Category: Palaeontological articles

The Earliest Horned Dinosaur in North America?

Aquilops americanus – The Implications

When it comes to the horned dinosaurs of North America, there has been a lot of focus in the last few years on mapping the extraordinary diversity of Ceratopsians that once roamed the landmass known as Laramidia.   There has been much debate over the ethnicity of the Dinosauria, as suggested by the myriad of fossil finds and indeed the debate has been reignited recently with the publication of the research undertaken by the UK’s Dr. Nick Longrich and the “northern Pentaceratops” - Pentaceratops aquilonius.  Let’s face it, ever since the publication of “New Perspectives on Horned Dinosaurs”, there seems to have been an addition to the Late Cretaceous Ceratopsidae every couple of months or so.  For instance, Mojoceratops, Kosmoceratops, Utahceratops, Nasutoceratops, Xenoceratops and so forth.

To read about the recent research of Dr. Nick Longrich: Finding a New Species of Horned Dinosaur in a Canadian Museum.

However, many scientists have been turning their attention to another part of the horned dinosaur’s family tree.  These researchers have been trying to piece together (literally), the fossil evidence that hints at the presence of basal, more primitive members of this great group of Ornithischians much earlier in the Cretaceous of North America.  The search for the Neoceratopsian dinosaurs, may not garner quite the same publicity as work on their Campanian and Maastrichtian cousins such as Styracosaurus and Triceratops, but this dedicated team are helping scientists to understand how these dinosaurs evolved and migrated out of their Asian ancestral home.

That is why the paper published this week in the academic journal PLOS One is so important.  This paper describes the partial skull and lower jaw of a horned dinosaur, the fossils represent the earliest evidence of Neoceratopsian dinosaurs recorded in North America.  Say hello to Aquilops americanus, about the size of a King Charles spaniel that roamed southern Montana somewhere between 109 and 104 million years ago.

 A Tiny Skull that is Making a Big Difference

Skull fossil that can sit in the palm of your hand.

Skull fossil that can sit in the palm of your hand.

Picture Credit: Reuters

Prior to this fossil discovery, the Neoceratopsian dinosaurs of North America were represented by isolated teeth and skull fragments, collected from places as far apart as Utah and Maryland, the Cedar Mountain Formation and the Arundel Formation respectively.  The paucity of the fossil record was severely hampering the work of scientists as they tried to understand the pattern of migrations between Asia and North America.  During the Cretaceous, Asia and North America were joined, they shared a land bridge between them, most likely there were many occasions when fluctuating sea levels and geological activity permitted a land bridge to be formed.  It seems that the horned dinosaurs evolved in Asia but migrated via what is now the Bering Straits over to Canada and the United States.  Aquilops seems closely related to Early Cretaceous horned dinosaurs known from Asia such as Liaoceratops and Auroraceratops, it has been speculated that there were at least intermittent connections between these two continents throughout the Late Early Cretaceous, likely followed by a long period of geographic isolation that permitted a number of new genera to evolve before a final reconnection towards the end of the Mesozoic.

The skull measures just 8.4cm in length, it is likely that Aquilops americanus (the name means “American eagle face”), was an unobtrusive herbivore, selectively grazing young shoots and leaves from the protection of the undergrowth.  It may even have been nocturnal or perhaps it may have lived in a burrow.

Line Drawing of the Skull and a Reconstruction of the Dinosaur

Skull sketches top and middle with an artist's impression underneath.

Skull sketches top and middle with an artist’s impression underneath.

Picture Credit: PLOS One, life restoration by Brian Engh

 The line drawings of the skull have been based on better known Neoceratopsian specimens from Asia.  Note the large orbit (eye-socket), this has led to speculation that this little dinosaur may have lived in low light conditions or might possibly have been nocturnal.

Commenting on the study, one of the authors of the scientific paper Dr. Andrew Farke (Raymond M. Alf Museum of Palaeontology, California) stated:

“This was a small plant-eater and we know from its hooked beak that it was pretty selective, nipping off whatever vegetation was around.”

 An Illustration of Aquilops americanus

Earliest horned dinosaur known from North America.

Earliest horned dinosaur known from North America.

Picture Credit: Brian Engh/Raymond M. Alf Museum of Palaeontology

One of the mysteries with the Ceratopsian dinosaurs is when did the Asian migrations occur, and where there any significant migrations of North American fauna into Asia?  Before this discovery, the oldest known horned dinosaur from North America was Zuniceratops, which roamed New Mexico and Arizona some 90 million years ago.

Dr. Farke added:

“Aquilops lived nearly twenty million years before the next oldest horned dinosaur named [and described] from North America.  Even so, we were surprised that it was more closely related to Asian animals than those from North America.”

The discovery of these fossils, does support the theory that these type of bird-hipped dinosaurs did evolve in Asia and that they spread into North America, most likely via a northern latitude route, however, as the authors of this scientific paper say themselves, more field studies and more fossils will be needed before anyone can state anything else with a degree of certainty.

Chinese “Sea Dragon” Fossil Hints at Triassic Fauna Recovery

Monster Nothosaur from China Suggests Ecosystem Recovery after Mass Extinction Event

A team of Chinese scientists, supported by palaeontologists from Bristol University, Washington D.C. and Australia, writing in the academic journal “Nature: Scientific Reports”, have described the fossilised remains of a giant marine reptile.  This fearsome hunter provides evidence that by around 245 million years ago, much of the world’s marine habitats had recovered sufficiently from the Permian/Triassic mass extinction event to support complex food chains.  The Permian/Triassic extinction event is often referred to as the “Great Dying”, a huge portion of life on Earth died out, scientists debate just how many different types of organisms perished, but it has been suggested that as much as 95% of all life on Earth became extinct.

To read more about how mass extinction events are defined: When is an Extinction Event a Mass Extinction?

The fossil represent a new species of Nothosaur, it is potentially the largest Nothosaur discovered to date.  The discovery is significant as it indicates that on the eastern side of the Paleotethys Sea, marine life had recovered sufficiently to support complex food chains, with carnivorous marine reptiles as the apex predators in the environment.  As similar sized apex predators are known from the western fringes of the Paleotethys Sea and also from the eastern seaboard of the Panthalassa Ocean, this provides evidence to support the theory that by the early part of the Middle Triassic there had been a global recovery (a synchronous global recovery), of marine fauna and flora.

The Nothosaur fossil consisting of an almost complete lower jaw, isolated teeth and post cranial elements was discovered in 2008.  The only known specimen was collected from Bed number 165 of the Dawazi section of strata, a highly fossiliferous zone that represents a shallow marine environment.  The fossils are located in Luoping County, Yunnan Province in the far south-west of China.  This part of the world is famous for its Middle Triassic marine fossils, many thousands of specimens have been collected including a number of Ichthyosaurs as well as other marine reptiles.

The Nothosaur Fossil Material (a) Line Drawing (b)

The specimen has been named Nothosaurus zhangi

The specimen has been named Nothosaurus zhangi

Picture Credit: Nature: Scientific Reports

Nothosaurs were a group of marine reptiles related to the better known Plesiosaurs.  They evolved from terrestrial ancestors and typically were between one and three metres in length.  They had relatively long snouts, quite narrow skulls, and their fingers and toes may have been webbed to help propel them through water.  The were also capable of hauling themselves up onto land and although well adapted to a marine environment, they probably rested and bred on land.  The Nothosaurs evolved very early on in the Triassic Period and as a group they persisted up until the beginning of the Jurassic.

 A Model of a Typical Nothosaur (Safari Prehistoric Sealife Toob)

One of the models in the Safari Prehistoric Sealife Toob.

One of the models in the Safari Prehistoric Sealife Toob.

Picture Credit: Everything Dinosaur

The picture above shows a typical Nothosaur bauplan (body plan), it is one of the models from the fantastic “Prehistoric Sealife Toob”, part of the range of prehistoric animal and plant replicas made by Safari Ltd.

To view this range: Safari Ltd Prehistoric Replicas

This new giant species of Nothosaur has been named Nothosaurus zhangi.  The species or trivial name honours the discoverer of the Luoping biota, scientist Qiyue Zhang.  Although far from complete, a comparative analysis using fossil material from the Nothosaur species known as N. giganteus, whose fossils come from Middle and Upper Triassic aged rocks in Germany, suggests that Nothosaurus zhangi was between five and seven metres in length.  Think of this ancient reptile being about the size of a large Nile crocodile (Crocodylus niloticus).

The jaw was lined with a number of sharp, pointed teeth, many of which projected outwards to give the impression of elongated fangs.  These were adaptations to grabbing and subduing struggling prey, such as fish and cephalopods.  Given the size of Nothosaurus zhangi, it very probably hunted other, smaller marine reptiles in the shallow, tropical sea that once covered much of China.

These fossils from what would have been the eastern side of the Paleotethys Sea, when considered with the fossilised remains of other enormous Middle Triassic marine reptiles, suggests that across the world marine environments had recovered sufficiently to support complex food chains by around 245 million years ago.

A Map of the Middle Triassic Showing the Location of Apex Predator Marine Fossil Finds

Marking the location of apex predator fossils.

Marking the location of apex predator fossils.

Picture Credit: Nature: Scientific Reports with additional material from the Palaeobiology database

The map shows a whole world projection of the Middle Triassic. The super continent of Pangea is firmly established and the locations of potential apex predator marine reptile fossils have been marked.

Key

  • Thalattoarchon O – (T. saurophagis) a giant Ichthyosaur estimated to have measured 8-9 metres in length (YELLOW)
  • Cymbospondylus (several species), a basal Ichthyosaur estimated to have reached lengths in excess of 10 metres (BLUE)
  • Nothosaurus giganteus – estimated to be about 5-7 metres long (PURPLE)
  • Nothosaurus zhangi – estimated to be about 5-7 metres long (RED)

Thanks to the astonishing variety of fossils from the Luoping Province, scientists have been able to build up a great deal of knowledge about life in the seas surrounding the ancient land mass on the western fringes of Pangea, that was to eventually become China. The researchers have been able to develop a complex food chain diagram and the newly described Nothosaurus zhangi is placed at the top of the food chain as the largest predator discovered to date.

A Food Chain Constructed Using Luoping Biota Fossil Data

Nothosaurus zhangi at the top of the food chain.

Nothosaurus zhangi at the top of the food chain.

Picture Credit: Nature: Scientific Reports

It may have taken terrestrial life slightly longer to recover from the end Permian extinction event, but based on this evidence, many of the shallow sea environments had recovered fully and new types of fauna had filled ecological niches.

To read an article published in April 2014 about the discovery of a bizarre type of marine reptile (Atopodentatus) from the Luoping Biota: Bizarre Triassic Marine Reptile Described

Recommended Christmas Reading for Dinosaur Fans

“Dinosaurs of the British Isles” – An Ideal Christmas Gift

Not sure what to buy a budding palaeontologist for Christmas, well, Everything Dinosaur recommends “Dinosaurs of the British Isles” by Dean Lomax and Nobumichi Tamura (Siri Scientific Press).  This book provides a comprehensive guide to the dinosaur discoveries that have been made in the United Kingdom and it takes the reader from the Triassic through to the Late Cretaceous, cataloguing all the various dinosaurs in geochronological order.

The Front Cover of Dinosaurs of the British Isles

A comprehensive guide to British dinosaurs over 400 pages.

A comprehensive guide to British dinosaurs over 400 pages.

Picture Credit: Siri Scientific Press

Dean and Nobumichi have painstakingly compiled a comprehensive review of all the major dinosaur fossil finds and this book is aimed at the general reader as well as at fossil collectors and dinosaur fans.  Southern England and the Isle of Wight may be globally significant locations when it comes to Early Cretaceous dinosaurs, but readers may be surprised to find that the sandstones in Morayshire (Scotland) have provided tantalising clues to life on the super-continent Pangaea during the Triassic and the oldest dinosaur tracks can be spotted at Barry in the Vale of Glamorgan (south Wales).

The authors are to be commended, as they provide a fascinating introduction to the Dinosauria, their classification and the emergence of palaeontology as a science.  This all follows a well-written foreword by Dr. Paul Barrett, a highly respected academic and vertebrate palaeontologist at the Natural History Museum (London).  With the Dinosauria well and truly introduced, it is time to meet some of the amazing prehistoric creatures that once roamed the British Isles.  For example, at least three types of tyrannosaurid may once have roamed across this part of the world.  There’s the Proceratosaurus (P. bradleyi) whose fossilised remains, come from Gloucestershire, the fearsome, five-metre long Juratyrant, a terror of the Late Jurassic whose fossilised remains have been discovered near Swanage (Dorset) and Eotyrannus (E. lengi), represented by a partial skeleton found on the Isle of Wight.

 Documenting the Theropoda of the British Isles

A potential Compsognathidae?

A potential Compsognathidae?

Picture Credit: Siri Scientific Press

 It is not just the meat-eaters that palaeontologist Dean Lomax has documented in collaboration with California based, palaeoartist Nobumichi Tamura.  The United Kingdom boasts some very impressive (and gigantic) herbivorous dinosaurs too. This book also provides a comprehensive account of the huge Sauropods that once stomped across the British Isles, many of which rivalled the long-necked dinosaurs of North America in terms of size.

To visit the website of Siri Scientific Press to learn more about “Dinosaurs of the British Isles”: Siri Scientific Press

Author Dean Provides a Scale for Cetiosaurus

A belly up view of "Whale Lizard".

A belly up view of “Whale Lizard”.

Picture Credit: Dean Lomax

The full colour photographs are very informative and support the text extremely effectively.  This is a rare example of a book that will appeal to serious academics as well as to the general reader.  ”Dinosaurs of the British Isles” provides a fascinating introduction to the Dinosauria, before moving on to describe every dinosaur species represented by the known fossil record from this part of the world in great detail.

Highly recommended.

“Dinosaurs of the British Isles” by Dean Lomax and Nobumichi Tamura is available from Siri Scientific Press (Siri Scientific Press), length 414 pages, ISBN: 978-0-9574530-5-0.

Those Plucky Placoderms

Armoured Fish Made a Significant Contribution to Vertebrate Evolution

The Placoderms were a hugely diverse and very successful group of fishes, whilst they lasted. For in terms of this groups’ persistence, in geological terms they make a relative short appearance in the history of life on Earth.  As a group the Placoderms were around for approximately sixty-five million years, not a bad innings but nothing like the longevity of other types of fish such as the sharks, rays and certain Actinistians, the Coelacanth for example.  The Placoderms, or to be more correct, the Class Placodermi first evolved in the Late Silurian and they disappear from the fossil record at the end of the Devonian Period.

Perhaps the most famous Placoderm is the giant predator Dunkleosteus.  Several species are known and with some specimens estimated to have reached lengths of around ten metres or more, at the time, (Dunkleosteus lived towards the end of the Devonian something like 370 – 360 million years ago), this fish would have been one of the largest vertebrates ever to have evolved.

Dunkleosteus – An Illustration

Fearsome marine predator of the Late Devonian.

Fearsome marine predator of the Late Devonian.

Picture Credit: Everything Dinosaur

Dunkleosteus may have looked like a typical Placoderm with its head and thorax covered in articulated armour plate, but the Placodermi, it turns out are being seen as one of the most important group of vertebrates to have existed  It is not just because they evolved into the likes of Dunkleosteus, regarded by many as the world’s first, vertebrate, super-predator, but this group of armoured fishes seems to have achieved a number of “firsts” in terms of the Chordata (animals with a spine or spine-like structure in their bodies).

Firstly, palaeontologists have found a number of fossils that suggest that early members of the Placodermi were amongst the first types of vertebrate to evolve a jaw.  Recently, Everything Dinosaur wrote a short article about a remarkable fossil discovery form China which reveals some remarkable features: A Jaw Dropping Discovery.

In addition, although the majority of Placoderms seemed to have been poor swimmers, with most of them living close to the bottom, a number of families were active and nektonic, indeed these types of fish were the first to evolve paired pelvic fins, a fishy equivalent of legs, although not connected with the spine.  Paired pelvic fins are an anatomical feature found in most types of extant fish today.

Those plucky Placoderms may have been amongst the first types of animal to develop teeth.  Recently a team of scientists from Australia and Bristol University studying fossilised remains of Placoderms from Western Australia found evidence of the first types of teeth, teeth with a structure very similar to our own.  To read more about this: The Origins of a Toothy Grin

Fossils from the same rocks (Go Go Formation) western Australia gave palaeontologists a remarkable insight into the reproductive strategies of many types of ancient fish.  One species of Placoderm, known from just a single fossil specimen represents the oldest example of a vertebrate capable of giving birth to live young (viviparity). Materpiscis attenboroughi was a small, bottom of the reef dwelling fish whose fossilised remains preserved in a limestone nodule showed evidence of an embryo and an umbilical cord.  This was evidence of internal fertilisation within the fossil record and the oldest known case of viviparity.

Materpiscis attenboroughi – A Remarkable Placoderm

Materpiscus means "Mother Fish".

Materpiscus means “Mother Fish”.

Picture Credit: Museum Victoria

The remarkable Placodermi may have just added another evolutionary “first” to their string of impressive attributes.   A scientific paper published in the journal “Nature” provides details on a fossil discovery that hints at the very first example of copulation amongst vertebrates.  The international team of researchers that led the study into the Antiarch (an-tee-arc) Placoderm called Microbrachius dicki state that this was the earliest animal known from the fossil record to stop reproducing by spawning (external fertilisation).

Professor John Long (Flinders University, South Australia), was the lead author of the academic paper.  The Professor, a renowned expert on Devonian fishes had earlier worked on Materpiscus attenboroughi.  The fossils of M. dicki are relatively common.  This small freshwater Placoderm grew to about ten centimetres in length and lived around 385 million years ago.

Professor Long Explains the Key Points of the Research

Studying Placoderms and other Devonian fish.

Studying Placoderms and other Devonian fish.

Picture Credit: Flinders University

Commenting on the research, Professor Long stated:

“We have defined the very point in evolution where the origin of internal fertilisation in all animals began.  That is a really big step.”

A close inspection of a fossil revealed that one of the Microbrachius specimens had a peculiar “L-shaped” appendage.  Further study revealed that this was the male fish’s genitalia.

The Professor pointed out:

“The male had large bony claspers, These are the grooves that they used to transfer sperm into the female”.

On the other hand, the females had a small bony structure at the rear that helped to lock the male organ in place during mating.  Constrained by the anatomy, the fish probably had to mate side by side, a sort of “square dance position” as described by the researchers.

An Illustration Showing the Proposed Mating Position of M. dicki

Mating "square dance" style.

Mating “square dance” style.

Picture Credit: Flinders University/Nature

However, copulation using this method does not seem to have stayed around for very long in these Devonian fish.  As fish evolved, they reverted back to external fertilisation (spawning), whereby male and females release sperm and eggs respectively into the water and fertilisation relies more on chance.  It took several more millions of years before the ancestors of today’s sharks and rays evolved copulation.

The Placodermi may be most famous for the likes of Dunkleosteus, but scientists are beginning to realise that these strange, armoured fish may have contributed much more to the evolution of the vertebrates than just the first, back-boned  super-predator!

How Did Huge Sauropods Manage to Get Along Together?

Dietary Niche Partitioning Amongst the Sauropoda

A team of British scientists have been tackling one of the biggest puzzles in palaeontology and a sophisticated analysis of dinosaur skull bones might just have helped them solve a mystery of gigantic proportions.  Sauropods, that group of long-necked dinosaurs that include such famous creatures as Diplodocus, Brachiosaurus and Apatosaurus (formerly known as Brontosaurus), ate vast quantities of plant material.  These huge animals with many individuals exceeding twenty metres in length and weighing many times more than a bull African elephant, would have been capable of stripping an area of vegetation, but the fossil record shows that in many parts of the world, lots of different species of Sauropod seem to have co-existed.  The scientists, a joint research team from Bristol University and the Natural History Museum (London), propose that Late Jurassic Sauropod skulls became specially adapted to help them feed on different types of plant material.  In this way, the skull morphology helped the long-necked dinosaurs divide up the available food resources between them, therefore limiting the amount of direct competition.

Previous studies had shown that in areas where lots of different species of Sauropods co-existed their body shapes and ability to angle their necks may have allowed the development of different feeding strategies with each species preferring to feed on a particular part of the flora that was available.

Proposed Sauropod Feeding Strategies

Long necks for different feeding envelopes.

Long necks for different feeding envelopes.

Picture Credit: Everything Dinosaur

In the picture above, models made by Safari Ltd help to illustrate current thinking about the feeding adaptations of members of the Sauropoda.  Diplodocids such as Diplodocus and Apatosaurus with their very long necks and relatively horizontal feeding platforms probably specialised in feeding on ferns, cycads and plants that made up the vegetative understorey.  Whilst in the middle, dinosaurs such as camarasaurids a member of a different family of Sauropods called the Macronaria could feed on a wider range of plant material, cycads and seed ferns as well as being able to strip leaves off small trees.  The dinosaur in the bottom of the picture is a member of the Brachiosauridae (Brachiosaurus).  These dinosaurs had much longer forelimbs than hindlimbs and as a result, their heads were held much higher.  These dinosaurs probably specialised in feeding from the very tops of the tallest trees, parts of the vegetative canopy not available to other plant-eating dinosaurs (unless they knocked the trees down).  The tree in the picture is an Agathis conifer, a model also made by Safari Ltd.

To view Everything Dinosaur’s range of prehistoric plant models and dinosaurs (Safari Ltd): Carnegie Collectibles and Wild Safari Dinos Models

A Detailed Model of the Skull of Camarasaurus

Camarasaurus was probably the most common Sauropod living in the western United States during the Late Jurassic.

Camarasaurus was probably the most common Sauropod living in the western United States during the Late Jurassic.

Picture Credit: David Button

A spokesperson from Everything Dinosaur commented:

“Based on counts of the fossilised bones, Camarasaurus seems to have been the most common of all the different types of Sauropod known from the Morrison Formation.  Perhaps this dinosaur was more of a “generalist” when it came to diet.  A half-way house between the long-necked diplodocids and the giraffe-like brachiosaurids.  An ability to feed on a wide variety of plants, including the tougher plants not available to the likes of Diplodocus and Apatosaurus, could have led to this particular genus of long-necked dinosaur being one of the most successful in the Late Jurassic of the western North America, to the south of the Sundance Sea.”

Building on previous studies, the British team looked specifically at the Sauropod fauna associated with the Upper Jurassic Morrison Formation of the western United States.  At least ten different species of Sauropod are known from this formation, one of the most intensely studied fossiliferous formations in the Americas.  Although the Morrison Formation deposits represent a number of habitats, some of the most famous fossil beds such as those making up the Salt Wash Member indicate that some parts of the Morrison Formation represent deposits laid down in harsh, semi-arid environments, not the sort of place where one might expect vast numbers of different types of Sauropod.  Despite the harsh conditions, the fossil record shows that lots of different Sauropods co-existed.  When the diverse faunas of modern day Africa are considered, these habitats only support one truly huge, extant species – the elephant.  So how did the Sauropods get along with each other?

Bristol University’s PhD student David Button worked in collaboration with the Natural History Museum to examine how the skulls of different long-necked dinosaurs may have been adapted to help them feed on different types of plant.  Digital reconstructions were made of the skulls of Camarasaurus and Diplodocus using data compiled from Computerised tomography (CT scans).  From this data, a biomechanical model of the Camarasaurus skull was created and then this skull was compared to an existing digital model of the Diplodocus.  Finite Element Analysis (FEA), was used to assess the stresses that each skull could take.  FEA analysis is used in engineering to calculate loads and stress bearings in complex shapes, this research showed that the box-like skull of Camarasaurus gave this dinosaur a stronger bite.  Camarasaurus could have coped with tougher vegetation than Diplodocus.  The weaker bite and more delicate skull of Diplodocus would have restricted this animal to softer plant material such as ferns.  Diplodocus could have compensated for this to some extent by using its strong neck muscles to help detach plant material through movements of the head.

David Button concluded:

“Our results show that although neither could chew, the skulls of both dinosaurs were sophisticated cropping tools.  This study indicates that differences in diet between these two dinosaurs would have allowed them to co-exist.”

The research team used a number of biomechanical measurements from other Morrison Formation Sauropods to calculate the different types of feeding adaptations, providing evidence for different diets and overall a conclusion that dietary niche partitioning did occur in the Sauropoda.

Comparing the Skulls of a Typical Camarasaurid and Diplodocid

Analysis of fossil bone helped the researchers determine the size and location of jaw muscles.

Analysis of fossil bone helped the researchers determine the size and location of jaw muscles.

Picture Credit: David Button

In the picture above, the box-like skull of Camarasaurus is shown left (a) with a typical skull of a Diplodocus (b).

Co-author of the scientific paper, which has been published in the Proceedings of the Royal Society Biology, Professor Emily Rayfield (Bristol University) stated:

“In modern animal communities differences in diet such as this, termed dietary niche partitioning, allow multiple species to co-exist by reducing competition for food.  Although, dietary niche partitioning has been suspected between Morrison Formation Sauropods based on their structural features and patterns of tooth-wear, this is the first study to provide strong, numerical, biomechanical evidence for its presence in a fossil community.”

This new research may help palaeontologists to understand more about how the Sauropoda evolved.  Sauropods from the Dashanpu Quarry region of China dating from the Middle Jurassic may also show similar adaptations over skull morphology and bite strength as reflected in the research done on the slightly later Sauropods from the Morrison Formation.

In addition, this analysis may help scientists to unravel the mechanisms responsible for supporting the high diversities of mega-herbivores found in other Mesozoic and Cenozoic animal populations, particularly those in resource limited environments.

For related articles on Sauropod feeding strategies:

Ostrich Necks Provide Clues to Sauropod Neck Flexibility

Diplodocus Feeding – a biter or a comber?

Evidence for Seasonal Migrations Amongst Camarasaurids

Dinosaur Tracks in Danger of Becoming Extinct

Cal Orck’o Dinosaur Tracks Threatened

To the north-east of the city of Sucre in central Bolivia lies one of the most remarkable fossil sites anywhere in the world. The Huellas de Dinosaurio de Cal Orck´o which translates as the “dinosaur footprints on the lime hill”.  For here, preserved on a sheer slope, are the fossilised tracks of dinosaurs, more than 5,000 individual prints, in excess of 350 trackways providing a spectacular trace fossil record of life in the Late Cretaceous some 68 million years ago.  However, extraction of material to support the local cement works could be endangering the entire site according to local conservationists.

The Spectacular Dinosaur Tracks Exposed at Cal Orck’o

View from the viewing platform from the dinosaur museum.

View from the viewing platform from the dinosaur museum.

Picture Credit: Google Maps/AFP

 Although less famous than the Lark Quarry site (Australia) and the Sauropoda tracks found in Gansu Province (China), the Bolivian site represents one of the biggest, if not the biggest collection of dinosaur footprints discovered to date.   At least eight types of dinosaur trackways have been identified.  There are the huge footprints of gigantic Titanosaurs, tracks made by some of the largest land animals that ever existed.  Many of the individual prints measure more than 100 centimetres in diameter and indicate dinosaurs around twenty metres or more in length.  There are also tracks of Ornithopods and ankylosaurids.  Meat-eaters are represented too, the largest three-toed tracks identified as having been made by Theropod dinosaurs most probably represent tracks made by abelisaurids, the nearby Parque Cretácico (Cretaceous Park) contains a number of life-size, colourful replicas of the dinosaurs that once roamed this part of Gondwanaland.

Photograph of a Typical Late Cretaceous Abelisaurid (Carnotaurus Probably)

Cretaceous Park Museum illustrates the prehistoric fauna.

Cretaceous Park Museum illustrates the prehistoric fauna.

Picture Credit: Thewanderingscott.com

 The park and viewing platforms were opened in 2006, a collaboration between a number of scientific institutions including the Natural History Museum of Basel (Switzerland) whose research teams did much to document and map the tracks between 1998 and 2003, with the support of the Bolivian Government.  Fossilised tracks had been found by cement industry workers and quarry men for many years before the discovery in 1994 of the extensive trackways.  The cliff site and the nearby Cretaceous Park attract in the region of 120,000 tourists each year.

However, the nearby cement factory could be endangering the fossilised footprints as the quarrying of limestone takes place nearby.  The quarry work and frequent dynamiting of rock faces to expose new material could be undermining the entire site and making the sixty-eight million year old fossils in danger of collapse.

Elizabeth Baldivieso, the administrator of Parque Cretácico stated:

“The cliff has been quite affected by the many years of extraction of raw material.”

The regional Tourism and Cultural Secretary, Juan Jose Padilla disagrees, referring to Elizabeth Baldivieso’s description as “somewhat alarmist”.  The cement company, Fancesa jointly owned by a local university, the city and regional administrators has vowed to protect the site.

Pointing Out a Set of Dinosaur Tracks on the Near Vertical Surface
Dinosaur tracks on the near vertical cliff face.

Dinosaur tracks on the near vertical cliff face.

Picture Credit: Google Maps/AFP

The dinosaur tracks appear to indicate that these ancient creatures were climbing an almost sheer vertical cliff face.  However, back some 68 million years ago, the landscape was flat and muddy.  Over time plate movements pushed up the floodplain creating the near vertical trackways which stretch for around fifteen hundred metres or so.

This location was proposed as a UNESCO World Heritage site in 2009, but the cement company opposed the application and it was eventually turned down.  Campaigners are hoping to re-apply for UNESCO World Heritage status in 2015.  This would provide much greater protection to the fossil trackways and we at Everything Dinosaur wish the Bolivian Government and conservationists every success with the re-submission.

To read an article written by Everything Dinosaur about the discovery of some Early Cretaceous dinosaur footprints in Bolivia: Farmer Describes Dinosaur Tracks to Scientists

From Dinosaur Arms to the Wings of Birds

New Study Helps to Explain How Dinosaurs Got their Wings

Most scientists now agree the feathers originated in the Dinosauria and that Aves (birds) are descendants from a group of bipedal, very bird-like dinosaurs that make up a portion of a larger group of dinosaurs known as the Theropoda.  In essence, the birds we know today evolved from dinosaurs (specifically the Maniraptora).  However, despite a lot of fossil evidence to indicate that the birds are closely related to and descended from the Dinosauria there have been one or two areas that have led to some confusion.  Take for example, the wrist bones.  The numerous wrist bones in dinosaurs and their relatively immobile wrists evolved over time into the highly flexible wrists with fewer bones that scientists see today in living birds.  The wrist bones in birds helps to manage the forces involved in the movements of the wing in flight.  They also permit the wings to be folded back when the bird is not flying, so how the wrist bones of dinosaurs evolved into the specialised and highly modified wrist bones of birds has been the subject of much debate.

The Evolution of a Wrist Designed for a Wing

The evolution of a wrist bone adapted to flight.

The evolution of a wrist bone adapted to flight.

Picture Credit: Davide Bonnadonna

A new study by a team of scientists based at the Universidae de Chile (University of Chile), Santiago, Chile and published in the academic journal PLOS Biology may have solved this palaeontological puzzle.

Nine into Four Does Go

Let’s start with a very simple explanation of the problem.  Scientists studying living species, in this case birds and specifically ducks, chickens, lapwings, finches and budgerigars that were used in this study, can examine in minute detail the living organism.  They can also study embryos to see how the bones in the wrist are formed.  The scientists can also study the wrist bones and embryos of reptiles such as caiman to provide data on the wrist bones and embryonic growth of other types of Archosaurs.  The Archosauria is the Division of Reptilia that contains the dinosaurs and crocodiles, it is from the Archosaurs that the birds evolved.  These scientists can see how the anatomy of an animal develops.  Techniques such as cell and molecular biology studies can reveal all sorts of information with regards to how the wrists of extant (living organisms) form.  Palaeontologists, on the other hand, (no pun intended) only have a very incomplete fossil record to study.  So scientists are using different data sources to study wrist bone evolution.

Research to help identify the wrist bones in dinosaurs and the corresponding bones in the wrists of birds draws data from two radically different sources:

  • cell biology, extant organisms and embryology
  • fossils of birds, fossils of dinosaurs, studies of the bones of extinct animals

This new study shows how the modern bird wrist with its four bones, arranged in an approximate square shape corresponds to the nine bones found in non-avian dinosaurs.  The team have looked at how dinosaur wrists evolved and report on previously undetected evolutionary processes including loss, fusion and in one case, a re-evolution of a bone once lost in the Dinosauria.

A Critical Advance in Understanding

This new study effectively combined these two areas of research.  The laboratory run by Alexander Vargas (University of Chile) and lead author of the study, developed a new method of looking at specific proteins in the embryos and produced three-dimensional maps to demonstrate how the wrist bones formed.  This new method has been named whole-mount immunostaining.  It allows scientists to observe skeletal development in embryos much better than before.  At the same time, the research team re-examined the fossils of dinosaurs and prehistoric birds in a bid to tie the two strands of research together.

The Semilunate Bone

Back in the 1960′s the palaeontologist John Ostrom, re-ignited the bird/dinosaurs debate by proposing that fearsome, sickle-clawed predators such as Deinonychus (D. antirrhopus) were agile, active animals and very bird-like.  He proposed that the semilunate bone, one of the four bones making up the square-shaped arrangement of bones in a modern bird’s wrist had actually formed from the fusing of two bones present in dinosaur fossils, such as those bones found in the wrists of dinosaurs like Deinonychus and its relatives.  This new technique, confirms that Ostrom was right.

Deinonychus Part of the Dinosaurs to Birds Story

A fearsome Deinonychus dinosaur

A fearsome Deinonychus dinosaur

Picture Credit: Everything Dinosaur

Whole-mount immunostaining and the mapping of cartilage formation and proteins in the embryos of birds, allowed the scientists to confirm that the semilunate in Aves does form from as two separate cartilages which fuse and ossify into a single bone, proving that Ostrom was very probably on the right track nearly fifty years ago.

Dr. Vargas explained:

“These findings eliminate persistent doubts that existed over exactly how the bones of the wrist evolved and iron out arguments about wrist development being incompatible with birds originating from dinosaurs.”

This research has helped scientists to work out how the nine bones found in the wrists of some Theropod dinosaurs gradually evolved into the four bones seen in modern birds.  In addition, this study produced a surprise, a result that was not expected.  A small bone present in the wrists of a group of dinosaurs known as the Sauropoda, disappeared in the bipedal Theropods, but re-evolved when some Theropods began to fly.

Sauropods and Theropod dinosaurs are closely related.  They represent the two types of dinosaur that make up the Saurischia (lizard-hipped dinosaurs).  Sauropods walked on all fours and had a small bone in their wrist called the pisiform that had a function in their four-legged, quadrupedal stance.  Theropod dinosaurs were essentially bipeds (walking on their hind limbs).  The arms of these dinosaurs were no longer used for walking but for catching and subduing prey.  Over millions of years the pisiform bone was lost from the wrists of the two-legged Theropods.  However, the authors of this study discovered that the pisiform had reappeared in early birds, probably as an adaptation for flight, where this small wrist bone permits the transmission of force on the down-stroke of a wing beat whilst restricting flexibility on the up-stroke phase of a wing beat.

The Evolution of the Wrist from Dinosaurs to Birds

From

From dinosaurs to birds ( Dinosauria – Theropoda – Maniraptora – Aves)

Picture Credit: PLOS Biology

The chart shows the colour coded bones and how they changed over time.  For example, the pisiform bone (red) can be found in the Early Jurassic Ornithopod Heterodontosaurus (not a Theropod) and in the Late Triassic Theropod Coelophysis.  This bone is lost in later Theropods such as Allosaurus and Guanlong but evolves again in primitive birds such as Sapeornis.  Sapeornis was about the size of a seagull, it seems to have been a strong flyer.  It lived during the Early Cretaceous.

The colour coded chart also shows how the square-shaped arrangement of bones in a modern bird such as the chicken evolved, with the fusion of the distal carpal 1 and the distal carpal 2 bones (yellow and green).  In the Maniraptoran Falcarius, a member of the Therizinosauroidea and not a direct ancestor of birds, these two bones are distinct.  However, in those Maniraptorans believed to be more closely related to the birds, indeed, the ancestors of Aves, dinosaurs such as Khaan, Deinonychus and Yixianosaurus these two carpals become fused to form the semilunate found in the wrists of modern birds.

New Research Suggests Multicellular Life Started Earlier

Evidence Suggests Multicellular Life 60 Million Years Earlier than Previously Thought

Researchers from the Virginia Tech College of Science in collaboration with counterparts from the Chinese Academy of Sciences have published new data on one of the most fundamental and significant changes that occurred in the history of life on our planet.  At some time during the Proterozoic Eon, multicellular life forms evolved.  These organisms evolved from single-celled entities and in a paper published in the academic journal “Nature”, the researchers propose that multicellular life forms evolved some sixty million years earlier than previously thought.

The team suggest that they have found fossil evidence of complex multicellularity in strata dating from around 600 million years ago, although microscopic fossils are known in Precambrian strata from several locations around the world (Australia, South Africa as well as China), this new research is helping to clarify some long-standing interpretations of micro-fossils.

Professor of Geobiology at the Virginia Tech College of Science, Shuhai Xiao explained the significance of this new fossil discovery:

“This opens up a new door for us to shine some light on the timing and evolutionary steps that were taken by multicellular organisms that would eventually go on to dominate the Earth in a very visible way.  Fossils similar to the ones in this study have been interpreted previously as bacteria, single-cell eukaryotes, algae and transitional forms related to modern animals such as sponges, sea anemones, or bilaterally symmetrical animals.  This paper lets us put aside some of those interpretations.”

It has long been known that simple, multicellular organisms evolved before more complex ones, such as red algae and sponges.  If a biological hierarchy existed (and most scientists believe that this is the case), then at some point in the past, single-celled organisms began to evolve into much larger, more complicated multicellular organisms.  The trouble is, with the paucity of the fossil record and the difficulties involved in interpreting Ediacaran fauna there is a lot of debate amongst biologists and palaeontologists as to when the solo living cells began to fuse into more cohesive, complex forms.

Evidence of Complex Multicellular Organisms from the Doushantuo Formation

Evidence of multicellular structures in 600 million year old rocks.

Evidence of multicellular structures in 600 million year old rocks.

Picture Credit: Virginia Tech College of Science

The researchers examined microscopic samples of phosphorite rocks from the Doushantuo Formation in Guizhou Province (south, central China).  This formation represents extensive marine sediments that were deposited from around 635 million years ago to around 550 million years ago.  They preserve a unique record of microscopic life (Metazoan life – animals) that existed during the Ediacaran geological period, the period in Earth’s history defined as immediately before the Cambrian and that marks the end of the Precambrian or the Proterozoic Eon.

What is an Eukaryote?

The scientists were able to identify a number of three-dimensional multicellular fossils that show signs of cell-to-cell adhesion, cells potentially performing different functions and programmed cell death.  These qualities are all found in complex eukaryotes, the organisms that dominate visible life on Earth to day, the fungi, animals and plants.  Eukaryotes range in size from single-celled amoebas to giant sequoias and blue whales.  We (H. sapiens) belong to the Domain Eukarya.   Eukaryote cells are complex, they have a distinct nucleus surrounded by a membrane.  The nucleus contains most of the genetic material.  The nucleus itself is a specialised area of the cell, it is referred to as an organelle.  Eukaryote cells have a number of specialised areas within them (other organelles as well as a nucleus).

Professor Xiao and his colleagues admit that these are not the first multicellular fossils found, nor are they probably the oldest, but the exceptional preservation permits the researchers to draw certain conclusions.  For example, it had been previously thought that these multicellular characteristics had started to develop much later in Earth’s history, perhaps as recently as 545 million years ago, a time shortly before the great Cambrian explosion.

What was the Cambrian Explosion?

The Cambrian explosion refers to the period in Earth’s history around 545 to 542 million years ago when there was a sudden burst of evolution as recorded by extensive fossil discoveries.  A wide variety of organisms, especially those with hard, mineralised body parts first appear.

This new research may help to shed some light on when multicellularity arose, but the reasons for this significant change remain unclear.  The complex multicellularity shown in these Chinese fossils is not consistent with that seen in simpler forms such as bacteria.  The scientists note, that whilst some earlier theories can be disregarded these three-dimensional structures can be interpreted in many ways and more research is required to construct the complete life cycle of these ancient organisms.

In summary, these fossils may show some affinity towards the stem-groups that led to the first members of the Kingdoms we know as Animalia, Fungi and Plantae, but much more data is needed to establish a more thorough phylogenetic relationship.

Spinosaurus “Four Legs are Better than Two”?

Spinosaurus – Steps into the Spotlight (Once Again)

And so, the long awaited paper that re-evaluates the fossil data on the Spinosaurus genus and specifically S. aegyptiacus was published in the academic journal “Science” yesterday.  Time to open a new chapter on this, one of the most enigmatic, mysterious and bizarre of all the known Theropoda.  Since the paper’s submission in the summer, there has been a lot of debate in scientific circles with regards to what this new study will show.  The paper’s title “Semi-aquatic Adaptations in a Giant Predatory Dinosaur”, is almost an understatement, when this is contrasted with the lurid headlines we have seen from a large number of media outlets.

Re-examining What We Thought We Knew About Spinosaurus

In very brief summary, the dedicated team of international researchers have re-assessed the known fossil material on Spinosaurus.  They have been able to track down the location in Morocco from which a number of Spinosaurus bones were excavated and sold via a fossil dealer.  The team have then re-examined this site and found further material.  Their efforts has led to a considerable re-think in terms of what this animal looked like and how it moved.  This new study interprets Spinosaurus as a sixteen metre plus dinosaur, that considered itself more at home in the water than on land.  Although capable of terrestrial locomotion, unlike every other large Theropod, a new rendering sees Spinosaurus as an obligate quadruped.  Here is a meat-eating dinosaur that walked on all fours.

A Semi-Aquatic Obligate Quadruped – Spinosaurus

Very much at home in the water.

Very much at home in the water.

Picture Credit: Davide Bonnadonna, Nizar Ibrahim, Simone Maganuco

In the picture above, a web-footed Spinosaurus pursues a prehistoric swordfish, known as Onchopristis.  Earlier studies and research based on other members of the Spinosauridae suggest that fish may have made up a substantial proportion of their diet.  Instead of perching on the river bank, attempting to claw fish out of the water like some form of giant, prehistoric Grizzly bear, an ecological niche trumpeted by ourselves to the CGI team helping with the rendering of Spinosaurus for an episode of the BBC television series “Planet Dinosaur” back in 2011, this latest interpretation goes a lot further.

Beyond “Planet Dinosaur” – The Transformation of Spinosaurus aegyptiacus

From paddler to swimming the "evolving" image of Spinosaurus.

From paddler to swimming the “evolving” image of Spinosaurus.

Picture Credit: BBC

Building Up a New Picture

Having re-visited what records and remaining photographs that exist of the original Stromer material excavated from the Western desert of Egypt around a 100 years ago, the dedicated research team then set about mapping previously known Moroccan finds including jaw bone fossils that had been discovered in the mid 197o’s.  To this eclectic mix they added information obtained from the fossils from the newly “rediscovered” Moroccan site, which itself makes up what is now known as the neotype for Spinosaurus aegyptiacus.  A neotype is a specimen that is deemed to represent a species in the absence of the holotype material that has either been lost or destroyed.  Add a pinch of material not known from the Spinosaurus genus but described from related animals baryonychids, spinosaurids and so forth, combined with a soupcon of inferred parts of the anatomy as the bones are not known at all in the fossil record and you have a “composite” view of the animal.

The Latest Interpretation of Spinosaurus (S. aegyptiacus)

Life-size reconstruction and supplemental figure

Life-size reconstruction and supplemental figure

Picture Credit: Davide Bonnadonna (top) Ibrahim et al (bottom)

The illustration (top), depicts Spinosaurus as a dinosaur that walked on four legs, in this new study the centre of gravity is positioned further forward, the pelvic girdle is estimated to have been much smaller and the hind limbs with their robust but very short femur  reflect the adaptations of a paddler more than that of a bipedal walker.

The picture below, referred to by a colleague as the “Spinosaurus colour chart” is a figure from the scientific paper’s supplementary data.  The colour coded bones illustrate the composite nature of this digital reconstruction.

The “Spinosaurus Colour Chart” Key

RED = the neotype fossils (FSAC-KK 11888)

ORANGE = the original bones from Stromer’s expeditions

YELLOW = isolated fossil material ascribed to Spinosaurus spp. from the same geological Formation as the neotype (Kem Kem Formation)

GREEN = scaled up bones derived from better known spinosaurids

BLUE = additions to help complete the skeleton based on no known fossils but derived from adjacent bones in the digital restoration

We at Everything Dinosaur applaud the efforts of the international team responsible for this new reconstruction.  A revaluation of the known Spinosaurus fossil material has been long overdue and this is the first time that palaeontologists have been able to relocate the bones from a private fossil collection to the actual site where they were excavated.  We commend the team for their perseverance.

Taking a Different Perspective

However, as with all good science, a number of counterpoints have already been made.

Scott Hartman, addresses these concerns in his web log: There’s Something Fishy About Spinosaurus

Scott, with a background in anatomy, and an expert in skeletal reconstructions, makes a number of excellent points in his article.

The dinosaur referred to as Spinosaurus aegyptiacus was one of the last of the Spinosauridae.  There is a British connection to this story.  One of the spinosaurids used in the comparative study was Baryonyx (B. walkeri).  When this dinosaur, whose bones were found in a Surrey clay pit, was formally described back in 1986 it was depicted as a semi-aquatic dinosaur, fish scales found in the body cavity suggested that fish made up at least a portion of its diet.

Commenting on this new research, Dean Lomax, (Honorary Visiting Scientist: School of Earth, Atmospheric and Environmental Sciences, The University of Manchester) and author of the recently published “Dinosaurs of the British Isles” which includes extensive information on the Baryonyx fossil finds, stated:

“The new discovery is very interesting as it potentially confirms what had been suspected for quite some time, that Spinosaurus lived a semi-aquatic lifestyle.”

For further information on the book “Dinosaurs of the British Isles” by Dean Lomax and Nobumichi Tamura, which includes some fantastic skeletal drawings by Scott Hartman visit: Siri Scientific Press

This new paper, marks a new chapter in the story of Spinosaurus, but it’s not the end of the story that’s for sure.  Ironically, although Stromer originally depicted S. aegypticacus as a biped, we recall that in the distant past (the 1970′s), Spinosaurus had previously been thought of as a dinosaur that walked on all fours.

An Illustration of Spinosaurus from 1976

Spinosaurus as a terrestrial quadruped.

Spinosaurus as a terrestrial quadruped.

Picture Credit: Giovanni Caselli (from the book “The Evolution and the Ecology of the Dinosaurs” by L. B. Halstead)

We suspect there are going to be a few more twists and turns in the Spinosaurus story.

Fossil Damaged at Dinosaur National Monument (Utah)

Dinosaur Fossil Damaged and a Piece Stolen from Dinosaur National Monument

It once was a near perfect fossil of the upper arm bone of a Sauropod dinosaur, now it is broken and damaged with a fist-sized chunk missing.  Rangers at the Dinosaur National Monument in Utah have reported the vandalism and theft of part of a humerus.  It is extremely sad to have to report on yet another theft of a dinosaur fossil, officials at the Monument are appealing to members of the public to help them trace the culprit(s).

The Damaged Portion of the Dinosaur Fossilised Bone

The damaged dinosaur bone.

The damaged dinosaur bone.

Picture Credit: National Parks Service

The picture above shows the missing section of the dinosaur bone, the bone seems to have been deliberately smashed.

The Dinosaur National Monument is well-named.  Managed by the United States Department of the Interior National Parks Service, the park covers some 85,000 hectares and overlies the border between the states of Colorado and Utah (although the main dinosaur quarry site is in Utah, close to the town of Jenson).  The Monument is world famous for its amazing collection of dinosaur and other vertebrate fossils which date from the Upper Jurassic.  At least ten different types of dinosaur genera are known from the Morrison Formation exposures.  The Utah sequence represents high energy riverine deposits and on show at the visitor centre is a sandstone “wall” that reveals some 1,500 dinosaur bones.  Dinosaurs were probably swept away and drowned during floods.  At bends in the river as the current slowed down, so debris, including the carcases of dinosaurs was deposited.  The Dinosaur National Monument preserves these “log jams” of dinosaur bones.  Genera associated with the Monument include Camarasaurus, Allosaurus, Stegosaurus, Apatosaurus, Diplodocus and Dryosaurus.

On Tuesday, September 2nd , a park ranger was leading a tour party along the Fossil Discovery Trail when the damaged bone was noticed.  The vandalism and theft probably took place sometime between the Monday guided walk along the Fossil Discovery Trial and Tuesday morning.  The Fossil Discovery Trail is a 1.2 mile trail that runs between the Quarry Visitor Centre and the Quarry Exhibit Hall where the famous sandstone “wall”of dinosaur bones that we described above, is located.  The trail is unique as it is one of the few places where visitors can hike to see and touch dinosaur fossils and fragments in situ.  It allows visitors to experience what it may have been like for palaeontologist Earl Douglass (Carnegie Museum of Natural History), when he discovered the first fossils in what is now the Monument.

A spokes person from Everything Dinosaur commented:

“This is such a shame as the Dinosaur National Monument is going to celebrate its centenary next year and to have fossils damaged and stolen is deeply upsetting.  Although the fossils along the trail are of limited scientific value they provide a wonderful opportunity for members of the public to get up close to real dinosaur fossils.”

The Sauropod Humerus (before and after) Photographs

Two photographs showing the fossil before and after the theft.

Two photographs showing the fossil before and after the theft.

Picture Credit: National Parks Service

The picture above shows two photographs, the picture of the humerus without the damage (left) and a close up showing the damaged portion (right).  Although our dinosaur experts cannot be certain, the bone portion in question looks like the distal end of a left humerus, probably part of a Camarasaurus.  Park officials are seeking help from the public and anyone with information regarding this theft are invited to contact staff on (435) 781-7715.  A reward of $750 USD has been put up by the Intermountain Natural History Association for information that leads to a conviction.

The Part of the Fossil Discovery Trail where the Bone was Situated

The arrow shows the position of the damaged dinosaur bone.

The arrow shows the position of the damaged dinosaur bone.

Picture Credit: National Parks Service

Everything Dinosaur would like to take this opportunity to stress that visitors to the Dinosaur National Monument are not allowed to collect/damage any fossils or rocks.  Under Federal law, all features, artifacts and resources are protected. No collection of park geological resources for commercial sale, private collections or for classroom educational purposes is permitted.  We advise all visitors to National State Parks of America to familiarise themselves with the various protection laws and polices that relate to that particular location.

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