Travelling Australia - Journal 2012
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15 March 2012 - Age of Fishes Museum, Canowindra
Age of Fishes Museum
The Age of Fishes Museum in Canowindra.


The Age of Fishes Museum at Canowindra displays slabs of sandstone containing thousands of fossilised fishes which died about 360 million years ago when a waterhole or lake suddenly dried up. The dead fish were soon covered by sediment which, during millions of years, turned into sandstone deep underground. Normal processes of uplift and erosion eventually deposited the sandstone near the surface.

The sandstone rocks containing the fossilised fish were unearthed during road construction near Canowindra in 1956. A bulldozer driver saw unusual marks on sandstone, put a large piece aside, and continued road building. The sandstone slab was later reported to the Australian Museum simply as a rock containing something unusual which looked like it might be a reptile fossil. Staff from the Museum recognised the fossils as fish and the slab was moved to the Museum in Sydney where it was put on display but the contents were not analysed. The road construction project continued and the spot the rock had been found became unidentifiable.

Many years later, Dr Alex Ritchie, then palaeontologist at the Australian Museum, began searching for the forgotten site of the fossils. The local shire provided assistance in the form of excavation machinery and the sandstone deposit was re-located in a test pit in January 1993. A major excavation in July 1993 recovered 70 tonnes of rock slabs containing about 3,000 fossil fish specimens. There was such a large number of specimens recovered that the decision was made to leave the fossils in Canowindra to form the basis of a local specialised museum.

The museum was called the "Age of Fishes Museum" because the fossils date from the Late Devonian period. The Devonian period (416 to 360 million years ago) is known as the Age of Fishes because of the number and variety of fish species which evolved then and because of the number of fish existing.

While the purpose-built museum was built (1995-1998) the specimens were set up a temporary museum in the vacant Court House. Stage One of the Museum was completed in late 1998 and officially dedicated in 1999. Stage Two was completed in March 2001.

The Museum employs three staff, a Manager, Public Programs Manager and an Exhibition Office. More than two dozen volunteers assist with the daily operation of the Museum and act as tour guides.

In the main part of the museum slabs of sandstone are laid out at low level with many magnifying lenses available for visitors who want to examine the fossils in detail. Information on several species, either very common, or very rare, or very well preserved, is presented. There is often an artists impression of what the fish looked like in life, sometimes there is a three-dimensional model with information on how the fish is thought to have lived. A personal audio tour guide is available free-of-charge to visitors. This invaluable aid provides a mass of useful, and interesting, information for each display. Numbers on each display, visible in some photographs, are pressed to listen to the guide for that item.

Age of Fishes Museum, Canowindra - page 2
Inside Age of Fishes Museum
Inside the Age of Fishes Museum in Canowindra. Slabs of rock containing fossils are laid out on low stands, often with the positive moulds alongside. More slabs are resting against the walls.


The Fossils
When the fossils formed, the fish decomposed under a layer of sediment leaving an impression of their bodies, sometimes complete with scales, in the sediment. The sediment turned into sandstone while retaining the original impression of the dead fish so that sandstone slabs taken out of the ground contain moulds (or negative impressions) of the original fish bodies which are not easy to recognise. But casts (positives) made from the impressions are readily recognised and are on display in the museum alongside copies of the original sandstone.

Preparation The reddish material is the cast recognisable as the head of a fish. This cast was made from the irregular hole in the original sandstone slab immediately to the right of the head; this hole is the mould left when the fish head decomposed. The magnifying lenses allow visitors to examine the sandstone slabs in detail.



Species
The Canowindra fossil fish deposits include a contrasting range of species. Of the more than 3,500 fish so far identified, 97% are two armoured fish species Bothriolepis yeungae and Remigolepis walkeri with more than 1,500 specimens of each found so far in Canowindra rocks. Bothriolepis and Remigolepis have both been found in many other sites around the world. Bothriolepis was particularly widespread and has been found in numbers in every continent. These armoured fish (known as Placoderms) had bodies enclosed in bony plates protecting them from carnivores. Eyes and nose were close together at the front, the mouths were underneath. They are believed to have been bottom feeders and to have concentrated in shallow waters.
Age of Fishes Museum, Canowindra - page 3
Armoured fish Typical selection of the several thousand armoured fish fossils in the Canowindra deposits. This is a photograph of part of the mould taken from the original sandstone slab.

Armoured fish Reconstruction of Bothriolepis yeungae showing the bony armoured shell surrounding the body with the fleshy tail extending behind. The fins were also enclosed in bony plates and there has been considerable speculation about possible uses for these stiff fins.



Canowindra grossi
Unlike the thousands of specimens of the armoured fishes, the Age of Fishes holds a single example of Canowindra grossi, which was found in the original sandstone slab excavated during road-works in 1956. This is the only specimen of this species at Canowindra and is not found anywhere in the world. Canowindra grossi has been adopted by the Age Of Fishes Museum as its logo and appears on letterheads and on the name board outside the museum building.

Canowindra grossi fossil Fossilised Canowindra grossi in the original sandstone slab recovered in 1956. The fish is in the top centre of the photograph.

Age of Fishes Museum, Canowindra - page 4
Canowindra grossi Reconstruction of Canowindra grossi. The fish is estimated as 50 cm long. This reconstruction is based on the compressed body of the fish and much of the body and fin shape has been estimated after reference to related species; these interpretations change with new research results. In this model the nose is blunter than in the Age of Fishes logo.

Canowindra grossi is described as a "lobe-finned fish". The scales are reinforced by bone and the fish was able to breathe air through a nasal system as well as taking up oxygen from the water via the gills.

Several other species of fish identified at Canowindra are mentioned on the Age Of Fishes web site (at www.ageoffishes.org.au/)


TimeLine Panels
A grassy area behind the museum building has been set aside for a useful series of display panels set along a footpath. These panels consecutively describe each geological/paleontological period in the Earth's history including a brief description of life in that era with a map showing Australia's position in the world then. Additional sections on the panels show typical life forms of that era and a table showing the era sequence of and the duration of each.

The display panels are useful for putting Australian fossil sites into context. Whether dealing with stromatolites in Western Australia, ichthyosaurus and dinosaurs in Central Queensland, or fish in Canowindra, this succession of informative panels is invaluable.

Era Panel Informative panel for the Silurian Period (before the Devonian Age of Fishes).



The Future
The main excavation in 1993 recovered 70 tonnes of fossil-bearing sandstone but many tons of rock could not be recovered and remain in place, now under the road.

The over-riding long-term goal of the Age Of Fishes Museum is to recover the rest of the fossil-bearing sandstone which has been so productive. This will require re-routing the road and the scale of the project cannot be underestimated. But several years ago building the museum would have been viewed as a near-impossibility yet it is now a fact so who can tell what the future holds?

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