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/Palaeontological articles

Articles, features and information which have slightly more scientific content with an emphasis on palaeontology, such as updates on academic papers, published papers etc.

8 03, 2017

Unravelling a Fishy Tale

By | March 8th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|2 Comments

Reassessment of Ichthyosaur Material Solves Century Old Mystery

Ichthyosaurs were a very successful group of marine reptiles. They originated during the Triassic and thrived in the seas of the Mesozoic and had a global distribution, but towards the end of the Cretaceous, these dolphin-shaped animals, that seemed so perfectly adapted to their environment, became extinct.  They were the first, large extinct reptiles brought to the attention of the scientific world.  It is difficult to avoid mention of the Ichthyosaurs when looking at information that outlines the history of palaeontology, however, despite first having been described nearly 200 years ago, (1821), there is still a lot we don’t know about these iconic “fish lizards”.

The Iconic Ichthyosaurus

An Ichthyosaur illustration.

An Ichthyosaur (courtesy of Robert Richardson).

Picture Credit: Robert Richardson

The Long History of Ichthyosaur Research

It is the long history of scientific study and research into the Ichthyosaurs that has proved to be a bit of a headache for today’s palaeontologists.   Dean Lomax, a palaeontologist and Honorary Scientist at The University of Manchester, working with Professor Judy Massare of Brockport College, New York, have studied thousands of Ichthyosaur specimens and have delved through hundreds of years of records to solve an ancient mystery, a mystery that dates back to the early 1820’2, when the English geologist William Conybeare, described the first species of Ichthyosaurus.

Many Ichthyosaur fossils were found in England during the early 19th century, but it was not until 1821 that the first Ichthyosaur species was described called Ichthyosaurus communis.  This species has become one of the most well-known and iconic of all the British fossil reptiles, after all, an Ichthyosaurus even featured on a set of specially commissioned Royal Mail stamps to celebrate 150 years of British palaeontology!

To read article about the Royal Mail commemorative stamps: Royal Mail Issues New Prehistoric Animal Stamps

In 1822, three other species of Ichthyosaurus were described, based on differences in the shape and structure of their teeth.  Two of the species were later re-identified as other types of Ichthyosaur, whereas one of these species, called Ichthyosaurus intermedius, was still considered closely related to I. communis.

In the years that followed, many eminent scientists, including Sir Richard Owen (the man who coined the word dinosaur), studied “fish lizard” fossils collected from Dorset, Somerset, Yorkshire and other locations in England.  Their studies and observations of Ichthyosaurus communis and I. intermedius resulted in confusion with the species, with many skeletons identified on unreliable grounds.

Commenting on this palaeontological puzzle, Dean Lomax stated:

“The early accounts of Ichthyosaurs were based on very scrappy, often isolated, remains.  This resulted in a very poor understanding of the differences between species and thus how to identify them.  To complicate matters further, the original specimen of Ichthyosaurus communis is lost and was never illustrated.  Similarly, the original specimen of I. intermedius is also lost, but an illustration does exist.  This has caused a big headache for palaeontologists trying to understand the differences between the species.”

Hunting for Clues to Help Solve a “Fish Lizard” Mystery

Dean Lomax and Judy Massare examining Ichthyosaur specimens.

Dean Lomax and Judy Massare examining Ichthyosaur specimens in the marine reptile gallery at the Natural History Museum (London).

Picture Credit: Dean Lomax

In the mid-1970’s, palaeontologist, Dr Chris McGowan was the first to suggest that Ichthyosaurus communis and I. intermedius may represent the same species.  He could not find reliable evidence to separate the two species.  Subsequent studies argued for and against the separation of the species.

In this new research, Dean and Judy have reviewed all of the research for and against the separation of the two species.  This is the most extensive scientific study ever published comparing the two Jurassic-aged marine reptiles.   The pair of scientists have confirmed that the species are the same and that features of Ichthyosaurus intermedius can be found in other Ichthyosaur species, including I. communis.

It seems that the fossil material ascribed to the species Ichthyosaurus intermedius lack any autapomorphies – distinctive features or derived characteristics and traits that are unique to that taxon.

Thanks to the efforts of these two researchers, a fishy tale that is over a hundred years may have been resolved.

In recent years, the duo have described three new species and have provided a reassessment of historical species.  Their work has provided a far superior understanding of the species than has ever been produced.

The research has been published in Journal of Systematic Palaeontology: http://dx.doi.org/10.1080/14772019.2017.1291116.

2 03, 2017

Very Near to “Near Bird”

By | March 2nd, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Closest View Yet of Anchiornis “Near Bird”

More than 225 fossils of the Late Jurassic feathered dinosaur Anchiornis (A. huxleyi) have been found to date and this relative abundance of fossil specimens in conjunction with some very sophisticated laser technology, has enabled scientists to gain the best idea yet as to what dinosaurs actually looked like.  Anchiornis huxleyi fossils come from the Tiaojishan Formation of Liaoning (China) and the dinosaur’s name means “Huxley’s near bird”, honouring the 19th Century English scientist Thomas Henry Huxley, an early supporter of Darwin’s theory of evolution, and one of the first academics to propose a close evolutionary relationship between the birds and the Dinosauria.  How apt that the use of a relatively new technique in palaeontology, that of the production of laser-stimulated fluorescence images, has enabled palaeontologists to get closer to “near bird” than ever before.

An Illustration of the Late Jurassic Dinosaur Anchiornis (A. huxleyi) Based on the New Images

An illustration of Anchiornis huxleyi.

An illustration of Anchiornis huxleyi.

Picture Credit: Julius Csotonyi

Laser-stimulated fluorescence (LSF)

Writing in the journal “Nature Communications”, researchers from the University of Hong Kong in collaboration with scientists from Linyi University (Shandong Province), the Chinese Academy of Sciences and a number of American research institutions, report on the reconstruction of a feathered dinosaur’s body outline based on high-definition images of preserved soft tissues and their integumental covering.

The Body Plan of Anchiornis huxleyi Created from the High-Definition Images

Anchiornis reconstructed body outline.

Reconstructed body outline of the bird-like feathered dinosaur Anchiornis using laser-stimulated fluorescence images.

Picture Credit: Wang X L, Pittman M et al

The coloured areas represent different fossil specimens and the black areas are approximated reconstructions.  For the first time palaeontologists have an accurate body outline of a bird-like dinosaur.  The scale bar in the image is 1 cm and the body length of Anchiornis (head to tail) is approximately 40 cm.

Laser-stimulated fluorescence (LSF), is a revolutionary new technique using high power lasers that makes unseen soft tissues preserved alongside the bones, literally “glow in the dark” by fluorescence, until the application of this new technique, palaeontologists had to infer body plans based on the fossilised bones and evidence of muscle scars using extant animals as comparisons.  One of the corresponding authors of the scientific paper, Dr Michael Pittman (Department of Earth Sciences, the University of Hong Kong), explained how he and his co-workers reconstructed the first highly detailed body outline of a feathered dinosaur based on high-definition images of its preserved soft tissues.

A View of the Wing of Anchiornis Under Laser-stimulated Fluorescence

The wing of Anchiornis seen under laser-stimulated fluorescence.

The wing of the bird-like feathered dinosaur Anchiornis under laser-stimulated fluorescence.

Picture Credit: Wang X L, Pittman M et al

This ground-breaking research has helped palaeontologists to see just how closely, Anchiornis of the Late Jurassic, resembled modern birds.  For example, in the image above, folds of skin in front of the elbow and behind the wrist (referred to as a patagium), can be made out.  The patagium was covered in feathers, just like in modern birds.

The laser-stimulated fluorescence method was developed by collaborator Tom Kaye (Foundation for Scientific Advancement, Arizona, USA).  The technique involves scanning fossils with a violet laser in a dark room. The laser “excites” the few skin atoms left in the matrix making them glow, revealing what the shape of the dinosaur actually looked like.

Dr Michel Pittman with the Laser Scanner

Dr Pittman and the laser scanner.

Dr Pittman holding the laser scanner pictured behind is an illustration of Anchiornis.

Picture Credit: Dr M Pittman

Dr Pittman commented:

“For the last 20 years, we have been amazed by the wondrous feathered dinosaurs of north-eastern China.  However, we never thought they would preserve soft tissues so extensively.”

Over Two Hundred Specimens Examined

Dr Pittman and his colleagues examined over two hundred specimens of the feathered bird-like dinosaur Anchiornis to find the dozen or so that showed special preservation.  The quantitative reconstruction that the team developed shows the contours of the wings, legs and even perfectly preserved foot scales, providing new details that illuminate the origin of birds.  It seems that Anchiornis had “drumsticks” just like a modern bird too.

Dr Pittman at Work Checking a Specimen Using the Laser Technique

Scanning Anchiornis fossils.

Dr Pittman examines fossils using LSF in Shandong TianYu Museum of Natural History.

Picture Credit: Dr M Pittman

When first described in 2009, Anchiornis was heralded as an important transitional fossil between feathered dinosaurs and volant (flying) forms.  Using this new technique (LSF), Dr Pittman and his colleagues found that the shape of wing was in many ways similar to modern birds, but it also had some seemingly primitive characteristics like feathers arranged more evenly across the wing rather than in distinct rows.  This research suggests that Anchiornis could produce a relatively straight arm, a posture broadly found in many living gliding birds (for example, Cormorants, Albatrosses and Pelicans).  The research identifies a previously unknown aspect of arm morphology differentiation at the earliest stages of paravian evolution (at least by the Oxfordian stage of the Late Jurassic), that may even have been widespread.  These new insights provide crucial information for reconstructing how dinosaurs experimented and eventually achieved flight.

Dr Pittman Pictured with Images Created to Illustrate This New Research

Dr Pittman with a body Plan and drawing of Anchiornis.

Dr Pittman holding a drawing and a body plan of Anchiornis.

Picture Credit: Dr M Pittman

To read an article about the discovery of Anchiornis huxleyiOlder than Archaeopteryx

The scientific paper: Wang, X. et al. “Basal Paravian Functional Anatomy Illuminated by High-detail Body Outline” published in Nature Communications (Nat. Commun. 8, 14576 doi: 10.1038/ncomms14576 2017).

Everything Dinosaur acknowledges the help of Hong Kong University in the compilation of this article.

22 02, 2017

The Half Tonne Rat

By | February 22nd, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Super-sized Rodent Re-Writes Family Tree

The skull and jaws from a pair of giant rodents, that represent an extinct species that could have weighed as much as half a tonne, are helping to re-shape the rodent family tree.  Study of these new fossils have led researchers to propose a formal revision of the three known species of the genus Isostylomys into just one species, Isostylomys laurillardi.

These are the best-preserved fossils to date of this extinct group, which was previously known only from skull fragments and individual teeth, the scientists report in a new study, published in the “Journal of Systematic Palaeontology”,

The new fossils of the two rodents, an adult and a juvenile, paint a more complete picture of these extinct and massive rat-like animals.  For example, the fossil discoveries raised questions about how these giant rodents were classified within their genus, and hint that several species that were thought to be related may instead be a single species.  The fossils add to our knowledge regarding giant members of the Dinomyidae family and is helping palaeontologists to reappraise the phylogeny of this once diverse and speciose group of South American mammals.

The Giant Miocene Rodent Isostylomys laurillardi (Adult and Juvenile)

Isostylomys laurdillardi a giant prehistoric rodent.

Isostylomys laurillardi (adult and juvenile).

Picture Credit: Renzo Vaira/Taylor & Francis

The fossil material comes from the exposed cliffs in the Río de la Plata coastal region of southern Uruguay.  The fossils have been dated to the Miocene Epoch (9.5 to 10 million-years-ago approximately).  The researchers, including lead author, Dr Andres Rinderknecht of the Museo Nacional de Historia Natural (Uruguay), examined the teeth and skulls of fossil specimens, comparing them to the bones and teeth of the largest living rodent the Capybara (Hydrochoerus hydrochaeris).

The research team conclude that, due to similarities in the adult’s and the juvenile’s teeth structure, previously found fossils, which were smaller and thought to belong to a different species, were in fact from the same species.

Skull and Jaw Fossils of Isostylomys laurillardi

Isostylomys laurillardi fossil material (MNHN 2187)

Skull in ventral view (A), skull and mandible in left lateral view (B), and mandible in occlusal view (C).

Picture Credit: Taylor & Francis

The picture above shows the adult skull in ventral view seen from underneath, (A), and the skull and jaw viewed from the side (B).  Picture (C) shows the jaw in occlusal view, the scale bar is five centimetres.

The authors have consequently proposed that members of the subfamily Gyriabrinae could represent juveniles belonging to other subfamilies of Dinomyidae and that three known species of the genus Isostylomys should be merged into just one species, Isostylomys laurillardi.

Commenting on the team’s conclusions, Dr Rinderknecht stated:

“Our study shows how the world’s largest fossil rodents grow and we describe fossil remains of a giant rodent baby and an adult.  Comparing them we conclude that from very young the giant rodents already were very similar to the adults which allows us to deduce that the great majority of the hypotheses before posed were wrong.  The juvenile and the adult analysed here represent some of the largest rodents known to science with some of these animals weighing almost a ton.”

The Giant Incisor of the Adult Isostylomys

Giant rodent tooth fossil (Isostylomys)

MNHN 2187 the giant lower right incisor of (Isostylomys),

Picture Credit: Taylor & Francis

The adult remains found consist of an almost complete skull with a partial jaw, while the juvenile’s remains are of a complete lower jaw and the right calcaneum (heel bone).  Almost all previous discoveries of this kind have consisted of isolated teeth, and small fragments of skulls or jaws, which make this discovery some of the best-preserved remains of giant dinomids known to science.

“Making a Giant Rodent: Cranial Anatomy and Ontogenetic Development in the genus Isostylomys (Mammalia, Hystricognathi, Dinomyidae)”.

By Andrés Rinderknecht, Enrique Bostelmann and Martin Ubilla, published by Taylor and Francis.

The scientific paper: Access the scientific paper here.

21 02, 2017

The Tully Monster Just Lost its Backbone

By | February 21st, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

“Tully Monster” Mystery Not Solved

Back in March 2016, Everything Dinosaur published an article on the enigmatic “Tully Monster” (Tullimonstrum gregarium), a bizarre creature of coastal waters and estuaries, first described in 1966, but not classified until fifty years later.  Trouble is, the proposal that this thirty-centimetre long, stalk-eyed animal was a vertebrate has been challenged.  It seems that the mystery surrounding how to classify the State fossil of Illinois (fossils have only been found in the Mazon Creek area of Illinois and nowhere else in the world), has not been solved.

The Bizarre Carboniferous Marine Animal Tullimonstrum gregarium

The Paleo-Creatures "Tully Monster" model.

The Paleo-Creatures Tullimonstrum replica.

Picture Credit: Everything Dinosaur/Paleo-Creatures

Two separate recent studies had proposed that the “Tully Monster” was a soft-bodied vertebrate, one that is related to extant jawless fishes such as the very slimy Hagfish and the Lamprey (a fish, perhaps most famous for causing the demise of Henry I, the son of William the Conqueror, who died from a “surfeit of lampreys”.)

To read an article supporting the T. gregarium was a vertebrate theory: Tully Monster Riddle Solved

Vertebrate Theory Challenged

Palaeobiologists at the University of Pennsylvania have challenged the idea that Tullimonstrum was a primitive fish with a proboscis.  Writing in the academic journal “Palaeontology”, lead author Assistant Professor Lauren Sallan, (Dept. of Earth and Environmental Science) and her co-workers refute the vertebrate hypothesis.

Lauren stated:

​​​​​​​”This animal doesn’t fit easily in classification because it’s so weird.  It has these eyes that are on stalks and it has this pincer at the end of a long proboscis and there’s even disagreement about which way is up.  But the last thing that the Tully monster could be is a fish.”

Sallan and colleagues, which include Robert Sansom (University of Manchester), postdoctoral researcher John Clarke, Zerina Johnason (Natural History Museum, London), Sam Giles (Oxford University), Ivan Sansom of the University of Birmingham and Philippe Janvier of France’s Muséum National d’Histoire Naturelle, postulate that that the two papers which seemingly settled the Tully Monster debate are flawed, failing to definitively classify it as a vertebrate.

Junior Research Fellow Giles explained:

“It’s important to incorporate all lines of evidence when considering enigmatic fossils: anatomical, preservational and comparative.  Applying that standard to the Tully Monster argues strongly against a vertebrate identity.”

The Ancient Waters of the Mazon Creek Area 300 Million Years Ago

Life in Mazon Creek during the Late Carboniiferous.

Two “Tully Monsters” in the shallow waters of Mazon Creek.

Picture Credit: John Megahan

The Tully Monster has been known since the 1950’s, when the first fossils were found in the Mazon Creek fossil beds in central Illinois.  Since then, thousands of specimens have been identified from this locality, but they are not found anywhere else in the world.

Looking at the history of classification, Sallan explained that at first it was thought to be some sort of marine worm, then it was proposed that it was a form of mollusc, like a sea-slug.  Other palaeontologists have argued that this strange little animal has affinities with the Arthropoda, perhaps a distant relative of today’s shrimp.  Then in 2016, two research papers were published proposing that T. gregarium was actually a member of the back-boned group of animals – a vertebrate.

Evidence for the Vertebrate Theory

One study examined more than 1,200 Tullimonstrum fossils.  In some, the researchers observed a light band running down the creature’s mid-line, which they interpreted as a notochord, a kind of primitive backbone.  They also said it contained other internal organ structures, such as gill sacs, that identified it as a vertebrate, and that the animal’s teeth resembled those of a lamprey.

Assistant Professor Sallan and her colleagues noted that these conclusions are based on a misunderstanding of how fossils in Mazon Creek are preserved.  The Tully Monster samples come from what was once a muddy estuarine area and at Mazon Creek, internal soft tissues are very rarely preserved.  Lamprey fossils have been found in the Mazon Creek area and these fossils are markedly different from their supposed relative the Tully Monster.

In the other 2016 study, the researchers reported that scanning electron microscope images of the Tully Monsters’ eyes had revealed structures called melanosomes, which produce and store melanin.  That paper’s authors argued that the complex tissue structure they saw in the animals’ eyes indicated it was likely a vertebrate.  The Pennsylvania University led team counter this point by arguing that many Arthropods and Molluscs, also have complex eyes.

Sallan added:

“Eyes have evolved dozens of times.  It’s not too much of a leap to imagine Tully Monsters could have evolved an eye that resembled a vertebrate eye.”

Based on Sallan and her colleagues’ examination of Tullimonstrum eyes, these creatures in fact possess what is known as a cup eye, a relatively simpler structure that lacks a lens.

“So the problem is, if it does have cup eyes, then it can’t be a vertebrate because all vertebrates either have more complex eyes than that or they secondarily lost them.  But lots of other things have cup eyes, like primitive chordates, molluscs and certain types of worms,” the Assistant Professor stated.

In this research, not one of more than a thousand fossil specimens studied appeared to possess structures that are believed to be universal in aquatic vertebrates, namely otic capsules, components of the ear that allow animals to balance and a lateral line, a sensory structure along the flanks that enables fishes to orient themselves and to detect their surroundings.

Comparing the Anatomy of Tullimonstrum to Other Creatures

How to classify a "Tully Monster".

Comparing the “Tully Monster” to other creatures.

Picture Credit: Pennsylvania University

Lauren went onto state:

“You would expect at least a handful of the specimens to have preserved these structures.  Not only does this creature have things that should not be preserved in vertebrates, it doesn’t have things that absolutely should be preserved.”

The researchers said that an improper classification of such an unusual species has ripple effects on the larger field of evolution.

“Having this kind of misassignment really affects our understanding of vertebrate evolution and vertebrate diversity at this given time.  It makes it harder to get at how things are changing in response to an ecosystem if you have this outlier.  And though of course there are outliers in the fossil record, there are plenty of weird things and that’s great, if you’re going to make extraordinary claims, you need extraordinary evidence.”

It looks like, for the time being at least the “Tully Monster” has lost its backbone.

13 02, 2017

Spiny, Armoured Slug Provides Best Evidence for the Ancestry of Molluscs

By | February 13th, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Spiny but Slimy and with a Radula – Calvapilosa kroegeri

Scientists from the University of Bristol have uncovered a 480-million-year-old slug-like fossil in Morocco which sheds new light on the evolution of molluscs, a diverse group of invertebrates that includes clams, snails and cephalopods like squid and cuttlefish.

A Model of the Newly Described Calvapilosa kroegeri

Viewed from the top (left) and the bottom (right) - Calvapilosa kroegeri.

Calvapilosa kroegeri dorsal and ventral views.

Picture Credit: Dr Jakob Vinther

One of the defining characteristics of the molluscs is the possession of a radula, a kind of toothed-tongue which is used to rake up or rasp food.  The radula houses hundreds of teeth, the patterns of which can be used to determine diet and identify species.  Whilst not all molluscs have a radula, a radula cannot be found in any other group of animals.  It is a characteristic of the Mollusca Phylum.

Dr Jakob Vinther, from the Schools of Biological Sciences and Earth Sciences, is lead author of the study, which is published today in the academic journal Nature.

Dr Vinther stated:

“The molluscs are amongst the earliest animals identifiable in the fossil record, however determining what their ancestor looked like is difficult since many of the groups appear within a small window of time, making the sequence of evolutionary events difficult to piece together.”

The recent discovery of a new species of mollusc in the Anti-Atlas region in Morocco has enabled palaeontologists to revisit this problem and infer the appearance of the ancestor of all molluscs.  The new species discovered, Calvapilosa kroegeri, is part of the Fezouata Biota, a group of organisms from the early Ordovician period (485-470 million years ago), which are found in rocks in south-eastern Morocco.  The Fezouata Biota is famed for its exceptional preservation, allowing palaeontologists to identify details not preserved from any other fossil site.

Co-author of the scientific paper, Luke Parry, a PhD student at the University of Bristol, added:

“Calvapilosa kroegeri resembles a slug covered with short spines all over its upper body and with a large ‘fingernail-like shell’ over its head.  In the centre of the head of this species are two rows of teeth which we demonstrate is a radula.”

The discovery of this feeding structure firmly identifies Calvapilosa kroegeri as a mollusc.  Additionally, it suggests that similar fossil forms, such as Halkieria, a two-plated slug-like fossil, are also molluscs and possessed a radula.  Following an analysis to determine the family tree of molluscs, Calvapilosa kroegeri was revealed to be the most primitive member of the lineage leading to chitons.  Chitons can still be found today and are characterised by their possession of eight shell plates and spines around their margin, similar to what is seen covering the body of Calvapilosa.

Looking Like a Hairy Fingernail Calvapilosa kroegeri Fossil

Calvapilosa looks like a "hairy fingernail".

The fossil of Calvapilosa kroegeri, preserving the feeding apparatus (radula) and all the spines that covered the body.

Picture Credit: Peter Van Roy

Dr Vinther concluded:

“If we trace back the evolution of chitons, we can see that the number of their shells has increased with time.  It is therefore likely that the ancestor to all molluscs was single-shelled and covered in bristle-like spines, not dissimilar to Calvapilosa kroegeri.”

The Scientific Paper: “Ancestral Morphology of Crown-group Molluscs Revealed by a New Ordovician Stem Aculiferan” by J. Vinther, L. Parry, D. Briggs and P. Van Roy, published in Nature.

Everything Dinosaur acknowledges the help of a press release from Bristol University in the compilation of this article.

29 01, 2017

Researchers Confirm Dinosaur Collagen

By | January 29th, 2017|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

2009 Brachylophosaurus Study Replicated

One of the most controversial areas of palaeontology is the extraction and assessment of traces of organic remains preserved in the fossil record.  Indeed, the study of preserved proteins and other organic remains such as potential red blood cells from within fossils tens of millions of years old, is perhaps, one of the most controversial subjects in the whole of science.  Researchers from North Carolina State University, eminent figures such as Professor Mary Schweitzer have been at the very forefront of this relatively new area of study, essentially long extinct animal molecular biology.  Organic material from fossils of dinosaurs is being reported more frequently, however, being able to repeat analyses and confirm previous results remains fundamental to the results of such studies gaining acceptance in the wider scientific community.

A new paper has been published in the “Journal of Proteome Research” by scientists from North Carolina State University who, in collaboration with colleagues from North-western University and the University of Texas – Austin, have applied the most rigorous testing methods used to date to isolate additional collagen peptides from an 80-million-year-old dinosaur thigh bone.  This study helps strengthen the idea that organic molecules can persist within the fossil record for many millions of years.  Repeating an experiment and replicating previous results has implications for our ability to study the fossils of long extinct creatures at the molecular level.  The job of “dinosaur biologist” may have come one step closer.

The Brachylophosaurus (B. canadensis) Femur

Brachylophosaurus femur.

MOR 2598 the Brachylophosaurus femur in its field jacket prior to the peptide study.

Picture Credit: North Carolina State University

The picture above shows the dinosaur thigh bone used in the study.  The area for sampling has been marked on the bone, demonstrating that not everything within this cutting-edge form of palaeontology is that sophisticated.

North Carolina State postdoctoral researcher Elena Schroeter, along with Professor Mary Schweitzer and co-worker Wenxia Zheng wanted to confirm the results of an earlier (2009) assessment of organic material retrieved from the femur of a duck-billed dinosaur (Brachylophosaurus canadensis).  Advances in mass spectrometry and clean room technology since the first experiments, would permit the team to produce a more robust set of results, with less risk of contamination or false “positive” results.

Explaining the team’s reasoning for repeating the 2009 study, Elena Schroeter stated:

“Mass spectrometry technology and protein databases have improved since the first findings were published, and we wanted to not only address questions concerning the original findings, but also demonstrate that it is possible to repeatedly obtain informative peptide sequences from ancient fossils.”

The Hunt for Collagen

Collagen is a protein, it forms fibrous strands and, ironically it happens to be the most abundant protein found in our own bodies.  The proteins that make up collagen are themselves composed of peptides, which are chains made up of amino acids.  If peptides can be identified within a dinosaur bone (or any fossil bone for that matter), palaeontologists will be able to determine the evolutionary relationships between members of the Dinosauria and their relationship with extant animals.  This would help solve such puzzles as whether or not the dinosaurs were warm-blooded and provide much more information about the lives of these long extinct animals, far more information than could be derived from an anatomical analysis of preserved bones and teeth.  In addition, this type of study would help to answer other intriguing questions. related to the fossilisation process itself.  For example, which characteristics of collagen proteins permit preservation over deep geological time?

Brachylophosaurus canadensis

Brachylophosaurus was a member of the Hadrosauridae family of bird-hipped dinosaurs (Ornithischians) and it is known from relatively abundant (bonebed) fossil material excavated from Upper Cretaceous deposits of North America (Judith River Formation of Montana, USA and the contemporaneous Oldman Formation of Alberta, Canada).  This herbivorous dinosaur lived some 80-78 million years ago, (Campanian faunal stage of the Late Cretaceous).  It was formally named and scientifically described in 1953.

The Late Cretaceous Duck-billed Dinosaur Brachylophosaurus canadensis

The Late Cretaceous Brachylophosaurus.

Brachylophosaurus illustrated.

Picture Credit: Houston Museum of Natural Science

Professor Schweitzer commented:

“We collected B. canadensis with molecular investigation in mind.  We left a full metre of sediment around the fossil, used no glues or preservatives and only exposed the bone in a clean, or aseptic environment. The mass spectrometer that we used was cleared of contaminants prior to running the sample as well.”

The sample of bone that was analysed was from the specimen’s femur (thigh bone).  The bone used was specimen number MOR 2598.  Using mass spectrometry, the team recovered a total of eight peptide sequences that form collagen (collagen I).  Two peptide sequences were identical to those recovered in the 2009 research, six are new, not having been found in previous studies.  The peptide sequences show that the collagen in a dinosaur (B. canadensis) has affinities with extant Aves (birds) and crocodylians, a result expected given the close phylogeny between the Dinosauria and these two groups.

Elena Schroeter added:

“We are confident that the results we obtained are not contamination and that this collagen is original to the specimen.  Not only did we replicate part of the 2009 results, thanks to improved methods and technology, we did it with a smaller sample and over a shorter period of time.”

Phylogenetic Affinity

Phylogenetic analyses place the recovered sequences within basal Archosauria and when only the six new sequences are considered, B. canadensis is grouped more closely to crocodylians.  However, when all sequences (current and those reported in 2009), are analysed, B. canadensis is placed more closely to stem Aves.  The researchers conclude that their data robustly supports the hypothesis of an endogenous origin for these peptides, (they originated from within the organism’s bone), confirming the idea that peptides can survive in specimens tens of millions of years old, and being able to repeat the experiment and obtain the same results bolsters the validity of the earlier (2009) study.

Professor Schweitzer, a stalwart for organic molecular research in the fossil record explained:

“Our purpose here is to build a solid scientific foundation for other scientists to use to ask larger questions of the fossil record.  We’ve shown that it is possible for these molecules to preserve.  Now, we can ask questions that go beyond dinosaur characteristics.  For example, other researchers in other disciplines may find that asking why they preserve is important.”

Testing a Hypothesis

Although this research remains controversial, there is a growing body of evidence that suggests the minute traces of organic matter can be preserved within the fossil record.  In order for this research to gain wider acceptance it must be shown that peptide sequences can be reliably obtained from fossil material and that these experiments can be repeated with the same outcomes.  Intriguingly, as our ability to identify organic molecules improves, so these highly fragmentary sequences for ancient proteins can be increasingly expanded.

To test the hypothesis that peptides can be repeatedly detected and validated from fossil tissues many millions of years old, the research team applied updated and more sophisticated extraction methodology, in conjunction with improved sterile, clean-room conditions.  High resolution mass spectrometry and bioinformatics analyses on a Brachylophosaurus canadensis specimen (MOR 2598), from which collagen I peptides were recovered in 2009, led to the identification of eight peptide sequences in the repeated experiment.  This new study further augments the idea that within fossilised elements, which, perhaps have been preserved under exceptional conditions, do indeed, contain minute organic remnants of long dead organisms.

To read a related article about the potential for finding blood remnants with dinosaur fossils: The Blood of a Brachylophosaurus

The scientific paper: “Expansion of the Brachylophosaurus canadensis collagen I sequence and additional evidence for the preservation of Cretaceous protein”.

Authors: Elena Schroeter, Mary Schweitzer and Wenxia Zheng, NC State University; Caroline DeHart, Paul Thomas, Neil Kelleher, North-western University; Timothy Cleland, University of Texas-Austin; Marshall Bern, Protein Metrics.  Published: Journal of Proteome Research

18 12, 2016

Marked Variation in the Body Size of Australopithecus afarensis

By | December 18th, 2016|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Fossil Footprints from Tanzania Shed Light on Marked Body Size Variation in A. afarensis

Newly discovered footprints of early hominins found by researchers from the University of Dar es Salaam in collaboration with Italian colleagues, show marked body size variation in our 3.66 million-year-old ancestors.  Analysis of the footprints hints at a social grouping structure more akin to modern gorillas than to chimpanzees and bonobos.   The impressions were created when a group of ancient bipeds walked across wet volcanic ash, these new prints, showing evidence of two individuals walking together were found within 150 metres of the hominin trace fossils discovered in 1978.  The 1978 fossils were attributed to the species of hominin (a primate more closely related to our species than to a chimpanzee), dubbed Australopithecus afarensis.  These newly described tracks too, have been attributed to this species.  They show two individuals, named S1 and S2 in the study, moving on the same palaeosurface and in the same direction as the three hominins documented in the 1978 discovery.

In the scientific paper published in the journal “eLife”, the researchers report that the specimen referred to as S1 had much larger feet than any other member of this group.  Size estimates for this individual indicate an Australopithecus standing 1.65 metres tall (five feet, five inches tall), not as tall as a modern man (H. sapiens), but around five centimetres taller than the height of the average British woman.

Ancient Footprints May Indicate Marked Body Size Difference in Australopithecus afarensis

Footprints (A. afarensis).

Ancient footprints from a second site in Laetoli (Tanzania).

Picture Credit: Raffaella Pellizzon with additional annotation by Everything Dinosaur

In the photograph above, the footprints can be clearly made out, along with tracks made by a number of other Pliocene animals.  The red arrow in the bottom left hand corner marks the direction of travel of the hominins.

The research team propose that these new tracks when reviewed in conjunction with the 1978 trace fossil discovery, may provide clues as to how this ancient species of early human lived.  The newly discovered prints, including the large prints of S1, might be the tracks of a male walking with a collection of smaller females and their offspring.

An Australopithecus Harem?

Commenting on the implications for social behaviour, lead researcher Professor Giorgio Manzi (University of Roma, Italy) stated:

“This novel evidence, taken as a whole with the previous findings, portrays several early hominins moving as a group through the landscape following a volcanic eruption and subsequent rainfall, but there is more.  The footprints of one of the new individuals are astonishingly larger than anyone else’s in the group, suggesting that he was a large male member of the species.”

A Closer View of the Hominin Tracks

Laetoli fossil footprints.

The prints preserved in volcanic ash suggest a large member of the species.

Picture Credit: Raffaella Pellizzon with additional annotation by Everything Dinosaur

Standing around 1.65 metres tall, makes S1 the largest Australopithecus individual described to date.

Commenting on the significance of this new trackway and its proximity to the other Australopithecus tracks, co-author Jacopo Moggi-Cecchi (University of Florence) said:

“Now that we’ve found a new set of footprints it opens up a completely different window and there could be a number of new possibilities to study what is a photograph in time of the everyday life of this species.”

The finding of a male perhaps walking with several females could mean their social structure was closer to the gorilla-like model than to chimpanzees or to modern humans.  These tracks could be interpreted as a large, dominant male walking with his troop of female mates, a sort of Australopithecus harem.

A Map Showing the Location of the Trackways in Northern Tanzania

A map of the Laetoli area (Tanzania)

The site of the Australopithecus trackways in Tanzania.

Picture Credit: eLife

This new trackway evidence, in combination with a comparative reappraisal of the 1978 footprints has important implications for the Pliocene record of early hominin behaviour and morphology.  The results are consistent with considerable body size variation and, probably a degree of dimorphism between males and females within a single species of bipedal hominin as early as 3.66 million years ago.

A Line Drawing of the Hominin Tracks and Other Associated Features

Line drawing of the fossil trackway.

A line drawing of the Laetoli tracks.

Picture Credit: eLife

The four excavated pits that make up the new trackway evidence are represented above in the line drawing.

Dashed lines indicate uncertain contours. Some of the most interesting tracks are coloured: hominins in orange (heel drags in dark grey), prehistoric horses in dark green (M9), rhinoceros in red (M9), giraffe in light brown (M10), and guinea fowl in blue (M10).  Large roots and the bases of trees are in light green (L8).  The main faults/fractures are indicated by brown lines.  Raindrop impressions occur in the northern part of L8 (dotted areas).

The scientific paper: “New Footprints from Laetoli (Tanzania) Provide Evidence for Marked Body Size Variation in Early Hominins” published in the journal eLife.

2 12, 2016

Fossilised Bacteria Shed Light on Life Before Oxygen

By | December 2nd, 2016|Geology, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Ancient African Rocks Provide Evidence of Life Before Oxygen

The fossils of ancient bacteria that existed in deep water environments during the Neoarchean Era some 2.52 billion years ago, have been identified by an international team of researchers.  They don’t represent the oldest known life on our planet, recently, Everything Dinosaur published an article on some new research that postulates that microbial colonies existed on Earth some 3.7 billion years ago*, but these South African fossils may represent the oldest evidence of a bacteria capable of oxidising sulphur (within the Class Gamma Proteobacteria), found to date.

A Highly Magnified Image of a Fossilised Bacteria

Fossilised bacteria.

A view of one of the spherical structures identified as fossil bacteria.

Picture Credit: Andrew Czaja

This discovery is significant as it sheds light on a time in Earth’s history, when, essentially, all the microbial forms that exist today had probably evolved, but the fossil record for their existence is particularly sparse. Writing in the journal of the Geological Society of America, the researchers which include scientists from the University of Cincinnati and the University of Johannesburg, report on large, organic, smooth-walled, spherical microfossils representing organisms that lived in deep water, when our planet’s atmosphere had less than one-thousandth of one percent of the oxygen we have today.

Microscopic Life in the Archean

The research team discovered the microscopic fossils preserved in black chert that had been laid down at the bottom of a deep ocean, in the Griqualand West Basin of the Kaapvaal craton of South Africa (Northern Cape Province).  Geologist Andrew Czaja (University of Cincinnati), explained that this part of South Africa was one of the few places in the world where rocks of this great age were exposed.  The fossils are very significant as they represent bacteria surviving in a very low oxygen environment, the bacteria existed prior to “Great Oxygenation Event”, sometimes referred to as the GOE, a period in Earth’s history from about 2.4 billion to 2.2 billion years ago, when water-borne cyanobacteria (blue-green bacteria), evolved photosynthesis and as a result, oxygen was released into the atmosphere.  More oxygen in our atmosphere helped drive the evolution of complex organisms, eventually leading to the development of multi-cellular life.

Commenting on this research Assistant Professor Andrew Czaja stated:

“These are the oldest reported fossil sulphur bacteria to date and this discovery is helping us reveal a diversity of life and ecosystems that existed just prior to the Great Oxidation Event, a time of major atmospheric evolution.”

Radiometric dating and geochemical isotope analysis suggest that these fossils formed on an ancient seabed more than one hundred metres down.  The bacteria fed on sulphates that probably originated on the early super-continent Vaalbara (a landmass that consisted of parts of Australia and South Africa).  With the fossils having been dated to 2.52 billion years ago, the bacteria were thriving just before the GOE, when shallow water bacteria began creating more oxygen as a by-product of photosynthesis.

Czaja’s fossils show the Neoarchean bacteria in plentiful numbers while living within the muddy sediment of the seabed.  The assistant professor and his co-researchers postulate that these early bacteria were busy ingesting volcanic hydrogen sulphide, the molecule known to give off a rotten egg smell, then emitting sulphate, a gas that has no smell.  This is the same process that goes on today as extant microbes recycle decaying organic matter into minerals and gas.  The team surmise that the ancient oceanic bacteria are likely to have consumed the molecules dissolved from sulphur rich minerals that came from the land rocks associated with Vaalbara or from volcanic rocks on the seabed.

Andrew Czaja Points to the Rock Layer where the Fossil Bacteria was Found

Indicating the layer of rock from which the fossil bacteria was collected.

Andrew Czaja (University of Cincinnati), points to the rock layer from which fossil bacteria was collected.

Picture Credit: Aaron Satkoski

Sizeable Bacteria

These fossils occur mainly as compressed and flattened solitary shapes that resemble a flattened, microscopic beach ball.  They range in size from 20 microns (µm), about half the thickness of a human hair, up to a whopping 265 µm, that’s some very large bacteria, about forty times bigger than a human red blood cell, making the fossils exceptionally large for an example of bacteria.  The research team hypothesis that these ancient bacteria were similar in habit to the modern, equally large-sized bacteria Thiomargarita, which lives in oxygen-poor, deep water environments.

Described as being morphologically similar to Proterozoic and Phanerozoic acritarchs and to certain Archaean fossils interpreted as possible blue-green bacteria (cyanobacteria), these fossils are the oldest reported sulphur processing bacteria described to date.  They reveal that microbial life was diverse as early as 2.5 billion years ago and provide further evidence that organisms can thrive in very low oxygen environments.  This may have implications for astronomers as they search for evidence of life on other planets and moons within our solar system.

Images of the Microstructures (Dark, Round Spots within Ancient Rocks)

Microstructures indicate sulphur oxidising bacteria.

Images of microstructures that have physical characteristics with the remains of spherical bacteria.

Picture Credit: Andrew Czaja

*To read Everything Dinosaur’s recently published article (September 2016), about the possible identification of evidence of microbial colonies in strata some 3.7 billion years old: 3.7 Billion-Year-Old Microbes

The scientific paper: “Sulfur-oxidizing Bacteria prior to the Great Oxidation Event from the 2.52 Ga Gamohaan Formation of South Africa”, published in “Geology” the journal of the Geological Society of America.

24 11, 2016

Fossil Footprints Hint at Decline of Amphibians

By | November 24th, 2016|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

The Rise of Reptiles as the World Dried Up

Places like the “Jurassic Coast” of Dorset, or the beaches that surround Whitby (North Yorkshire), might be synonymous with fossil hunting, but surprisingly, even some of our great cities can lay claim to be at the centre of palaeontological research.  Take the city of Birmingham (West Midlands), for example, not the sort of place that one would immediately associate with fossils (the exception being the amazing Wren’s Nest site to the north-west of Birmingham, Britain’s first national nature reserve for geology).  However, the study of a series of sandstone slabs, excavated from a quarry a few miles to the north of the centre of Birmingham is helping palaeontologists to plot global climate change some 310 million years ago, that led to the demise of amphibians and provided ideal conditions for the evolution and radiation of reptiles.

Birmingham, Like Most of the British Isles was once Covered in a Lush Tropical Carboniferous Rainforest

A carboniferous scene.

By the Carboniferous the insects were already highly diversified and the lush forests and swamps were dominated by Temnospondyls (primitive amphibians).

Picture Credit: Richard Bizley (Bizley Art) for more of Richard Bizley’s artwork visit: Bizley Art

In 1912, schoolteacher and amateur botanist Walter Henry Hardaker presented a paper to the Geological Society of London detailing the discovery of a series of Tetrapod footprints and trackways that he had discovered in a quarry located in the village of Hamstead.  Hamstead, itself has long since been swallowed up in the urbanisation of the area as the city of Birmingham expanded.  The quarry too, has gone covered up as houses, shops and offices were built, after all, the quarry was located just a stone’s throw from Hamstead railway station.

The sandstones became part of the Lapworth Museum of Geology’s fossil collection at the University of Birmingham.  Hardaker, an alumnus of Birmingham University, probably would have been fascinated by the recent research work undertaken by third-year Palaeobiology and Palaeoenvironments MSci student Luke Meade (University of Birmingham) and colleagues as they applied 21st Century analytical techniques to reveal a glimpse of the world when reptiles were beginning to take over from the amphibians as the dominant Tetrapods.

Using funding provided by the Palaeontological Association, the students scanned the twenty or so red sandstone slabs using state-of-the-art photogrammetric technology to provide a three-dimensional analysis of each track.  Colour coding of the images permitted the research team to produce topographic maps showing the individual contours of each specimen.  These three-dimensional images were then compared to other ichnofossils (trace fossils) to identify the types of animals which produced the footprints.

The footprints and tracks provide a remarkable insight into vertebrate life during the Pennsylvanian Epoch of the Late Carboniferous.  These trace fossils were formed as animals crawled over soft mud next to river channels.  A subsequent flood event covered these tracks with sand and helped to preserve snapshots in deep time.  The red sandstone slabs preserve amazing details, not only of the footprints and tracks but also raindrops and cracks in the mud that were formed as the area dried out.

To read an article on Carboniferous fossils from North Wales: Tropical North Wales 300 Million Years Ago

The research on these trace fossils indicates that the most common tracks were formed by amphibians, ranging from just a few centimetres in length (Batrachichnus salamandroides) to more than a metre long Limnopus ichnospecies).  Other types of creature traversed the mud, leaving their tracks, animals such as large Pelycosaurs (synapsids distantly related to modern mammals).  Although the tracks are much less common, their presence indicates that monitor lizard-sized Reptiliomorphs also roamed the swamps and low lying forest that was eventually to become the West Midlands of England.  The three-dimensional models of the footprints that the team were able to recreate, led to the identification of these tracks having been made by the ichnogenus Dimetropus.  Smaller reptilian tracks were identified as having been made by sauropsid reptiles, (Dromopus lacertoides), whose descendants gave rise to the crocodiles, marine reptiles, pterosaurs, dinosaurs and birds.

Limnopus Trace Fossils Used in the Study

Limnopus trace fossils (West Midlands).

Carboniferous footprints from the West Midlands (England) indicate the rise of amniotes.

Picture Credit: University of Birmingham/PeerJ

The photograph above shows a well-defined example of Limnopus isp tracks from the Hamstead quarry.  The top photograph shows a dorsal view of the fossil material, (B) tracks rendered to show relief with an arbitrary scale, whereas, (C) shows tracks rendered to highlight areas of steep gradient, digitally isolating the outline of the tracks to aid genus recognition and cross comparison.

Scale bar = 10 cm.

This ichnofauna associated with the Hamstead trace fossils contrasts with the slightly stratigraphically older, more extensive and better-studied assemblage from Alveley (Shropshire), which is dominated by small amphibians with relatively rare Reptiliomorphs and Dromopus tracks are absent. The presence of Dromopus lacertoides at Hamstead, identified from this new study supports the theory that the world was gradually becoming more arid through the Late Carboniferous and different types of reptile were beginning to flourish.

Batrachichnus salamandroides Tracks Preserved in the Red Sandstone of Hamstead Quarry

Batrachichnus fossil trackway.

Hamstead quarry red sandstone showing trace fossils of the Carboniferous amphibian Batrachichnus.

Picture Credit: University of Birmingham/PeerJ with additional annotation by Everything Dinosaur

In the picture above, tracks made by the amphibian Batrachichnus salamandroides are shown, the red line indicates the direction of travel, the long thin lines are tail drag marks.

As the world become drier, so those animals that did not have such a reliance on water compared to the amphibians would have had a distinct advantage.  The synapsids and the diapsids being amniotes (they lay eggs on land or retain a fertilised egg within the female), would have had a significant evolutionary advantage over the amphibians that relied on returning to water to reproduce.

The scientific paper: A Revision of Tetrapod Footprints from the Late Carboniferous of the West Midlands, UK (PeerJ).

20 11, 2016

Just When Did the Dinosaurs Dominate the Land?

By | November 20th, 2016|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Ixalerpeton polesinensis and Buriolestes schultzi Co-existed

New fossil evidence suggests that the rise of the Dinosauria was more gradual than previously thought.  Many people’s perception of the dinosaurs is that they are all super-sized monsters, dominating life on land and rapidly out competing the other, more primitive Triassic reptiles.  Scientists writing in the journal “Current Biology” challenge this view, as they describe the discovery in the same rock formation of an early dinosaur and a lagerpetid, a member of a group of animals that are recognised as precursors of dinosaurs.  This is the first time that a dinosaur and a dinosaur precursor have been found together, indicating that true members of the Dinosauria Order and their near relatives co-existed.

The Skull of the Dinosaur (Buriolestes schultzi) in Situ

Buriolestes skull at the dig site.

The skull of the sauropodomorph Buriolestes.

Picture Credit: Cabreira et al

A Sauropodomorph and a Lagerpetid

 A team of researchers including Sergio Furtado Cabreira (Museu de Ciências Naturais, Universidade Luterana do Brasil, Brazil) and Alexander Wilhelm Armin Kellner (Departamento de Geologia e Paleontologia, Museu Nacional-UFRJ, Rio de Janeiro, Brazil) have described two new species of Dinosauromorpha from Upper Triassic rocks in central, eastern Brazil (the Paraná Basin).  The fossil material represents a lagerpetid, which has been named Ixalerpeton polesinensis and a new basal sauropodomorph (Buriolestes schultzi), the remains of these animals were found in the Alemoa Member of the Santa Maria Formation, specifically, within the Hyperodapedon (rhynchosaur) Assemblage Zone which dates from the Carnian faunal stage of the Upper Triassic.  Ixalerpeton has been assigned to the family Lagerpetidae which together with the Dinosauria and other closely related Archosaurs, make up the clade Dinosauromorpha.  B. schultzi has been assigned to the Sauropodomorpha, a clade of lizard-hipped dinosaurs that would evolve into the long-necked giants such as Diplodocus, Apatosaurus and Brachiosaurus.

Line Drawings and Photographs of the Fossilised Remains of the Two New Species of Dinosauromorph

Fossils and drawings of the two Dinosauromorpha.

Line drawing (A) of I. polesinensis and fossilised remains of (B-H) and line drawing (I) of B. schultzi with fossil remains (J-P).

Picture Credit: Current Biology

The lagerpetid (Ixalerpeton) has been described from skull bones including the braincase, vertebrae, one shoulder blade, the left humerus, parts of the pelvis, a thigh bone (femur) and some lower leg bones.  This biped is estimated to have measured around half a metre in length. The larger Buriolestes is estimated to have measured around 1.8 metres long and it has been described from a partial skull, which includes the premaxilla, maxilla and the dentary, a large number of vertebrae including posterior dorsal vertebrae and caudal bones, the left arm, parts of the pelvis and a nearly complete left hind leg.

Etymology

Ixalerpeton polesinensis – The genus name means “leaping reptile”, whilst the trivial name references São João do Polêsine, the town where the fossils were found.

Buriolestes schultzi – The genus name means “Buriol robber”, a reference to the family name of the land owners and recognises that this dinosaur was most likely carnivorous.  The species/trivial name honours Cesar Schultz (professor of vertebrate palaeontology at the Universidade Federal do Rio Grande do Sul).

A Timeline Showing the Relationship between B. schultzi and I. polesinensis within an Overview of Early Dinosauromorphs

A timeling showing the evolutionary relationships of early dinosauromorphs.

Phylogeny of early dinosauromorphs.

Picture Credit: Current Biology

The research team are confident that further analysis of the Ixalerpeton fossil material will add to our understanding as to how the dinosaurs evolved their anatomical characteristics.  The teeth of Buriolestes indicate that this sauropodomorph, a distant ancestor of the huge herbivorous Sauropods, was actually carnivorous.  This evidence supports the theory that the giant plant-eating dinosaurs such as Diplodocus were descended from small, bipedal, meat-eaters.

A Close View of the Teeth of Buriolestes Indicating that this Dinosaur was a Carnivore

The teeth of Buirolestes

A close view of the teeth of Buriolestes. The highly recurved and serrated teeth indicate that this sauropodomorph was a carnivore.

Picture Credit: Cabreira et al

The Dietary Preferences of Dinosauromorphs

An analysis of the fossil teeth of these newly described Archosaurs has helped scientists to assess the dietary preferences of a range of dinosauromorphs.  This research suggests that the very first dinosaurs were all meat-eaters and over time there was a move towards herbivory and an omnivorous diet within certain groups.

The Dietary Preferences of Dinosauromorphs

The diets of dinosauromorphs.

The dietary preferences of members of the Dinosauromorpha.

Picture Credit: Current Biology

The diagram above shows a cladogram of dinosauromorphs and photographs of their teeth.  The top photograph shows the teeth of the dilophosaurid Theropod Dracovenator (Neotheropoda), a carnivore.  Next comes a picture of the teeth of Buriolestes, assigned to the Sauropodomorpha but regarded as carnivorous by the researchers.  The third photograph features the teeth of Pampadromaeus, which coincidentally, was named by Sergio F. Cabreira, Cesar L. Schultz et al.  This little dinosaur has been assigned to the Sauropodomorpha too, it is also believed to be meat-eater.  The final set of teeth belong to the later sauropodomorph Plateosaurus, that lived some fifteen million years after Buriolestes and Pampadromaeus.  The teeth of Plateosaurus seem to be adapted to a plant-eating diet.

The hypothesis about feeding preferences advocated by the researchers in this paper is shown on the left of the cladogram, with alternative arrangements shown on the right.

Key

green coloured line = herbivory and/or omnivory

black coloured line = unknown or ambiguous

orange = carnivore (faunivory – feeding on other animals)

An Illustration of a Buriolestes Catching a Hyperodapedon whilst a Group of Ixalerpeton Scatter

A Buriolestes and Ixalerpeton illustrated.

A Buriolestes catches a Rhynchosaur whilst a group of Ixalerpeton hunt for lizards and grubs in the undergrowth.

Picture Credit: Oliveira Maurílio

This research lends weight to the hypothesis that dinosaurs evolved in the southern hemisphere and that the Dinosauria were carnivorous in their basal forms, it also supports the idea that lagerpetids and early dinosaurs were contemporaries since the first stages of dinosaur evolution.

The scientific paper: “A Unique Late Triassic Dinosauromorph Assemblage Reveals Dinosaur Ancestral Anatomy and Diet” published in Current Biology.

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