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 FAQsFossils
How easy is it to identify a fossil?Many fossils are found as fragments which can make them harder to identify. It is important to know the locality where the fossil was found - a reference to the geology of the area on, for example, a geological map provides information on the age of the rocks and hence the type of fossil to be expected. It can be useful to learn the characteristics of common fossils such as brachiopods, gastropods, ammonites and trilobites, using textbooks and field guides that are available in your local library or from most large bookstores. You can also look at our fact sheet:
Some characteristics of common fossils:
When are 'fossils' not fossils?Some examples of natural geological formations that may be mistaken for fossils are concretions. These are rhythmic deposits of iron around a node/core that may be organic eg root of a tree and dendrites, that can resemble leaves but are of a mineralogical origin. Common perceptions of what a fossil is and what it should look like are often a long way from the reality. Often we have a "it looks like something therefore it is" mindset, and it can sometimes be very difficult to convince someone that their valued specimen is not what it appears to be and that it may not be of great value. However, many of these mineral formations are just as interesting as fossils. The following fact sheet explores some of these formations:
What are opalised fossils?Opalised fossils have had some of their structure replaced with opal. The opalisation is more recent than the processes that originally created the fossils and usually occurred in the Tertiary Period, about 45-50 million years ago. Opalised shells from Coober Pedy are the most common Australian opalised fossils. Lightning Ridge yields vertebrate fossils including plesiosaur teeth. The Australian Museum has several examples, including Eric, the opalised pliosaur. What are some common local fossils in and around Sydney?These will usually be Triassic plants (eg Dicrodium ferns or Phyllotheca horsetails), Permian plants (in Permian coal measures, Glossopteris is very common) or Permian marine invertebrates (gastropods, crinoids, bryozoa etc). Permian fossil invertebrates are found in an arc from Wollongong through Lithgow to Newcastle. In central New South Wales, marine invertebrates are common. If vertebrate fossils such as fish and amphibians are found, they should be referred to Palaeontology staff, as they may be of interest to the Museum. For more information, look at the fact sheet Common Fossils of the Sydney Region. Where can I go on a fossil dig?Some useful contacts for fossil digs include:
Where can I find fossils?There is no comprehensive list of fossil sites for you to visit in Australia. However, there are some museums that display fossils from nearby localities. Contact these museums before you visit for information about sites that you can visit around the local area. Remember you can fossick in many areas, but you must always ask permission if the area you intend to visit is on private property.
See also Where can I go on a fossil dig? The Dinosaur Club is designed for kids who are interested in dinosaurs. The Sydney contact is c/o the Australian Museum Dinosaur Club on 9320 6000 or 9320 6072. Links
Useful References
What are the laws governing the ownership of fossils?
Responsible fossil collecting involves some simple discretion on the part of the collector:
I have found some bones. Are they fossils?Bones that are dug up from the ground may not always be fossilised.
The Australian megafauna became extinct within last 20,000 years and were reasonably common in New South Wales. Their fossils are most easily identified by the size of long bones and by the teeth. Skulls and jaws with teeth should be referred to Palaeontology staff if they can't be identified as recent bones. A comparison with the bones of domestic and native animals can be helpful. Marsupials have distinctive premolars that are virtually species-specific. search & discover at the Australian Museum has a wide range of bones from commonly found species, as well as identification guides. Does the museum buy fossils?We only purchase fossils that we determine would improve our collection. Specimens we do purchase have to be scientifically important or of an exceptional quality. Does the museum value fossils?We have a policy of not valuing fossils for the public other than informing them that their specimen is of little or no value or that it is worth what they can get someone to pay for it. Opal dealers may value opalised fossils. Can you identify fossils from countries other than Australia?Overseas fossils can be difficult to identify but there are also some very common ones that surface quite regularly eg Brazilian Cretaceous fish and trilobites or ammonoids and orthocone nautiloids from Morocco. Fossils from Brazil may have been illegally exported - CITES legislation covers this activity. Also, fossils from other states in Australia can be referred to the museum in the state where it was found. Can you identify fossils over the phone?No. Palaeontology staff need to see at least a good photograph with scale included before we can attempt an identification. How do you clean fossils?Each individual fossil needs to be assessed separately as the chemical composition of the fossil itself and the surrounding rock will influence how the fossil should be cleaned. There are some books that may help or you can contact a private conservator. Fossils should not be coated, nor should they be constantly handled. Based on text by Robert Jones, Palaeontology. 25/10/94
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