Fossil of Baby Ichthyosaur may be Most Complete Specimen Found to Date in Australia
Discovered in an area of Australia known as the “dinosaur trail” due to the number of dinosaur and marine reptile fossils found in that region, an infant Ichthyosaur fossil has got palaeontologists waving their geological hammers in excitement. The fossil, which was actually found in 2011 may represent the most complete specimen of an infant Ichthyosaur ever found on the continent.
Ichthyosaurs are an Order of fast swimming, nektonic, predatory marine reptiles with dolphin-shaped bodies. They evolved in the Early Triassic and finally became extinct during the Late Cretaceous. The fossil was found near the town of Richmond, a location famous for its marine reptile fossils. Scientists examining the fossil believe that they might have ninety-nine percent of the bones of the animal – a rare find indeed as the corpses of small animals such as this creature would have been quickly eaten by larger predators in the Early Cretaceous sea that covered this part of Australia.
A number of Ichthyosaur specimens have been found in the Richmond area over the years, they turn up in some surprising places, such as in a school’s vegetable patch that was being dug over.
To read more about the fossil discovery amongst the vegetables: Ichthyosaurs Amongst the Vegetables
One of the researchers currently examining the fossil material stated:
“There’s so much material that’s never been found, so we’ve never had a really good understanding of what’s happening with Ichthyosaurs, because quite often they’ve all broken up, eaten by other animals, and disintegrated when they’ve been preserved. So for a palaeontologist to find any complete creature, especially a vertebrate creature, that is really special.”
A Model of an Ichthyosaur – Fish Lizard
Picture Credit: Everything Dinosaur
One puzzle is why the specimen is so complete? Scientists believe that parts of the seabed of the shallow ocean that covered much of Australia must have been anoxic (no oxygen present). Very still and calm segments of the water column could have led to tracts of the seabed becoming devoid of oxygen, thus preventing bottom dwelling animals that would have fed on the carcase from being present. The remains of the Ichthyosaur are as they would have been laid out shortly after the animal died, the backbone (made up of vertebrae) is virtually intact as is most of one front paddle. The fossil is slowly being cut out of its limestone block and it is hoped that this specimen will soon be put on display at the nearby Kronosaurus Korner Museum.
The Baby Ichthyosaurus Specimen (in situ)
Picture Credit: Supplied
The picture above shows the less than one metre long specimen. Important parts of the skeleton are labelled (coracoids – shoulder bones), the backbone, ribs etc. The hand brush provides scale to the photograph.
There may also be the fossilised remains of a much larger Ichthyosaurus nearby. Palaeontologists are optimistic that this specimen too may be in an excellent state of preservation.