosaurs that came close to water’s edge.

The research team speculate that more robust limbs with claws may have been retained by these mosasaurs as they could have used their feet and claws to clamber over the bottom of the river just as extant crocodiles do today.  At six metres in length [about the size of a modern-day Nile crocodile (Crocodylus niloticus)], these mosasaurs were the largest predators within this Late Cretaceous river environment.

Virtually all the other known mosasaur fossils have been found in strata which was laid down in marine environments.  Previously, the only exception to this was some fragmentary fossils of the marine, nektonic mosasaur known as Plioplatecarpus which was discovered in non-marine rocks in Western Canada (Alberta).  The Plioplatecarpus remains include teeth and a partial vertebra collected from the a mudstone unit in the middle of the Lethbridge Coal Zone.

These bones could have been re-deposited there after a tsunami or other flood event, or perhaps they represent individuals who went upstream from estuaries in a similar way to modern Bull sharks.

The genus name for this new mosasaur comes from the ancient Roman province of “Pannonia”, which contained this part of Hungary, the specific name “inexpectatus” means unexpected in Latin, a reference to the surprising occurrence of  mosasaur fossils in a non-marine palaeoenvironment.

A More Typical Mosasaur (Marine Reptile Museum Exhibit)

Fossil material from the freshwater mosasaur Pannoniasaurus inexpectatus.

Picture credit: PLoS One/Makádi et al

The size of the individual fossil bones collected so far indicate that these bones represent a number of differently-sized creatures.  The smallest seem to have been less than a metre in length, the average overall length would have been around three to four metres.  This suggests that many animals of various sizes and ages were present together living in these prehistoric rivers.

Everything Dinosaur supplies a wide variety of marine reptiles including replicas of mosasaurs: Papo Marine Reptiles, Dinosaurs and Prehistoric Animal Figures.

In the paper, published in the on line scientific journal PLoS One (Public Library of Science), the research team state that their studies suggest no fossilisation bias and that the Pannoniasaurus fossils probably represent the population quite accurately.  This suggests that a population of these reptiles was living in the river system, it is unlikely that the fossils ended up in non-marine strata as mosasaurs migrated upstream to take advantage of seasonal food opportunities or in order to give birth in freshwater rather than in the open sea.

This part of Europe during the Late Cretaceous consisted of a series of tropical islands, other fossils found in the Csehbánya Formation include fish, amphibians, crocodiles, turtles, several dinosaur genera, pterosaurs and birds.

The scientific paper: “The First Freshwater Mosasauroid (Upper Cretaceous, Hungary) and a New Clade of Basal Mosasauroids” by László Makádi, Michael W. Caldwell and Attila Ősi published in PLoS One.

Pauline avibella – A new Species of Silurian Ostracod named after Professor’s Wife

It may be difficult to believe, especially after the sub-zero temperatures endured by many people in the United Kingdom over recent days, but once the landmass that was to form England sat much closer to the equator than it does today.  Back in the Silurian, much of the land that we now know as the UK was underwater, part of an extensive, shallow sub-tropical sea that marked the boundary between two landmasses, Laurentia in the west and Baltica in the north.  Scientists from the University of Leicester (East Midlands), have identified a new species of crustacean, an animal that lived in this warm, shallow sea something like 425 million years ago.

Silurian Ostracod

The one centimetre long shelled creature had been found in rocks in Herefordshire, from a site that University of Leicester researchers describe as a “treasure trove” of fossil material.  It seems that part of the sea bed had been covered by a fine layer of volcanic ash as a volcano to the west erupted.  This ash layer buried much of the lifeforms that existed in the area at the time, preserving their bodies and hard shells in exquisite detail.  The fossils have soft tissue and even components such as eyes and mouth parts have been preserved.

Pauline avibella

Professor David Siveter, who led the research, has named the new species Pauline avilbella in honour of his late wife who supported him throughout his career.  Ostracods are relatively abundant in the fossil record.  These primitive shelled arthropods of the Order Crustacea are related to crabs, lobsters, barnacles and shrimps.  The fossils of these tiny creatures first appear in Cambrian rocks and although these creatures first evolved in a marine environment, many modern species can be found in freshwater.  Like all Arthropoda, these animals have bilateral symmetry and their paired body parts are usually enclosed in a hinged, bivalve-like shell made of magnesium calcite.  One piece of the shell structure is normally bigger than the second part of the shell and these shells are commonly preserved in the fossil record, however, being able to identify soft tissue parts in Silurian aged fossils is extremely rare.

A Computer Generated Image of the New Ostracod Species

425 million year old Ostracod with a shell shaped like a “bird’s wing”.

Picture credit: Press Association/University of Leicester

An Important Discovery

Commenting on the new species, Professor Siveter, the lead author of the scientific paper, stated that this was a very important discovery as it represented one of only a handful of fossil Ostracods with the soft-tissues preserved.  The species name “avibella” was chosen as the two piece shell resembles the shape of a bird’s wing.  Most Ostracod shells are kidney or bean shaped, but this particular shallow water species had a shell that was swept back, similar to the shape of the wing of a bird.  The name “avibella” means “beautiful bird”.

The process of extracting the tiny microfossils from the surrounding limestone matrix involves slowly grinding the specimen down, micron by micron with scanning photographs taken at each stage.  When the mechanical process is completed the data is fed into a powerful computer which can produce a detailed three-dimensional image of the organism, including its delicate soft body parts.  With each specimen more than five hundred images were produced, resulting in an extremely detailed picture of the organism – a sort of “virtual fossil”.

Diversity of Marine Fauna During the Silurian

The work of the Leicester University based team is helping scientists to understand the diversity of benthic (animals and plants that live on the sea floor), marine fauna during the Silurian period, an important period in the evolution and diversity of marine organisms as rising sea levels created a number of warm, shallow sea environments and fauna was almost entirely restricted to marine habitats.

For figures and replicas of iconic animals from the fossil record such as famous invertebrates like ammonites and trilobites: Ammonites, Belemnites, Trilobites and Other Prehistoric Animal Models (CollectA).