Psittacosaurus Switched from Four Legs to Two as it Grew

Scientists Explore how Psittacosaurus Changed as it Grew

A new study published in the scientific journal “Nature Communications” has shed light on how the dinosaur known as Psittacosaurus grew.  It seems that when very young these animals adopted a quadrupedal stance and only as they matured did their back legs grow large enough for them to adopt a bipedal way of walking.

The Psittacosaurus genus is perhaps the best represented genus of all the Dinosauria in the fossil record.  Regarded as a transitional form between the Ornithopods and the horned dinosaurs, this small type of dinosaur has more species attributed to the genus than any other dinosaur.  Known from Cretaceous aged strata from China, Russia, Mongolia and Thailand  this dinosaur can also lay claim to be the most extensively researched of all the dinosaurs.  The great number of fossils, ranging from tiny, recently hatched individuals to mature adults some two metres long has provided palaeontologists with an extensive fossil resource to study.

An Illustration of a Mature Psittacosaurus (Human Figure for Scale)

New study suggests that as these animals grew they adopted a bipedal stance.Picture Credit Everything Dinosaur

The first remains of Psittacosaurus were found in 1922 by the American Museum of Natural History expedition to Outer Mongolia.  This dinosaur was named and described by the famous American palaeontologist Henry Fairfield Osborn, who was also responsible for naming Tyrannosaurus rex.  It was named after its square skull and distinctive large, beak that reminded scientists of a parrots beak.  The name Psittacosaurus means “Parrot lizard”.

The Skull of a Species of Psittacosaurus (P. gobiensis) Compared to the Skull of an Extant Macaw

Psittacosaurus skull compared with a parrot's skull.

Picture Credit: Mike Hettwer

Ontogenic studies (studies of how animals grew and changed as they matured), are extremely difficult.  The paucity of the fossil record for each genus makes comparative studies extremely difficult.  However, a team of scientists from the Institute of Vertebrate Palaeontology and Palaeoanthropology (IVPP – Beijing), Bristol University (England) and the University of Bonn (Germany), have used a combination of bio-mechanical studies and analysis of bone growth of Psittacosaurus fossils (histology) to determine that these herbivorous dinosaurs changed their walking postures as they grew and developed.  In essence, by studying the bones of Psittacosaurs that represented individuals at different ages the scientists were able to determine that these dinosaurs started out on all fours but as they got older they moved to a two-legged stance.  Great care was taken to produce cross-sections of fossilised bones, which when scanned using high power electron microscopes and CT equipment would provide information on how quickly the animals grew.

PhD student Qi Zhao (now on the staff of the IVPP), carried out a detailed and in depth study of how these dinosaurs grew, looking at the fossilised remains of babies, juveniles, immature individuals and fully grown adults.   The student was given access to some extremely rare and delicate fossilised bones, including many that had come from remarkable excavations that indicate that these dinosaurs may have lived in burrows and young Psittacosaurs may have formed creches to protect themselves.

To read more about the discover of a dinosaur creche: Amazing Psittacosaurus fossil unearthed

Commenting on his painstaking research work, the now qualified Dr. Zhao stated:

“Some of the bones from baby Psittacosaurus were only a few millimetres across, so I had to handle them extremely carefully to be able to make useful bone sections.   I also had to be sure to cause as little damage to these valuable specimens as possible.”

With special permission from the IVPP,  the student sectioned two arm and two leg bones from sixteen individual dinosaurs, ranging in age from less than one year to ten years old, a fully grown adult animal.  He did the intricate sectioning work in a special palaeo-histology laboratory in Bonn, Germany, with the assistance and support of Professor Martin Sander of Bonn University.

The youngest specimens, those representing individuals around twelve months in age had long arms and relatively short back legs.  This suggest that these dinosaurs would have walked on all fours.  Analysis of the bone sections indicated that the arm bones were growing at their fastest when these reptiles were between one and three years of age.  From then on, the arm growth slowed and the hind legs showed a massive growth spurt, resulting in the hind limbs growing to nearly twice the length of the fore limbs.  The hind legs took over the role of locomotion, the adults could have ambled about on all fours if they wanted to (facultative quadrupeds).

A Change in Locomotion as these Dinosaurs Matured

As the animals grew and matured they adopted a bipedal stance.

Picture Credit: Institute of Vertebrate Palaeontology and Palaeoanthropology

Professor Xing Xu of the Beijing Institute, one of Dr Zhao’s thesis supervisors, stated:

“This is a remarkable study, the first of its kind, it shows how much information is locked in the bones of dinosaurs.  We are delighted the study worked so well, and see many ways to use these new methods to understand even more about the astonishing lives of the dinosaurs.”

Professor Mike Benton of the University of Bristol, whom team members at Everything Dinosaur have met on several occasions, and Dr. Zhao’s other PhD supervisor, added:

“These kinds of studies can also throw light on the evolution of a dinosaur like Psittacosaurus.   Having four-legged babies and juveniles suggests that at some time in their ancestry, both juveniles and adults were also four-legged, and Psittacosaurus and dinosaurs in general became secondarily bipedal.”

This study does ask a number of intriguing questions.  Psittacosaurus is regarded as a basal member of the Marginocephalia, a group of Ornithischian dinosaurs that would give rise to the Pachycephalosaurs and the Ceratopsians.  Many of the early horned dinosaurs (dinosaurs that were ancestral to giants such as Styracosaurus and Triceratops), were lithe, agile, bipedal dinosaurs, animals like Archaeoceratops and Liaoceratops.  It was only as larger genera evolved that these animals became quadrupeds.  If Psittacosaurus evolved from a type of Ornithopod then it is worth noting that Ornithopods such as Iguanodonts suggest that these animals as youngsters were bipedal, as they matured, they adopted a four-footed stance, the opposite of what is being seen with the Psittacosaur fossil material.  The exact taxonomic relationship between Early Cretaceous Ornithischian dinosaurs remains unclear, perhaps fossil material ascribed to the Barremian faunal stage of the Early Cretaceous and believed to represent a new genus of Iguanodontid with some advanced skull characteristics could provide further clues.

Ocker Hill Junior School Pupils Study Dinosaurs for Science Week

 Journey into the Jurassic for Junior School Pupils

Pupils at Ocker Hill Junior School are getting into all things prehistoric as  they embark on a week-long science themed teaching topic with a focus on the dinosaurs.  Based at Tipton, (West Midlands), just a geologist’s stones’ throw from the Wrens Nest Nature Reserve, the UK’s very first national nature reserve for geology, the staff at the school have been working on all sorts of clever and creative activities to help bring the past to life.

Looking at different types of dinosaurs and classifying them led to the development of a series of Venn diagrams as pupils under the tutelage of their teachers and support staff explored how best to present data relating to the Dinosauria.  Getting school children to understand the concept of deep time can be a little tricky, but teacher Mr Wilde, armed with some stakes and a hammer set out to provide a scale model of the various geological periods using the school grounds.  Each stake representing a period in geological time was carefully marked and hammered into place to give the budding young palaeontologists an idea of how old the Earth is believed to be.  This is an excellent idea, a very practical demonstration of geological time, one that will help the children to grasp what different types of creatures lived and when.

Team members at Everything Dinosaur were invited in to kick start the week by holding a series of workshops with pupils in years three to six.  The chance to explain what fossils can tell scientists and to explain a little about the science of palaeontology.  Sarah Southall, one of the year three teachers was surprised to learn that there is a dinosaur named “Sarahsaurus, whilst Mrs Brookes (year 5 teacher) and some of her charges discovered just how big or (how small), the arms of Tyrannosaurus rex actually were.

Mr Goodwin (year six), had been helping his class to learn more about marine reptiles.  Under the expert guidance of school artist Darrell Wakelam the pupils had created a wonderful reconstruction of the fossilised skeleton of an Ichthyosaurus.

Bringing the Past to Life

Year six pupils constructed their own Ichthyosaurus fossilised skeleton

Year six pupils constructed their own Ichthyosaurus fossilised skeleton

Picture Credit: Ocker Hill Junior School

Everything Dinosaur had some coprolite (fossilised poo) from the body cavity of an Ichthyosaur skeleton team members had been working on, the children were delighted when Mr Goodwin got to handle the 180 million year old fossil poo and to demonstrate what the creature had been eating by being able to point out the fish scales still preserved within the specimen.

It is certainly going to be an exciting week for the students.  The enthusiastic teaching team have lots and lots of dinosaur themed maths, science and art activities planned all helping to enthuse and motivate the next generation of scientists.

Juvenile Dinosaur Fossil from within the Arctic Circle

Evidence of Baby Dinosaurs – Pachyrhinosaurus perotorum

Over the last few years a number of dinosaur discoveries from Upper Cretaceous sediments from well inside the Arctic Circle have provided palaeontologists with some remarkable data regarding dinosaurs living at high latitudes.  When asked to conjure up images of dinosaur fossil discoveries, most people might think of the Badlands of the western United States or the dusty, arid, inland areas of Mongolia, the frozen, bitterly cold wastes of Alaska do not readily spring to mind.  However, a team of researchers from the Perot Museum of Nature and Science (Dallas, Texas), have been busy working their way through over ten tonnes of fossil material excavated from a site more than two hundred miles inside the Arctic Circle and they have been rewarded with the discovery of evidence of a juvenile dinosaur.

A new species of Pachyrhinosaurus was named and described by Perot Museum scientists back in 2011 from a bone bed consisting of at least eleven individual specimens excavated from a quarry associated with the Prince Creek Formation (Upper Cretaceous).  This new type of horned dinosaur was named Pachyrhinosaurus perotorum, the third species to be assigned to the Pachyrhinosaurus genus.

To read more about this discovery: New Species of Pachyrhinosaurus Announced

In addition to finding fossils of adults, the scientists have identified portions of the skull from a juvenile.  The presence of such a young dinosaur so far north suggests that far from migrating north each year to take advantage of the long days and good feeding opportunities the extra daylight brought, some dinosaurs may have been permanent residents coping with the harsh, cold winters at high latitudes.

Elements from the skull of the juvenile came from the same bone bed where the adult material was found.  The site is known as the Kikak-Tegoseak Quarry and the rocks in this area represent material deposited by rivers, the strata has been dated to approximately 69 million years of age (Early Maastrichtian faunal stage).

North Alaska today is approximately 1,500 miles from the North Pole, however, back in the Late Cretaceous it was much closer, about 350 miles away, although the temperature was much warmer than today.  Snow would have fallen occasionally but the landscape was dominated by extensive conifer forests with an understorey of hardy flowering plants and ferns.  During that part of the year, when the North Pole faces the sun there would have been constant daylight.  However, when the North Pole tilts away from the sun, northern Alaska would have endured the best part of four months in total darkness.

A Museum Reconstruction of a Pachyrhinosaurus Fossil Specimen

A large horned dinosaur with a huge skull.

A large horned dinosaur with a huge skull.

The field team organised the removal and transport of the large amount of fossil material, transporting it by air and road to the preparation laboratory at the Dallas-based museum.  Dr. Tykoski, the member of staff responsible for the fossil preparation work and his colleagues set about removing the fossils from the surrounding rock.  The discovery of the juvenile dinosaur fossil material was made last  year, when Dr. Tykoski was working on a block of sediment about the size of a football.  The fossils represent elements from the skull, an incomplete nasal bone.  Fortunately, one of the key diagnostic features of this species of Pachyrhinosaurus is the area of skull represented by the nasal bone.  The immature, juvenile specimen has a small, narrow, hardened patch on its snout, whilst in mature animals this area of the skull thickens into a large and bumpy boss.  It has been suggested that these hardened and very thick parts of the skull were used in intra-specific head-butting contests between adults.

This newly described specimen, reported in a paper published in the online academic journal “PLoS One”, shows a mix of features in the nasal bone that helps palaeontologists to assess how skull characteristics of Ceratopsian dinosaurs changed as the animal grew.  The specimen consists of an incomplete nasal bone that includes the rearward part of the nasal horn, the dorsal surface between the horn and the left-side contacts for the prefrontal and frontal bones, and some of the left side of the rostrum behind and slightly underneath in relation to the nasal horn.  The combination of morphologies in the new specimen suggests either an additional stage of development should be recognized in the ontogeny (growth and development) of the nasal boss of Pachyrhinosaurus, or that the ontogenetic pathway of nasal boss development in P. perotorum was notably different from that of other species within the Pachyrhinosaurus genus.

How the Skull Features of P. perotorum Grew and Developed

How a baby P. perotorum grew up.

How a baby P. perotorum grew up.

Picture Credit: Museum of Nature and Science

A series of Pachyrhinosaurus perotorum skulls (on the left) and stylized life reconstructions (on the right) at three (of a proposed six) different life stages.  Stage 2 skull is based on juveniles of the closely related species Pachyrhinosaurus lakustai from southern Alberta.  The Stage 4 skull represents a ‘partially grown’ or ‘early adolescent’ individual, based on the new specimen (DMNH 21460) discovered in 2012 by the museum preparation team.  The Stage 6 skull is that of a mature adult, based on DMNH 22558, a nearly complete Pachyrhinosaurus perotorum skull described by Fiorillo and Tykoski in 2012 and currently on public exhibit in the Perot Museum of Nature and Science.  The ‘fleshed-out’ reconstructions are based on previously published ideas of Pachyrhinosaurus skin structures, but modified to reflect new information revealed by the new specimen (DMNH 21460).  Light tan indicates ‘normal’ skin, while dark brown indicates cornified (= thickened, hardened, horn-tissue-covered) scales, horns, sheaths, or other cornified tissue.  Scale bar equals 50 cm.

Commenting on the discovery of juvenile Pachyrhinosaurus mateial Dr. Tykoski stated:

“After a couple weeks of working on it, our question was ‘what on earth is this?’  It had features on it that looked like the big adult skull of the Pachyrhinosaurus perotorum that we had originally found, yet it was very narrow and skinny and didn’t have the big expanded nose of the adult.  After ruling out all of the possibilities through the process of elimination, we realised this was a juvenile specimen.  This provided us a snapshot in the development of the species – and that’s not common – so this was a very exciting moment for us.”

The finding of this juvenile specimen in and amongst the fossils of several adult animals has important ramifications.  This suggests that either very young animals migrated northwards, or perhaps they may have been born somewhere on route to the feeding grounds.  It also opens up the possibility that at least one species of large, herbivorous dinosaur was so at home in the harsh Alaskan environment that they were able to breed there and that they were perhaps permanent residents.

The Perot Museum of Nature and Science has already organised a number of return expeditions to North Alaska and the team have plans to study other likely fossil-bearing sites in a bid to learn more about these Late Cretaceous dinosaurs.

At present, there are three different species of Pachyrhinosaurs known, the last to be described was the Perot Museum’s North Alaskan discovery in 2011.  The species are differentiated by different morphologies on the skull.

An Illustration Showing the Differences in Skull Morphology of Pachyrhinosaurus species.

Three species of Pachyrhinosaur have been described to date.

Three species of Pachyrhinosaur have been described to date.

Picture Credit: Museum of Science and Nature

Everything Dinosaur acknowledges the help of the Perot Museum of Nature and Science in the compilation of this article.

The Rocking Horse – Ancient Fossil Decodes Horse Evolution

Ancient Horse Bone Yields Oldest Sequence of DNA Known to Science

A team of international researchers have been able to sequence a substantial portion of the genome of an ancestral horse from a leg bone of a horse that roamed about in Canada some 700,000 years ago.  This research sheds light on the evolution of the Equine family and dramatically extends the known limit of DNA survival.  DNA material has been recovered from other Pleistocene aged fossils, those of Cave Bears (Ursus spelaeus), Mastodons and Mammoths but this DNA recovery is from a sample more than half a million years older than other material successfully studied to date.

The study has just been published in the academic journal “Nature” the fossilised leg bone was part of a collection of horse fossils preserved in the Canadian permafrost of the Yukon.  The fossils were found at a location known as Thistle Creek (west-central Yukon Territory)

The fossils are estimated to be around 735,000 years old (Mid Pleistocene), and the fifteen centimetre long leg bone which was used in the DNA study, is part of a collection excavated out of the cold, hard permafrost back in 2003.  Leg bones, being relatively thick and robust have a greater potential for preserving organic material within them than smaller more fragile bone material.

Ancient Genetic Material Recovered from a Horse Fossil

700,000 year old genetic material recovered from a fossil bone.

700,000 year old genetic material recovered from a fossil bone.

Picture Credit: D.G. Froese/Nature Journal

In a recent study, the leg bones of 158 Moas (extinct, giant flightless birds), were used to develop a framework for estimating the half-life of DNA.  This controversial research from New Zealand suggested a half-life of DNA at just 521 years.  The scientists involved with this study programme calculated that fragments of DNA could survive in perfect preservation conditions for perhaps as long as 6.8 million years, but analysis of this highly unstable, ancient material would probably prove impossible.  This new study of DNA related to Equus (horses), may not be 6.8 million years old but the ancient horse leg bone has yielded the most ancient DNA sequence know to science thus far.

To read more about the study of genetic material in Moa bones: Controversial Research Proposes a Half-Life for DNA

Ludovic Orlando, an evolutionary biologist at the University of Copenhagen and one of the co-authors of the scientific paper, explained that the team wanted to determine whether there might be any biological molecules left in this sample.  The first step was to try to identify any evidence of amino acids that would have constituted any collagen (protein found in bone), within the specimens studied.  Once the team had established that there were these proteins present, the researchers moved on in their analysis with the aim of trying to extract DNA from the ancient horse’s leg bone.
Recently, a team of scientists from Manchester University were able to identify an animal from fragments of tibia (leg bone) found in the Yukon.  The fossil bone fragments, much older than the horse fossils (dated to around 3.5 million years ago), were found to belong to a type of ancient camel.  The Manchester-based team were able to make this conclusion by tracing minute amounts of collagen in the fossilised bone and then de-coding it to see how closely it resembled the collagen found in living species.  The technique is referred to as “collagen fingerprinting”.  However, Ludovic Orlando and his colleagues were able to go further and to identify a quantity of genetic material within their sample, allowing them to sequence about seventy percent of this ancient horse’s genome.
To read more about the study of ancient camels from the Yukon: Camels of the Arctic
Although for the majority of their 700,000 years of incarceration the horse fossils were protected from liquid water (ground water present in a fossil matrix can speed up the breakdown of organic material) and biological contaminants, the scientists were able to identify from climate change studies that the area in which the fossils had been found had thawed out on several occasions.  However, some of the Equus genetic material had still been preserved.  Of the twelve billion or so DNA molecules identified most were from bacteria that had populated the bone after the horse had died.  However, using DNA from the modern horse species as reference markers, the researchers were able to identify “endogenous DNA”, genetic material from the ancient horse itself.
Fragments of Fossil Bone Analysed for Their Genetic Content
"Flogging a dead horse" to extract DNA.
Picture Credit: Dr. Orlando
From the detailed analysis of the organic material, the scientists were able to identify about 3% of the total “pool of organic data” as being horse DNA, that’s about 40 million DNA molecules.
Orlando described this finding as:
“A bit of horse DNA in an ocean of microbial DNA.”
The multi-national team of researchers pulverised a fragment of the bone to recover its DNA, then subjected it to high-throughput, next-generation gene sequencing to unravel the blueprint of this ancient horse, which team members at Everything Dinosaur have nick-named “Old Ned”, a reference to the theme to the television series “Steptoe and Son”, father and son rag and bone men who owned a horse.

The first approach the team attempted resulted in relatively poor yields of horse-derived sequences, so they turned to a technology that could directly analyse single molecules of DNA.  Using very powerful computers the scientists were able to distinguish the horse DNA material from the contaminating bacterial DNA, eventually revealing about seventy percent of the entire genome.

Although far from complete, the resulting genetic data has led to some interesting conclusions.  For example, the presence of Y chromosome markers demonstrate that the fossil material came from a stallion (male).

The recovered DNA material was then compared to the genome of a modern donkey, zebras, the domestic horse and the Mongolian wild horse (Przewalski’s horse), this enabled the scientists to build up a comprehensive map outlining the evolution of Equus.  The “family tree” that was developed suggests that the Thistle Creek equine was a basal member of the horse family although the very first horses, as we know them today, the forerunner of the donkey, zebra and horse first evolved some 4 to 4.5 million years ago.  This new genetic dating evidence indicates that the horse family is much more ancient than previously thought.

In addition, when it comes to looking at the Przewalski’s horse, the last truly wild horse left on the planet, this new study suggests that the horse family tree that led to today’s wild horses split from the line leading to the domestic horse some fifty thousand years ago and not as previously thought some one hundred and sixty thousand years ago.

New Insight into the Evolution of Modern Horses

Przewalski's horse DNA studied as part of this research.

Picture Credit: AFP/JIJI

A survey of the recovered DNA sequence looking for specific material in the genes known as single nucleotide polymorphisms (SNPs) has enabled the scientists to estimate past population sizes.  It seems that over the last two million years or so, the horse family has experienced a number of significant population declines and then population explosions.  Analysis of climate change data shows that there is a close match between rising horse numbers and improving (warmer) climate.

The location of the genetic differences between the ancient and modern horses also provided tantalising clues into some of the possible consequences of these genetic differences, Dr. Orlando went onto explain:

“Once you have the genome, one thing you can do is to actually look at different genes that we know today are important for different traits.  What we’ve learned for example is the alleles that prime to the racing performance in domestics were not present at that time.”

Commenting on the wider implications of the study, co-author Eske Willerslev of the University of Copenhagen stated:

“Pushing back the time barrier is important because it has implications for our evolutionary understanding of anything from Hominins to other animals, because we can look further back in time than people have done previously.”

A spokesperson from Everything Dinosaur stated:

“Ten years ago, such developments in extracting viable genetic material from such fossil material was simply not possible, next generation sequencing technology has completely revised our expectations.  If DNA can be identified from fossil material more than 700,000 years old, then this widens the net for scientists as they seek to retrieve more genetic data from fossils.”

This branch of genetics is certainly leading to a whole range of new and exciting developments, not least of which is a more complete understanding of the evolution of extant types of horse – all 4 million years of it.  The fossil material from the Yukon is an example of a “rocking horse” that could well have “rocked” our understanding of the ability of organic material to survive fossilisation.

Dinosaur Fans Show Off Their Artistic Talents

Prehistoric Themed Artwork

Whilst examining some pictures of cave paintings from a cave in the Dordogne region of France it reminded us how our ancestors depicted life around them and engaged with the animals that shared their Stone Age world.  Today in schools we involve primary school children in a number of prehistoric animal themed artworks and we are always impressed by their enthusiasm.  We have worked with art students on a number of exciting projects, re-creating dinosaurs and impressive models of flying reptiles and marine reptiles.  Every day we receive a number of emails from  dinosaur fans and collectors keen to show off their latest creations and artwork, we are grateful for all the letters, pictures and emails that we receive and  we do read them all.

An Example of a Prehistoric Themed Artwork in a School

Even Mary Anning would be impressed!

Even Mary Anning would be impressed!

Picture Credit: Ocker Hill School

The wonderful skeleton of an Ichthyosaur was created by Year 6 school children studying prehistoric animals as part of their term topic.  A super illustration, one that we suspect will take pride of place in one of the school’s corridors.

Some of the artwork we receive is truly amazing.  We are always impressed by the talents of our many customers and we enjoy receiving illustrations, parts of our warehouse walls are simply covered in pictures, we used to have a large notice board where we placed them but this space was outgrown a long time ago.

Polacanthus – A Lovely Illustration of a Member of the Thyreophora (Shield Bearers)

Lovely example of a customer's artwork

Lovely example of a customer's artwork

Picture Credit: Chris

Above is a typical example of the artwork that we get sent in to us.  This is an illustration of the armoured dinosaur known as Polacanthus (P. foxii) , Chris the illustrator, has been careful to reproduce the sacral shield over the hips and to depict the numerous defensive spikes that this dinosaur known mainly from the Wessex and the base of the Vectis Formations.  Polacanthus was formally named and described in 1865, however the first fossils of this dinosaur to be studied were found in 1843, not long after the Dinosauria Order had been established by Owen.  A number of dermal plates (armour) were discovered near to Sandown on the Isle of Wight, however these fossils were lost when they were accidentally left in the back of a Hackney Carriage and to this day, no one has been able to trace these fossils whereabouts.

The colours chosen are wonderful, the rich, verdant green contrasting with the greyish underbelly and the fearsome looking bony projections on the back of this herbivorous dinosaur.  We are always delighted to receive artwork such as this, it helps to brighten up a dull June morning in our offices.

It’s not just pictures that we receive, we get sent letters from children, model collectors and dinosaur fans from all over the world, these too are read by the team, usually during one of our coffee breaks.  We encourage teachers, LSPs, and TAs in schools that we have visited to help Year 1 and Year 2 with their writing by getting them to send in letters to our team.  The children are always eager to do this and share their knowledge of prehistoric animals with us.

A Thank you Letter from Year 2 (7-8 years Old) School Children

Encouraging writing in schools.

Encouraging writing in schools.

These contributions to our very large mail bag always brighten our day and we loved meeting the “Year2asauruses” along with their enthusiastic teachers and teaching support staff.  We are grateful for the artwork and letters that we receive and we look forward to opening today’s mail bag to see what treasures lie in store for us.

The Most “Ugly” Pareiasaur Discovered to Date – Bunostegos

Pareiasaur from Niger with Bizarre Lumps and Bumps on Its Head

A team of international scientists have discovered that animals living in what was one of the central parts of the super-continent known as Pangea may have become geographically isolated, this led to a number of ancient genera surviving into the Late Permian, whilst these creatures became extinct elsewhere.

One of the more remarkable of these “living Permian fossils” was the cow-sized, herbivorous Pareiasaur which has been named Bunostegos akokanensis.  The term Pareiasaur refers to a diverse group of reptiles, the “shield lizards”.  These animals were heavily built, robust creatures whose bodies were covered in bony spikes, horns and plate-like projections.  Bunostegos is known from a partial skull and it is distinctive as this specimen has more bumps and lumps on its skull than any other known species of Pareiasaur described to date.

The skull material has been dated to around 260 million years ago (Late Permian), it was found a few years ago during fieldwork exploring the Moradi Formation of central Niger.  A research paper has just been published in the academic publication “The Journal of Vertebrate Palaeontology”.  The genus name means “knobbly roof” a testament to the strange lumps and bumps on the animal’s skull, which in life may have been covered in skin, rather like the bumps on the top of a giraffe’s head.  The species name honours the town of Akokan in central Niger, which is close to where the fossil material was found.

An Artist’s Impression of Bunostegos akokanensis

Lumpy and bumpy Pareiasaur.

Lumpy and bumpy Pareiasaur.

Picture Credit: BBC Media Images

Better known Pareiasaurs such as the three-metre long Scutosaurus have provided scientists with evidence that some of these skull and facial features developed with age.  Cheek projections in conjunction with nose and lower jaw spikes seem to have become more prominent as individuals grew larger and matured.  This has led some palaeontologists to speculate that these features were used in mating displays or fights amongst rivals (intra-specific competition).  If this is the case, then the skull material unearthed in Niger might represent a particularly old individual.

A Typical “Shield Lizard” – Scutosaurus

Robust, heavily armoured Pareiasaurs.

Robust, heavily armoured Pareiasaurs.

Picture Credit: Everything Dinosaur

Analysis of the skull has led the researchers to conclude that Bunostegos is related to older and more primitive Pareiasaurs, but it seems to have persisted in Niger whilst related species died out many millions of years previously.  This would have made Bunostegos a “living fossil”, a survivor from an ancient line of reptiles that had gone extinct elsewhere.  For much of the Permian, the land masses of the Earth were joined together into a huge super-continent (Pangea).  Scientists had thought that much of the fauna and flora was relatively uniform, in theory an animal could have walked from near to the South Pole almost to the North Pole.  The Middle and Late Permian fossil record documents a uniformity in fauna and flora as similar fossil species have been found in what would have been (back in the Permian), geographically dispersed locations.

However, this research work, focusing on the Moradi Formation of Upper Permian strata suggests that there was an isolated habitat in the central part of Pangea that enabled distinctive fauna and flora to evolve and more primitive reptiles to persist.  Bunostegos may have been around during the Late Permian as deserts surrounded its habitat providing a natural barrier preventing animals leaving the area and other creatures coming in.

Great Care is Taken when Excavating Fossil Material

Examining fossil material what we term a "dig station".

Examining fossil material what we term a "dig station".

Picture Credit: BBC Media Images

Commenting on the strange appearance of this reptile, Dr. Linda Tsuji from the University of Washington (Seattle) stated:

“We can’t say for sure, but it is most likely that the bony knobs on the skull of Pareiasaurs did not serve a protective function.  They vary quite markedly in size and shape between different species, with some species lacking prominent knobs entirely, so I think that they were purely ornamental. The most probable use was for inter-specific [between species] or intra-specific [within species] recognition.”

These deserts would have proven to be impenetrable barriers to these creatures, the fauna and flora would have been constrained to a central area, arid but with enough water and food to sustain an ecosystem.

Christian Sidor of the Department of Anatomy, New York College of Osteopathic Medicine, Old Westbury, New York, a co-author of the scientific paper concluded that:

“Our work supports the theory that central Pangea was climatically isolated, allowing a unique relict fauna to persist into the Late Permian.”

Elsewhere on the landmass of Pangea, animals and plants had much more freedom of movement with many fewer natural barriers.  This is reflected in the relatively uniform fossil record as found today in places such as South Africa and South America.

A View of the Bunostegos Skull Material

Two photographs of the skull material are at the top viewed as if looking down onto the fossil material.

Two photographs of the skull material are at the top viewed as if looking down onto the fossil material.

Picture Credit: Journal of Vertebrate Palaeontology

The line drawing below is an illustration of the skull, as if viewed from looking down onto the top of the skull (dorsal view).

A spokesperson from Everything Dinosaur stated:

“It is important to explore the geological and fossil record of the super-continent known as Pangea, especially the Upper Permian deposits.  The end of the Permian is marked by the greatest mass extinction in the history of life on our planet and scientists are still uncertain how this mass extinction event came about”.

The Evolution of the Ability to Throw

Study of Homo erectus Fossils Suggest that Early Hominins Had the Ability to Use Projectile Weapons

Our shoulder joints are effectively a loose fitting “ball and socket” joint.  The shoulder joints in humans have given our arms great manoeuvrability and mobility.  However, as a relatively loose fitting joint with a large degree of motion, injuries can occur.

The ability to use our arms and shoulders to throw an object, something like a roughly shaped spear, could have enhanced our ancestor’s ability to hunt game.  The addition of more meat into their diet would have enabled them to grow larger bodies, develop bigger brains and to raise more offspring, thanks to better, protein rich nutrition.  Research by a team of scientists from George Washington and Harvard universities (United States), suggests that shoulders capable of hurling an object at speed evolved some two million years ago.

The research paper, published in the academic journal “Nature” proposes that Homo erectus evolved the ability to throw.

H. erectus was a long-lived species of hominid.  It evolved around two million years ago and survived at least until about 300,000 years ago, this makes it the longest surviving species of hominid known to science.  These ancient hominids evolved in Africa but spread into south-eastern Europe and Asia.  Although very different looking to modern humans with their long, low skulls and distinctive brow ridges they used fire and made sophisticated stone tools.  Intriguingly, they were the first species along the human branch of the hominid family tree to live environments outside their African savannah homelands.  Their brains were also considerably bigger than earlier human ancestors.  Could the ability to hunt using throwing spears have enabled Homo erectus to master new environments?

Homo erectus – The First Hominid Species to be Able to Throw a Projectile?

Early hominid with a strong throwing arm?

Early hominid with a strong throwing arm?

Picture Credit: Everything Dinosaur

The American research team used stop-motion photography to capture the range of movement and muscle action when college athletes were involved in throwing activities.  They then compared their studies with the anatomy of chimpanzees.  The team discovered that humans have the ability to throw at very high speeds, much faster than our closest living relative, the chimpanzee.   Professional athletes can reach speeds in excess of ninety miles per hour, whilst chimps, although with stronger arms and superior grip strength, they can only reach throwing speeds of twenty miles per hour.

The bio-mechanics of the throw action was analysed and it was observed that the shoulder performs like a sling-shot as the arm rotates backwards.

The Evolution of Our Ability to Throw

The shoulder joint, our most mobile joint.

The shoulder joint, our most mobile joint.

Picture Credit: Neil Roach

The picture above shows that the maximum shoulder rotation (pictured middle) is when elastic energy is able to power the throw.

The ligaments and tendons surrounding the shoulder then stretch and store elastic energy, which powers the forward throw.  When this energy is released it generates what scientists found was the fastest motion the human body produces.

Neil Roach, (George Washington University) who led the study, stated that the changes in the anatomy of early humans enabled energy storage in the shoulder that permitted fast throwing.  From this evidence it could be implied that more effective hunting methods could have come about.

He went onto add:

“Success at hunting allowed our ancestors to become part-time carnivores, eating more calorie-rich meat and fat and dramatically improving the quality of their diet.  This dietary change led to seismic shifts in our ancestors’ biology, allowing them to grow larger bodies, larger brains, and to have more children, and it also did interesting things to our social structure.  We start to see the origins of divisions of labour around that time, where some would be hunting, others would be gathering new foods.  It probably also allowed us to move to new environments, such as areas that did not have vegetation to support us before we had the ability to hunt.”

Professor Daniel Lieberman, (Harvard University) declared that for him the most fascinating aspect of this research was that half the power the humans generate from the throwing action comes from elastic energy stored in the shoulder muscles.

He commented:

“That’s not a by-product of evolution for something else, it’s clearly an adaptation.  There were shifts in our anatomy that enabled us to throw accurately, so we want to understand better just what those early hunting challenges were.”

With no evidence of spears having been found in the earliest fossils of H. erectus, this interpretation of fossil material by the American team has raised a few eyebrows (or should that be brow ridges).  Other scientists, including those that specialise in studying human and other primate anatomies have suggested that a more holistic approach to comparative anatomy be used.

Comparing Human Anatomy with that of a Chimpanzee

Chimp chest (pictured left) compared with human chest (pictured right)

Chimp chest (pictured left) compared with human chest (pictured right)

Picture Credit: Brian Roach/Neil Roach

Professor Susan Larson from Stony Brook University, (United States), a scientist not involved in the study, has queried the conclusions drawn from this research.  Her work also focuses on the shoulder anatomies of primates and humans in order to study their evolution.  She said it could be easy to over interpret what was significant from a fossil.

“We’re looking at the same fossils, it’s a question about how you interpret the anatomy that you see in those fossils.  Homo erectus was not necessarily such a proficient thrower.  I think [Dr Roach and colleagues] are discounting the combination of features of how the shoulder as a whole has to work.”

The few fossils of Homo erectus arms and shoulders suggest that they had an extensive range of movement.  Their hands too, were very capable of manipulating objects and showing great dexterity, however, more work is required before such conclusions can be made.

Professor Larson added:

“You cannot look at just one thing and say how a complicated piece of anatomy works, especially something like the shoulder.  You have to understand how all parts work together to bring about a broad range of motion.”

One interesting point to note, if ancient hominids like H. erectus were throwing spears, chances are they would favour either the left or right hand.  The paper has been regarded as an interesting hypothetical model rather than a definitive explanation of fossil evidence by many scientists working in this field.  For example, the humeral torsion, the angle at which the head of the humerus (funny bone) articulates with the scapula (shoulder bone) in H. erectus specimens does not fall within the range of modern throwing athletes.  There is also no evidence of asymmetry in the humeral torsion angle in H. erectus fossils that one would expect if one limb was preferred over the other for throwing.

Interesting thought, those ball tosses at Wimbledon by today’s tennis players may have a very ancient evolutionary lineage.

Collecta Deluxe Parasaurolophus Video Review

Everything Dinosaur Reviews the 1:40 Scale Collecta Deluxe Parasaurolophus

Collecta have introduced a replica of a duck-billed dinosaur into their Deluxe scale model range of prehistoric animals.  This is the first Hadrosaur in this scale-model series and an excellent replica it is to.  Team members at Everything Dinosaur have produced a brief (5:22 minutes) video review in which we explain some of the features seen on this model and discuss the fossil evidence regarding Parasaurolophus and Hadrosaurs in general.

Everything Dinosaur’s Review of the Collecta 1:40 Scale Parasaurolophus

Video Credit: Everything Dinosaur

In this video we explore how the flamboyant crest may have been used and what purpose it may have served.  We discuss the scale of this model and look at some of the anatomical features that are based on the latest fossil discoveries.

To view the range of Collecta Deluxe prehistoric animal models available: Collecta Deluxe Prehistoric Animal Models

Updates on Jurassic Park IV – Marine Reptiles and All

Jurassic Park IV Due for Release in 2015

With problems over the filming now resolved it seems there has been new life breathed into the once extinct Jurassic Park IV movie and a new release date has been proposed.  Originally scheduled for June 13th 2014, the world-wide release of this long awaited film, the fourth in the Jurassic Park franchise, is likely to be summer 2015.  Although, there have been a number of leaks relating to the storyline the plot is a closely guarded secret.  However, it does seem that the action will mostly take part on the island of Isla Nublar, this was the location used largely for the first film in the franchise, the site of John Hammond’s dinosaur-themed safari park.

A source claims that the prehistoric animals shown in the movie will include marine reptiles for the first time.  There will be dinosaurs that had appeared in the previous films, the fearsome, over-sized Velociraptors and the monstrous T. rex, for example, but giant carnivorous sea monsters will make an appearance too.

Isla Nublar is now a fully operational theme park, a tourist attraction on a huge scale.  Theropod dinosaurs roam but they are muzzled.  In one sequence, a giant marine reptile will perform in a Sea-World like attraction, a sort of prehistoric version of Shamu the Killer Whale.  The huge beast leaps out of the water to devour a strung up Great White Shark, all for the pleasure of the tourists.  Looks like the shark from “Jaws” is put in its place in terms of the prehistoric pecking order.

There were certainly many very large and dangerous marine reptiles in the seas of the Mesozoic, Pliosaurs and Mosasaurs for example.  Tylosaurus (T. proriger) a Mosasaur whose fossils have been found in North America, may have reached lengths in excess of fourteen metres.  The Pliosaur, known as Liopleurodon (L. macromerus), may have been even bigger, perhaps twenty metres in length, although estimates of a weight in the region of 150 Tonnes in our view are a little excessive.

A Mosasaur Attacks a Pteranodon (P. longiceps)

Fearsome marine reptiles to feature in Jurassic Park IV

Fearsome marine reptiles to feature in Jurassic Park IV

Picture Credit: BBC Worldwide

Insiders claim that there will be a new type of dinosaur villain in this film, one that has not appeared in the previous three movies.  This dinosaur breaks out of its cage and rampages across the park, killing and eating a number of people that get in its way.  We at Everything Dinosaur have speculated what this new dinosaur might be – an Abelisaurid such as a Carnotaurus or a member of the Carcharodontosaurids (Great White Shark Lizards – back we go to “Jaws” again); a predatory dinosaur such as Carcharodontosaurus or perhaps a Giganotosaurus.

We shall have to wait and see.  Roll on 2015.

Przewalski’s Horse Success Story

Checking on the Progress of a Herd of Wild Horses (Przewalski’s Horse)

The efforts of a conservation team to build up the population of Przewalski’s horses in a remote part of north-western China seem to be succeeding after the survival of a foal born last summer.  Recording the number of horses is very difficult, as even though a handful of horses will tolerant the company of humans, most run away when people get within two hundred metres of them.

The horses, named after a Russian explorer (Nikolai Przhevalsky), once roamed much of Asia and Europe during the Stone Age but with excessive hunting and habitat loss these animals, only distantly related to domesticated horses became all but extinct in the wild.  A global conservation effort using animals kept in safari parks and zoos has enabled the numbers of horses to increase and in the latter part of the 20th Century a number of preserves and wild ranges were created allowing some of these remarkable animals to be re-introduced to the wild.  One such reserve is the 1.6 million acre West Lake National Nature Reserve in Gansu Province.  The reserve is approximately the size of the county of Devon in the United Kingdom.

Getting Close to an Ancient Horse

Feeling at home on the reserve.

Feeling at home on the reserve.

Picture Credit: AFP/JIJI

This nature reserve is one of a number that have been set up around Mongolia and China, the horses being very important symbols in the folklore of these remote areas.  However, the freezing winters and very hot summers make life difficult for these tough little horses.  To help the herds survive and to get them into a fit condition for breeding extra forage is fed to the animals during the winter and scientists have worked hard to open up new water resources with the establishment of a number of new wells in the protected area.

An official, Sun Zhicheng, explained how the animals were first discovered more than 2,000 years ago telling of an ancient Chinese legend, whereby an exiled criminal came across a horse whilst on the Silk Road.  The man had been banished from the oasis of Dunhuang and whilst walking he saw one of these strange, stocky, tan-coloured horses.  He made a mannequin and put it on the path where the horse walked, one day he lay down, taking the place of the dummy and he was able to catch the horse which he offered to the Emperor.

The man lied to the Emperor (Han Wudi), claiming that the horse had jumped out of a spring, the Emperor convinced that this horse was a gift of the Gods, kept the animal.

Chinese authorities have been keen to re-introduce Przewalski’s horse (pronounced she-wal-ski or pres-wal-ski) back into the wilds of China.

In 1986 China purchased eighteen of the horses from the United States, Britain and Germany and has since bred them in captivity, with their numbers growing to more than seventy.  Three years ago, groups of horses were released into the nature reserve.

Przewalski’s Horse

Stone Age survivor being slowly re-introduced to the wild.

Stone Age survivor being slowly re-introduced to the wild.

Picture Credit: Everything Dinosaur

According to Sun, numbers have slowly risen, he stated:

“Now there are 27, 16 females and 11 males.  We even registered the birth of a foal in July 2011, a new success in our re-introduction process.”

Przewalski’s horses require daily access to water that is within a 30-kilometre (20-mile) range and does not freeze in winter.  They also need 22 pounds (10 kilogrammes) of dry food per day, relatively close to the water.  In a region that receives less than 1.5 inches of rain per year, many of these conditions could become problematical, however, help is on hand with park officials ensuring that the grazing horses get their diet supplemented by additional feeding of alfalfa, straw and corn.

Hoping to establish a population of more than one thousand animals in the next fifty years or so, the hard-working team at the West Lake National Nature Reserve hope that they will continue to have success with the breeding programme.

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