A chance discovery by a roadworker in 1956 has led, 37 years later, to one of the world’s great fossil discoveries in central New South Wales.
The fossil site was discovered during the grading of an unsealed road between Canowindra and Gooloogong, in central west New South Wales when a bulldozer overturned a large rock slab with strange impressions on its undersurface. The slab was pushed aside and saved, and the Australian Museum in Sydney was informed.
Mr. Harold Fletcher, the Museum’s palaeontologist and Dr. Ted Rayner, New South Wales Mines Department, visited the site. The original fossil slab, one of the most remarkable discoveries ever made in Australia, was removed to Sydney where, since 1966, it has been on display in the Australian Museum. It reveals dramatic evidence of a mass-kill event around 360 million years ago, in Late Devonian times (the so-called ‘Age of Fishes’).
The original Canowindra slab, 2 metres by 1 metre, carried the detailed impressions of more than 100 Late Devonian fishes, most of them complete. Four types of fish were present. Two strange, long-extinct, armoured fishes Bothriolepis and Remigolepis dominated the fauna; a third armoured fish, Groenlandaspis, was very rare. Also present was one beautifully preserved specimen of an air-breathing, lobe-finned fish later described and named Canowindra grossi, after the nearest town and a famous German palaeontologist.
By the time the original slab was recovered, the road and its margins were graded and the exact position of the fossil layer was lost. During the 1970′s and 80′s Dr Alex Ritchie, Australian Museum palaeontologist, visited Canowindra several times trying to relocate the fish layer, without success. Heavy earth-moving equipment was clearly required but funds were not available.
In September 1992, Dr Ritchie gave a talk to Canowindra Rotary on the “Great Canwindra Fish-Kill”, stimulating local interest in the site and its potential. In January, 1993 Cabonne Shire Council offered the use of earth-moving equipment and a trial dig was carried out on the site.
In less than 3 hours the fish layer was relocated and traced for 20 metres clear of the road. The remarkable abundance of fossil fishes was maintained throughout this length, demonstrating the enormous potential of the site, the presence of thousands of superbly preserved complete fish specimens and the likelihood of remarkable new discoveries. This was confirmed by the recovery of parts of two very large, lobe-finned fishes which must have been about 1.5m long when alive. Plans were then made for a major excavation of the site and, from 12th to 22nd July, 1993, the Canowindra fish site was excavated using the same Council excavator and driver, Fred Fewings. It also received full support of the Canowindra community – business people, farmers, lorry drivers, teachers, students, local residents and others.
Results exceeded expectations! Some 70 tonnes of fossil slabs were recovered, sone weighing more than 2 tonnes! The slabs, now stored undercover in Canowindra Showground on 100 pallets, contain around 3000 fish specimens. Almost all are complete and they represent at least 6 species, some new to science. Initial cleaning (hosing and scrubbing) of the fossils was carried out by senior pupils from Canowindra High School (30 students, Years 11/12) and Canowindra Catholic School (7 students, Year 10).
As suspected, the Canowindra fauna is dominated by two types of armoured fishes Bothriolepis and Remigolepis. Some 20 complete specimens of another armoured fish, Groenlandaspis, were also recovered. Three or tour types of lobe-finned fishes were also present, up to 1.6 metres long, with their head regions preserved in three dimensions.
The recovery of these remarkable fossils is only the last link in a unique chain of unusual events which began about 360 million years ago when a large lake or river, with tens of thousands of fishes living in it, dried up during a severe drought. The fish, tightly concentrated in a small area, were rapidly but gently covered with sand soon after death and before they broke up.
Buried deep underground, the sand turned to rock until, some 360 million years later, this unique evidence of a long-forgotten mass-kill event was brought to the surface again by natural erosion. This happened just at the exact point where a country road intersected the fossil layer, which was thus spotted by a sharp-eyed bulldozer driver and saved for posterity. One wonders how many other such finds are never seen or reported, and are lost to science.
All the new finds will remain in Canowindra, to form the basis of a unique, local ‘Age of Fishes’ museum. A committee of local residents and Cabonne Council representatives is currently drawing up plans for this museum and seeking both government funding and private sponsorship.
FISHES’ MUSEUM
The centrepiece of Canowindra’s new museum will be a realistic reconstruction of part of the original pool (8m x 4m) displaying around 1000 fishes, lying in the positions in which they died and were buried, 360 million years ago. Shown nearby will be life-size models of the same fishes in an ‘underwater’ setting.
The displays will include original Canowindra ‘touch’ slabs; Devonian fossil fish from other parts of Australia, Antarctica and Northern Hemisphere sites, for comparison; superb fossil fish specimens from other world-famous sites (U.S.A., Germany, Italy, Brazil and Lebanon) and from different geological periods to illustrate the history of fishes throughout time.
Canowindra’s ‘AGE OF FISHES’ museum will be a combined research, educational and tourist centre and a base for future research work in central west New South Wales, where visitors can watch Canowindra slabs being prepared, moulded and cast for research and display.
The Canowindra Project has developed in exciting, unexpected directions and will include three complementary attractions, all based on fossil fish, but in different ways; an ‘AGE OF FISHES’ museum in Canowindra, an on-site display at original locality and a ‘hands-on’ fossil fish collecting site near Canowindra
The original plan to fill in and landscape the main site on the Goolagong road was scrapped when the undersurface of the main fish bed was discovered to retain superb impressions of hundreds of fish, small and large, including some complete fish up to 1.6m long! This caused a quick change of plans – the lower fish layer was temporarily covered with heavy duty plastic, hay and several metres of soil and rock. When funding is available the original site will be re-opened and roofed to form a unique, on-site exhibit where visitors can see and admire, first-hand, the original surface on which the Great Canowindra Devonian Fish-Kill took place!
Much of central west New South Wales (around Canowindra, Grenfell, Cowra, Forbes and Parkes) is underlain by Devonian rocks, with potential for new fossil finds. This has been dramatically confirmed recently by the discovery of yet another Late Devonian fossil fish site, 20 km southwest of Canowindra.
The new site, a quarry on private land near the main Cowra-Forbes road, cuts through and exposes a 10 metre thick, black shale deposit. Fossil fish occur throughout the shale and almost every specimen is complete. They provide a complete growth series, from juvenile to adult, of yet another type of Late Devonian armoured fish.
This new site, now fenced and secured, presents a unique opportunity for a long-term systematic excavation programme and for a unique hands-on, fossil-finding experience. Scientific investigation of the site will take years of work. Excavation and collecting is being carried out by organised groups (university, school, natural history clubs, general public, etc.) working under supervision. Everyone taking part experiences the thrill of actually splitting rock and finding a fossil fish.
However, at present, all fossil specimens recovered from both sites are being retained for scientific study and analysis, but replicas of the finest specimens will be eventually be produced for sale.
Canowindra’s ‘AGE OF FISHES’ museum, plus an on-site display, and a fossil-collecting site in the same general area, will thus provide a unique set of three complementary natural attractions, all based on major local fossil discoveries, with enormous potential benefits for tourism, education and science.
Meanwhile, anyone wanting to participate in Canowindra’s ‘Age of Fishes’ Project can do so by joining in a regular monthly working weekend, supervised by Dr. Alex Ritchie, or one of his colleagues. Profits go to the “Age of Fishes Museum” Fund.
Information about dates, details and costs is available from Monica Yeung, Gondwana Dreaming Earth Science Tours, P.O. Box 3017,Weston, A.C.T. 2611 or tel/fax (06) 285-1872.
Author:
Dr Alex Ritchie
Palaeontologist, Australian Museum
