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Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

20 02, 2019

Dinosaur Trackways Saved from Floods

By | February 20th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

A Unique Set of Australian Dinosaur Tracks on the Move

A series of dinosaur tracks located around ninety minutes’ drive away from the town of Winton in Queensland, representing three different types of Late Cretaceous dinosaur, are being moved in order to protect and preserve them.  The dinosaur footprints including a set of Sauropod tracks, the hind prints of some which measure more than a metre across, represent the first substantial evidence of Sauropod locomotion to be recorded from this part of Australia.  In addition, the track of a chicken-sized Theropod is preserved at this location, along with the larger, tridactyl prints of an Ornithopod.

These tracks are the first recorded evidence of substantial walking tracks for Sauropods in Australia and the first Cretaceous-aged sequence of solitary Ornithopod tracks to have been identified “down under”.

An Aerial View Showing the Exposed Dinosaur Tracksite

An aerial view of the trackway site.

An aerial view showing the extent of the Sauropod trackway.

Picture Credit: Australian Age of Dinosaurs Museum

First Tracks Exposed Nineteen Years Ago

The fossil trackways site was first exposed in the summer of 2000, when a small creek changed its course following substantial flooding across this part of central-west Queensland.   The footprints were not recognised at first and lay exposed to the elements, slowly being bleached by the extreme heat and subjected to infrequent but devastating water damage.  However, a major project to map and remove the tracks was begun in April 2018 by volunteers and staff from the Australian Age of Dinosaurs Museum.

It was soon realised that the dinosaur tracks, a series of depressions (hyporelief preservation), were extensive.  The Sauropod tracks consist of at least twenty prints and run for approximately forty metres.  There is also evidence of the tracks having been made on the prints left by other Sauropods including the tracks of a smaller long-necked dinosaur, tentatively described as a sub-adult.

Exposing the Dinosaur Tracks Using an Air Blast Hose

Using an air blast hose to clean away the overburden.

Cleaning the overburden from around the Sauropod tracks using an air blast hose.

Picture Credit: Australian Age of Dinosaurs Museum

Restoration and excavation work has been undertaken to help protect the fragile sandstone prints, conserve them and to prepare them for transport to the Museum, where they will form part of a major new exhibit, safe from further erosion.

Incredibly Rare Dinosaur Trackway Assemblage

It is incredibly rare to have major Sub-orders of the Dinosauria (Theropoda, Ornithopoda and Sauropoda), represented at the same fossil trackway site, in the same bedding plane.

Dr Stephen Poropot of the Australian Age of Dinosaurs Museum and the lead researcher on the project stated:

“The small Ornithopod and Theropod footprints were clearly made by very similar [if not identical] trackmakers to those preserved at Dinosaur Stampede National Monument, which is located about 100 kilometres south of this site”.

To read about the Dinosaur Stampede National Monument tracks preserved at Lark Hill Quarry: Lark Quarry Dinosaur Footprints – Scientists Re-examine the Evidence

Dr Stephen Poropot Carefully Measuring the Dinosaur Tracks

Mapping and measuring a dinosaur tracksite.

Dr Steve Poropot mapping and measuring the tracks.

Picture Credit: ABC Science/Belinda Smith

Significant Sauropod Tracks

According to Dr Poropot, the longest sequence of Sauropod tracks identified at the site can be followed continuously and the thumb claw impressions from the front feet can be clearly made out.  The Sauropod prints are being heralded as the best of their kind found to date in Australia.  The tracks were created approximately 95 million years ago (Cenomanian faunal stage of the Late Cretaceous) and many of the Sauropod tracks are surrounded by concentric mud cracks that were spread through the wet sands as these giant creatures moved across the landscape.

The Three Different Types of Dinosaur Track in Close Proximity

Highlighting different types of dinosaur track.

Sauropod tracks outlined in blue, Theropod tracks (red) and the Ornithopod tracks outlined in green.  Dr Stephen Poropot’s boot in the top left corner provides scale.

Picture Credit: Swinburne University of Technology

Made by Titanosauriform Sauropods

These trace fossils cannot be assigned to any particular species of dinosaur.  However, the deposit in which the fossils were found represents the Winton Formation and three genera of Sauropods (all Titanosaurs), have been described from these sandstone sediments to date:

  • Savannasaurus elliottorum named in 2016.
  • Diamantinasaurus matildae named in 2009 (it has been speculated that the Sauropod tracks could have been made by Diamantinasaurus).
  •  Wintonotitan wattsi named in 2009.

Exposing the Titanosauriform Sauropod Tracks

Titanosauriform tracks exposed at the site.

The edge of the Titanosauriform Sauropod trample zone revealed. The tracks were made by a dinosaur estimated at around 18 metres in length. These are the best preserved Sauropod tracks at the site.

Picture Credit: Australian Age of Dinosaurs Museum

David Elliott, Executive Chairman of the Australian Age of Dinosaurs Museum, who has been heavily involved with this Sauropod-sized excavation and restoration project, explained that the relocation of the trackway began in September 2018 and twenty-five per cent of the total area, including all of the fragile footprints that were in danger of being destroyed, have now been removed.

He commented: “This is a very slow and painstaking process.  The total weight of the trackway is in the vicinity of 500 tonnes and we are transporting it back to the Museum, one two-tonne trailer load at a time.”

A scientific analysis of the trackways interpreting dinosaur body size, gaits and potential Sauropod herd dynamics, has been submitted for peer review by Dr Poropot and his colleagues and Mr Elliott is hoping that the attraction, named “March of the Titanosaurs”, will be open to the public from May of next year.

A Major Boost For Queensland Tourism

David Elliott added:

“Very few museums in the world can boast a multi-sequence Sauropod trackway as one of their in-house exhibitions, much less one fifty-five metres long with the footprints of all three major groups of Dinosauria represented.”

A Close-up View of the Sauropod Tracks

Sauropod tracks.

The exposed and cleaned Sauropod tracks.

Picture Credit: ABC Science/Belinda Smith

It is hoped that once opened in May 2020, “March of the Titanosaurs” will provide a major boost to tourism in this part of Queensland, especially after this area was hit by devastating floods recently.  Had the project to remove the dinosaur tracks been delayed, it is likely that many of the prints would have been destroyed in the flooding.

A spokesperson from Everything Dinosaur commented:

“This has been a tremendous conservation effort, we congratulate all those involved.  Thanks to this dedicated team, a hugely significant set of dinosaur trace fossils have been preserved.”

18 02, 2019

A New African Titanosaur is Announced

By | February 18th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Mnyamawamtuka moyowamkia – Heart-shaped Tail Bones Help to Flesh Out Titanosaur Evolution

Scientists writing in the on-line, open access journal PLOS One, have published details of a new species of African Titanosaur.  It took several years to carefully remove the fossil material from a high cliff wall overlooking the Mtuka riverbed in south-western Tanzania, but the fossils, representing a not fully mature dinosaur, are providing palaeontologists with important information about how African ecosystems changed over the course of the Cretaceous.  The new Titanosaur has been named Mnyamawamtuka moyowamkia (pronounced Mm-nya-ma-wah-mm-too-ka mm-oh-yo-wa-mm-key-ah).  The name is derived from Kiswahili for “animal of the Mtuka river with a heart-shaped tail”.

The heart-shaped tail element of the name refers to the strange shape of the most intact middle caudal vertebra described in the paper.  It bulges out at the sides (dorsolateral expansion of the posterior articular surface of the centrum), a unique tail bone morphology that resembles the shape of a romantic, love heart.

A Life Reconstruction of a Pair of  Mnyamawamtuka moyowamkia Titanosaurs

Mnyamawamtuka moyowamkia illustration

Mnyamawamtuka moyowamkia life reconstruction.

Picture Credit: Mark Witton

The first evidence of the dinosaur fossils was noted in 2004 and some fossils were excavated from the cliff face, in what were quite hazardous conditions, with field team members having to be lowered over the cliff on numerous occasions to work on the exposed bones.  Annual excavations took place until 2008, it was important to keep returning to the site as the fossils were in danger of being lost to the river in seasonal floods.

A Line Drawing of the Quarry Site Showing the Extent of the Annual Excavations

Quarry map of M. moyowamkia site.

Quarry map showing the layout and excavation timeline of the M. moyowamkia fossil material.

Picture Credit: PLOS One

Around 110-100 Million Years Old

The specimen was excavated from the Mtuka Member of the Cretaceous Galula Formation, which was deposited around 110 to 100 million years ago (Aptian to Cenomanian faunal stage of the Cretaceous).  A substantial portion of the postcranial skeleton has been recovered.

Dangerous Work!  The Excavation Site in 2007

The location of the Mnyamawamtuka moyowamkia fossils.

The quarry dig site above the Mtuka riverbed in south-western Tanzania.

Picture Credit: Ohio University

Commenting on the importance of this discovery, in relation to the evolution of African Titanosaurs, lead author of the paper, Dr Eric Gorscak, a recent PhD graduate of Ohio University and now an assistant professor at the Midwestern University (Illinois), stated:

“Although Titanosaurs became one of the most successful dinosaur groups before the infamous mass extinction capping the Age of Dinosaurs, their early evolutionary history remains obscure, and Mnyamawamtuka helps tell those beginnings, especially for their African-side of the story.  The wealth of information from the skeleton indicates it was distantly related to other known African Titanosaurs, except for some interesting similarities with another dinosaur, Malawisaurus, from just across the Tanzania–Malawi border.”

Adding to the Diversity of Titanosaurian Sauropods from Africa

The field team responsible for this discovery have also found the fossilised remains of two other Titanosaurs in this part of Africa.  In 2017, Everything Dinosaur reported upon the discovery of Shingopana songwensis.

To read about S. songwensisA New Species of African Titanosaur is Named

In addition, Rukwatitan bisepultus another Titanosaurian Sauropod dinosaur, was named and described in 2014: A New Species of Titanosaurian Sauropod Rukwatitan bisepultus

The researchers conclude that Mnyamawamtuka moyowamkia was distantly related to both Shingopana songwensis and Rukwatitan bisepultus, fossils of which come from younger Cretaceous sediments, although it did share some anatomical characteristics with Malawisaurus dixeyi from Malawi, that might have been contemporaneous.  This new fossil discovery is helping palaeontologists to better understand the distribution of Titanosaurs between Africa and South America and their evolutionary relationships.

Heart-shaped Tail Bones

One of the middle caudal centra (tail bone from the middle portion of the tail), exhibits a unique dorsolateral expansion of the posterior articular surface of the centrum.  This unique characteristic was found to be present in the most intact middle caudal vertebra described.  This unique shape inspired the dinosaur’s name.

Heart-shaped Tail Bone Centrum (Rear View)

Heart-shaped tail bone.

A posterior view of a middle caudal vertebra showing the characteristic heart shape.  The term dle = dorsolateral expansion.

Picture Credit: PLOS One

Tail Bones of Different Titanosaurs Compared

Titanosaur tail bne comparison.

A comparison of caudal vertebrae between three Titanosaurs. Mnyamawamtuka moyowamkia (A), compared with Malawisaurus dixeyi (B) and Lohuecotitan pandafilandi of the Late Cretaceous of Spain (C). Posterior views and lateral views, scale bar = 10 cm.  The term dle = dorsolateral expansion.

Picture Credit: PLOS One

The scientific paper: “A New African Titanosaurian Sauropod Dinosaur from the Middle Cretaceous Galula Formation (Mtuka Member), Rukwa Rift Basin, Southwestern Tanzania” by Eric Gorscak and Patrick M. O’Connor published in PLOS One.

12 02, 2019

Reflecting on the Eyes of Cretaceous Spiders

By | February 12th, 2019|Dinosaur and Prehistoric Animal News Stories, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

Early Cretaceous Spiders Reveal Reflective Eyes

A team of scientists, including a researcher from the University of Kansas, writing in an academic journal (Journal of Systematic Palaeontology), have described spiders from the Early Cretaceous that had reflective eyes, an adaptation to permit these tiny predators to hunt at night.  The remarkable fossils were discovered in black shale beds from South Korea which form part of the Jinju Formation (Albian faunal stage) and the flattened fossils preserve the remains of spiders that lived between 113 and 110 million years ago.

The Light Reflective Properties of the Crescent-shaped Tapetum

UV light reveals the ancient tapetum of spiders.

The two tapetum can be seen as crescent-shaped objects on the anterior portion of the head.

Picture Credit: Paul Selden/University of Kansas

Two of the fossils from the extinct spider family Lagonomegopidae feature reflective eyes.  The fossils represent the first non-amber Lagonomegopidae to be described, with the first preservation of a spider eye tapetum recorded in the fossil record.

C0-author of the scientific paper, Paul Selden, Gulf-Hedberg Distinguished Professor of Geology and the Director of the Palaeontological Institute at Kansas University’s Biodiversity Institute and Natural History Museum, explained:

“Because these spiders were preserved in strange slivery flecks on dark rock, what was immediately obvious was their rather large eyes brightly marked with crescentic features.  I realised this must have been the tapetum — that’s a reflective structure in an inverted eye where light comes in and is reverted back into retina cells.  This is unlike a straightforward eye where light goes through and doesn’t have a reflective characteristic.”

Selden said that some contemporary spiders feature eyes with a tapetum, but the new paper is the first to describe the anatomical feature in a fossilised spider.  The research team said the discovery provides evidence for lagonomegopid enlarged eyes being posterior medians.

“In spiders, the ones you see with really big eyes are jumping spiders, but their eyes are regular eyes — whereas wolf spiders at night time, you see their eyes reflected in light like cats.  So, night-hunting predators tend to use this different kind of eye.  This was the first time a tapetum had been in found in fossil.  This tapetum was canoe-shaped — it looks a bit like a Canadian canoe.  That will help us place this group of spiders among other families.”

Selden’s collaborators were Tae-Yoon Park of the Korea Polar Research Institute and amateur fossil hunter Kye-Soo Nam of the Daejeon Science High School for the Gifted, who found the fossils preserved in the shale.

The description of the fossils increases the number of known spiders from the Jinju Formation from a single specimen to eleven.

Commenting on their remarkable state of preservation, Paul added:

“This is so rare because they’re very soft — they don’t have hard shells so they very easily decay.  It has to be a very special situation where they were washed into a body of water.  Normally, they’d float.  But here, they sank, and that kept them away from decaying bacteria, it may have been a low-oxygen condition.  These rocks also are covered in little crustaceans and fish, so there maybe was some catastrophic event like an algal bloom that trapped them in a mucus mat and sunk them, but that’s conjecture.  We don’t really know what caused this, but something killed off a lot of animals around the lake at one time or on an annual basis.”

According to Selden, the shale preserved the spider fossils in a manner that highlighted the reflectivity of the tapetum, a feature that may have been missed had the spiders been preserved in amber instead, as is more typical.

Preserved in the Black Shale an Almost Perfect Impression of an Early Cretaceous Spider

Fossilised remains of an Early Cretaceous spider with reflective eyes.

The black shale preserved perfect impressions of the ancient spiders.

Picture Credit: Paul Selden/University of Kansas

The discovery of these spiders will help researchers to piece together a better understanding of the environment that existed in South Korea during the Early Cretaceous.

Everything Dinosaur acknowledges the assistance of a press release from the University of Kansas in the compilation of this article.

11 02, 2019

Two Ancient Seed-eating Birds Described

By | February 11th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Eofringillirostrum boudreauxi  and Eofringillirostrum parvulum Passerines from the Early Eocene

A scientific paper has just been published in the journal “Current Biology”, that describes two Early Eocene, seed-eating, perching birds (passerines).  The birds are closely related, assigned to the same genus but one fossil was discovered in Wyoming, the other comes from the famous Messel shales of Germany and they are separated by around 5 million years.  These species are amongst the oldest fossil birds to exhibit a finch-like beak and provide the earliest evidence for a diet focused on small, hard seeds in crown birds.  The discovery of these two early granivores, will help scientists to better understand the evolution and radiation of this important group of birds, that make up 65% of all extant bird species.

The Wyoming Specimen – Holotype of Eofringillirostrum boudreauxi

Eofringillirostrum boudreauxi holotype from the Green River Formation of Wyoming.

(A) Photograph and (B) line drawing of the holotype skeleton of Eofringillirostrum boudreauxi (FMNH PA 793).

Picture Credit: Current Biology

The Ancestors of Sparrows, Finches, Crows, Robins etc.

Passerines might be ubiquitous these days, but once they were rare and only made up a small proportion of avian biotas.  We still have a lot to learn about their evolution.

Commenting on the significance of the fossil discoveries, one of the co-authors of the paper Lance Grande (Field Museum, Chicago), stated:

“This [Eofringillirostrum boudreauxi] is one of the earliest known perching birds.  It’s fascinating because passerines today make up most of all bird species, but they were extremely rare back then.  This particular piece is just exquisite.  It is a complete skeleton with the feathers still attached, which is extremely rare in the fossil record of birds.”

The Wyoming specimen, E. boudreauxi, is the earliest example of a bird with a finch-like beak, similar to many of the birds you see today inhabiting parks and gardens.  This legacy is reflected in its name; Eofringillirostrum means “dawn finch beak”, whilst the specific epithet honours Terry and Gail Boudreaux, who donated the holotype to the Field Museum.

The Green River Formation

The Wyoming specimen heralds from the famous Early Eocene Green River Formation, extensive fine-grained deposits formed in a lacustrine environment.  The area is famous for its beautifully preserved but compressed vertebrate fossil specimens.

Lead author of the research, Daniel Ksepka from the Bruce Museum (Connecticut), commented on the importance of finding fossil birds with finch-like beaks adapted to eating seeds:

“These bills are particularly well-suited for consuming small, hard seeds.  Anyone with a birdfeeder knows that lots of birds are nuts for seeds, but seed-eating is a fairly recent biological phenomenon.”

The earliest birds probably ate insects, plant material and even fish, although a recent theory has been proposed that the ability to consume seeds may have helped some kinds of birds survive the catastrophic End-Cretaceous mass extinction event.

To read an article about this: Seed-eating may have Helped Birds Survive Mass Extinction Event

Comparing the Two Specimens

Both the Wyoming and the German specimens have similar shaped beaks, although the German fossil represents a slightly smaller type of bird.  Beak shape infers information about the bird’s diet and as such, beak shape plays a key role in avian radiations and is one of the most intensely studied aspects of avian evolution and ecology.

With two specimens that were both temporally and geographically dispersed the researchers were able to conclude that these types of birds were widespread during the Eocene.

The Messel Shale Passerine Specimen – Eofringillirostrum parvulum

Eofringillirostrum parvulum from the Messel Shales.

Holotype slab (IRSNB Av 128a) and (G) counter slab (IRSNB Av 128b) of Eofringillirostrum parvulum with enlargements showing details of (H) skull and (I) carpometacarpus.

Picture Credit: Current Biology

Found in Subtropical Habitats Not Open Plains

Whilst many Passeriformes (passerines or perching birds), are synonymous with open, grassland environments today, the researchers note that these fossil specimens occurred in subtropical palaeoenvironments.  Given that seed-eating (granivory), is a key adaptation that allows passerines to exploit open temperate environments, the seed-eating habit may have evolved prior to the movement of these types of birds into more open habitats.  The ability to consume and digest seeds may not have been a driver in allowing these types of birds to exploit new habitats, but this type of feeding behaviour would have proved to be extremely beneficial as the world became much cooler towards the end of Eocene and the once widespread rainforests gave way to more open landscapes.

Everything Dinosaur acknowledges the assistance of a press release from the Field Museum (Chicago), in the compilation of this article.

The scientific paper: “Oldest Finch-beaked Birds Reveal Parallel Ecological Radiations in the Earliest Evolution of Passerines” by Daniel T. Ksepka, Lance Grande and Gerald Mayr published in Current Biology.

8 02, 2019

New Species of Late Cretaceous Oviraptorid Named

By | February 8th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Gobiraptor minutus – The Diversity of the Oviraptoridae in the Late Cretaceous

A new species of oviraptorid dinosaur (Oviraptoridae family), has been described by an international team of scientists.  The little dinosaur was probably feathered and it possessed thickened jaws, an adaptation to feeding on hard food items such as seeds, nuts or the shells of bivalves, molluscs and crabs (durophagous).   The fossilised remains of a single, very young individual were found in the Altan Uul area of Ömnögovi Province, Mongolia, in strata from the famous Upper Cretaceous Nemegt Formation.  The new species has been named Gobiraptor minutus and it helps to demonstrate that this part of Asia in the Late Cretaceous was home to diverse variety of oviraptorids, many of which, probably occupied specialist niches within the ecosystem in a bid to minimise competition for resources.

A Life Reconstruction of Gobiraptor minutus

Gobiraptor minutus life reconstruction.

A life reconstruction of Gobiraptor minutus.

Picture Credit: Do Yoon Kim with additional annotation by Everything Dinosaur

Rare for the Altan Uul Area of Southern Mongolia

Oviraptorid fossil specimens are relatively rare in the Altan Uul area of the Gobi Desert, however, within the Upper Cretaceous deposits exposed within the Gobi Desert, some ten oviraptorid taxa have so far been named and described.  Gobiraptor increases the diversity of oviraptorids known from the Nemegt Formation and demonstrates that these types of Theropod dinosaurs were exceptionally abundant in the mesic environment* of that part of the world during the Late Cretaceous.

A mesic environment* – is a term used in ecology to describe an environment with a moderate amount of water.  Much of this part of Asia during the Late Cretaceous may be associated with a dry, arid environment, for example numerous types of other Theropod fossils come from strata that represent almost desert-like conditions.  These fossils are found in the older Barun Goyot Formation which was laid down under more arid conditions.  The rocks in which the fossils of Gobiraptor were found consist mainly of river channel deposits, indicating that the palaeoenvironment changed and the environment became considerably wetter.

Thus, the finding of a new member of the Oviraptoridae family in the Nemegt Formation, which consists mostly of river and lake deposits, confirms that these dinosaurs were extremely well adapted to wet habitats.

Fragmentary Fossils and Skeletal Reconstruction of Gobiraptor minutus

Gobiraptor minutus skeletal reconstruction.

Grey shaded bones indicate known fossil material.  Note scale bar on skeletal drawing – 10 cm.

Picture Credit: PLOS One

Robust and Thickened Jaws Hint at a Dietary Specialism

Gobiraptor minutus, can be differentiated from other members of the Oviraptorosauria clade in having unusually robust and thickened jaws.  This unique mandibular morphology suggests that Gobiraptor was adapted to feeding on hard food items, it used its strong jaws to crush, indicating potential niche partitioning in the palaeoenvironment to reduce competition amongst small Theropods and within the local population of oviraptorids.  Osteological analysis of the femur suggests that the fossil material represents a very young individual.

The phylogenetic analysis carried out by the researchers defines Gobiraptor as a derived oviraptorid closely related to three taxa from the Ganzhou region of southern China, but, ironically, the analysis suggests that it was rather distantly related to other Nemegt oviraptorids which, as the results of recent studies, are also not closely related to each other.

The authors propose that different dietary strategies may explain the wide taxonomic diversity and evolutionary success of this group of dinosaurs in this part of Asia.

Post-cranial Elements of G. minutus

Post-cranial elements of Gobiraptor.

Left femur in caudal view (A) and medial view (B).  Partial right humerous (C) and ilium (D).  (E) left metatarsal I and pedal digit I in medial view.  (F) left pedal digit IV in lateral view.  Scale bar = 5 cm.

Picture Credit: PLOS One

The genus name honours the Gobi Desert, whilst the specific epithet is from the Latin for small, a reflection on the small size of the holotype.

The scientific paper: “A New Baby Oviraptorid Dinosaur (Dinosauria, Theropoda) from the Upper Cretaceous Nemegt Formation of Mongolia” by Sungjin Lee, Yuong-Nam Lee , Anusuya Chinsamy, Junchang Lü, Rinchen Barsbold and Khishigjav Tsogtbaatar published in PLOS One.

7 02, 2019

Defensive Dicraeosaurids – Forward Facing Spikes Deter Predators

By | February 7th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Bajadasaurus pronuspinax – Sauropod Defences

A newly described Sauropod from northern Patagonia (Argentina), has provided palaeontologists with evidence to help explain why some of these long-necked dinosaurs evolved long, paired spines on the necks.  These features may have had a primary role as defensive structures helping to deter attacks from Theropod predators.  The dinosaur has been named Bajadasaurus pronuspinax and it has been assigned to the Dicraeosauridae family, a sister family to the Diplodocidae within the Sauropoda.  Dicraeosaurids are characterised by having relatively shorter necks and distinctive vertebrae which had long, paired neural spines.  The function of these spines has long been debated.  They have been interpreted as playing a role in visual communication, sexual display and thermoregulation, however, this newly described dinosaur suggests that within this family of long-necked dinosaurs they evolved as a form of defence.

Illustrating Bajadasaurus pronuspinax and the Fossil Find Location

Bajadasaurus skeletal reconstrution and fossil find location.

A skeletal reconstruction of Bajadasaurus, location map of fossil finds and drawing of the fossil material in situ.

Picture Credit: Gallina et al published in Scientific Reports

The image (above), shows a skeletal reconstruction of the head and neck of Bajadasaurus (A), with the preserved fossil material shown in white.  On the right of the image is a location map (B), showing the site of the fossil find, close to the Ezequiel Ramos Mexía lake in Neuquén Province, Argentina.  A line drawing is provided (C), that shows the association and the location of the fossils found at the dig site.

Interpreting Fossils One Cervical Vertebra at a Time

The authors of the scientific paper, propose that the elongated neural spines of this dinosaur always faced forward, presenting a formidable obstacle for any meat-eating dinosaur wanting to attack the animal’s neck.  However, it is worth noting that if the image (above), is studied, the theory of Bajadasaurus having a neck topped with defensive spikes, like some sort of Victorian railings is based on the discovery of a single neck bone, in the skeletal illustration placed in the position of the fifth cervical vertebra.  The appearance of B. pronuspinax is inferred by comparing these fossils to the better-known Amargasaurus (A. cazaui).  Until more fossils are found the appearance of Bajadasaurus and the orientation of those neural spines can only be speculated.

A Model of the Dicraeosaurid Amargasaurus

A model of Amargasaurus.

The Amargasaurus has been mounted onto a bespoke base.  The appearance of Bajadasaurus is based on a comparison with better-known, related dicraeosaurids such as Amargasaurus cazaui.

Picture Credit: Everything Dinosaur

Lead-author of the study, Pablo Gallina and his colleagues, propose that these neural spines may have been covered with keratin and therefore much longer than the spines themselves.  The extent of the neural spines, the length of the keratin sheaths that covered them and the direction they pointed in, remains unknown.  Until more fossils of Bajadasaurus are found, those elongated neural spines remain a mystery.

Naming a New Dinosaur

That one cervical spine forms the basis for the species epithet.  The genus honours Bajada (Spanish for downhill), a reference to the fossil find location – Bajada Colorada.  The species name means “bent over, forward spines”, we shall see if more fossil discoveries reaffirm this interpretation.  Importantly, the fossil material assigned to Bajadasaurus includes much of the skull, thanks to these fossils, the palatal bones, the braincase and a nearly complete left dentary, palaeontologists have a much better idea about the size and morphology of dicraeosaurid dinosaur skulls.

Skull Material Associated with Bajadasaurus pronuspinax and Line Drawing

Bajadasaurus and line drawing.

Skull of Bajadasaurus pronuspinax, specimen number MMCh-PV 75 and line drawing.

Picture Credit: Gallina et al published in Scientific Reports

The skull is quite small for a Sauropod, dicraeosaurids described to date were not as big as some of their diplodocid cousins.  Size estimates range from around 10 to 13 metres in length.  The size of Bajadasaurus is unknown, but based on these fossils, it is likely that this dinosaur was within this size range too.  The orbits are quite large and their position on the top of the skull suggests that when this dinosaur had its head down and it was feeding, it was capable of seeing ahead (forward-directed, stereoscopic vision).

Comparing Bajadasaurus to the Geologically Younger Amargasaurus

The strata of the Bajada Colorada Formation represent sediments laid down at the very beginning of the Cretaceous (Lower Cretaceous, Berriasian/Valanginian faunal stages).  Bajadasaurus roamed Patagonia some 140 million years ago.  Amargasaurus, lived in the same part of South American but around fifteen million years later.  The researchers suggest that the temporal difference between Bajadasaurus and Amargasaurus, supports the idea that the development of an array of defensive spines was likely adaptive over a long time period.  How effective these spines may have been against predators, is once again, open to speculation.  However, the presence of elongated neural spines would have given the impression of a larger animal with a thicker neck.  To a hungry, carnivorous dinosaur the appearance of a bigger more robust adversary may have been enough of a deterrent.

The scientific paper: “A New Long-spined Dinosaur from Patagonia Sheds Light on Sauropod Defence System” by Pablo A. Gallina, Sebastián Apesteguía, Juan I. Canale and Alejandro Haluza published as an open access article in the journal “Scientific Reports”.

5 02, 2019

Iconic Feather Fossil Did Not Belong to Archaeopteryx

By | February 5th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Single Feather Not From Archaeopteryx

One of the most significant fossils to have ever been found, an iconic fossil in vertebrate palaeontology – a single fossilised feather from the Upper Jurassic Solnhofen limestone, is not quite what it seems.  The feather, long thought to be from an Archaeopteryx, is probably not from the “urvogel” at all.  The feather most likely was lost by a dinosaur, before it was blown into a shallow, calm lagoon and preserved as a carbonised film for 150 million years.

The Iconic Single Feather Fossil – Once Synonymous with Archaeopteryx is Not What it Seems

The Berlin feather - preserved as a carbonised film.

The slab from the Berlin museum showing the iconic feather, so long associated with Archaeopteryx but now thought to have belonged to a dinosaur.

Picture Credit: Everything Dinosaur

An international research team which included Dr Michael Pittman (University of Hong Kong), have applied a novel, high-tech, imaging method called Laser-Stimulated Fluorescence (LSF), to  help solve a 150-year-old mystery and to confirm that this feather was not from Archaeopteryx.

Discovered in 1861

The specimen was discovered in 1861 and actually consists of a slab and counter slab component, housed in museums located in Berlin and Munich.  A year later, the fossil feather was formally described and heralded as coming from an Archaeopteryx (A. lithographica), although unlike most feather impressions associated with the dozen or so Archaeopteryx specimens known to science, this feather was preserved as a dark, carbonised film.  This was the first fossil feather ever discovered and at the time fossils of Archaeopteryx were heralded as evidence of a “missing link”, supporting Darwin’s recently published theory of natural selection.

The detailed scientific description published in 1862 commented upon a rather long quill visible on the fossil, but this is unseen today.  Even recent X-ray fluorescence and UV (ultraviolet), imaging studies did not end the controversy of the “missing quill”.  The original existence of this quill has therefore been debated and it was unclear if the single feather represented a primary, secondary, or primary covert feather from Archaeopteryx.

Writing in the academic journal Scientific Reports, the researchers outline their work using the LSF technology and demonstrate its potential for providing new information about extensively studied fossil specimens.  The application of Laser-Stimulated Fluorescence is being developed by Thomas G Kaye of the Foundation for Scientific Advancement, Sierra Vista, Arizona (USA) and Dr Pittman.

Dr Pittman stated:

“My imaging work with Tom Kaye demonstrates that important discoveries remain to be made even in the most iconic and well-studied fossils.”

Detecting the Geochemical Presence of the Lost Quill

The application of LSF technology permitted the scientists, which included lead-author of the study Tom Kaye, to detect the geochemical halo from the rachis, matching the 1862 description.

Views of the Isolated Solnhofen Feather – Not from Archaeopteryx

Images of the Solnhofen isolated feather.

The isolated feather viewed under natural light (top), the original drawing from 1862 by Hermann von Meyer and under (LSF) showing the halo of the missing quill (bottom). Scale bar is 1 cm.

Picture Credit: University of Hong Kong

The shape of the feather has led the researchers to discount the idea that it came from an Archaeopteryx.  Instead, they conclude that it probably came from an unknown species of feathered dinosaur that lived alongside Archaeopteryx in the Solnhofen Archipelago.

Daniela Schwarz, a co-author of the scientific paper based at the Museum für Naturkunde, Berlin, commented:

“It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill.”

This new insight into an iconic fossil specimen also suggests that the diversity of feathered dinosaurs was likely higher in the ancient island archipelago than previously thought.

Tom Kaye added:

“The success of the LSF technique here is sure to lead to more discoveries and applications in other fields.  But, you’ll have to wait and see what we find next!”

1 02, 2019

Pachyrhinosaurus perotorum – New Research is Published

By | February 1st, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Puzzling Pachyrhinosaurs – The Remarkable Pachyrhinosaurus perotorum

Researchers from the Perot Museum of Nature and Science (Dallas, USA), in collaboration with the University of Toronto (Canada), have published an update on their research into one of the most remarkable Late Cretaceous dinosaurs known to science.

Back in 2011, Everything Dinosaur reported that field work in the high Arctic led by palaeontologists from the Perot Museum of Nature and Science had uncovered the fossilised remains of at least ten individual dinosaurs representing a new species of Ceratopsian.  This horned dinosaur, a Pachyrhinosaur, was named Pachyrhinosaurus perotorum and it became the third species to be assigned to this centrosaurine genus.  With numerous specimens to study, the palaeontologists could gain a fresh perspective on how horned dinosaurs changed as they grew up and develop a better understanding of the cranial ornamentation associated with the Ceratopsidae.

The Ontogeny of P. perotorum

Illustrating the ontogeny of a Pachyrhinosaurus (P. perotorum).

How a baby P. perotorum grew up.  With numerous individuals represented at the same dig site, palaeontologists can examine variation within a species and assess how these dinosaurs changed as they matured.

Picture Credit: Perot Museum of Nature and Science

Updating Their Findings

The authors of the original scientific paper describing P. perotorum, Anthony Fiorillo and Ronald Tykoski, have published a new report in conjunction with Kentaro Chiba of the Department of Ecology and Evolutionary Biology at the University of Toronto, updating their research and providing more information on how this species can be distinguished from the two other species of Pachyrhinosaurus.  The continued preparation of fossil specimens collected from the type locality, the  Kikak-Tegoseak Quarry (Prince Creek Formation), has produced more skull elements to study.  The researchers note that their original reconstruction of the type parietal bone was incorrect, the parietal along with the squamosal bone form the neck frill in horned dinosaurs.  The parietal of P. perotorum is similar to the parietal bones of the other species – P. canadensis and P. lakustai.

It is postulated that Pachyrhinosaurus perotorum can be identified by an upturned tip of the rostrum, a dorsally shifted rostral bone lacking a sharply downturned, parrot-like beak and an enlarged median ridge at the posterior end of the nasal boss.  Other differences in cranial morphology are also tentatively proposed in the new scientific paper, published in the Journal of Systematic Palaeontology.

A Speculative Illustration of the High Northern Latitude Ceratopsian Pachyrhinosaurus perotorum

A northern Ceratopsian with a shaggy coat.

A speculative illustration of Pachyrhinosaurus perotorum with a shaggy coat of feathers.  Although northern Alaska was warmer in the Late Cretaceous than today, it would have been distinctly chilly, too cold for ectothermic reptiles and it has been speculated that the dinosaur biota of high latitudes may have been specifically adapted to cold climates.  In this illustration, Pachyrhinosaurus has been depicted with a long, shaggy coat of feathers to help keep out the cold.

Picture Credit: Mark Witton

The Sister Taxon of P. canadensis

A cladistic analysis undertaken by the team using this new dataset in conjunction with previous research confirms that the Pachyrhinosaurus genus is monophyletic (all descended from a common ancestor) and that Pachyrhinosaurus canadensis is the sister taxon to P. perotorum.  In addition, this research supports the idea that parietal and squamosal frill ornamentations alone do not adequately address the variables in craniofacial morphology needed to distinguish between species of Pachyrhinosaurus.

The continuing research into horned dinosaurs that lived at high latitudes is helping palaeontologists to gain a better understanding of a unique ecosystem that existed towards the end of the dinosaur age.  Pachyrhinosaurus perotorum is not only the youngest Pachyrhinosaur species known, it is also the geologically youngest known centrosaurine.  With three species assigned to the genus, Pachyrhinosaurus is the most speciose of all the Centrosaurinae genera.

A spokesperson from Everything Dinosaur commented:

“Pachyrhinosaurus perotorum holds a special place in Ceratopsidae research.  It lived at a higher latitude than any other horned dinosaur known to science and, as a consequence, had to endure some very tough and harsh climatic conditions.  Whether this dinosaur was a seasonal migrant to the area in summer to take advantage of the 24-hours of daylight that permitted abundant plant growth, or whether this reptile was a permanent resident remains uncertain.  However, the discovery of the fossilised remains of a juvenile at the Kikak-Tegoseak Quarry, suggests that this dinosaur could have been indigenous to northern Alaska during the Maastrichtian faunal stage.”

To read Everything Dinosaur’s original article from 2011 that announced the discovery of a third species of Pachyrhinosaurus: A New Species of Pachyrhinosaurus – P. perotorum.

The scientific paper: “New Data and Diagnosis for the Arctic Ceratopsid Dinosaur Pachyrhinosaurus perotorum” by Ronald S. Tykoski, Anthony R. Fiorillo and Kentara Chiba published in the Journal of Systematic Palaeontology.

31 01, 2019

A Newly Described Archosauromorph from Antarctica

By | January 31st, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Geology, Main Page, Photos/Pictures of Fossils|0 Comments

Antarctanax shackletoni – Rise of the Archosaurs

A team of researchers, including scientists from the Field Museum (Chicago, USA), the University of Witwatersrand (South Africa) and the Burke Museum (University of Washington, USA), have published a scientific paper announcing the discovery of an archosauriform archosauromorph, that roamed Antarctica in the Early Triassic.  The fossil discovery suggests that early Archosaurs were more geographically widespread than previously thought and demonstrates that the biota of Antarctica may have been very different from other parts of the super-continent Pangaea as the planet recovered from the End-Permian mass extinction event.

A Diverse Fauna in Antarctica During the Early Triassic

Antarctica around 250 million years ago (Antarctanax shackletoni is in the left foreground).

A typical scene in Antarctica during the Early Triassic.   Antarctanax is in the left foreground.

Picture Credit: Adrienne Stroup (Field Museum, Chicago)

The illustration above depicts a typical ecosystem that existed in Antarctica approximately 250 million years ago.

Along the banks of a river, three Archosaur inhabitants of the dense Voltzia conifer forest cross paths, Antarctanax shackletoni attempts to sneak up on an early titanopetran insect, an archosauromorph Prolacerta rests on a log, and an enigmatic large Archosaur pursues two unsuspecting Dicynodonts, (Lystrosaurus maccaigi).

“Antarctic King”

Commenting on the significance of the discovery of the iguana-sized animal, co-author of the scientific paper Brandon Peecook (Field Museum) stated:

“This new animal was an Archosaur, an early relative of crocodiles and dinosaurs.  On its own, it just looks a little like a lizard, but evolutionarily, it’s one of the first members of that big group.  It tells us how dinosaurs and their closest relatives evolved and spread.”

The fossil skeleton is far from complete.  The material was collected from a site representing Lower Fremouw Formation deposits in the central Transantarctic Mountains.  The fossils consist of cervical and dorsal vertebrae, a single humerus and foot bones.  The reptile has been named Antarctanax shackletoni.  The genus name means “Antarctic King”, although this ancient, basal member of the group of reptiles that was to give rise to the dinosaurs, pterosaurs, crocodiles and birds, was probably not an apex predator.  This cannot be stated with certainty, after all, only one fossil specimen has been found, but Antarctanax shackletoni co-existed with a number of other vertebrates including amphibians, synapsids and at least one large archosauriform, which may have been the top predator.

The species name honours the polar explorer Ernest Shackleton.  It is suggested that Antarctanax hunted insects as well as smaller vertebrates.

Antarctanax – Where it Lived and When

Brandon Peecook, a member of the Integrative Research Centre, at the Field Museum explained that this fossil find (made in the 2010/11 field season), is significant because it demonstrates that the ecosystem in Antarctica bounced back relatively quickly after the End-Permian mass extinction event and that  archosauriforms were quite widespread at this time.

He stated:

“The more we find out about prehistoric Antarctica, the weirder it is.  We thought that Antarctic animals would be similar to the ones that were living in southern Africa, [Karoo Basin biota] since those landmasses were joined back then, but we’re finding that Antarctica’s wildlife is surprisingly unique.”

The fauna of the Lower Fremouw Formation traditionally has been considered to represent a subset of the Lystrosaurus Assemblage Zone of the Karoo Basin of southern Africa, with discrepancies largely a result of pronounced differences in sampling intensity.  However, a review of recent changes to the fauna, as well as a reassessment of occurrences based on older literature, indicates that significant discrepancies, including the co-occurrences of taxa known from both earlier and later in time and the presence of endemic forms in Antarctica, exist between the faunas of the Lystrosaurus Assemblage Zone and Lower Fremouw Formation.  In essence, Antarctica 250 million years ago had a different ecosystem to that associated with the contemporaneous Karoo Basin deposits.

A Slab of Rock Containing Exposed Post-cranial Material Attributed to Antarctanax shackletoni

Antarctanax shackletoni fossils

Antarctanax shackletoni fossil material.

Picture Credit: Brandon Peecook, Field Museum

As life on Earth recovered in the Early Triassic, so the Archosaurs rapidly diversified and laid the foundation for the evolution of the Dinosauria, Pterosauria, crocodiles and those other Archosaurs still very much with us today – the Aves (birds).

Post-doctoral Fellow Peecook, went on to state:

“Before the mass extinction, Archosaurs were only found around the Equator, but after it, they were everywhere.   Antarctica had a combination of these brand-new animals and stragglers of animals that were already extinct in most places, what palaeontologists call ‘dead clades walking.’  You’ve got tomorrow’s animals and yesterday’s animals, co-habiting in a cool place.”

The fact that scientists have found Antarctanax helps bolster the idea that Antarctica was a place of rapid evolution and diversification after the mass extinction.

A spokesperson from Everything Dinosaur commented:

“Antarctica is an extremely difficult part of the world to prospect for fossils.  However, as more of the frozen continent is mapped and explored, so more fossil discoveries are going to occur.  Antarctanax shows that there was a diverse faunal assemblage on this part of Pangaea during the Early Triassic and this discovery will help palaeontologists to plot the evolution and distribution of Archosaurs.”

Everything Dinosaur acknowledges the assistance of a press release from the Field Museum (Chicago), in the compilation of this article.

The scientific paper: “A Novel Archosauromorph from Antarctica and an Updated Review of a High-latitude Vertebrate Assemblage in the Wake of the End-Permian Mass Extinction” by Brandon R. Peecook, Roger M. H. Smith and Christian A. Sidor published in the Journal of Paleontology.

25 01, 2019

Link Between Bird Beak Shape and Feeding Ecology Not That Strong

By | January 25th, 2019|Animal News Stories, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Bird Beak Shape Did Not Evolve to Help Process Different Types of Food

A team of international researchers, including scientists from Bristol University, have published a new scientific paper that provides a new perspective on how the beaks of birds adapted over time. It seems that the “strong relationship” between bird beak shape and what the bird eats might not be that strong a relationship after all.

New Research Shows a Link Between Beak Shape and Feeding Ecology but it is not as Strong as Previously Suggested

The highly modified mandible of the Black Skimmer.

The highly modified mandible of the Black Skimmer indicates a strong link between feeding ecology and beak shape, but this relationship might not be as strong as previously thought.

Picture Credit: hoganphoto.com

Darwin and the Galapagos Finches

Charles Darwin famously observed that finches on different islands of the Galapagos possessed distinctive beak shapes.  He postulated that the beak shapes had come about due to natural selection as the birds adapted to fill unique niches within the ecosystem.  It had been assumed that this form-function relationship holds true across all species of bird.  In a new study looking at a total of 176 extant avian species and published in the academic journal “Evolution”, it is suggested that the beaks of birds are not as adapted to the food types they feed upon as it is generally believed.  After all, birds use their beaks for a variety of functions not just for feeding.

Puffins on the Island of Skomer – Beaks Perform a Variety of Tasks

Bird beaks used for various tasks not just feeding.

The beak on a bird is used for various tasks.  Functions of the beak include visual display, preening and feeding.

Picture Credit: Sergio Martínez-Nebreda and Paula Medina-García

The research team, consisting of scientists from the UK, the United States and Spain, used mathematical and computational statistical techniques to map the connection between beak shapes and functions in birds.  By measuring the beak shape in a wide range of modern bird species from museum collections and looking at information about how the beak is used by different species to consume different foods, the scientists were able to examine the link between beak shape and feeding behaviour.  Did feeding behaviour influence beak shape evolution?  If it did, how strong a link was this?

Co-author of the study, Professor Emily Rayfield (Bristol University), commented:

“This is, to our knowledge, the first approach to test a long-standing principle in biology: that the beak shape and function of birds is tightly linked to their feeding ecologies.”

Lead author of the research, Guillermo Navalón, a PhD student at Bristol University’s School of Earth Sciences added:

“The connection between beak shapes and feeding ecology in birds was much weaker and more complex than we expected and that while there is definitely a relationship there, many species with similarly shaped beaks forage in entirely different ways and on entirely different kinds of food.  This is something that has been shown in other animal groups, but in birds this relationship was always assumed to be stronger.”

Research co-author, Dr Jesús Marugán-Lobón from Universidad Autónoma de Madrid, explained:

“These results only made sense when you realise birds use the beak for literally everything!  Therefore, it also makes sense they evolved a versatile tool not just for getting food, but also to accomplish many other tasks.”

Important Implications for the Study of Fossil Birds

The study is part of a larger research programme by the team in collaboration with academics from other universities across Europe and the USA to better understand the main drivers of the evolution of the skull in birds, the only living members of the Theropoda.  Similar results were identified in a study of birds of prey, but this is the first time that the link between beak shape and ecology has been examined across a wide variety of bird families.

Guillermo Navalón added:

“These results have important implications for the study of fossil birds.  We have to be careful about inferring ecology in ancient birds, which we often assume based solely on the shape of the beak.”

A Fossil Bird – Eoconfuciusornis

Eoconfuciusornis fossil bird.

The fossilised remains of a Lower Cretaceous bird from China (Eoconfuciusornis).  This new study has implications for how the beaks of fossil birds are interpreted.

Picture Credit: Dr Xiaoli Wang (Linyi University)

What About the Pterosauria?

This study may also have implications for the Pterosauria.  Pterosaurs are extinct and they have no living close relatives, so what we know about these volant animals has to be deduced from their fossils.  There are many different types of beak associated with these flying reptiles and the link between shape and feeding ecology may not be as strong as previously thought.  The beaks of pterosaurs may not be as adapted to the food types they are thought to have fed upon.

A Wide Range of Different Beak Types Demonstrated in the Pterosauria

Examples of pterosaurs from the Museum Nacional collection.

The Pterosauria exhibit a wide variety of different types of mandible.

Picture Credit: Everything Dinosaur

If the mandibles of pterosaurs were employed in a variety of functions such as display, preening and visual signalling as well as feeding could their beaks be not as well adapted to the food types they fed on as is generally believed?  These reptiles had more manipulative function in their hands and fingers than extant birds, but the function of the hand would have been limited by the animal’s wing membranes.

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

The scientific paper: “The Evolutionary Relationship between Beak Shape, Mechanical Advantage and Feeding Ecology in Modern Birds” by G. Navalón, J. A. Bright, J. Marugán‐Lobón and E.J. Rayfield published in the journal Evolution.

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