About 360-70 million years ago in a time known as the Devonian Period, thousands of strange-looking armoured fish perished in a freshwater lake or billabong as it dried up during a severe drought. The whole fish population, adults and juveniles alike, were tightly concentrated in a small area. They were then rapidly covered with sediment that later hardened to rock, preserving them for posterity.
Today that same rock preserves and provides evidence of the mass kill event that took place all those millions of years ago, during what is now known as the 'Age of Fishes'.
Canowindra's unique fossil fish deposit was discovered by chance in 1955, when a council road worker, who was grading an unsealed road between Canowindra and Gooloogong in central west New South Wales, turned over a large rock slab with strange impressions on its under surface. He pushed the slab aside to the fence line, where it was later spotted by a local bee-keeper who recognised its importance and notified the Australian Museum in Sydney. Expert examination of the slab later confirmed it to be one of the most remarkable discoveries of its kind anywhere in the world.
In January 1993, after a 20 year search, an exploratory dig led by Dr Alex Ritchie (right), palaeontologist at the Australian Museum, rediscovered the source of the 1955 fossil fish slab. In July 1993, with local community support and with earth moving equipment provided by Cabonne Shire Council, Alex Ritchie supervised a 10-day major excavation of this world-class fossil fish site.
The finds exceeded all expectations and some 70-80 tonnes of rock slabs, containing around 4,000 fish specimens were recovered from the Canowindra site. Many thousands of complete fish specimens still remain buried at the original site, awaiting excavation. These could well include other animals new to science and possibly even the skeletal remains of some of the earliest known amphibians, our distant ancestors - an exciting prospect!
Life in the Devonian
The Canowindra fauna was dominated by two kinds of strange armoured (or placoderm) fishes, Bothriolepis and Remigolepis, which belong to a long-extinct placoderm group called the antiarchs. A third, less common, armoured fish known as Groenlandaspis belonged to another placoderm group called arthrodires.
The largest fishes found at Canowindra belong to the air-breathing, lobe-finned sarcopterygians, which included the ancestors of the first vertebrates to invade dry land, amphibians. The larger sarcopterygians from Canowindra have been named after local towns, councils and localities- Canowindra grossi, Mandageria fairfaxi, Cabonnichthys burnsi and Gooloogongia loomesi.