Fish Fish

There was a vast range of fish living 100 million years ago in the inland sea.  Many of these fish have not yet been scientifically studied. Below is information on three identified species.

Cooyoo Cooyoo
The Cooyoo was a large predatory fish that grew up to 1.1m in length. An almost complete skull, vertebral column and the upper part of the tail fin of a small Cooyoo are preserved in the centre. It had an array of small pointed teeth. Cooyoo means "fish" in the language spoken by the Jarambali who lived in the Upper Flinders, Hughenden and Dutton River districts.
Richmondichthys Richmondichthys

The elongated body of Richmondichthys was covered in large thick scales to help protect it from predators.  These scales were covered in ridges of bony material to add strength.  Small scales along the top and bottom aided flexibility. 

Richmondichthys was the largest known member of an extinct family of armoured fish and grew to over 1.6m in length. It had an elongated, toothless jaw and a system of fine filaments in its gills, indicating that it was probably a filter feeder that strained plankton from the water much like some modern whales.
 
Although fossils of this fish have been collected since 1872. it was only recognised as a new type in 2004 and named Richmondchthys (Richmond Fish) after the local region.
Pachyrhizodus marathonensis Pachyrhizodus marathonensis

Dr Alan Bartholomai formerly with Queensland Museum offers the following description of a fish specimen discovered 12km north of Richmond in August 2008. (pictured above)

It is a pachyrhizodontoid teleost, Pachyrhizodus marathonensis.  It is by far and away the most complete specimen I have seen anywhere, even without the fossilized gut contents.  Age of the specimen is the same as other Toolebuc/Allaru Formation species viz.latest mid to late Albian (Lower Cretaceous) based on dinoflagellate zonation and spore-pollen analyses from elsewhere in the Basin.