The Armour of Borealopelta markmitchelli

With the publishing of the formal description of the nodosaurid Borealopelta markmitchelli in the academic journal “Current Biology” this week, Everything Dinosaur has received a number of emails concerning this amazing fossil discovery.  The specimen, was lovingly prepared by museum technician Mark Mitchell who worked on the fossil for five and a half years, a total of something like 7,000 hours, as the dinosaur was exposed from its matrix one grain at a time.

The holotype (TMP 2011.033.0001), is currently on display at the Royal Tyrrell Museum, part of an exhibition entitled “Grounds for Discovery”.  This exhibition highlights the personal stories and amazing fossils that have been discovered as a result of the Museum’s collaboration with numerous industries such as road construction, house building, mining, and oil and gas extraction.

The emails we received concerned aspects such as the animal’s size (5.5 metres long and weighing around 1.3 tonnes) and from which part of Alberta did the fossil come from (north-eastern Alberta).  However, most of the emails were enquiring about the preservation of the armour.

The diagram below should help.

A Schematic Drawing of the Borealopelta markmitchelli Holotype Specimen

Schematic line drawing of the dermal armour of Borealopelta.

Picture Credit: Current Biology

The picture above shows a schematic drawing of Borealopelta (A), with line drawings (B) and (C) showing the skull in dorsal and lateral views.  The different colours illustrate the preservation of different tissue types and the photographs (D to G) with accompanying line drawings show the range of dermal armour including osteoderms and scutes.  A close-up view of the neck (D), shows alternating cervical osteoderm bands (and preserved keratinous sheaths) and polygonal scales.

Photograph (E) shows a close-up view of the flank illustrating lateral thoracic osteoderms (with keratinous coverings) and polygonal scutes (scales).  A close view of the sacral shield area (F) showing more elements that make up the dermal armour and (G) shows a view of the forearm of Borealopelta (antebrachium) showing the amour (osteoderms and scales).

Note

Scale bar = 1 metre (A) and scale bar = 10 cm (B to G).

Body Armour in Life Position

The wonderful thing about this particular armoured dinosaur is that the osteoderms and scales that make up the body armour have been preserved in the position they were in when this dinosaur roamed Alberta during the Early Cretaceous.  The three-dimensional nature of the fossil has really helped the research team to understand how the mosaic of scutes, scales and osteoderms combined to provide the dermal armour.  The remains of the keratin sheaths and overlying skin was also preserved in some areas, melanosomes identified provide evidence of this dinosaur’s colouration.

To read an article about Borealopelta markmitchelli: Amazing Armoured Dinosaur Fossil Reveals Countershading

Students Looking to Test Mars Rovers Discover Dinosaur Fossils

University students looking for a suitable landscape to test robots to take part in the exploration of Mars, have stumbled across the remains of a duck-billed dinosaur eroding out of the landscape.  Members of the University of Saskatchewan Space Design Team (USST), were visiting Midland Provincial Park in southern Alberta (Canada), in early June, scouting for suitable sites for an upcoming robotics contest.  The team were looking to identify terrain that resembled that found on the surface of Mars, the object of the competition being to test designs for Mars Rovers – robotic vehicles that could help with further exploration of the red planet.  What the team did not anticipate, was that their search would lead to the discovery of several fossilised bones from a Late Cretaceous hadrosaurid.

Duck-billed Dinosaur Bones Discovered

Duck-billed dinosaur bone discovered by University of Saskatchewan students.

Picture Credit: Adam McInnes

Dinosaur Bone Discovery

The students were exploring the area around Drumheller in a bid to identify sites suitable for hosting the first Canadian International Rover Challenge, a globally significant event, with a number of universities and institutions showcasing their robotics and automated vehicles that could help future scientific missions to Mars.  The team were looking for locations which were very dry, with lots of rocky terrain, plenty of sand and a mixture of different stone sizes coupled with a minimal of vegetation.  For a palaeontologist, areas with lots of rocky exposures, very few plants and which are subject to high levels of erosion, can also be great places to find fossils, especially if the rock is sedimentary in nature.  This part of Alberta is famous for its extensive exposures of Upper Cretaceous strata and numerous dinosaurs have been identified from their fossilised remains.

An Eroded Hadrosaurid Jaw Bone from the Site

Partial jaw bone from a duck-billed dinosaur.

Picture Credit: Adam McInnes

The picture above shows a very weathered portion of a jaw bone from a duck-billed dinosaur.  The grooves seen in the fossil equate to locations in the jaw for the dental battery, the rows of tightly packed teeth that helped this herbivore process the coarse plant-material such as pine needles that this type of dinosaur consumed.  Hadrosaurid fossils are probably the most common large dinosaur fossils to be found in this part of Canada, team members at Everything Dinosaur, whilst working with Royal Tyrrell Museum staff have come across several specimens themselves. Often the fossils are too weathered and fragmentary to permit extraction and formal identification down to the species level.

Severely Weathered Dinosaur Bones

A Severely Weathered Dinosaur Fossil Bone

It may look like a jumble of “weird-looking” rock but that is a dinosaur bone.

Picture Credit: Adam McInnes

Conservation officials from the Alberta Parks Department and staff from the Royal Tyrrell Museum (Drumheller), were able to assist the USST members and helped them to identify suitable venues for the robotic vehicle tests.  The locations chosen were well away from sites of significant geological interest, after all, it is hardly a valid test for a potential Mars Rover to be able to ascend and descend a dinosaur bone, that is one object that these machines are not going to encounter on Mars.

A Femur (Thigh Bone) from a Hadrosaurid

Hadrosaurid leg bone.

Picture Credit: Adam McInnes

USST President, Danno Peters explained that whilst discovery dinosaur bones certainly generated a degree of excitement amongst the group, none of the USST members were thinking of changing their careers and becoming palaeontologists.  Plans are already well underway for the 2018 Mars Rover competition and the USST team were looking forward to pushing their designs to the limit in even more challenging terrain.

Everything Dinosaur acknowledges the help of the media team at the University of Saskatchewan for their help in the compilation of this article.

Corythoraptor jacobsi – Built Like an Ostrich with the Crest of a Cassowary

Yet another new species of oviraptorid has been named from fossils found in Ganzhou, Jiangxi Province (southern China).  This new dinosaur, which was probably feathered, had a longer neck than its oviraptorid contemporaries making it resemble an ostrich.  It also possessed a crest on top of its skull, called a casque, which was very similar to that seen in the extant, Australian flightless bird, the Cassowary.  This could be a case of convergent evolution between a dinosaur and a non-avian dinosaur.

This new dinosaur has been named Corythoraptor jacobsi, the genus name translates as “helmet speedy thief”, whilst the trivial name honours Professor Louis L. Jacobs of the Southern Methodist University, (Dallas, Texas, USA), who acted as a mentor to three of the authors of the scientific paper, published in the journal “Scientific Reports”.

An Illustration of the Newly Described Oviraptorid from Southern China (Corythoraptor jacobsi)

Corythoraptor jacobsi illustration.

Picture Credit: Zhao Chuang

The Magnificent Seven

The naming of Corythoraptor brings the total of Late Cretaceous oviraptorids known from this part of China to seven.  All seven oviraptorids come from the Nanxiong Formation which relates to the Late Campanian/Early Maastrichtian faunal stages of the Late Cretaceous, around 73 – 71 million years ago.  Palaeontologists are uncertain as to why this part of China seems to have been a “hot spot” for Oviraptorosaurs, the palaeoenvironment might have favoured these cursorial Theropods, which are believed to have been omnivorous, or this type of dinosaur may simply be under represented in other Upper Cretaceous deposits elsewhere in the world.

Intriguingly, of the seven oviraptorid dinosaurs named to date some are known to have been crested and different shaped crests have been identified.  All these dinosaurs are approximately the same size, around two metres in length and all of them were probably feathered.  The long neck (twice as long as the dorsal vertebral column), of Corythoraptor might have evolved to permit this dinosaur to exploit a food source that its contemporaries could not, in the same way that many modern-day antelopes on the African savannah have different neck lengths to help them browse on different plants – an example of niche partitioning.

The Crest of Corythoraptor

The cranial casque of Corythoraptor. Fossil material (a), line drawing (b) and colour restoration (c).

Picture Credit: Scientific Reports

The Seven Oviraptorids from the Nanxiong Formation (so far) – green text indicates information on crests (casques)

• Banji long (named and described in 2010) small, flat crest.
• Ganzhousaurus nankangensis (named and described in 2013) with a potentially, slightly raised crest.
• Jiangxisaurus ganzhouensis (named and described in 2013) potentially crested – small crest.
• Nankangia jiangxiensis (named and described in 2013) insufficient fossil material to establish a crest being present.
• Huanansaurus ganzhouensis (named and described in 2015), potentially crested (top part of the skull is missing, but in a phylogenetic analysis carried out by the authors, Huanansaurus was found to be the sister taxon to the newly described Corythoraptor jacobsi.  H. ganzhouensis skull material is insufficient to conclusively prove the presence of a crest although the thickened naris and parietal indicate that a crest is likely.
• Tongtianlong limosus (named and described in 2016), it possessed a small crest.

To read a previous article on the discovery of an oviraptorid Huanansaurus (Huanansaurus ganzhouensis), which is believed to be very closely related to Corythoraptor: 2015 – New Oviraptorid Dinosaur from the Late Cretaceous of Southern China

A Close View of the Skull and Jaws with a Line Drawing of Corythoraptor

A close up of the skull, jaws and the head crest of Corythoraptor with a line drawing showing body plan.

Picture Credit: Scientific Reports

The picture above shows a close-up of the skull, crest and jaws of the holotype material, accompanied by a line drawing showing the estimated size and Corythoraptor and what it probably looked like.  The scale bar in (c) is 8 centimetres and the scale bar in (d) is 1 metre.   Note that the shape of the crest is inferred, as the actual portion of the skull that represents the majority of the proposed crest is not present, only the lower portion of the bony core of the casque (crest) is preserved.  The preserved portion of the nasals exhibits highly pneumatised bone structure.  The suture between the parietal and frontal is not clear, but it seems the bones project dorsally and formed a distinct crest together with the nasals, very reminiscent of the crest shape seen in living, non-avian dinosaurs, the Cassowaries.

What were the Crests (Casques) used for?

Lead author of the study,  Junchang Lü (Chinese Academy of Geological Sciences), proposes studying the living Cassowary to help shed light on the functional role played by the casque.  This could represent an example of convergent evolution, where a similar physical character has evolved independently in two, unrelated species.  A study of the fossilised bones suggest that this specimen represents an immature individual, a sub-adult Corythoraptor that may have been around eight years of age when it met its demise.  The casque may not have been fully formed when it died, but its function remains a mystery.  However, such a prominent casque could have served a multitude of purposes, just like the crest of the Cassowary.

Crest (Casque) Function

• With lots of different oviraptorids living in the same habitat, the crest could have played a role in species recognition (interspecific recognition).
• The crest could have been used in visual communication, in displays to determine social hierarchy or perhaps in ritualised displays over mate selection (intraspecific combat).
• Crest shape could have indicated maturity, with crest shape changing as the animal became older.
• The crest (or casque) could have indicated fitness for breeding during the mating season.
• This structure could have played a role in helping to differentiate between males and females (sexual dimorphism).
• The crest (or casque) shape in oviraptorids could represent the evolution of character as part of sexual selection.

A Cassowary – Note the Shape of the Casque

For an article describing the discovery of T. limosus: Stuck in the Mud Dinosaur and Oviraptorosaur Diversity

Links to the Dinosaurs of China Exhibition at Wollaton Hall (Nottinghamshire)

Readers in the UK, have the opportunity to get up close to a number of Chinese feathered dinosaurs including a specimen of Oviraptor (O. philoceratops) and a giant relation of the oviraptorids, the giraffe-sized Gigantoraptor, at the Dinosaurs of China exhibition in Nottingham.  In addition, the superb illustrations found throughout this exhibition and seen at the nearby Nottingham Lakeside Arts Centre, were created by Zhao Chuang, who was responsible for illustrating Corythoraptor in the scientific paper (illustration is seen at the top of this article).

For further information on the Dinosaurs of China exhibition: Dinosaurs of China

Hiker Finds Part of a Tyrannosaur Skull Near Tumbler Ridge

Fossil hunter Rick Lambert was hiking in the Tumbler Ridge area of British Columbia when he spotted an unusual object partially exposed in a large rock.  It turns out the eagle-eyed chiropractor from Vancouver Island had found the maxilla bone from a Tyrannosaur skull.    The maxilla is part of the upper jaw, this fossil and the teeth/teeth sockets that it contains, can help palaeontologists to identify the type of dinosaur down to genus level.  This is the first dinosaur skull fossil material to have been found in this area and although the one-hundred-kilogram rock containing the fossil is not part of the local strata, it was probably moved to the site as part of a landscaping project, it’s discovery could help scientists to better understand the geographic distribution of a genus of Tyrannosaur from the Late Cretaceous.

The Tumbler Ridge Tyrannosaur Skull Fossil (Maxilla)

A view of the Tumbler Ridge Tyrannosaur jaw fossil.

Picture Credit: The Canadian Pres/HO/Richard McCrea

A Significant Tyrannosaur Fossil Find

Large Theropod footprints have been found in the Tumbler Ridge area in the past, indeed, this location has provided the palaeontologists based at the Peace Region Palaeontology Research Centre, which was established back in 2003 to study the fossils, with hundreds of dinosaur teeth, fragmentary bones as well as the remarkable trace fossils, but this upper jaw bone could be a real game changer for the region.

The director of the Peace Region Palaeontology Research Centre, Richard McCrea commented:

“We are in a frontier in British Columbia because there’s been no research in this area.  This is quite a jump for us.”

Having studied and worked in geology, Rick Lambert knew he had found something significant, but he had no idea how important his fossil find could prove to be.  Rick was used to finding fossils in the area, but he wasn’t expecting to find a bone from the skull of a Theropod dinosaur, a skull that would have measured more than a metre in length.

Rick explained:

“I never expected to find something like that.  It’s not anything I actually kept my eye out for.  I thought at least they would have four or five of those in a drawer somewhere.”

An Illustration of a Typical Tyrannosaur Skull Showing the Location of the Maxilla Bone

A diagram of a typical Tyrannosaur showing the location of the maxilla.

Picture Credit: The Peace Region Palaeontology Research Centre

McCrea said finding this specific piece of bone is significant because it can be used to determine the type of Tyrannosaur it originated from.  Elements from the skull can be very helpful when it comes to identifying dinosaurs, however, the sandstone rock in which the fossil was found rules out a Tyrannosaurus rex.

A spokesperson from Everything Dinosaur explained:

“The Cretaceous-aged exposures in this area, mostly date from the Upper Cretaceous but they are nowhere near young enough to permit the preservation of a T. rex or any close relative of that iconic dinosaur.  The sandstone block containing the fossil material is very similar in composition to nearby deposits that are around 74-75 million years old, many millions of  years younger than the Cenomanian/Turonian strata from this locality.  The sandstone dates from the Campanian, so the maxilla very probably comes from a member of the Tyrannosauridae family that lived during that time – something like an Albertosaurus or perhaps a large Gorgosaurus.”

From a Large Tyrannosaur

Roughly shaped like a reversed capital “C”, the fossil measures between 30 to 40 centimetres in length and is around 25 centimetres wide.  It is a sizeable bone, indicating that this belonged to a very large Tyrannosaur, something in excess of eight metres in length.  Local palaeontologists calculate that the entire skull of this Theropod, if it could be found, would measure over a metre.

The curator and collections manager at the Peace Region Palaeontology Research Centre, Dr Lisa Buckley commented:

“The exposed maxilla and teeth are eroded, but their shape is perfectly preserved, including fine details of the delicate serrations that form the cutting edge of the teeth. The specimen has twelve teeth evident, with the potential to expose more.  The tooth count and tooth shape make it likely that this is part of the skull of a tyrannosaurid like Albertosaurus, and is probably around 75 million years old.  We aim to establish the point of origin of this rock.”

A View of One of the Teeth Associated with the Jaw Fossil

A close up of a Tyrannosaur tooth found in association with the maxilla bone at Tumbler Ridge (British Columbia).  The tooth serrations can be clearly seen.

Picture Credit: The Peace Region Palaeontology Research Centre

The forested terrain, steep gullies and lack of roads in this part of British Columbia makes prospecting for fossils quite challenging, however, field team members and volunteers can study the sandstone formation from which the block came from in the hope of finding more elements from the skull.

An Illustration of a Typical Tyrannosaurid (Albertosaurus)

An illustration of Albertosaurus sarcophagus.

Picture Credit: Everything Dinosaur

To read an article about Theropod dinosaur prints found in the Tumbler Ridge area: Dinosaur Footprint Discovered in British Columbia