Apatoraptor pennatus – Helps to Tie Together the Caenagnathidae

A University of Alberta PhD student working in collaboration with one of the world’s most respected palaeontologists has helped to unravel the connections between a bizarre toothless dinosaur from Alberta and its relatives from Asia.  In doing, so student Greg Funston was able to identify a new species of dinosaur, one that would have been at home in the steamy Late Cretaceous swamps that once covered southern Canada.  The new dinosaur has been named Apatoraptor pennatus, the genus name means “deceptive speedy thief”, as it was originally mistaken for another, more common dinosaur.

An Illustration of the New Feathered Dinosaur Apatoraptor pennatus

The presence of ulnar papillae on the ulna (bone of the forelimb) indicates the presence of long feathers on the arm.

Picture credit: Sydney Mohr

A near complete and partially articulated dinosaur specimen was discovered in 1993 by a field team exploring strata that makes up the Horseshoe Canyon Formation of southern Alberta.  The fossil material consisted of part of the lower jaw (mandible), articulated neck and back bones (cervical and dorsal vertebrae), elements from the forelimbs, a partial ilium (bone from the hip) and parts of the back legs.  Gastralia (stomach stones) were also found in association with the fossilised bones.  Although no traces of feathers were found with this specimen, marks on the ulna (a bone in the forearm), indicated that this 1.8 metre long dinosaur probably had feathers on its arms.

Misidentified as an Ornithomimidae Member

The fossil was originally thought to represent an ornithomimid (bird-mimic) dinosaur, as several genera of ornithomimid had been reported before (Ornithomimus, Struthiomimus and Dromiceiomimus).  As a result, the material was not studied extensively but stored at the Royal Tyrrell Museum (Drumheller, Alberta).  Much later the fossil was identified as a member of the Oviraptorosauria, a clade of very bird-like dinosaurs but ones that were not closely related to the ornithomimids – the bird-mimics.  Specifically, the fossil was assigned to the  Epichirostenotes genus (pronounced Ep-ee-ky-row-sten-oh-tees), a member of the enigmatic Caenagnathidae family.

Student Greg Funston, had the opportunity to conduct research on the bones as part of his PhD thesis and he began to realise that this specimen did not resemble other fossil material assigned to Epichirostenotes that he had examined previously.  Greg, with the support and collaboration of his PhD supervisor (Professor Phil Currie), concluded that this was indeed an example of a dinosaur more closely related to Oviraptor than to Ornithomimus,  but it was sufficiently different from Epichirostenotes to have a new genus – Apatoraptor erected.

Introducing the Caenagnathidae

The Oviraptorosauria are a clade of dinosaurs very closely related to modern birds.  They are part of a much larger group of dinosaurs the Maniraptora, which includes the sickle-toed, clawed “raptors” such as Deinonychus and Velociraptor.  The different dinosaur families that make up the Oviraptorosauria are usually split into two groups*:

1. Caenagnathidae
2. Oviraptoridae

*The classification of the Oviraptorosauria is controversial, most genera are only known from fragmentary remains and exact phylogenetic relationships are difficult to determine.

Caenagnathids (pronounced see-nag-na-fids) differ from oviraptorids in a number of ways.  There are differences in the jaws, the skulls tend not to be so deep and the finger proportions are different.  These and other subtle anatomical help to distinguish the two families.

A Simplified Cladogram Showing the Phylogenetic Relationship between the Caenagnathidae and the Oviraptoridae

A simplified cladogram of the Oviraptorosauria.

Picture credit: Everything Dinosaur

A Feathered Dinosaur that Probably Liked to Display

A study of the arm bones of Apatoraptor revealed large muscle scars indicating that the relatively short arms were strong.  Prominent notches on the ulna (ulnar papillae) suggest that the arms possessed long, quill feathers.  Greg concluded that this dinosaur moved its arms quite vigorously, probably some form of display with its long feathered arms, perhaps these displays were used in mate selection or to intimidate potential predators.

Apatoraptor pennatus

As Apatoraptor pennatus fossil material represents the first articulated caenagnathid skeleton from anywhere in the world (meaning the bones are still in the same position as when the animal died) and is by far the most complete caenagnathid skeleton from Alberta.  Apatoraptor has helped palaeontologists to understand more about the taxonomic relationships within the Caenagnathidae.  It turns out that A. pennatus (the name means deceptive, winged speedy thief), may be more closely related to Asian dinosaurs than to other caenagnathids from North America.

Commenting upon the significance of this research, Greg stated:

“This is my first time naming a new dinosaur.  It’s really exciting on a personal level, but what I am most excited about is what it means for this field of palaeontology.  In future studies, it will help us to better understand these dinosaurs.  It’s a really important specimen, because it is a relatively complete skeleton. it helps resolve the relationships of caenagnathids, which have always been problematic.  Most caenagnathids are represented by isolated material or single bones, which means that we can’t tell if they came from the same animal.  Apatoraptor gives us a better idea of what these animals looked like, which tells us if the features we have been using to separate species are significant or not.”

Greg Funston with a Model of the Jawbone

Greg with a model of the Apatoraptor jawbone.

Picture credit: University of Alberta

Apatoraptor pennatus – A Prehistoric Heron?

Dating from around 70 million years ago (Maastrichtian faunal stage of the Late Cretaceous), Apatoraptor roamed the swamplands of southern Alberta.  The climate was sub-tropical and the region resembled the Florida Everglades of today.  It may have waded through shallow water feeding on crustaceans, fish and amphibians as well as grazing on water weeds.  It may have resembled a heron as it carefully picked its way through the water.  It was likely covered in a coat of shaggy feathers, although it was far to big to be able to fly.

Greg added:

“Oviraptorosaurs, the bigger group to which Apatoraptor and other caenagnathids belong, were probably some of the flashiest dinosaurs.  We know of three separate ways—head crests, tail feathers and now arm feathers—that they would display to their mates.”

For models and replicas of feathered dinosaurs: CollectA Age of Dinosaurs Popular Figures.

Ancient “Spider” Reveals “Eye-opening” Secrets

Amazing three-dimensional images resulting from the interpretation of CT scans of a 305 million-year-old fossil have revealed that the forerunners of today’s arachnids had two sets of eyes rather than one.

Researchers from the University of Manchester, in collaboration with colleagues from the American Museum of Natural History (New York), say the highly magnified images reveal exquisite anatomical details not often found in invertebrate fossils.  Writing in the journal “Current Biology”, the scientists report that this research will add a great deal to the evolutionary story of the diverse and very successful group of Arthropods, the group that includes spiders, mites, scorpions, harvestmen and ticks.

Ancient Arachnid

A False Colour Image of the Prehistoric Arachnid H. argus

Hastocularis argus – an ancient harvestmen (arachnid) that had lateral eyes unlike modern harvestmen.

Picture credit: Manchester University

Hastocularis argus

The specimen represents the primitive harvestman called Hastocularis argus.  The specimen is part of a collection of Late Carboniferous (Pennsylvanian Epoch), fossils from eastern France.  The CT scans and resulting computer generated images reveal that this tiny creature not only had median eyes (eyes found near the centre of the body), but eyes located on the side of the body as well (lateral eyes).

Commenting on the research, one of the co-authors of the scientific paper, Dr. Russell Garwood (University of Manchester) stated:

“Although they have eight legs, harvestmen are not spiders; they are more closely related to another arachnid, the scorpion.  Arachnids can have both median and lateral eyes, but modern harvestmen only possess a single set of median eyes – and no lateral ones.  These findings represent a significant leap in our understanding of the evolution of this group.”

Fossil Evidence Supported by Genetic Data

In order to confirm their analysis, the scientists examined the genes for the expression of eye stalks in extant harvestmen.  They found that modern harvestmen embryos had evidence of a “switched off” part of the genetic code that hinted at lateral eye formation.  Modern harvestmen have lost their lateral eyes, but the genetic evidence suggests that way back in the evolutionary history of these creepy-crawlies, lateral eyes were present.

Postdoctoral researcher, Prashant Sharma (American Museum of Natural History) commented:

“Terrestrial Arthropods like harvestmen have a sparse fossil record because their exoskeletons don’t preserve well.  As a result, some fundamental questions in the evolutionary history of these organisms remain unsolved.  This exceptional fossil has given us a rare and detailed look at the anatomy of harvestmen that lived hundreds of millions of years ago.  What we were also able to establish is that developing modern harvestmen embryos retain vestiges of eye-growth structures seen only in the fossil.”

Dr Garwood added:

“Harvestmen fossils preserved in three dimensions are quite rare and our X-ray techniques have allowed us to reveal this exceptional fossil in more detail than we would have dreamed possible just a couple of decades ago.”

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

Visit Everything Dinosaur’s website: Visit Everything Dinosaur.

CT Scan of Ancient Whale Reveals Evolution of Echolocation

There are many different types of dolphins, porpoises and toothed whales around today.  These sleek, marine mammals are characterised by their superb adaptations to their environment, social behaviours, their intelligence and also their ability to use a complex sensory system to make sense of their underwater world.

Echolocation in Whales

Modern toothed whales (Odontocetes), use sonar frequencies (echolocation) to communicate with each other, for navigation and to locate and capture prey.  These are the only marine mammals to have evolved the ability to hear and make sense of such high frequency sounds.  But how did this super sensitive system evolve?  This is a question that we are part way to solving thanks to a remarkable piece of research carried out by scientists at Monash University and  Museum Victoria (Australia).

An Illustration of a Prehistoric Whale – Dorudon

Fossils of ancient whales trace their evolution, but when did echolocation evolve?

Picture credit:  Julius Csotonyi.

CT Scan of Ancient Whale Inner Ear Bone

In a paper published in the Royal Society’s journal “Biology Letters”, the researchers which included PhD student Travis Park (School of Biological Sciences, Monash University and Geosciences, Museum Victoria, both in Melbourne, Australia) explain how they borrowed a fossilised inner ear (cochlea) from the vertebrate fossil collection of the Smithsonian Institute and subjected the object to a CT scan (computerised tomography) to see inside and reveal the intricate structures that made up the hearing mechanism.

Student Travis Park Compares the Fossil Bone to the Inner Ear of an Extant Dolphin

The fossil cochlea (left) compared to the cochlea of a modern dolphin (right). Study suggests ancient toothed whales had echolocation.

Picture credit: Ben Healley

Comparing Extant with Extinct

Today’s dolphins and toothed whales produce high frequency sounds in their nasal passages.  These are transmitted through air sinuses and a specialised organ, the melon, which consists of a mass of fatty tissue.  It is the melon that propagates these sounds into the surrounding environment.  These sounds “bounce” of objects in the animal’s surroundings and the reflected signals reach the inner ear (cochlea) via acoustic fat pads that are located at the end of the lower jaw bone and the middle ear.

The CT scan produced a three-dimensional image of the cochlea and an assessment of the ancient creature’s hearing abilities could then be made using the cochlea of modern, extant dolphin as a benchmark.

Ancient Whale Fossil Ear Bone

The 26-million-year-old fossil ear bone from a xenorophid (one of the earliest Odontocetes known) revealed internal structures that were remarkably similar to those found in extant toothed whales.  The team concluded that ancient Oligocene whales had ears tuned for hearing high frequency sounds and therefore the ability to use echolocation.

A Computer Model Generated from the CT Scan Reveals the Intricate Structure

CT scan shows sophisticated cochlea of Oligocene fossil whale.

Picture credit: Biology Letters

The picture above shows (a) the fossil bone with the inner ear structure superimposed on the transparent image, (b) a cross-sectional element from the CT scan showing key features of the inner ear.  Images (c) and (d) are computer models created from the CT scan that shows the shape and structure of the ancient cochlea.  From an assessment of the morphology and the structure of this cochlea, scientists have been able to determine the likely hearing abilities of the long extinct animal.

Commenting on the outcomes of the research, Travis Park stated:

“When I first looked at the inner ear of the xenorophid, I was blown away by just how similar this incredibly old toothed whale was to a modern echolocating dolphin.”

Intriguing Questions Remain

This means that even the most ancient ancestors of today’s toothed whales and dolphins had ears tuned for hearing high frequency sound, and therefore the ability to echolocate like their living relatives.  It is likely that echolocation evolved in the ancestral Odontocetes but the fossil record is incomplete and a number of tantalising questions remain, as explained by co-author of the study Dr. Erich Fitzgerald (Museum Victoria):

“Our paper shows even the earliest known fossil Odontocetes have all the tools for echolocation seen in living dolphins.  But they must have evolved from something that didn’t quite have all the tricks of the Odontocete trade.  What were those animals like and how did they start down the path to sonic super senses?  The quest for the origins of this extraordinary group of creatures continues.”

Plotting the Evolution of Echolocation in the Toothed Whales

Plotting the evolution of whale echolocation using a 26 million-year-old fossil inner ear bone.

Picture credit: Biology Letters

Charting the Evolution of the Inner Ear of Cetaceans

The diagram above charts the evolution of the inner ear in cetaceans (whales).  The fossil bone used in the study has been assigned to the Xenorophidae family (fossil specimen used in the study is USNM-534010).  The researchers suggest that over millions of years, the inner ear of these creatures evolved into organs more capable of hearing high frequency sounds.

Everything Dinosaur has written a number of articles that feature the research of Dr Fitzgerald (Senior Curator of Vertebrate Palaeontology at the Museum Victoria), he has certainly been involved in an eclectic range of studies including mapping Australia’s dinosaur diversity, looking at the origins of seals and examining the fossilised bones of a bird with “pseudo teeth” in its beak.

Australia’s diverse dinosaurs: Australia – A Dinosaur Melting Pot

The first seals of Australia: Australia’s First Seal – A Pliocene Pinniped

Giant bird with a toothy grin: Giant “Toothed” Birds Once Soared Over Australia

Triassic Fossil Study Suggests Fossil Size a Poor Predictor of Maturity in Ancient Reptiles

Scientists at the Department of Geosciences at Virginia Tech (Blacksburg, Virginia, USA), have published a paper in the “Journal of Vertebrate Palaeontology”, that challenges some of the long-held assumptions about the growth of ancient reptiles.  Using an analysis of muscle tissue scars preserved on limb bones of Triassic fossils combined with cross-sectional bone studies to examine growth and the age of individuals, the researchers conclude that dinosaurs and their close relatives within the Archosauria had much more variation in growth patterns than expected.  The growth variation does not seem to be linked to gender.

Triassic Fossils

Size of the Fossil Bone May Not be Directly Linked to the Maturity of the Animal

A study of the bones of the Triassic reptile Asilisaurus.

Picture credit: Virginia Tech

Lead author of the scientific paper Christopher Griffin is pictured above holding two differently sized leg bones (femora) of Asilisaurus kongwe the study suggests that bone size is not a good indicator of animal maturity.

Asilisaurus kongwe – On the Road to the Dinosaurs

Fossils of the silesaurid Asilisaurus kongwe were used in the study.  Sufficient fossil material had been excavated over the course of nearly ten years of field trips to the Middle Triassic sediments of Tanzania to provide a suitable sample set and this little carnivore was, most likely an ancestor of the Dinosauria.  It has been assigned to the Dinosauriforms, a clade of archosaurs that gave rise to the dinosaurs and the birds.

The researchers found that when they examined the large number of bones associated with this species, they found that mature, adult bone size did not uniformly split into two distinct groups (male and female).  Instead, they found much more variation in bone size.  It might be difficult to apply this research to the whole of the Dinosauria, but as co-author Professor Sterling Nesbitt states:

“The earliest dinosaurs grew just like their closest relatives, and there are very few features that make dinosaurs unique from their closest relatives.”

If this is the case, then the Asilisaurus study could shed light on the growth habits (ontogeny), of the dinosaurs, at least the first types of dinosaur that evolved a few million years after Asilisaurus roamed Africa.

An Illustration of Asilisaurus kongwe

Depicted as a lithe, agile, active animal.

Picture credit: Andrey Atuchin

The large sample size (most silesaurids and early dinosaurs for that matter are known from highly fragmentary fossil material), permitted the scientists to study several individual specimens that appeared to be more mature than larger specimens and individuals of the same approximate size that appeared to be a different stages of growth.

Analysis of Muscle Scars

Analysis of the scars found on the surface of the bones where tendons and muscles once attached and cross-sectional studies showing the internal structure of the bone itself, allowed the scientists to plot changes in the anatomy and bone tissue.  The researchers found that although the sample set lived roughly at the same time and in the same location, they grew differently from each other.

Think of the analogy of a modern family with siblings and cousins of different heights and weights.

The more mature an individual was at death, the larger its bone scars appeared.  As with any animal or person, an individual skeleton goes from possessing few scars to possessing many during life, with scars appearing in a particular order as the age of the individual increases.

Size is Probably a Poor Predictor of Skeletal Maturity in Silesaurids

The researchers conclude that except for the smallest and largest individuals in the study (the least and most mature respectively), size of bones is probably a poor predictor of skeletal maturity in Asilisaurus and therefore, probably in other silesaurids and ultimately the early members of the Dinosauria as well.

Commenting on the implications for this research, Master’s student Christopher Griffin explained:

“Our study includes more individuals and more bone scars and with this increase in sample size we found that individuals fall on a trajectory that is more similar to maturity difference.  This suggests that similar variation in bone scars in early dinosaurs is variation in growth not male and female difference.  Because this variation appears to be widespread among early dinosaurs and their closest relatives, it is likely that high variation in growth between individuals characterised the most recent common ancestor of Asilisaurus and all dinosaurs.”

Articulating the Fossils of an Individual (Asilisaurus kongwe)

Fossil material laid out to represent Asilisaurus (femora labelled).

Picture credit: Virginia Tech with additional annotation by Everything Dinosaur (note the skull to the left of the picture is a model)

Growth Rates Not Well Understood

The growth rates of early, rapidly diverging ancestral dinosaurs is very poorly understood.  This study that assessed the thigh bones (femora) of Asilisaurus kongwe provides an opportunity to examine in detail the ontogeny of one of the closest known relatives of the Dinosauria.

Everything Dinosaur has written about the discovery of Asilisaurus, to read the article: Dinosaurs Around Ten Million Years Earlier than Previously Thought

Everything Dinosaur recognises the help of Virginia Tech in the compilation of this article.

Looted Dinosaur Fossils Returned Home to Mongolia

This week saw another success in the fight against illegal fossil smuggling and the black market in rare artefacts such as prehistoric animal fossils.  Officials from the U.S. Immigration and Customs returned a number of dinosaur skeletons and other fossils to the Mongolian government.  In a ceremony held in New York, investigators from the U.S. Immigration and Customs Enforcement’s (ICE) Homeland Security Investigations (HSI) handed over fossils that had been recovered from Wyoming and the “big apple”.

Dinosaur Fossils

An Articulated Psittacosaurus Dinosaur Skeleton on Display

Psittacosaurus fossils on display at the Senckenberg Naturmuseum (Frankfurt).

Picture credit: Everything Dinosaur

The Removal of Fossils from Mongolia

A law passed in the 1920s forbids the removal of artefacts deemed to be of significant cultural value from Mongolia, the returned items include nearly complete skeletons of the basal horned dinosaurs Protoceratops and Psittacosaurus, along with a beautifully preserved nest of Protoceratops eggs.  In addition, the fossils of the duck-billed dinosaur Bactrosaurus and the skull of a tyrannosaurid Alioramus as well as the skull of Psittacosaurus were returned.

Commenting on the significance of the returns, Peter Edge, (HSI’s Executive Associate Director) stated:

“Today’s ceremony is an excellent demonstration of the co-operation between HSI, our colleagues at the Department of Justice and our foreign counterparts with the Government of Mongolia.  A successful repatriation requires extensive co-operation among all parties involved, which is rewarded by the knowledge that we’ve returned what rightfully belongs to the people of Mongolia.”

Building on the Success of the Tarbosaurus bataar Repatriation

U.S. customs most noteworthy success came in 2013 with the high profile repatriation of a mounted Tarbosaurus bataar skeleton that had originally been put up for auction in New York the year before.  Tarbosaurus, like Alioramus was a member of the Tyrannosauridae family, this case resulted in the prosecution and eventual jailing of Florida fossil dealer Eric Prokopi.

To read more about this:  American Fossil Dealer Jailed for Dinosaur Smuggling

The Tarbosaurus case brought to the world’s attention the problem of illegal fossil dealing, it laid the foundation for much greater co-operation between governments and other federal bodies and sent a very clear message to the unscrupulous dealers and their middle men.  In this latest ceremony, a total of twenty-three dinosaur fossils were handed over to the Mongolian government.

A spokesperson from Everything Dinosaur commented:

“We would like to take this opportunity to congratulate all the parties involved in achieving such a successful conclusion.  These efforts will further strengthen cross-border co-operation and bilateral ties between nations as authorities attempt to reduce the level of fossil smuggling and the illegal removal and export of rare artefacts from Asia.”

An Almost Complete Protoceratops Skeleton

Picture credit: Everything Dinosaur

For models and replicas of Protoceratops and other horned dinosaurs (whilst stocks last): Beasts of the Mesozoic Figures.

Trained Investigators

HSI’s specially trained investigators, assigned to both domestic and international offices, partner with governments, agencies and experts to protect cultural antiquities.  They also train investigators from other nations and agencies to investigate crimes involving stolen property and art, and how to best enforce the law to recover these items when they emerge in the marketplace.  Those involved in the illicit trafficking of cultural property, art and antiquities can face prison terms of up to twenty years, fines and possible restitution to the purchasers of the items.

This is just the latest success for the HSI, since 2007 this American organisation has repatriated more than 8,000 items to more than thirty countries.

Everything Dinosaur acknowledges the help of the U.S. Immigration and Customs Enforcement media team for the compilation of this article.

Visit Everything Dinosaur’s website: Everything Dinosaur.

Dinosaur Eggs from the Early Cretaceous

Parts of China have provided palaeontologists with ample evidence of dinosaur nesting behaviour, fossils of nests, eggshells and complete eggs themselves have been excavated from a number of locations.  Guandong Province (southern China) in particular is famous for the relative abundance of dinosaur egg fossils that have been found.

Dinosaur Eggs

However, the vast majority of these egg fossils from China come from Upper Cretaceous deposits, indeed from a global perspective, dinosaur eggs that date from the Lower Cretaceous are much rarer than their Upper Cretaceous counterparts.  Up until now, the only confirmed dinosaur egg fossils from Lower Cretaceous age deposits from China have been excavated from sites in Liaoning Province in the north-east of the country.

A Dinosaur Egg Fossil

A dinosaur egg fossil. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Scientific Paper Published

A press release from the Chinese Academy of Sciences which provides information on a new paper published in the academic journal “Vertebrata PalAsiatica” changes all that.  A new type of dinosaur egg is described, although the fossils are fragmentary, the largest piece of eggshell found to date in only a few centimetres in diameter, a microscopic analysis of the eggshells structure has revealed new characteristics indicating that this is a new type of dinosaur egg, but as to which dinosaur laid the eggs, that remains a bit of a mystery.

A Fragment of the Dinosaur Egg Fossil (Eggshell)

(A) scale bar = 1 cm and (B) scale bar = 1 mm

Picture credit: Chinese Academy of Sciences

The picture above shows the largest eggshell fragment discovered to date (A), the second picture (B) is a close up of the highly weathered surface of another piece of dinosaur eggshell from the same location.

From Lower Cretaceous Deposits

The fossils come from the uppermost siltstone layer of exposed Lower Cretaceous sediments in Gansu Province.  These rocks make up the Lower Cretaceous Hekou Group in the Lanzhou-Minhe Basin, north-western China.  Exposed Lower Cretaceous strata in Gansu Province has yielded extensive dinosaur and bird tracks, but these are the first dinosaur egg fossils to have been found in this part of China.

To read an article about some intriguing sauropod tracks found in the same area as these egg fossils: Swimming or Walking Sauropods

Important Implications for the Study of Dinosaur Eggs

The eggs have been assigned to a new oogenus, a new oospecies has been erected.  Just like fossilised animal tracks, palaeontologists can establish a scientific name for egg fossils, such names have the prefix “oo”, from the ancient Greek for egg, placed in front of them to indicate these names refer to an egg.  With trace fossils the prefix “ichnos” is used, this too comes from ancient Greek, (ichnos means track).

The oogenus is Polyclonoolithus and the oospecies is Polyclonoolithus yangjiagouensis, the dinosaur eggs can be distinguished from other Chinese dinosaur eggs as under the microscope the eggshell  showed unique features such as highly branched eggshell units not having a compacted layer near the outer surface of the shell and very irregular pore canals.

Microscopic Study of the Eggshell Revealed Unique Features

Microscopic analysis of the eggshell structure revealed unique features in this Lower Cretaceous dinosaur egg.

Picture credit: Chinese Academy of Sciences

The authors of the scientific paper conclude that the eggshell fossils represent a more basic type of dinosaur egg, especially when compared to the highly diverse forms of dinosaur egg found in Upper Cretaceous deposits.  Its taxonomic relationship to other oogenera is not known, but these fossils might represent an early form of egg that led onto the evolution of more rounded, spherical eggshell shapes (spheroolithid eggs).

Polyclonoolithus yangjiagouensis

As for the name Polyclonoolithus yangjiagouensis (pronounced Pol-ee-klon-ooh-lith-us yang-gee-ah-gou-en-sis), the oogenus name is derived from the Greek for “egg stone with many small branches”, the oospecies name honours the town of Yangjiagou, in the border region of Lintao and Yongjing counties, Gansu Province, which is close to where the fossils were found.

By honouring the local town in this way the scientists hope to deter pilfering of fossil material, unfortunately, there is an extensive illegal trade in fossils in China and although the authorities have worked hard to stamp out the black market, many hundreds, if not thousands of rare artefacts such as dinosaur fossils are smuggled out of China each year.

Trade in unlawfully gained fossil material is significant, dinosaur eggs are particular favourite of unscrupulous traders as they are relatively small , portable but retain a high resale value.  Last year Everything Dinosaur reported on the seizure of huge haul of stolen dinosaur eggs from Guandong Province, to read more about this: Chinese Authorities Seize Hundreds of Dinosaur Eggs in Raid

Which Animal Laide These Dinosaur Eggs?

The eggs were probably little more than ten centimetres in diameter, not huge when compared to the eggs of sauropods for example.  However, the palaeontologists cannot be certain as to which type of dinosaur laid the eggs.

Only a handful of dinosaurs are known from the siltstone strata (late Early Cretaceous).  Evidence of basal titanosaurs have been found along with the fossils of an iguanodontid Lanzhousaurus magnidens.  The eggshell fragments come from the same locality where fossils of an armoured dinosaur, a nodosaurid (Taohelong jinchengensis) have been discovered.  It is not possible at this time to identify which type of dinosaur produced these intriguing eggs.

For dinosaur models and replicas: Dinosaur and Prehistoric Animal Models.