Amazing Cretaceous Bony Fish Preserved in Flint

For a local Kent resident the habit of picking up unusual objects to place in his rockery at home has enabled scientists to get to grips with a rare example of a fossilised Cretaceous fish.

The stone shaped fish head was spotted by Peter Parvin and his wife whilst they beach-combed on a caravan holiday to Pevensey in East Sussex in 1993.  Found amongst the pebbles as the tide was going out, Mr Parvin thought nothing of his find, simply placing it amongst the other curiosities he had collected in this rockery.  However, a chance conversation with a volunteer from Maidstone museum in a pub, led to him bringing this rare, ancient relic to the museum for closer examination.

Fossil Fish

The fish head fossil measures approximately 15 cm across, it is shown in the photograph facing to the right of the screen.  The eye, mouth and shape of the gills can clearly be seen.

“I have never seen one of these before”, commented Dr Ed Jarzembowski, the Keeper of Natural History at Maidstone Museum.  “Quite simply it’s priceless”.

In contrast with most fossils found from this period (which are associated with chalk), the fish head has been preserved in flint, this makes it particularly rare and valuable.  The hard flint would have helped maintain the quality of preservation, even as this stone was bumped and bashed on the shoreline of Pevensey beach.

Found on Pevensey Beach

The fish has been dated to around 80 million years ago (Late Cretaceous) and is a representative of the modern bony fish group the Teleosts.  This type of fish, with its streamlined fins, highly manoeuvrable body and ability to open its jaws wider than other more primitive fish forms evolved from the Acanthodian fishes.  Bony fish dominate the world’s freshwater and oceans with a greater diversity of animals at the taxonomic level of Family than any other group of vertebrates.

During the Late Cretaceous, most of the UK was covered with a warm, shallow tropical sea.  These seas swarmed with life and there are a number of common fossils associated with flint nodules.  Sponges are often found in association with flint nodules.  Flint occurs as extremely hard nodes in chalk deposits.  It is formed by chemical reactions within the chalk sediments and it is composed of silica in the form of microscopic quartz crystals.

The silica came mainly from the exoskeletons of dead sea sponges (these are made of silica), and they were subject to dissolving into solution under the alkaline environment of the chalk deposits.  The silica tended to re-solidify if it encountered local acidic conditions such as the acidic conditions surrounding decaying organic material such as this fish head.  This may help to explain how this fish head fossil was formed.

There are plans to put the fish head on display at the local museum, although it may be ultimately sold in order to help raise funds for the museum’s development.

Everything Dinosaur stocks a range of prehistoric fish figures including prehistoric sharks and Dunkleosteus.

To view the models in stock: Dinosaur and Prehistoric Animal Models.

Scientists Discover Remains of Juvenile Tarbosaurus

A joint Japanese and Mongolian expedition have successfully recovered a nearly complete skeleton of a young dinosaur, a relative of the monstrous Tyrannosaurus rex.  This rare and important find will enable palaeontologists to better understand how Theropod dinosaurs grew and developed.

Juvenile Tarbosaurus

The dinosaur, a Tarbosaurus (Tarbosaurus bataar) is a juvenile and the skeleton is nearly complete, all that is missing are some neck vertebrae and a few bones from the tip of the tail.  Tarbosaurus was a member of the Tyrannosauridae and this creature is the largest known predator from Asia.  Associated with the very end of the Cretaceous, just like its North American cousin T. rex (Maastrichtian faunal stage), this fierce carnivore grew up to 12 metres in length.  Although known for at least sixty years, scientists still debate whether Tarbosaurus is sufficiently different from Tyrannosaurus rex to be regarded as a distinctive genus.  The fossils found to date (there are more Tarbosaurus remains to study than its more famous relative T. rex), indicate that these two animals were very similar.  There are minor differences in skull morphology, with Tarbosaurus having a proportionately larger head but a shallower snout and less powerfully built lower jaw.  Some scientists claim that Tarbosaurus was more lightly built than Tyrannosaurus rex, perhaps the result of the slightly different ecosystem in Mongolia and China compared to Late Cretaceous western North America.  A more agile, gracile predator Tarbosaurus may have specialised in tackling lighter prey animals.

PNSO Prehistoric Dinosaur Models: 51 Chuanzi the Tarbosaurus.

The picture (above) shows a replica of a Tarbosaurus in the PNSO Age of Dinosaurs range.

To view this range of figures: PNSO Age of Dinosaurs Models and Figures.

The joint Mongolian/Japanese expedition, made up of scientists from the Mongolian Academy of Scientists and the Hayashibara Museum of Natural Sciences in Japan first found the fossilised remains of this dinosaur in August 2006.  The skeleton was encased in a block of sandstone and it has taken nearly two years of careful, patience preparation to extract this young dinosaur from its rock tomb.

Commenting on the completeness of the fossil, Takuji Yokoyama, a spokesperson for the Hayashibara Museum stated:

“We were so lucky to have found remains that turned out to be a complete set of all the important parts”.

Fossilised Skeletons

Fossilised skeletons of young dinosaurs are extremely rare and the discovery of such a well-preserved and complete specimen is an exceptional find.  The bones of juveniles, being lighter than adults are often scattered and broken up or destroyed by weathering on the surface.  The corpse of a young dinosaur would have been attractive to any passing scavenger and many remains would have been devoured leaving little chance of fossilisation for the fragments that are left over.  This fossil was probably covered very soon after death and this has led to the preservation of over 95% of the bones.

The latest discovery from the Gobi desert will help provide more information on the ontogeny of dinosaurs (growth rates and development).  The animal was over 2 metres long when it died and it is believed to have been around the age of 5.  It has not been possible to determine the gender, but had this dinosaur lived to reach adulthood it would have been the top predator of the area and may have exceeded 12 metres in length.