The Skeleton in the Closet
A large fossil pelvis and seven attached vertebrae were discovered decades ago hanging in an old locker in the Australian Museum. Nothing is known about these bones except that they belong to a moa, a large, extinct flightless bird that was unique to New Zealand. There were nine species of moa, ranging in weight from 12 to 250 kg. What species of moa did these bones come from? We did a bit of detective work to find out.
We began by studying the morphology of the mysterious fossil and compared it with moa specimens in the Museum’s palaeontology collection. This allowed us to narrow down the fossil’s identity to one of the three species in the moa genus Pachyornis.
Based on the dark sediment that had been stuck to the fossil, we could tell that the moa came from a swampy environment. We used X-ray diffraction to find out what minerals were present in the sediment. This revealed the presence of the mineral mica, which is typical of moa fossil sites on the South Island of New Zealand.
Together, all of these pieces of evidence suggest that the fossil is from a Heavy-footed Moa (Pachyornis elephantopus). This was one of the largest species of moa, weighing up to 163 kg, and went extinct about 500 to 600 years ago.
After hanging in a locker for many years, the moa fossil has now found a new home in the Museum’s Palaeontology collection.
Eugene Kwok, Denison Research Scholarship student, University of Sydney
Dr Jacqueline Nguyen, Research Scientist (Ornithology and Palaeontology), AMRI