Pint-sized but with a Nasty Bite – Eodromaeus from the Triassic of Argentina
It may have been small, but it was quick, agile and had a nasty bite, researchers have announced the discovery of a new genus of dinosaur from Argentina. The dinosaur has been formally named and described – Eodromaeus murphi and it was a basal theropod, an ancestor of ferocious dinosaurs such as Giganotosaurus, Allosaurus and Tyrannosaurus rex.
South America is regarded as the “cradle of dinosaur evolution”, with a number of primitive dinosaurs known from Argentina, in particular the Middle Triassic strata of the Ischigualasto Formation in an area known as the Valley of the Moon. This new theropod, known from two specimens that were found in close proximity to each other, measured approximately 1.2 metres in length (mostly tail), it would have weighed around 5 kilogrammes.
The paper on this dinosaur has been published in the scientific journal “Science”.
Triassic Dinosaur
The dinosaur’s name means “dawn runner” and it is one of a number of basal theropods known from the Valley of the Moon area, other theropods such as Herrerasaurus and Eoraptor, although dinosaurs were not the most common animals in the area, there were many different types of reptile and many of them were much, much bigger than the dinosaurs.
Commenting on the new dinosaur discovery, Paul Sereno of the University of Chicago, a palaeontologist who has worked extensively in Argentina stated:
“It was very cute, you would want it as a pet. But it might be best as a guard dinosaur, to keep the dogs away.”
The fossilised bones of Eodromaeus have been dated to approximately 224 million years ago (late Carnian faunal stage). Unlike Herrerasaurus, this dinosaur had hands that had three-clawed fingers. It was very likely a fast runner and the narrow skull had some enlarged, sharply curved teeth at the front of the jaws.
Eodromaeus
Eodromaeus superficially resembles Eoraptor in size and anatomical structure, but scientists now believe that Eoraptor was an ancestor of the long-necked sauropods. The basal ancestry of the sauropods remains unclear but recently, a discovery of a primitive quadruped from Argentina may have provided vital clues as to the evolution of the Sauropoda.
As both genera were small, ran on two legs and lived around the same time, researchers believe that the common ancestor of all dinosaurs was also just about four feet in length and originated in South America.
Paul Sereno added:
“This gives us the earliest snapshot of dinosaurs. They were just a couple of million years away from the ultimate ancestor.”
The long shin bones and large metatarsals indicate an agile, speedy runner. The long tail would have helped this little dinosaur to balance and change direction quickly. Although a carnivore, Eodromaeus was not top of the food chain, there were plenty of predatory mammal-like reptiles and carnivorous rauisuchids that would have made short work of Eodromaeus had they been able to catch one.
Those clever people at Schleich, the German based model and figure manufacturer have produced another illustration showing their beautiful scale model dinosaurs. The range, marketed as the “Saurus” range consists of twelve, hand-painted prehistoric animal models including Allosaurus, Giganotosaurus and of course, T. rex representing the carnivores plus herbivores such as Brachiosaurus, Apatosaurus, Parasaurolophus and the armoured dinosaur Saichania.
The Schleich Saurus Dinosaur Frieze
Picture credit: Schleich
The illustration shows herbivores from the range with the pterosaur Quetzalcoatlus flying overhead. Of course, such a scene could never have happened, not only did the animals depicted in the picture lived millions of years apart, but many of them also lived in very different parts of the world. For example, the Stegosaurus in the image lived in what was the western United States, whilst Saichania was native to Asia.
Schleich Prehistoric Animal Models
The colourful poster is a great way for this German manufacturer to highlight their range. The poster provides a shop window for Schleich prehistoric animal models.
When working on bipedal dinosaur models, often the focus from a design point of view is achieving a stable prototype from which to work with. These ornithodirans can be a little tricky when it comes to the Theropoda, their bipedal stance causes all sorts of problems, after all, a 6,000 kilogramme T. rex walking on its hind legs is impressive, and you want to make an accurate representation of the creature, so the stance and position of the hind feet are all important.
As digitigrades (walking on their toes as opposed to walking on their heels), theropods such as T. rex are certainly a challenge, just producing a workable, realistic prototype. Then with T. rex there is another dimension to consider – their massive skulls.
Such a heavy head, positioned at the front of the animal model, compounds the balance issue, especially when a considerable portion of the weight of the replica is located far away from the centre of gravity over the hips, and, as in the case of T. rex often the head is elevated and becomes the highest part of any model.
One way of resolving this issue, is to take a novel approach to the head position and depict the tyrannosaur with a lowered head. An example would be the CollectA 1:15 scale and 1:40 scale Tyrannosaurus rex replicas.
A Picture of the CollectA 1:40 Scale Model T. rex
Interesting pose of this tyrannosaur dinosaur model.
In this model, the head is depicted in lowered position, jaws agape. The tail is elevated and becomes the highest part of the replica. Balance is not just the only consideration though, this type of stance may reflect typical behaviour of large carnivores as they attempt to intimidate rivals and prey.
Having your main weapons perched some fifteen feet in the air is not much good when confronting a quadrupedal ankylosaur. One look at that powerful jaw lined with huge teeth may have been enough to stop a herbivore in its tracks. Such intimidation may have been used before this carnivore attacked.
Many birds display by “head bobbing” and it is feasible that T. rexes displayed as well. Visual cues would have played a role in any such behaviour, the dipping and bobbing of heads, perhaps to show the size of the mouth and the gaping jaws would have been an effective way of settling disputes over territory or mates.
So a pose in a model of a bipedal dinosaur may actually serve two purposes, firstly to stabilise the replica and secondly to depict suggested behaviour. Sorting of “killing two birds with one stone” – looks like we are back to the ornithodirans again.
New Cretaceous Pterosaur Genus from British Columbia
Pterosaurs, that extinct group of flying reptiles that lived during the Mesozoic, evolved into a huge variety of forms before finally becoming extinct around sixty-five million years ago. The last of the pterosaurs, most notably the azhdarchids and the last surviving members of the Pteranodontidae were toothless. However, not all Late Cretaceous flying reptiles had toothless beaks, a discovery from British Columbia (Canada) provides an insight into a new genus of pterosaur with teeth at the end of its jaws described as resembling those of a piranha.
The fossil, part of the jaws of the flying reptile was found when a rock from a beach on British Columbia’s Hornby Island was split open. The area has produced a number of dinosaur fossils as the Cretaceous-aged cliffs are eroded away to expose potential fossil material, but this is the first pterosaur fossil found in the area.
Pterosaur fossils
Pterosaur fossils are extremely rare and to find skull and jaw material is very significant as it can give palaeontologists valuable information about what the animal may have eaten. This new species has been scientifically named – Gwawinapterus beardi. Although no other elements of the skeleton have been found to date, researchers estimate that it had a three-metre wingspan and have based their descriptions on the fossilised remains of other Later Cretaceous pterosaurs from the Northern Hemisphere.
The paper, reporting the finding of this important new fossil is featured in the January edition of the “Canadian Journal of Earth Sciences”, lead author is University of Alberta palaeontologist Victoria Arbour.
Commenting on this “uniquely Canadian species”, Arbour, a PhD student who has worked on a number of British Columbia Cretaceous fossils including ankylosaur material stated that British Columbia presented a series of challenges to fossil hunters, who in comparison with palaeontologists based in Alberta, have a more difficult task of finding fossils.
Gwawinapterus beardi
She stated that in practice; palaeontologists and field workers comb the beaches along the Pacific coast:
“They basically pick up rocks, and they crack them open, and sometimes, they have fossils inside.”
The reptile was identified from the fossil jawbone which was examined by Graham Beard, a well-known fossil collector who runs the Vancouver Island Palaeontological Museum in Qualicum Beach on Vancouver Island. Arbour named the species after him.
Graham thought it was part of a dinosaur’s jaw but once the object was passed on to Phil Currie, the eminent palaeontologist who is supervising Victoria in her studies, it was identified as pterosaur remains. Professor Currie was recently inducted into the Alberta Order of Excellence in recognition of his contribution to science and the study of dinosaurs in that Canadian province.
Professor Currie co-authored the formal scientific description, the name meaning “raven wing” in a local dialect with the species name honouring Graham Beard.
The distinctive, tightly spaced, arrow-like teeth are similar to teeth ascribed to a Cretaceous Pterosaur genus known from China.
When asked to describe the teeth, Victoria said:
“The teeth look a little bit like piranha teeth the way that they are packed really close together.”
The teeth are positioned to towards the front of the snout (anterior), as to what this pterosaur fed on remains a mystery, but it has been suggested that it may have scavenged carcases using its strong teeth and long beak to nip off pieces of meat that other scavengers could not reach. Although a predatory habit, swooping down on other pterosaurs, small mammals and lizards has also not been ruled out.
To view scale models and figures of pterosaurs such as Pteranodon, Dimorphodon and Guidraco, take a look at this model range here: CollectA Deluxe Prehistoric Life Models.
Addendum
Subsequent research published in 2012 identified the remains as having come from a saurodontid fish.
Scientists Put Forward New Theory for Cambrian Extinction Event
The history of life on planet Earth has been punctuated with a series of extinction events. More than fifty major extinctions have been identified over the last 500 million years or so. Life on Earth has had to get used to these setbacks, however, extinctions have permitted new organisms to evolve and they have helped to “spur on” evolution. A new paper has just been published in the scientific journal “Nature” that sheds light on one of the first major extinction events recorded in the fossil record – the Late Cambrian extinction.
Cambrian Extinction
Following the Cambrian explosion that saw the recording of all the known animal phyla in the fossil record from approximately 540 million years ago, life was thriving in the shallow seas of the Cambrian Period. Porifera (sponges) were widespread, along with the brachiopods and molluscs. Although there is evidence of the first chordates (back-boned animals or animals with a notochord), the most advanced creatures were the arthropods, creatures such as trilobites that had already evolved into many different families.
However, from approximately 520 million years to 490 million years ago, a series of swift extinction events took place, radically altering the types and quantity of marine invertebrate genera present. A team of geologists have completed a study of rock strata laid down in the middle of this geological period and their data showing high levels of sulphur and carbon indicate that changes to the atmosphere may be the cause for the dying out of many types of organism.
According to their study, reported in this weeks edition of “Nature” the ocean’s oxygen levels fell sharply and sulphur levels rose very quickly, killing off genera that could not adapt.
Benjamin Gill, one of the authors of the report (Post-doctoral Fellow and research Fellow assistant at Harvard University), commented:
“Around 499 million years ago, large portions of the ocean were oxygen deficient and also contained hydrogen sulphide.”
The geologists studied a specific subset of Cambrian extinctions that began approximately 499 million years ago and lasted for two to four million years. Low oxygen levels had been postulated as putting the brake on the advancement of life forms, but until now there was little supporting evidence for this theory.
The chemical analysis of the strata shows that from the six locations studied; there were unexpectedly high levels of various isotopes of carbon and sulphur. In modern oceans, these mix of elements only occur in oceans which lack oxygen, such as parts of the Black sea in the Crimea.
There has been some work done previously to show that there is a band of iridium deposited in some parts of the world, in rocks dating from around 500 million years ago. This rare Earth element has in this instance been associated with intense volcanic activity. The high levels of carbon and sulphur found in this study, may reinforce the theory that volcanic activity gave rise to a series of extinctions that led to something like 30% of all marine genera becoming extinct.
Gill and his colleagues remain unsure as to what caused the oxygen levels to collapse, however, anoxia (lack of oxygen) would have been devastating to life in the oceans at the time.
New Teaching Lesson Plans from Everything Dinosaur
With more and more schools in the UK adopting the creative curriculum, team members at Everything Dinosaur have responded by introducing a new range of teaching sessions and lesson plans to aid reception students through to key stage 4. Our trained and qualified teachers have prepared a number of innovative and enriching lesson plans based around palaeontology and dinosaurs. The aim of these sessions is to engage and involve young people with the fascinating subject of Earth Sciences.
Everything Dinosaur
Working under the concept of “Dinosaur detectives” we use real case studies regarding new fossil discoveries to develop effective and very “hands on” dinosaur themed teaching schemes.
As part of our work in this important area of education, we have developed a number of advertisements to support our teaching activities and dinosaur workshops.
So if you want to involve your class in a dinosaur themed topic such as “Jurassic Forest” or Everything Dinosaur’s dinosaur detectives lesson plans simply log onto our website: Everything Dinosaur to view the extensive range of dinosaur themed toys and gifts we stock.
The Everything Dinosaur Logo
Everything Dinosaur logo – a sign of quality and reliability.
Picture credit: Everything Dinosaur
In addition, if you require any advice about the products that we stock you are most welcome to drop Everything Dinosaur an email: Contact Everything Dinosaur.
A busy day ahead of us, some of the staff members have come in for a couple of extra hours today, to review and respond to all the customer feedback forms that arrived after Christmas.
For every parcel sent out to UK customers we include a FREEPOST feedback form. With so many orders despatched up to the Christmas break, now is the time of year that we get back all the feedback forms that customers of Everything Dinosaur have kindly sent in.
Customer Feedback
We review all our customer correspondence, every letter, fax, email and such like. We then divide them up between us and respond in person to any that require a reply. One of the most important jobs that is undertaken after the Christmas break is to deal with all the feedback forms that come into us in the first few days of January. We have to sort through them, putting them into piles so that all staff can have a look at them and send out a response if needed.
Everything Dinosaur
It is always a pleasure to hear from customers, we really appreciate the feedback, kind words about the Everything Dinosaur customer service, new product suggestions, dinosaur drawings and so on.
To visit Everything Dinosaur’s award-winning and user-friendly website: Everything Dinosaur.
French and U.S. Scientists Help to Unlock the Mystery of an Ammonite’s Diet
Ammonites are an extinct group of cephalopod molluscs that lived in spiral shaped, chambered, coiled shells. The fossilised remains of these marine creatures are abundant and can be found in Mesozoic sediments throughout the world. The fossils are extremely important and many different genera are used to help confirm the relative ages of rock strata, this process is called biostratigraphy.
Particular zones in a series of layers of sedimentary rock are classified by the distinct fossils that each zone contains and due to the abundance of ammonite fossils and the readiness of this particular group of creatures to evolve into myriad forms, ammonites make ideal fossils for biostratigraphy.
Ammonite Fossils
A Wonderful Early Jurassic Ammonite Fossil
An ammonite partially eroded out of a nodule. We think this is an example of Dactylioceras commune.
Picture credit: Everything Dinosaur
A beautiful ammonite (Dactylioceras?) preserved as a pyretic specimen from the English coast.
Although very common as fossils, there is still a great deal that scientists have yet to learn about these ancient relatives of squid and cuttlefish. For example, without any soft parts of the animal fossilised, it is very difficult to determine what these creatures fed on, where in the food chain did they fit?
They did form an important part of the diet of many of the larger animals that shared the ammonite’s marine environment, scientists believe that many types of marine reptiles, such as mosasaurs and ichthyosaurs fed on ammonites. With the extinction of the ammonites 65 million years ago, did this also mean the end of the mosasaurs that relied on them as prey?
Such is the connection between marine reptiles and ammonites that Safari, the American based figure manufacturer, recently introduced a new model of an ichthyosaur that had an ammonite in its mouth.
The Safari Ltd Carnegie Collection Ichthyosaurus
Picture credit: Everything Dinosaur
Ichthyosaurs Feeding on Ammonites
Just how many ichthyosaurs fed on ammonites is a bit of a mute point, as many genera had toothless beaks, perhaps better suited to tackling soft-bodied cephalopods rather than hard-shelled ones.
A new study by a joint team of French and U.S. based scientists, published in the scientific journal “Science” provides fresh evidence on the diet of one particular ammonite. It seems that the larval stage of snails and tiny crustaceans were on this particular cephalopods menu.
Lead author of this new paper, Isabelle Kruta of the Musee National d’Histoire Naturelle (Paris) commented on using very powerful X-ray beams to see inside the fossilised remains of a Baculites ammonite. It revealed the last prey consumed was a small larval snail and three tiny crustaceans.
The French and American researchers have been able to reveal the lives and deaths of a number of different ammonite specimens in amazing detail. Using a technique called synchrotron X-ray microtomography, an advanced form of CT scanning, three-dimensional images of several ammonite fossils were created. These images have provided new information about ammonites, including providing some data on the types of prey that certain genera may have consumed.
Ammonite Jaws and the Radula
The researchers determined ammonites possessed jaws and a radula, which is like a tongue covered with teeth. Garden snails have radulas, their affect can be seen if you leave a lettuce leaf out in the garden on a wet summers evening. In this study different types of ammonite teeth were identified, from slender ones to sabre-like or even ones shaped like the teeth on a comb.
Each colour in the computer images produced shown above shows a different type of tooth on the radula-like structure of the Late Cretaceous ammonite Baculites. This image was created by synchrotron radiation microtomographic slices.
Commenting on the images, lead author, Kruta explained:
“Ammonites used their radula to trap the food in the mouth and convey it through the oesophagus.”
The oesophagus describes the part of the alimentary canal from the mouth to the stomach.
This feeding system, along with the fossilised last supper remains, suggests that ammonites were adapted for eating small prey, such as tiny crustaceans and plankton, floating in the water.
This research could have a bearing on theories related to the extinction of marine organisms at the end of the Cretaceous Period. An extra-terrestrial impact could have killed many of the small nektonic or planktonic organisms that ammonites relied on for prey. This in turn, would have led to the collapse of much of the marine environment’s food chain.
Ammonite Diet
In a separate paper also published in journal Science, palaeontologist Kazushige Tanabe of The University of Tokyo postulates that newly hatched ammonites were particularly dependent upon such small prey items.
He stated:
“The abrupt decline of phytoplankton at the end of the Cretaceous led to the collapse of marine food webs and would have greatly affected the survival of newly hatched ammonites.”
When asked why so little is known about ammonites, despite the abundant fossil record, Tanabe said:
“Ammonites are some of the most famous invertebrate animals in Earth’s history. Yet as biological entities they are poorly understood, largely owing to the absence of a direct living counterpart.”
The new high-resolution, three-dimensional images may help to solve some of the ammonite mysteries. They also help to explain why one of the world’s most successful animals, in terms of abundance and species longevity, suddenly bit the dust along with the dinosaurs, marine reptiles and pterosaurs.
Whilst discussing the affect on food chains of the loss of the Ammonites, Kruta stated:
“Known predators of ammonites were, for example, mosasaurs and plesiosaurs.”
It was speculated that the disruption of the food chains would have had a significant effect on apex predators such as the marine reptiles.
Kruta and her team hope additional research can help to further unravel what happened to ammonites and other prehistoric animals.
Those answers may come sooner rather than later, as Tanabe believes the new uninvasive X-ray technique “can be widely applicable to other fossilised delicate organismicstructures preserved in sedimentary rocks, such as specimens preserved in museum collections.”
Commenting on the research papers, Neil Landman, curator in the Division of Palaeontology at the American Museum of Natural History (New York) stated:
“When you take into consideration the large lower jaws of ammonites in combination with this new information about their teeth, you realise that these animals must have been feeding in a different way from modern carrion-eating Nautilus.”
The Nautilus is an extant cephalopod, superficially similar to the extinct ammonites.
He concluded:
“Ammonites have a surprisingly large lower jaw with slender teeth, but the effect is opposite to that of the wolf threatening to eat Little Red Riding Hood. Here, the bigger mouth facilitates feeding on smaller prey.”
The CollectA Age of Dinosaurs Popular Ammonite Model
CollectA Age of Dinosaurs Popular Size Pleuroceras ammonite model.
Long, dark nights, not much chance to go fossil hunting, but still plenty to look forward to as the winter edition of Prehistoric Times is on its way. Prehistoric Times is the magazine for dinosaur model collectors and dinosaur enthusiasts. It is packed full of news stories, articles about new models, dinosaur discoveries, artwork, just about everything and anything to do with the Dinosauria and other extinct creatures.
Winter Edition of Prehistoric Times
Picture Credit: Mike Fredericks/Everything Dinosaur
This is the ninety-sixth edition of the magazine, it has been running for seventeen years and it does not look likely to go extinct. The magazine is popular with dinosaur model collectors and fans of prehistoric animals, it has a worldwide readership.
Team members review each issue and to see prehistoric animal themed games and dinosaur toys, including models of animals often featured in Prehistoric Times: Everything Dinosaur.
A giant rodent is featured on the front cover of the latest edition of the magazine called “Prehistoric Times”.
Front Cover of Issue 96
Giant rodent on the front cover.
Picture credit: Everything Dinosaur
Prehistoric Times
Everything Dinosaur team members provide a detailed review of each edition of this quarterly magazine. For models and replicas, dinosaur themed games and toys which include many of the prehistoric animals featured in the magazine, visit: Everything Dinosaur.
