Category: Photos/Pictures of Fossils

Carcharodontosaurus – A Very Popular Dinosaur

Carcharodontosaurus – An Enormous Carnivorous Dinosaur

Paleo Paul has been busy with his camera again as this week, team members at Everything Dinosaur were emailed some photographs of the latest addition to his fossil collection, a magnificent broken tooth from a very large Theropod dinosaur.  In his email, Paleo Paul explained that the tooth was from a North African, meat-eating dinosaur called Carcharodontosaurus, a dinosaur whose fossils first came to the attention of the scientific community in the early part of the 20th Century, although Carcharodontosaurus was not named and formally described until 1931.

The Large Theropod Tooth (Carcharodontosaurus)

Dinosaur fan sends picture of dinosaur tooth into Everything Dinosaur

The large, broken Theropod dinosaur tooth identified as Carcharodontosaurus.

Picture Credit: Paleo Paul

Carcharodontosaurus saharicus

Paleo Paul wrote to say that this dinosaur was named and described by the famous German palaeontologist Ernst Stromer von Reichenbach and this is a beautiful specimen.  In many of the fossil carcharodontid teeth that we have examined, the tip of the tooth is often missing and Paleo Paul is lucky to have this specimen in his fossil collection.  This is a broken tooth, the root is missing, this tooth was most probably shed when this dinosaur was alive.  The tooth may have been lost when this carnivore was either feeding or fighting.  Scientists now know that North Africa around 98 million years ago (Late Albian to Early Cenomanian faunal stages) was home to a number of large predatory dinosaurs.  Carcharodontosaurus saharicus is regarded as an apex predator, some of the teeth associated with this species are nearly twenty centimetres long!

A Close up of the Denticles (Serrations on the Teeth)

A close up of the denticles on the side of a Theropod dinosaur tooth.

A close up of the serrations on the side of the tooth.

Picture Credit: Paleo Paul

The photograph above shows a close up the tooth serrations (denticles) which are found on the carinae (sharp edges) of the tooth.  The shape, number and size of these denticles are helpful when attempting to identify which dinosaur the tooth likely came from.  Denticles can be found on both the leading edge (anterior) and the rear edge of the tooth (posterior), most Theropod teeth have two carinae therefore, in bilateral symmetry, but not always, the carinae can be offset or even split in some genera.  Being able to see clearly defined denticles such as these reflects the high degree of preservation of this particular fossil tooth.  Well done to Paleo Paul for getting a super close up photograph!

An Apex Predator

Carcharodontosaurus saharicus was very probably the top predator in its environment.  In the Everything Dinosaur database, we record C. saharicus as being potentially, up to fourteen metres long, reaching a head height of nearly six metres and weighing in excess of 6,000 kilogrammes.  It really was a formidable animal.  Carcharodontosaurus is very popular amongst dinosaur fans and Paleo Paul also sent in a couple of pictures of his CollectA Deluxe Carcharodontosaurus model

The CollectA Deluxe Carcharodontosaurus in a Dinosaur Diorama

The CollectA Carcharodontosaurus dinosaur model.

The CollectA Carcharodontosaurus provides an excellent example of what palaeontologists think this dinosaur looked like.

Picture Credit: Paleo Paul

The CollectA Carcharodontosaurus provides an excellent example of what palaeontologists think this dinosaur looked like.

To view the CollectA Deluxe range of scale prehistoric animal models: CollectA Deluxe Scale Prehistoric Animal Models

Paleo Paul likes to modify and repaint his prehistoric animal replicas, but in this instance he has decided that the CollectA Carcharodontosaurus needs no such makeover. It is just fine as it is.

The CollectA Deluxe Carcharodontosaurus on the Prowl

CollectA Carcharodontosaurus model.

CollectA Carcharodontosaurus prehistoric scene.

Picture Credit: Paleo Paul

Our thanks once again to Paleo Paul for sharing his photographs with us.

Titanosaurs Crossing Continents – Savannasaurus elliottorum

“Wade” Finally Gets a Name – Savannasaurus elliottorum

An Australian Titanosaur, nicknamed “Wade”, whose fossilised bones were discovered in 2005, has been formally described and named.  Say hello to Savannasaurus elliottorum, the scientific name may not be as catchy as its nickname, but this specimen does represent one of the most complete Titanosaurs discovered in Australia to date and its discovery is helping palaeontologists to piece together how these giant, herbivorous dinosaurs crossed continents, spreading out from South America and reaching Australia via Antarctica.

An Illustration of the Newly Described Titanosaur Savannasaurus elliottorum

Savannasaurus elliottorum

An illustration of the newly described Australian Titanosaur Savannasaurus.

Picture Credit: Travis Tischler/Australian Age of Dinosaurs Museum

An Australian Giant

David Elliot, one of the co-founders of the Australian Age of Dinosaurs Museum, the museum established close to the town of Winton in Queensland that exhibits many of the Cretaceous fossils found in this region, spotted some fossil bones sticking out of the ground early in 2005.  Mr Elliott returned to the site later in the day with his wife Judy to take a closer look at the fossil fragments.  He hoped that the bones might represent a Theropod, but this idea was quickly put to one side when his wife “clicked” two bones together to make a distinctive metatarsal (toe bone) of a Sauropod.

The site was excavated in September 2005 by a joint Australian Age of Dinosaurs Museum and Queensland Museum team and seventeen pallets of bones encased in rock were recovered.

The Location of the Savannasaurus elliottorum Fossil Find

Savannasaurus fossil site.

The quarry from which the fragmented bones later identified as Savannasaurus were excavated.

Picture Credit: Australian Age of Dinosaurs Museum/Site photo circa 2005

It has taken more than ten years or preparation work for the fossilised bones to be removed from the single silt stone concretion that encased them.  Everything Dinosaur has regularly reported on Australian dinosaur fossil discoveries and kept tabs on the progress of the “Wade” preparation work.

To read an earlier article (2013), on the preparation work: An Update on Wade the Aussie Dinosaur

Why “Wade”?

The nickname for this new species of Titanosaur honours Australian palaeontologist Dr. Mary J. Wade.  During her long career, Dr. Wade did much to help conserve and promote the extensive, exposed fossil bearing strata of Queensland.  She worked on a number of iconic Australian dinosaurs including Muttaburrasaurus as well as helping to map and study Precambrian fossils that were later to be described as Ediacaran biota.

Although one of the more complete Australian Titanosaur fossils yet described, the material is highly fragmentary and only about five percent of the skeleton has been recovered.  The fossils consist of one neck vertebra, several cervical ribs, eight dorsal vertebrae making up a partial sequence, several rib fragments, sacral vertebrae and at least five fragmentary tail bones (caudal vertebrae).  Limb bones are represented, several toe bones, elements from the ankle, bones from the manus (front feet) as well as incomplete humeri (upper arm bones).  The research team and volunteers were also able to recover a partial left radius and a highly fragmentary ulna and parts of the hip girdle.  Although no cranial (skull) material was recovered, the team were confident, almost from the start, that these bones represented a new species.  The fossils come from a site called “Belmont Station”, ironically, nearby cranial material from another, previously described Titanosaur was found (Diamantinasaurus matildae).  In the scientific paper which describes Savannasaurus, published in the journal “Nature”, the authors, which include lead researcher Dr Stephen Poropot, (Australian Age of Dinosaurs Museum), describe the braincase and neck bones of Diamantinasaurus.

The Fossil Bones of Savannasaurus elliottorum Mapped onto an Outline of the Dinosaur

Savannasaurus elliottorum skeletal material.

Savannasaurus elliottorum outline of skeleton.

Picture Credit: Australian Age of Dinosaurs Museum

Plotting the Distribution of the Titanosauria

These two Titanosaurs are being used to help map the dispersal of the Titanosauria across the super-continent Gondwana as this huge landmass began to break up.  Although the fossil record remains patchy to say the least, the fossils, which have been dated to around 98-95 million years ago (Cenomanian faunal stage of the Late Cretaceous), suggest that by this time in Earth’s history Titanosaurs had dispersed from South America, migrated across Antarctica and entered the landmass that was later to become Australia.

Commenting on the significance of these fossils, Dr. Stephen Poropot stated:

“We get a much better idea of the overall fauna.  And as a result, we can start piecing together how climate affected these dinosaurs, how the positions of the continent affected those dinosaurs and how they evolved through time as well.”

The Dispersal and Spread of Titanosaurs Across High Latitudes in the Southern Hemisphere

Mapping the dispersal of the Titanosauria

The spread and dispersal of Titanosaurs across southern latitudes.

Picture Credit: Ron Blakey (Colorado Plateau Geosystems Inc)

Although, palaeontologists have discussed a number of potential dispersal routes, it is likely that these types of dinosaurs had entered Australia from South America, presumably crossing Antarctica.  During the late Early Cretaceous the Earth went through a period of global warming.  Prior to this climate change, Titanosaurs, which were globally widespread in the Early Cretaceous were prevented from reaching Australia by the cold conditions in Antarctica.  Global warming facilitated the dispersal of Sauropods from South America to Australia via Antarctica.

David Elliott Co-founder of the Australian Age of Dinosaurs Museum Poses with the Savannasaurus elliottorum Fossil Material

David Elliott poses with the bones of Savannasaurus.

David Elliott holds one of the metatarsals (toe bones) of S. elliottorum.

Picture Credit: Australian Age of Dinosaurs Museum


The genus name is derived from the Spanish (Taino) “zavana”(savanna), a reference to the grassland and pasture in which the specimen was found.  The species name honours the Elliott family for their continuing contributions to Australian palaeontology.

Differences between Savannasaurus and Diamantinasaurus

Although Savannasaurus and Diamantinasaurus were contemporaneous of each other and these giant herbivores may have been roughly the same size, living in the same habitat, preliminary measurements indicate that the forelimbs of Savannasaurus are proportionally quite different from those of Diamantinasaurus.  This may suggest adaptation to a different feeding platform, allowing these large dinosaurs to co-exist without competing with each other for food.

Graduate Student Unlocks the Secrets of Sea Turtle Evolution

Ctenochelys acris Comes Out of its Shell

Palaeontologists have long puzzled over the origins of today’s extant species of sea turtle.  Thanks to the efforts of a post-doctoral student at the University of Alabama (Birmingham, Alabama, USA), scientists have been able to confirm the existence of a marine adapted turtle representing the oldest known member of the lineage that gave rise to modern sea turtles.  In a paper published in the academic publication “The Journal of Systematic Palaeontology”, lead author Drew Gentry, has been able to identify several 80-million-year-old fossils as Ctenochelys (tee-no-key-lees) acris, thus helping to piece together the evolutionary history of sea turtles.

Researchers from the College of Arts and Sciences’ Department of Biology worked with two relatively complete turtle skeletons, along with several smaller pieces, that are housed at Birmingham’s McWane Science Centre, the study confirms the existence of Ctenochelys acris, previously known only from a few isolated fragments.

A Scale Drawing of Ctenochelys acris Showing Some of the Fossils Used in the Research

Scale drawing of Ctenochelys.

A silhouette showing the proposed outline of Ctenochelys with a frogman providing scale.

Picture Credit: University of Alabama

The McWane fossils help solve a long-standing debate as to whether this animal was a unique species.  They also provide insights into the evolutionary history of living species of sea turtles, animals such as the Ridley, the Leatherback, the Green and the Loggerhead, all of which are, sadly, classified as vulnerable or endangered or critically endangered according to the IUCN Red List of Threatened Species.

Alabama During the Late Cretaceous

The area of the south-western United States was covered by a shallow, tropical sea for much of the Late Cretaceous.  The fossils ascribed to C. acris have been excavated from marine strata dated to around 80 million years ago (Campanian faunal stage), a time when sea levels were much higher than today and the Western Interior Seaway covered most of the United States.  During this time sea turtle diversity was very high and lead researcher on the project Drew Gentry explained:

“Climatic warming during the mid-Cretaceous resulted in elevated sea levels and temperatures that, in turn, provided an abundance of new niches for marine turtles to invade.  Represented today by only seven living species, sea turtles were once one of the most diverse lineages of marine reptiles.  Before the cataclysm that claimed the dinosaurs, there may have been dozens of specialised species of sea turtle living in different oceanic habitats around the world.”

A Diagram Showing North America Approximately 75 million years ago

The Western Interior Seaway.

A map showing the Western Interior Seaway of North America circa 75 mya.

Picture Credit: Everything Dinosaur

Not Sure of the Validity of Ctenochelys acris

Prior to the assessment of the McWane fossil specimens, palaeontologists were unsure as to the validity of Ctenochelys acris.  Not only do the newly discovered fossils prove C. acris existed, they may also be a critical piece in a much larger puzzle of sea turtle evolution.

Drew Gentry added:

“There is strong evidence which indicates freshwater turtles may have evolved to occupy marine environments at several points in the past.  But most of those lineages went extinct, making the exact origins of living or ‘true’ sea turtles somewhat of a mystery.”

The study suggests that the earliest ancestors of today’s sea turtles may have originated from waters covering the south-western United States.  By comparing the skeleton of C. acris with those of both extinct and living species of turtles, Gentry discovered that C. acris possessed traits of both sea turtles and their closest living turtle relatives, snapping turtles.

“This animal was a bottom-dwelling sea turtle that fed primarily on molluscs and small invertebrates.  Unlike the ‘rudder-like’ hind-limbs of today’s sea turtles, C. acris had large, powerful hind-limbs to help push it through the water, a lot like a modern-day snapping turtle.”

Scientists are hopeful that by learning more about the origins of sea turtles, this may lead to better protection for those species still found today.  Studying the diversity and evolutionary history of marine turtles during previous periods of climate change can provide meaningful insights into what effects climate and environmental changes might have on modern marine turtle populations.

The fossils that led to this research were discovered in 1986 and contributed to what was then the Red Mountain Museum.  The McWane Science Centre was founded in 1998 by the merger of the Red Mountain Museum and a nearby children’s museum, Discovery Place.

The palaeontological and archaeological collection at McWane is one of the largest in the south-eastern United States and houses a number of significant finds from across Alabama, including the recently announced Eotrachodon, a type of duck-billed dinosaur.

To read an article about Alabama’s very own duck-billed dinosaur: Duck-billed Dinosaurs – Sweet Home Alabama!

Everything Dinosaur acknowledges the assistance of the University of Alabama in the compilation of this article.

A Photograph of a Trilobite Fossil

A Trilobite Fossil

We were contacted by a teacher to help explain how Trilobite fossils formed, how old they were and what Trilobites actually looked like.  We were happy to email over a fact sheet all about the Trilobita and to send over some pictures of Trilobite reconstructions along with some photographs of fossils.

A Photograph of a Trilobite Fossil

A fossil of an Trilobite.

A beautiful Trilobite fossil.

We received a lovely email in return thanking us for providing such a lot of useful teaching material and for being so responsive.  The fossil above shows the headshield (cephalon) and the trunk but the tail-piece (pygidium) is missing.  We are not sure what family of Trilobita this fossil comes from.  As Trilobites shed their exoskeletons in order to grow (moulting), most Trilobite fossils are actually shed shells, rather than the corpses of dead animals.  Whatever the species, we are always keen to see pictures of Trilobites and we were happy to help out the teacher.

The Food Chains of Messel

Fossil Preserves Snake ate Lizard, Lizard ate Beetle

Scientists from the Senckenberg Museum of Natural History have published a paper on a spectacular fossil from the famous Messel oil shales that shows evidence of a food chain preserved from the Eocene.  A fossil snake contains the preserved remains of its last meal, a lizard inside its stomach, astonishingly the exquisite fossil has also preserved evidence of the unfortunate lizard’s last supper too – a beetle.  The discovery of a tripartite fossil food chain is unique for this UNESCO World Heritage site and the only other tripartite food chain known in the fossil record dates from the Early Permian*, coincidentally, it also was found in Germany.

Who’s Eating Who?  Remarkable Three Party Trophic Chain (Food Web)

The Messel Tripartite Food Chain fossil.

The snake fossil which contains a lizard fossil which contains a fossilised beetle.

Picture Credit: Dr. Krister Smith (Senckenberg Museum of Natural History)

Scientists from the Senckenberg Museum of Natural History in collaboration with colleagues from Argentina were able to study this “Russian Doll” of a fossil, that dates from around 48 million years ago and gain new information about the diets of these ancient creatures.  For example, the twenty centimetre long lizard, identified as Geiseltaliellus maarius, is only known from the Messel shales.  Specimens found to date with preserved stomach contents, only had plant remains within the body cavity, this new research indicates that G. maarius was not entirely herbivorous, insects such as beetles were also on the menu.

Commenting on the study, published in the Museum’s scientific journal, Doctor Krister Smith, one of the authors of the paper stated:

“In the year 2009, we were able to recover a plate from the pit that shows an almost fully preserved snake. As if this was not enough, we discovered a fossilised lizard inside the snake, which in turn contained a fossilised beetle in its innards!”

A Magnified View of the Snake Gut with Line Drawings Indicating the Presence of Other Fossil Specimens

Tripartite food chain in Messel fossil.

The orange represents the lizard fossil, the blue the beetle remains.

Picture Credit: Dr. Krister Smith (Senckenberg Museum of Natural History)

The picture above shows the bones of the snake outlined with the lizard shown in orange (skull to the left of the picture), the blue shape in the lizard gut indicates the fossilised remains of the lizard’s last meal- a small beetle.  Unfortunately, the scientists were not able to identify the beetle genus.  The way in which the lizard remains were overlapped by the ribs of the snake prove that the body of the little reptile was definitely inside the snake when the snake, identified as a type of early constrictor (Palaeopython fischeri), met its own demise.

There was an Old Lady who Swallowed a Fly…

This beautifully preserved fossil specimen reminds team members at Everything Dinosaur of the song “there was an old lady who swallowed a fly”.  For the scientists, the Palaeopython specimen provides a new insight into the feeding habits of these Eocene snakes.  The snake fossil measures around 89 centimetres in length, but adult Palaeopythons exceeded two metres in size and they were amongst the largest terrestrial predators known from the Messel shale biota.  Just like modern constrictors and pythons, the authors suggest that the diet of these snakes changed as the animals got bigger.  The juvenile Palaeopython represented here (specimen number SMF ME 11332), may have fed on small rodents and lizards, whilst the adult snakes may have taken larger vertebrates such as young Propalaeotherium (an ancestral horse).

Based on an assessment of the degree of preservation of the lizard’s remains when compared to digestive speeds in extant snakes, the researchers conclude that the snake died within 48 hours of consuming the lizard.  That’s a remarkable insight considering the age of the fossil itself (approximately 48 million-years-old).

The scientific paper: “Fossil Snake Preserving Three Trophic Levels and Evidence for an Ontogenetic Dietary Shift”.

Early Permian Trophic Chains

* The first direct evidence of a three-level vertebrate trophic chain was published in the “Proceedings of the Royal Society Biology” in January 2008.  The fossilised remains of a species of Xenacanthiformes freshwater shark (Triodus sessilis) contained the remains of two ancient amphibians (Archegosaurus decheni and Cheliderpeton latirostre) preserved within its gut.  The C. latirostre specimen contained the remains of a small fish, inside its digestive tract.  The small fish was identified as a juvenile Acanthodes bronni.

Xenacanthiform (T. sessilis) with Ingested Prey Items

Xenacanthiform ate amphibians which ate fish.

Three level trophic levels in Early Permian fossil.

Picture Credit: Proceedings of the Royal Society Biology

The picture above shows the siderite concretion that preserves the remains of the freshwater shark and evidence of a three-level food chain from the Early Permian of south-western Germany.  Below the fossil specimen photograph is a line drawing that highlights the material representing the shark as well as the fossils of two ingested Temnospondyl larvae.  One of the amphibian fossils contains the preserved remains of its last meal, a small fish (acanthodian).

Illustrating an Early Permian Food Chain

Fish east amphibians which ate fish.

Xenacanthiform eats amphibians which in turn consumed fish.

Picture Credit: Proceedings of the Royal Society Biology

The illustration above depicts the three level trophic food chain.  Its a question of fish eats amphibian which ate fish!

T. rex Skull Goes on Display

Burke Museum Hopes T. rex Skull Gives New Museum a “Head Start”

The partially prepared, jacketed skull of an adult Tyrannosaurus rex which wandered the plains of Montana some 66.3 million years ago has gone on public display at the Burke Museum (Seattle, Washington State).  One of only fifteen T. rex skulls known, the Hell Creek Formation specimen is described as “pristine” and is part of the fossilised remains of an individual animal, representing some 20% of the entire skeleton which was discovered on Bureau of Land Management land by two Burke Museum volunteers – Jason Love and Luke Tufts.  As a result, this Tyrannosaurus rex has been nicknamed “Tufts-Love Rex”.

Arriving at the Burke Museum (Washington State)

The T. rex skull fossil arrives at Burke Museum.

Arriving at the Burke Museum (T. rex skull specimen).

Picture Credit: Burke Museum

The Fossil Find of a Lifetime

The volunteers were exploring a sandstone ridge in northern Montana when they spotted several fragments of bone on the surface.  They followed the trail of tiny fossil bones until they came across a partly exposed vertebrae.  The size of the fossils and their honeycomb texture indicated to Jason and Luke that they had found the remains of a Theropod dinosaur.  The pair alerted their colleagues and what could be the most important excavation in the Museum’s one hundred and seventeen year history, began.

A Bone Fragment Showing the Typical Honeycomb Internal Structure (Theropod Dinosaur)

The tell-tale honeycomb structure of fossil bone indicates Theropod dinosaur.

A close up of the fossil bone shows the typical honeycomb structure indicative of a Theropod dinosaur.

Picture Credit: Jason Love/Burke Museum

Some twenty tonnes of rock has had to be removed to expose the disarticulated skeleton.  So far, teeth, ribs, vertebrae and that beautifully preserved skull have been identified.  The skull was removed in a single block, which in itself weighed more than a tonne.  A local farmer was called in to help provide the lifting gear to remove the plaster jacketed fossil.  The skull has gone on display at the Burke Museum and it is hoped that the Tyrannosaurus rex specimen will form the centrepiece of a new dinosaur exhibit when the refurbished museum fully opens in 2019.

Jacketed Ribs of the T. rex Lie Next to the Skull Block

T. rex fossils in the field being prepared for transport.

Ribs of a T. rex in their plaster jacket next to the skull block.

Picture Credit: Dave DeMar/Burke Museum

For the time being, visitors will have to content themselves with looking at the partially prepared skull fossil.  Dr. Greg Wilson (Burke Museum Adjunct Curator of Vertebrate Palaeontology and University of Washington associate biology professor), helped with the first phase of the excavation and he is very excited about this meat-eating dinosaur fossil discovery.

Dr. Wilson stated:

“When we started to see those teeth with the skull, we knew we had a fantastic specimen.  Not only is it a fantastic specimen, it is incredibly rare.  Although arguably the most iconic and well-known species of dinosaur, the T. rex skull is one of only about fifteen reasonably complete ones known to exist in the world.”

Field Team Members Located the Squamosal Bone (Bone from the Back of the Skull)

The squamosal bone of a T. rex is exposed.

The back of the skull of a T. rex (squamosal bone exposed).

Picture Credit: Larry Mose/Burke Museum

An Average-Sized Skull for a Tyrannosaurus rex

Although the exact dimensions of the skull have yet to be calculated, this can wait until the rock matrix has been removed, researchers estimate that the skull measures about 1.2 metres long by about a metre wide.  The bones represent an adult animal, one that may have been around fifteen to twenty years of age and with an estimated length of more than ten metres, the fossils represent a sizeable beast.  The strata represent deposits laid down in an ancient riverbed.  The dinosaur might have drowned in the river, or more likely the corpse of the T. rex was washed downstream and buried before it could be scavenged by other predators.

Given the excellent state of preservation of the bones discovered so far, the scientists involved with the “Tufts-Love Rex” are confident that they will be able to learn much more about this particular dinosaur, perhaps even if the fossils represent a male or a female “Tyrant Lizard King”.

The Turtle Shell Evolved to Help with Burrowing

Fossorial Origins of the Turtle Shell – Eunotosaurus africanus

Writing in the “Current Biology” a team of international scientists, led by Dr. Tyler Lyson (Denver Museum of Nature and Science), have concluded that the “shell” of turtles, terrapins and tortoises evolved not for protection but as an adaptation for burrowing and living underground.  As the feather did not evolve for flight, so then the carapace (top) and plastron (underneath) of the SuperOrder Chelonia, may not have evolved as shield.  Like flight feathers, the shell of a tortoise and its use in defence was a secondary outcome of an evolutionary process.

Fossils excavated from the famous Permian-aged deposits of the Karoo Basin (South Africa) suggest that the earliest evolutionary beginnings of the turtle’s shell resulted from adaptations to accommodate a burrowing or fossorial (digging) lifestyle.

Karoo Basin Fossils of the Proto-Turtle Eunotosaurus Indicate Fossorial Adaptations

Eunotosaurus adapted to a burrowing lifestyle.

The proto-turtle Eunotosaurus burrows into the banks of a dried up pond to survive in the harsh, arid South African environment about 260 million years ago. In the background, a herd of Bradysaurus, a type of reptile, crowds around some muddy water.

Picture Credit: Audrey Atuchin

A Widening of the Ribs

Dr. Lyson had the opportunity to learn more about Chelonian evolution when he, along with collaborators form the Smithsonian Institute studied the fossilised remains of a highly specialised parareptile, Eunotosaurus africanus, back in 2013.  These fossils, which also came from Late Permian aged deposits in South Africa, indicated that a widening of the ribs was the first stage in the evolution of the shell.

To read more about the origins of the shell in turtles: How the Turtle Got Its Shell

Tyler Lyson explained:  “We knew from both the fossil record and observing how the turtle shell develops in modern turtles that one of the first major changes toward a shell was the broadening of the ribs.”

However, for a quadruped, the widening of the ribs has a very serious effect on mobility.  Breathing is restricted and movement becomes more difficult.  Ribs are primarily used to support the torso during locomotion and they play a vital role in lung function.  Broader ribs, means a stiffer body which will lead to a shortening of stride length and less efficient breathing.  In the harsh and dangerous world of the Permian, these modifications would have seriously disadvantaged any Tetrapod.

Rib bones in vertebrates show hardly any variation, team members at Everything Dinosaur have recently been examining the rib bones of a prehistoric elephant, these ribs are very similar to the ribs of a large dinosaur such as a Stegosaurus.  The Chelonia are an exception, their ribs are highly modified as they form the majority of the shell.

Significant Fossil Discovery

The discovery of several, exceptionally well-preserved specimens of Eunotosaurus africanus allowed the team to examine shell evolution in much more detail than before.  A number of the fossils were found by the study’s co-authors, doctors Roger Smith and Bruce Rubidge (University of Witwatersrand, Johannesburg).  However, the most important specimen used in this study was found by a young boy on his father’s farm in the Western Cape.  Eight-year old Kobus Snyman, took the fossil that he found to his local museum, the Fransie Pienaar Museum in Prince Albert (Western Cape).  The articulated fossil measures around fifteen centimetres in length, the body (and those all important ribs) are preserved along with the hands and feet but the skull is missing.

Dr. Lyson praised young Kobus for his observational skills and for taking his find to the local museum, he stated:

“I want to thank Kobus Snyman and shake his hand because without Kobus both finding the specimen and taking it to his local museum, this study would not have been possible.”

The Eunotosaurus Fossil Found by Kobus Snyman

Fossil of Eunotosaurous found by an 8-year-old.

The fossil of Eunotosaurus found by eight-year-old Kobus Snyman.

Picture Credit: Dr. Tyler Lyson

Extant turtles, terrapins and tortoises have shells that serve mainly as protective devices.  These armoured animals are notoriously slow.  However, in this new study, developmental evidence from embryos combined with these newly described Karoo Basin fossils suggest that one of the first steps towards the shelled body-plan was a widening of the ribs.  Eunotosaurus africanus is thought to be a basal member of the Chelonia and the broad ribs of this animal have been proposed as support and stabilising mechanisms to help support a powerful forelimb digging action.  The adaptations for a fossorial lifestyle would have facilitated the movement of stem turtles into aquatic environments early in the group’s evolutionary history.

In the scientific paper, entitled “Fossorial Origin of the Turtle Shell”, the researchers propose that adaptations related to digging provided the initial impetus for shell development and that the fosssorial lifestyle may explain why basal turtles survived the catastrophe that marked the end of the Palaeozoic (End Permian mass extinction event).

To read an article from Everything Dinosaur that suggest that turtles and their kind evolved from diapsid reptiles: Study Suggests Chelonia Evolved from Diapsids

An Illustration of Eunotosaurus africanus 

A drawing of Eunotosaurus.

An illustration of the stem turtle Eunotosaurus.

Picture Credit: Everything Dinosaur

An article on a Mid Jurassic turtle discovery: The Grandfather of All Tortoises and Turtles

Bird Wing Preserved in Amber

Early Bird Wings Preserved in Amber from Myanmar

A team of international scientists including researchers from Bristol University, have published research on two specimens of 99 million-year-old amber from Myanmar (called burmite), which have revealed the preserved remains of two tiny, baby birds.  The scientists conclude that these birds were active shortly after hatching (precocial) and that sadly they met their demise when they became trapped in sticky tree resin.

The Amber Has Preserved the Feathers in Exquisite Detail

Preserved in amber, the remains of a bird's wing.

The remains of the wing can be clearly made out trapped in the amber.

Picture Credit: Royal Saskatchewan Museum (R.C. McKellar)

The photograph above shows a close up of the feathers preserved in one of the burmite specimens.  The researchers led by Dr. Xing Lida (China University of Geosciences), along with colleagues from the USA, Canada and Professor Mike Benton from the School of Earth Sciences (Bristol University), have identified three long fingers, each tipped by a sharp and strongly curved claw, one of which can be seen in the top right of the picture above.

Amber fossils from Myanmar (formerly called Burma), have provided palaeontologists with a fascinating insight into life in the primordial forests of the Cretaceous.  In the spring, Everything Dinosaur published two articles regarding remarkable fossil discoveries which had only been possible due to fossil finds within burmite.  In one article, we reported on the potential origins of the malaria parasite, in the second we provided information regarding the discovery of the fossilised remains of tiny lizards.

To read about the evolutionary origins of the malaria: The Origins of Malaria Traced Back 100 Million Years

To read more about the lizard fossil discovery: Lizards Preserved in Amber

Although Burmese amber has produced fossils of isolated feathers, this is the first time in which portions of birds have been discovered.

One of the Fossil Specimens Has Been Nicknamed “Rose”

Enantiornithes wing and skin sections encased in amber.

Pieces of skin and parts of an ancient wing preserved in amber.

Picture Credit: Royal Saskatchewan Museum (R.C. McKellar)

Tiny Fossil Wings

The fossil wings are very small, between two and three centimetres long. the long, bony fingers can be made out along with the three digits on each wing.  The anatomy of the hand has allowed the scientists to identify these as members of the Enantiornithines (Enantiornithes), group of birds, a diverse clade of toothed birds that possessed prominent wing claws.  The Enantiornithines, thrived during the Cretaceous and some eighty species have been named, although a number are only known from single bones.  These birds became extinct at the end of the Cretaceous and they are thought not to have been very closely related to modern Aves (Neornithes).

Under High Magnification the Fine Details of the Feathers Can Be Clearly Made Out

Minute details on the feathers were preserved.

Tiny details on the feathers have been preserved. Ultra violet light and X-rays were used to analyse the fossil material.

Evidence of Precocial Behaviour in Enantiornithes

The two specimens have been nicknamed “Rose” and “Angel Wings”.  After careful polishing, the fossils were analysed using white light, UV light and powerful X-rays.

Commenting on the research, one of the authors of the paper published in the academic journal “Nature Communications”, Professor Mike Benton stated:

“These fossil wings show amazing detail.  The individual feathers show every filament and whisker, whether they are flight feathers or down feathers, and there are even traces of colour – spots and stripes.”

The scientists conclude that the birds, although babies were highly mobile.  This indicates that these birds were very well developed when they hatched and capable of being independent from their parents.  Sadly, their mobility seems to have been their downfall.   As the clambered around the branches and trunks of trees they became trapped in sticky tree resin.  Larger animals would have had the strength to pull free, but these youngsters were doomed.  The amber even preserves claw marks and scratches as the birds tried to pull themselves free.

A Desperate but Ultimately Doomed Struggle

Fossils from Myanmar show bird's wing.

Preserved in amber the wings of baby birds that once became trapped in tree resin.

Picture Credit: Chung-tat Cheung

The beautiful illustration above shows an imagined scene in which one of these young birds find itself trapped and unable to break free of the glue-like tree resin.

Lead author of the study, Dr. Xing Lida added:

“The fact that the tiny birds were clambering about in the trees suggests that they had advanced development, meaning they were ready for action as soon as they hatched [precocial].  These birds did not hang about in the nest waiting to be fed, but set off looking for food, and sadly died perhaps because of their small size and lack of experience.  Isolated feathers in other amber samples show that adult birds might have avoided the sticky sap, or pulled themselves free.”

Scientists Can Identify Different Pigments in the Fossilised Remains of the Feathers

Feathers preserved in Burmese amber.

Different pigments in the feathers can be made out quite clearly in this feather preserved in Burmese amber.

Researchers Hope to Learn More About Aves/Dinosaur Evolution

Exquisite details on the fossilised feathers can be made out.

Fine details of the fossilised feather can be clearly seen in the amber.

Picture Credit: Royal Saskatchewan Museum (R.C. McKellar)

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

The scientific paper from which this article is drawn: “Mummified precocial bird wings in mid-Cretaceous Burmese amber” by Lida Xing, Ryan C. McKellar, Min Wang, Ming Bai, Jingmai K. O’Connor, Michael J. Benton, Jianping Zhang, Yan Wang, Kuowei Tseng, Martin G. Lockley, Gang Li, Weiwei Zhang and Xing Xu.

Bizarre Ant “Unicorn” From Burmese Amber

Amber Provides Insight into Ant Evolution

Burmese amber has provided scientists with some remarkable evidence of some of the smaller creatures that co-existed alongside the dinosaurs during the Cretaceous.  Trapped in, what was once tree resin, insects, mites, seeds, spiders, pollen grains and such like have enabled scientists to build up a fascinating picture of life in miniature at a time when the Earth was dominated by huge reptiles.  Writing in the academic journal “Current Biology” a team of scientists including researchers from Rennes University, Kansas University and the Nanjing Institute of Geology and Palaeontology (Chinese Academy of Sciences), have shed light on the evolution of the humble ant.

Preserved in 99-Million-Year-Old Amber

Ceratomyrmex ant fossil in amber

The preserved remains of a new species of basal ant (Ceratomyrmex) in Burmese amber.

Picture Credit: Wang Bo/Nanjing Institute of Geology and Palaeontology

The Unicorn Ant

Measuring around one centimetre in length, the ant possessed a bizarre horn-like structure on the head and super-sized mandibles that probably evolved to tackle prey at least as large as the ant itself.  The new species of Cretaceous insect has been named Ceratomyrmex ellenbergeri (pronounced Sera-to-my-ah-mex) and the genus name is from the Greek for “ant with a horn”.  Most ants today live in colonies and are eusocial, that is, the colony exhibits a great deal of co-operative behaviour and organisation.  However, not all extinct ants were likely to be colonial, just like a few specialist genera around today, some were probably solitary hunters and the researchers suggest that Ceratomyrmex was a solitary, specialist hunter preying on Arthropods.  The evolutionary history of the ant family is not well known, however, specimens preserved in amber, have, over last two decades, been extensively studied and it is now believed that the first ants evolved from wasps sometime between 110 and 130 million years ago.

Described as a stem group ant and assigned to the Haidomyrmecini clade, Ceratomyrmex demonstrates that relatively early on in their evolutionary history ants evolved into highly specialised forms.  The presence of such a bizarre horn-like structure and the oversized mandibles that actually extended over the animal’s head, features unseen in extant or any other extinct ant species known, provides evidence for more complex and highly diversified Cretaceous ant genera than previously thought.

An Illustration of Ceratomyrmex ellenbergeri 

A drawing of the Cretaceous ant  Ceratomyrmex.

An illustration of the basal Cretaceous ant Ceratomyrmex.

Image credit: Yang Dinghua

Commenting on the discovery of a new species, Vincent Perrichot (University of Rennes), a specialist in ant evolution and one of the authors of the scientific paper stated:

“The horn is covered with long bristles along its anterior surface, plus a brush with short spines on the end part spatula.  In insects, such bristles or thorns always have a sensory function, we then deduce that this sensory system needed to properly assess the size and position of the object seized between the jaws and the horn or even stabilise the friction with thorns.”

Big Game Hunter

It is not known whether Ceratomyrmex was an arboreal hunter or whether it lived amongst the leaf litter.  With such large jaws it probably was a formidable hunter, but what did it eat?  For Vincent Perrichot, a specialist in the study of ancient insects, the answer is quite clear, the presence of the bizarre horn and the huge jaws had a macabre not mundane purpose.

He added:

“These structures were used for predatory purposes, rather than to manipulate twigs or eggs and larvae of the colony.  The additional presence of two pairs of very long bristles projecting forward, the mandibles, similar in every way to those observed in trap-jawed, modern ants that hunt alone, indicates a mechanism for the fast-closing of the jaws.  This ant could not catch small prey as it would have escaped, it probably preyed on all kinds of crawling Arthropods at least equal in size to itself – millipedes, arachnids, cockroaches and why not other ants.”

Machairoceratops Plugs a Four-Million-Year Gap

Machairoceratops cronusi – “Bent Sword Horned Face”

The discovery of skull bones that have proved to represent a new species of Late Cretaceous horned dinosaur has helped palaeontologists to plug a four-million-year gap in the Ceratopsidae fossil record.  Researchers, writing in the on line, open access journal PLOS One, describe Machairoceratops cronusi, believed to be relatively basal member of the Centrosaurine group of horned dinosaurs.  The fossils, from Utah, help to fill an evolutionary gap in the horned dinosaur fauna known from southern Laramidia, with Machairoceratops fitting in between the earlier Centrosaurine Diabloceratops and the later Centrosaurine Nasutoceratops.

An Illustration of the Bizarre Bent-Horned Centrosaurine Machairoceratops cronusi

An illustration of a small herd of  Machairoceratops dinosaurs by Mark Witton.

An illustration of a small herd of Machairoceratops dinosaurs by Mark Witton.

Picture Credit: Mark Witton

A wide variety of North American ceratopsid dinosaurs have been described over the last decade or so.  Last week for example, Everything Dinosaur reported on the discovery of a new species of horned dinosaur from the Judith River Formation of Montana – Spiclypeus shipporum.  To read an article about this dinosaur: New Horned Dinosaur from the Late Cretaceous of Montana.

A field team first unearthed fragments that represented elements of the skull in 2006 at the famous Grand Staircase-Escalante National Monument, in southern Utah.  A further three seasons in the field were required to complete the exploration, sadly no post cranial material could be found.  However, from the configuration of the epiparietals and the horn cores the scientists were soon convinced that they had found a new species.

The Fossils of Machairoceratops cronusi and a Ghost Outline of the Complete Skull

Machairoceratops fossils

A right lateral view of the fossil material associated with Machairoceratops.

Picture Credit: Lund et al (PLOS One)

The picture above shows (A) a right lateral view of the fossil material associated with Machairoceratops cronusi mapped against a ghosted outline of the inferred skull.  To the left of the picture the braincase (BC) is shown.  Diagram B shows the skull in dorsal view, whilst diagram C shows a complete reconstruction of the entire skull, note the curvature of the central parietals (p1 left and p1 right), it is these curved elements that gave this dinosaur its name.

Head Spikes More Than a Metre Long

Each curved head spike (represented by p1 left and p1 right in diagram A above), would have measured around 1.2 metres in length, that’s slightly longer than a driver in a set of golf clubs used by a professional, male golfer.  However, despite this impressive headgear, the researchers estimate that Machairoceratops was not huge by horned dinosaur standards.  Based on skull comparisons with more complete specimens, palaeontologists have suggested that this dinosaur would have been around six metres in length and would have weighed around two tonnes.  Lead author of the scientific paper, graduate student Eric Lund (Ohio University Heritage College of Osteopathic Medicine), suggests that the head crest ornamentation may have had a role in visual signalling, such as selecting mates and establishing a social position within the herd.

Stratigraphic Assessment of the Position of Machairoceratops in Relation to Other Horned Dinosaur Fossils

A stratigraphic profile of the Wahweap and the Kaiparowits Formation.

A stratigraphic profile of the Wahweap and the Kaiparowits Formation.

Picture Credit: Lund et al (PLOS One) with additional notation by Everything Dinosaur

Filling a Four-Million-Year Old Gap in the Centrosaurinae

The discovery of M. cronusi in strata that was laid down some 77 million years ago has helped to plug a four-million-year gap in the Centrosaurine fossil record from the Grand Staircase-Escalante National Monument.  Fossils of an earlier Centrosaurine called Diabloceratops eatoni have been found in rocks that date to around 80 million years ago.  The fossil material related to Machairoceratops fills the gap between Diabloceratops and the later, almost equally bizarrely horned Centrosaurine Nasutoceratops titusi, whose fossils are associated with the overlying Kaiparowits Formation and date to around 75-76 million years ago.

Commenting on the naming of this new type of Late Cretaceous herbivorous dinosaur, Eric Lund stated:

“The  finding fills in an important gap in the fossil record of southern Laramidia, an area that included Utah, Colorado, New Mexico, Texas and Mexico during the Late Cretaceous period.  The discovery of Machairoceratops not only increases the known diversity of Ceratopsians from southern Laramidia, it also narrows an evolutionary information gap that spans nearly 4 million years between Diabloceratops eatoni from the lower middle Wahweap Formation and Nasutoceratops titusi.”

Once again, palaeontologists have gained fresh insight to the amazing diversity and variety of horned dinosaurs from North America.  The genus name is from “ceratops”, meaning horned face and the Greek “machairis” for bent sword, in deference to those curved central parietals.  The species name is from the mythical Greek titan (Cronus, also known as Kronos), whose symbol is a scythe or curved sword.

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