Fossil of Extinct Giant Echidna Found in Victorian Museum Collection

A fossil fragment excavated in 1907 from a cave in eastern Victoria has been identified as belonging to an extinct species of giant echidna. The discovery, made in a museum collection, fills a significant geographical gap in the known distribution of the species, which had previously been recorded in other Australian states but not in Victoria.

The Discovery

The fossil is a skull fragment, approximately the length of a human finger, that was excavated from Foul Air Cave in the Buchan cave complex in East Gippsland, Victoria. The specimen was collected in 1907 by museum officer Frank Spry during an expedition.

For over a century, the fragment was stored among unsorted fossils in the collection of the Museums Victoria Research Institute. During this time, it was reportedly mistaken for a hind limb bone of a small kangaroo.

In 2021, Tim Ziegler, the collection manager of vertebrate palaeontology at the institute, noticed the fragment. He identified it as part of an echidna beak based on its symmetrical structure, the arch of a palate, and internal spaces consistent with air passages.

Identification and Verification

To confirm the identification, researchers conducted 3D scans of the fossil and compared it with scans of modern echidna specimens and other fossil echidna specimens from museum collections across Australia. Historical archives were also consulted to verify the specimen's origin and collection details.

The research confirmed the fragment belongs to Megalibgwilia owenii, commonly known as Owen's giant echidna. The findings have been published in the peer-reviewed journal Alcheringa: An Australasian Journal of Palaeontology.

Species Characteristics

• Era: Owen's giant echidna lived during the Pleistocene epoch, which began approximately 2.5 million years ago.
• Size: The species grew to about one metre in length and weighed up to 15 kilograms. This is roughly twice the size of modern Australian echidnas.
• Physical Build: According to the research, the skeleton of Megalibgwilia owenii was more robust than comparably sized modern long-beaked echidnas (Zaglossus) found in New Guinea. The limb bones show deeper muscle scars and larger ligament attachment points.
• Potential Behavior: Tim Ziegler stated that these robust skeletal features suggest the animal used greater physical force when interacting with its environment. He suggested possible behaviors could have included digging for larvae, beetles, or bogong moths, or tearing tree bark to access food.

Significance for Species Distribution

The identification of the Victorian specimen is significant for understanding the historical range of the species.

• Previous Finds: Fossils of Owen's giant echidna had been previously discovered at sites in Western Australia, South Australia, New South Wales, and Tasmania. The earliest collected fossils were from New South Wales in the 1860s.
• Filling a Gap: The absence of the species from the Victorian fossil record had represented a distribution gap of approximately 1,000 kilometres. The newly identified fragment from East Gippsland addresses this absence.
• Historical Geography: During the Pleistocene epoch when this animal lived, Tasmania was likely connected to mainland Australia by a land bridge.

Regarding the discovery, Tim Ziegler stated, "It turns out they were there all along. And we just needed the right moment to recognise their presence."