Anglesea amber reveals Australia’s prehistoric past

A SCIENTIFIC analysis of fossilised tree resin from Anglesea has caused a rethink of Australia’s prehistoric ecosystem.

Deakin Institute for Frontier Materials (IFM) and Monash University researchers used nuclear magnetic resonance to investigate the make-up of 50-million-year-old amber samples recovered from sites in Anglesea and Strahan, Tasmania.

IFM senior lecturer in magnetic resonance Dr Luke O’Dell said the amber captured a period in time during the Eocene Epoch (56 to 33.9 million years ago) and was “an unparalleled method of preservation, providing insights into past organisms, ecosystems and environments”.

Also called resinite or fossilised resin, amber is organic material created through the fossilisation of the resins of seed plants.

“Our collaboration aimed to identify the original plant sources of amber at Anglesea and Strahan and to establish the way they degraded during their tens of millions of years underground,” Dr O’Dell said

“This degradation could potentially have a major impact on the preserved palaeobiological information contained within the samples, and the sort of information we can recover about Earth’s ancient past.”

By grinding the amber into a fine powder and using magnets to measure how each sample absorbed and re-emitted electromagnetic radiation, Dr O’Dell was able to probe the physical and chemical properties of the amber and identify distinct botanical sources.

The study’s lead author, Monash School of Earth, Atmosphere and Environment honours student Andrew Coward, said amber could be separated into different classes based on which plants it came from.

He said the discovery of Class II amber from the Anglesea site could mean certain prehistoric plants capable of producing cardinene-based amber were native to Australia during the Eocene period, which has previously been unproven due to their absence from the fossil record.

Co-researcher Associate Professor Jeffrey Stilwell said the discovery was even more significant due to Australia’s sparse amber record, with the largest known deposits being roughly up to 23 million years old.