Australasian Science: Australia's authority on science since 1938

Fossil Treasures in Urban Australia

By John Long

Our biggest cities remain great places to search for fossils. Here are some tips about where to start looking.

In mid-November our team of palae­ontologists were air-lifted in by helicopter to do fieldwork along the Genoa River in east Gippsland. It was a tough week, walking up and down the river to access outcrops of exposed rock, but it’s all part and parcel of the fossil research game.

While many fossils sites like this one are located in remote wilderness environments, and take a great deal of logistical planning to access, some fossil sites could be located right near where you live. Luckily, our two biggest cities, Sydney and Melbourne, are built upon fossiliferous sedimentary rocks that yield some extra­ordinary fossils from time to time. You just need know where to look, and how to recognise a good fossil.

Growing up in Melbourne I became interested in fossils at the age of 7. My first collecting trip was to an abandoned quarry near Lilydale to find marine fossils of Devonian age. Although this quarry is now filled in, and no longer accessible, several of Melbourne’s suburbs are home to good sites where anyone can collect excellent examples of fossils of various ages.

For example, along the Yarra River, just opposite the Studley Park Rd bridge, is an outcrop of shale where lower Silurian graptolites can be found. These represent the chitinous or collagenous tubes that small colonial creatures called pterobrachs once lived, floating around the ancient seas filtering their food from the seawater. They are useful fossils for dating the Early Palaeozoic rocks around Victoria, especially in the goldfields areas where they are commonly found in the Ordovician black shales.

The jewel in the crown of Melbourne suburban palaeontology is Beaumaris beach, where the 5–7 million-year-old marine exposures have yielded many kinds of fossil invertebrates, sharks teeth, fossil whales, dolphins, seals, sea birds and even land mammal remains that got swept into the ancient sea. Beaumaris is a real treasure that needs be carefully protected against possible future developments to allow both researchers and members of the public access to its diverse fossil bounty.

The greater Sydney area is built largely on Triassic age sedimentary rocks about 250–200 million years old, that give it its distinct sandstone terraces exposed at some of its beaches. These rocks largely represent continental deposits formed in rivers and lakes. Quarries at St Peters, Brookvale and Somersby have produced a great variety of beautiful complete fossil fishes, giant amphibians called labyrinthodonts, and the remains of a variety of plants, especially seed ferns and conifers. The complete 3-metre skeleton of the amphibian Paracyclotosaurus davidi was found in the brick pits at St Peters about 70 years ago.

Even today, road outcrops or exposures from old quarries continue to yield good fossil specimens. In fact, wherever Triassic rocks are exposed one can search for fossils. The best finds can be found in lag deposits that represents a stream channel, or in an ancient lake deposit characterised by well-laminated layered rocks.

Ask your local museum or geological survey for information about what sites might be located close to your home. Just make sure you have the owner’s permission if the site is on private land or an abandoned quarry, and that collecting is permitted for public areas. National parks are not allowed for hobby collectors, as a research permit is required.

Happy hunting!

John Long is Strategic Professor in Palaeontology at Flinders University, and is current President of the Society of Vertebrate Paleontology.