Identifying fossils

Identifying fossils can be a complex and involved process. Fossil plants, animals and other organisms show as much variation as do all the living forms of life. Fossil identification can be a challenging task.

It is first essential that you recognise that you have a fossil, not just a pseudofossil or a fortuitously shaped rock. To understand this it is essential to identify what type of preservation is present in your fossil. For more information please download our pseudofossils fact sheet.


Bones are only rarely preserved as anything but the original bone in filled with minerals such as clays or rock cements. Bones generally have an outer compact zone and an inner spongiose zone. Fossilised bones tend to be heavier than the bones from recently dead animals as they are filled with minerals in a process known as permineralisation.

Many ancient invertebrate animals possessed a skeleton which readily preserves as a fossil. In rocks of marine origin, fossils can be very common. Shells of molluscs and some other marine creatures are made of calcium carbonate and preserve in tact within the rock. Often the shells dissolve, leaving a space in the rock, creating a mould.

Fossil plants either preserve by petrification, that is replacement by silicon dioxide, or are compressed to a thin carbon film or impression. A common misidentification is that of dendrites which can be mistaken for fern fronds.

A useful staring point for any fossil is a general picture index book on fossils. Most of these are published in the northern hemisphere and will not contain many, if any, Australian fossils. The book should however identify the general type of fossil organism. To go further than this it will be necessary to examine specific books and scientific literature on Australian fossils. Much of this information will not be readily available.

An easy way to have your fossil identified is to bring it to the Inquiry Centre, or send a photograph for identification. Our staff have access to a vast amount of information on most fossil groups and can generally assist.

Queensland Museum's Find out about... is proudly supported by the Thyne Reid Foundation and the Tim Fairfax Family Foundation.