Microscopy technology at The University of Western Australia that enabled an international team of researchers to locate ancient DNA in fossilised egg-shells for the first time has paleontologists around the world crowing.
The extraction of ancient DNA from the heaviest bird that ever existed, the extinct elephant bird, and other big birds such as thunderbirds, different species of moas, dabbling ducks, emus and owls, will help scientists learn more about how diets have changed over time in response to environmental shifts.
Associate Professor Paul Rigby from UWA's Centre for Microscopy, Characterisation and Analysis located the DNA in the eggshells that were up to 19,000 years old by applying a nucleic acid stain to the shell fragments and then imaging them under an ultra-violet confocal microscope.
Assoc/Professor Rigby was part of a team led by Murdoch University paleontologist Dr Mike Bunce and PhD student Charlotte Oskam. Other members were from the UK, Denmark, New Zealand, and the US. The eggshells of the ancient megafauna were collected from sites in Australia, New Zealand and Madagascar.
The team's work, published in Proceedings of the Royal Society B, was possible because fossilised eggshell has 125 times less bacterial load than fossilised bone, making it a highly suitable material for analysis. It is also structured differently from bone, leaving its original organic constituents intact.
Until this project, paleontologists had relied on bone, tissue, hair, nails, coprolites and feathers for DNA extraction. New methods including the UWA microscopy enabled the team to extract important information about the different birds from even powdered fossilised eggshells found in hostile environments.