All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
22 02, 2017

The Half Tonne Rat

By | February 22nd, 2017|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Super-sized Rodent Re-Writes Family Tree

The skull and jaws from a pair of giant rodents, that represent an extinct species that could have weighed as much as half a tonne, are helping to re-shape the rodent family tree.  Study of these new fossils have led researchers to propose a formal revision of the three known species of the genus Isostylomys into just one species, Isostylomys laurillardi.

Isostylomys laurillardi

These are the best-preserved fossils to date of this extinct group, which was previously known only from skull fragments and individual teeth, the scientists report in a new study, published in the “Journal of Systematic Palaeontology”,

The new fossils of the two rodents, an adult and a juvenile, paint a more complete picture of these extinct and massive rat-like animals.  For example, the fossil discoveries raised questions about how these giant rodents were classified within their genus, and hint that several species that were thought to be related may instead be a single species.  The fossils add to our knowledge regarding giant members of the Dinomyidae family and is helping palaeontologists to reappraise the phylogeny of this once diverse and speciose group of South American mammals.

The Giant Miocene Rodent Isostylomys laurillardi (Adult and Juvenile)

Isostylomys laurdillardi a giant prehistoric rodent.

Isostylomys laurillardi (adult and juvenile).

Picture credit: Renzo Vaira/Taylor & Francis

For models and replicas of prehistoric animals: Prehistoric Animal Models and Figures.

Isostylomys laurillardi Fossils from Southern Uruguay

The fossil material comes from the exposed cliffs in the Río de la Plata coastal region of southern Uruguay.  The fossils have been dated to the Miocene Epoch (9.5 to 10 million-years-ago approximately).  The researchers, including lead author, Dr Andres Rinderknecht of the Museo Nacional de Historia Natural (Uruguay), examined the teeth and skulls of fossil specimens, comparing them to the bones and teeth of the largest living rodent the Capybara (Hydrochoerus hydrochaeris).

The research team conclude that, due to similarities in the adult’s and the juvenile’s teeth structure, previously found fossils, which were smaller and thought to belong to a different species, were in fact from the same species.

Skull and Jaw Fossils of Isostylomys laurillardi

Isostylomys laurillardi fossil material (MNHN 2187)

Skull in ventral view (A), skull and mandible in left lateral view (B), and mandible in occlusal view (C).

Picture credit: Taylor & Francis

The picture above shows the adult skull in ventral view seen from underneath, (A), and the skull and jaw viewed from the side (B).  Picture (C) shows the jaw in occlusal view, the scale bar is five centimetres.

Revising the Taxonomy

The authors have consequently proposed that members of the subfamily Gyriabrinae could represent juveniles belonging to other subfamilies of Dinomyidae and that three known species of the genus Isostylomys should be merged into just one species, Isostylomys laurillardi.

Commenting on the team’s conclusions, Dr Rinderknecht stated:

“Our study shows how the world’s largest fossil rodents grow and we describe fossil remains of a giant rodent baby and an adult.  Comparing them we conclude that from very young the giant rodents already were very similar to the adults which allows us to deduce that the great majority of the hypotheses before posed were wrong.  The juvenile and the adult analysed here represent some of the largest rodents known to science with some of these animals weighing almost a ton.”

The Giant Incisor of the Adult Isostylomys

Giant rodent tooth fossil (Isostylomys)

MNHN 2187 the giant lower right incisor of (Isostylomys),

Picture credit: Taylor & Francis

The adult remains found consist of an almost complete skull with a partial jaw, while the juvenile’s remains are of a complete lower jaw and the right calcaneum (heel bone).  Almost all previous discoveries of this kind have consisted of isolated teeth, and small fragments of skulls or jaws, which make this discovery some of the best-preserved remains of giant dinomids known to science.

“Making a Giant Rodent: Cranial Anatomy and Ontogenetic Development in the genus Isostylomys (Mammalia, Hystricognathi, Dinomyidae)”.

By Andrés Rinderknecht, Enrique Bostelmann and Martin Ubilla, published by Taylor and Francis.

The scientific paper: Access the scientific paper here.

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22 02, 2017

A Dinosaur and Fossil Day at Great Wishford Primary School

By | February 22nd, 2017|Early Years Foundation Reception, General Teaching, Key Stage 1/2|Comments Off on A Dinosaur and Fossil Day at Great Wishford Primary School

A Day of Dinosaurs and Fossils

Situated in the heart of rural Wiltshire is the delightful village of Great Wishford.  Many of the rocks used as local building materials were laid down during the Jurassic geological period.  Children at Great Wishford Primary have just started learning about dinosaurs and fossils, quite appropriate really, when the school is situated in a part of the world renowned for its Jurassic marine fossils.  The children are living in their very own “Jurassic Park”.

A Dinosaur and Fossil Day

The children in the mixed Reception and Year 1 class had been challenged to build their own dinosaur over the half-term break.  The models made an excellent display in the classroom.  Lots of different materials had been used in the project, the children (and their grown-up helpers) can be very proud of their efforts.

Half-term Project Building Prehistoric Animal Models

Dinosaur and fossil day at Great Wishford Primary school.

Dinosaur and fossil models on display in a classroom. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Great Preparation for the Next Term Topic

Dinosaur and prehistoric animal figures in the classroom.

An amazing collection of prehistoric animal models made by the children. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Dinosaur Workshops with Year5/6 and Reception/Year 1

The morning was spent working with the children in Upper Key Stage 2.  The focus was on developing the concept of working scientifically, using evidence to formulate ideas and theories.  Our lesson plan had been prepared with the aim of enriching the scheme of work that had been prepared by the dedicated teaching team.

Themes such as extinction, evolution, adaptation and natural selection were covered and the class was given the chance to look at a real palaeontological puzzle as they tried to work out, based on the fossil evidence, what a prehistoric fish had for its dinner!

What Had a Prehistoric Fish Had for its Dinner?

Papo Megalodon model

The Papo Otodus megalodon model in anterior view. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture above shows a Papo prehistoric shark model.

To view the range of Papo prehistoric animal figures: Papo Prehistoric Animal Models.

A Provocation Session

In the afternoon, it was the turn of the Reception and Year 1 children, an opportunity to provide a provocation session to kick-start the dinosaur themed term topic.  The enthusiastic children moved quietly through the forest and employed their super-power when a Tyrannosaurus rex was looking for something to eat.

They learned that most fossils feel cold when you first touch them and that some fossils can be big or even massive!  Over the course of the day we proposed a series of age-appropriate extension activities to help support the well-crated term topic plans of the teaching team.  The children in Year 5/6 were challenged to research the story of the Coelacanth and to look at the evidence that helps support the theory that the dinosaurs are not actually extinct.  The mixed Reception and Year 1 class were challenged to have a go a drawing their very own dinosaur, but they had to label the body parts including the skull.

A Scale Drawing of a Coelacanth

Scale drawing of a Coelacanth. What is a Coelacanth?

A scale drawing of a Coelacanth.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The well-organised and tidy classrooms were most impressive and the care and attention the school staff had taken to create exciting and rewarding learning environments was clearly evident.  Lots of different activities supporting the learning needs of the children had been prepared.  For example, in the Reception/Year 1 classroom the outline of a long-necked dinosaur (Sauropoda) had been created on the floor using masking tape.  The dinosaur’s tail stuck out into the corridor!  This simple exercise can help children to appreciate just how big some dinosaurs were as well as helping to reinforce differences between ourselves and animals.

Visit Everything Dinosaur’s website: Everything Dinosaur.

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