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29 07, 2015

Research to Get Your Teeth Into

By | July 29th, 2015|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Structural Secrets of Theropod Teeth

Theropod dinosaurs, the majority of which were carnivorous, had a distinct advantage over other Mesozoic predators.  Their teeth had a deeply folded, serrated tooth structure that allowed them to rip and tear into the bodies of their victims.  This crucial, layered structure to the teeth has been identified by researchers from the University of Toronto Mississauga, with the assistance of colleagues from Taiwan and published today in the academic journal “Scientific Reports.”

A Specialised Tooth Structure for Feeding on Large Prey

Gorgosaurus feeding - thanks to its specialised teeth.

Gorgosaurus feeding – thanks to its specialised teeth.

Picture credit: Daniele Dufault

The picture above shows a feathered Gorgosaurus, a member of the Tyrannosauridae family, feeding on a young Corythosaurus.  The research team used scanning electron microscopes and a synchrotron located in Taiwan to study a wide variety of Theropod teeth from the collections of Canadian museums, including the Royal Tyrrell, and the Royal Ontario Museum.  Meat-eating dinosaurs in the study, included Gorgosaurus, the Triassic predator Coelophysis, Tyrannosaurus rex, Allosaurus, and the giant African Theropod Carcharodontosaurus.  Other non-Dinosauria creatures involved in the teeth study were Smilodon spp. and the shark C.  megalodon, as well as early Archosaurs, as the scientists tried to identify the evolutionary origins of these rather unique inter-dental folds.  Extant animals were also included in the research.  The only living animals with similar dentition and internal teeth structures are the Monitor Lizards, most notably the formidable Komodo dragon (Varanus komodoensis).  It is the largest lizard alive today and specialises in hunting large animals, thus reinforcing the theory put forward by the Canadian research team that these inter-dental folds evolved specifically to assist with predation of large herbivores.

Dr. Kirstin Brink, a post-doctoral researcher in the Department of Biology, one of the authors of the paper commented:

“What is so fascinating to me is that all animal teeth are made from the same building blocks, but the way the blocks fit together to form the structure of the tooth greatly affects how that animal processes food.  The hidden complexity of the tooth structure in Theropods suggests that they were more efficient at handling prey than previously thought, likely contributing to their success.”

Dr. Kristin Brink with one of the Theropod Teeth Examines the Evidence

A special arrangement of layers of dentine at the base of each serration in the tooth.

A special arrangement of layers of dentine at the base of each serration in the tooth.

Picture Credit: University of Toronto Mississauga

The picture above shows Dr. Brink examining the special arrangement of layers of dentine at the base of the each tooth serration (denticle).  She is holding a tooth from the giant Theropod Carcharodontosaurus.

A lot of research has been undertaken into the bite forces of extinct animals, but this is the first time a study of this type has been carried out.  The teeth may have an outer coating of enamel, just like our teeth, but the tough dentine inside has a unique configuration of dental folds and this gives the teeth of Theropod dinosaurs enlarged serrations, ideal for tearing into flesh.

The shape of the teeth (morphology) and their development, both in terms of their evolution and how they develop in an individual. can provide palaeontologists with a lot of information on the evolution of extinct animals and provide insights into feeding behaviour.  Theropod teeth, the only group of the Order Dinosauria, known to have produced meat-eaters, are characterised by the presence of serrations, known as denticles on the cutting edges of their teeth.  These serrations vary between genera, with troodontids for example, having relatively large denticles, whilst spinosaurids have proportionately much smaller ones.

Teeth that are serrated along the cutting edge are referred to as ziphodont teeth.  In a study, Everything Dinosaur reported upon last year, the same University research team, examined the ziphodont teeth of Dimetrodon (D. grandis).  They concluded that the serrations gave this Pelycosaur an evolutionary advantage over other Permian predators.

To read more about this study: Dimetrodon with Teeth Like a Steak Knife

In this new paper, the researchers conclude that the structures previously thought to prevent tooth breakage, instead, first evolved to shape and maintain the characteristic denticles throughout the life of the tooth.  The relatively novel and complex dental folds produced at the base of the teeth characterises the Theropods, with the exception of those genera that evolved a modified diet and a less meat intensive diet.  The scientists conclude that these teeth structures are vital for allowing the predation and consumption of large prey animals.

A Close up of a Gorgosaurus Tooth (Royal Ontario Museum Collection)

A close up of the tooth of Gorgosaurus

A close up of the tooth of Gorgosaurus – G. libratus

Picture Credit: Scientific Reports

The picture above shows an illustration of the skull of the tyrannosaurid Gorgosaurus (A), drawing by Danielle Dufault.  The complete tooth (ROM 57981) is shown in (B) with extreme close ups of the denticles on the cutting edges of the tooth.  The tooth illustrated is from the upper jaw (maxilla).

Key

  • dej = dentine/enamel junction
  • e = enamel (outer coating of the tooth)
  • if = inter-dental fold
  • is = inter-dental sulcus
  • pd = primary dentine

The Sharp Edges of Predators Teeth Viewed Under Scanning Electron Microscopy

c

Theropod teeth have two sharp edges these are called carinae.

Picture Credit: Scientific Reports

The cutting edges (carinae) of various predators (all are examples of ziphodont teeth).  Pictures are from scanning electron microscopy images.  Note the scale bars and the pictures to the right of the black and white images are thin cross sections showing internal structure.

Key

  • C = unknown Phytosaur
  • D = Coelophysis bauri
  • E = Allosaurus fragilis
  • F = Carcharodontosaurus saharicus
  • G = Gorgosaurus libratus
  • H = Tyrannosaurus rex

This adaptation may have played an important part in the initial radiation and subsequent success of the Theropoda as terrestrial apex predators.  After all, the Theropod body shape and bauplan, especially those teeth, permitted them to dominate terrestrial ecosystems for the best part of 160 million years.

29 07, 2015

Just 48 Hours Left to Enter Everything Dinosaur’s Guidraco Competition

By | July 29th, 2015|Dinosaur Fans, Everything Dinosaur News and Updates, Main Page, Press Releases|0 Comments

Win a 1:4 Scale Flying Reptile Model with Everything Dinosaur (Contest is Closed)

WIN! WIN! WIN! with Everything Dinosaur!  Just 48 hours left to enter Everything Dinosaur’s competition to win an amazing 1:4 scale replica of the Pterosaur called Guidraco.

We have got another super, prehistoric animal replica to win in a fantastic, free to enter contest.  CollectA have already brought out some amazing dinosaur models this year and to celebrate this and the fact that Everything Dinosaur will be 10 years old on August 1st we are holding a special competition, a chance to win a wonderful 1:4 scale replica of a Pterosaur.  CollectA have added to their “Supreme” range of big scale models and the new for 2015 Pterosaur replica (Guidraco), with its moveable, articulated jaw is super and it makes a great prize in our special tenth birthday competition.

Contest to Celebrate Everything Dinosaur’s Tenth Birthday 
Win this 1:4 scale model!

Win this 1:4 scale model of a Guidraco Pterosaur!

Picture Credit: Everything Dinosaur 

Our tenth anniversary prize giveaway is this beautiful Guidraco with an lower articulated jaw.  The replica measures more than twenty-five centimetres in height and more than twenty-six centimetres in length.  Its colouration is based on a modern sea bird, a puffin and our replica needs a name.  What name will you come up with?

To enter Everything Dinosaur’s competition, all you have to do is “Like” Everything Dinosaur’s FACEBOOK page, share, then comment on the picture (either here or on Everything Dinosaur’s Facebook page) don’t forget to include a suggestion for a name for this fabulous flying reptile.

Please note, this competition is now closed.

Everything Dinosaur on FACEBOOK: “LIKE” Our Facebook Page and Enter Competition

For instance, if you believe our Guidraco Pterosaur should be called “Glenda”, then put your comment on our Facebook page or underneath this article in the comments section of this blog!

We will draw the lucky winner at random and the name caption competition closes on Friday, July 31st at midnight.  Good luck to everyone who enters our contest.

Just visit Everything Dinosaur’s Facebook page, give our page a “like” and then leave a comment on the picture showing the Guidraco Pterosaur replica.  What flying reptile names can you think of?

“Like” Everything Dinosaur’s Page on Facebook

Like our Page (please).

Like our Page (please).

 

A Fantastic CollectA Guidraco Replica to Win Thanks to Everything Dinosaur
Just like our Facebook page to enter.

Just like our Facebook page to enter this competition.

Picture Credit: Everything Dinosaur 

To view Everything Dinosaur’s huge range of CollectA prehistoric animals: CollectA Dinosaurs and Other Replicas

To see the full range of CollectA scale prehistoric animal replicas: CollectA Scale Prehistoric Animals

Terms and Conditions of the Everything Dinosaur Tenth Anniversary Contest

Automated entries are not permitted and will be excluded from the draw.

This promotion is in no way sponsored, endorsed or administered by, or associated with, Facebook.

Only one entry per person.

The prize is non-transferable and no cash alternative will be offered.

The Everything Dinosaur tenth anniversary competition runs until midnight on Friday 31st July 2015 (don’t forget the competition closes at midnight on 31st July).

Winner will be notified by private message on Facebook.

Prize includes postage and packing.

For full terms and conditions contact: Contact Everything Dinosaur

Please note, this competition is now closed!

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