A remarkable discovery has emerged from the dusty archives of Museums Victoria, where a fossil fragment collected over a century ago has finally been identified as belonging to Owen's giant echidna, Megalibgwilia owenii. This Pleistocene monotreme, roughly the size of a small child, once roamed the landscapes of Ice Age Victoria, filling a significant gap in our understanding of Australia's ancient megafauna. Published in the journal Alcheringa: An Australasian Journal of Palaeontology, the research by Tim Ziegler and Jeremy Lockett from Museums Victoria Research Institute marks the first confirmed record of this species in Victoria, bridging a 1,000-kilometre distributional void between known sites in South Australia and New South Wales.

The fossil, a partial cranium measuring just seven centimetres, was unearthed during early 20th-century expeditions to Foul Air Cave in the Buchan Caves Reserve, East Gippsland. Its identification not only rewrites the biogeography of this extinct giant but also highlights the untapped potential of museum collections for revealing deep-time secrets.

The Forgotten Fossil's Journey

In 1906–1907, museum officer Frank Palmer Spry, along with caves curator Francis Moon and geologist Thomas Sergeant Hall, ventured into the treacherous depths of Foul Air Cave. Known for its toxic gases—hence the name—the cave acted as a natural pitfall trap, preserving bones of ancient animals that fell in over millennia. Spry collected over 150 fossil elements, including those from massive marsupials like palorchestids and the marsupial lion Thylacoleo carnifex.

The echidna skull fragment, initially misidentified or overlooked, ended up in Museums Victoria's collection labeled NMV P256921. It languished until 2021, when Tim Ziegler spotted it among unsorted bones during routine cataloging. 'I plucked out this one bone fragment, which isn’t much longer than your finger,' Ziegler recalled. Instinct told him it was an echidna beak—and a huge one at that.

Historical detective work confirmed its origin: diaries, maps, and newspaper articles linked it definitively to Foul Air Cave. Modern visits to the site, equipped with headlamps and ropes, verified the cave's role as a fossil hotspot on Krauatungalung Country.

Unveiling Owen's Giant Echidna

Megalibgwilia owenii, named after anatomist Sir Richard Owen, combines Greek 'mega-' for large and 'libgwil,' the Wemba Wemba word for echidna. This species stood out among Pleistocene monotremes with its metre-long body and 15-kilogram weight—double that of today's short-beaked echidna, Tachyglossus aculeatus.

Its skull featured a long, straight beak without teeth, bony ridges on the palate for tearing, and robust limb bones with deep muscle scars, suggesting powerful digging for beetle larvae or bogong moths in hard soils or fallen logs. Unlike modern echidnas that favor soft-bodied termites and ants, this giant adapted to tougher prey, akin to New Guinea's long-beaked echidnas (Zaglossus spp.).

3D scans and comparisons with specimens like TMAG Z2031 from Tasmania confirmed the match, distinguishing it from slimmer, possibly Zaglossus-like fossils hinted at in prior Victoria finds.

Monotremes: Australia's Living Fossils

Echidnas and platypuses, the world's only monotremes (egg-laying mammals), trace back 200 million years. Fossil records show a diverse past, with giants like Murrayglossus hacketti and Megalibgwilia robusta in Pleistocene Australia. M. owenii's robust build points to a semi-aquatic or forest-dwelling lifestyle in temperate habitats.

The Pleistocene (2.58 million to 11,700 years ago) saw Australia's megafauna thrive amid fluctuating climates. Victoria's caves, like Buchan, preserved snapshots of this world, with species coexisting before aridification and human arrival contributed to extinctions around 46,000 years ago.

Buchan Caves: Victoria's Fossil Treasury

The Buchan Caves Reserve, in Palaeozoic limestone karst, has yielded fossils since the late 1800s. Foul Air Cave's vertical shafts trapped unwary animals, amassing remains of extinct kangaroos (Sthenurus sp.), koalas (Phascolarctos cinereus ancestors), and predators.

Prior studies noted diverse Quaternary faunas, but no full inventory exists. This echidna adds to palorchestids, thylacoleonids, and more, painting Gippsland as a megafauna hotspot. Ongoing surveys promise more revelations.

Methods Behind the Identification

Ziegler and Lockett used digital callipers for measurements, focus-stacked photography, and 3D scanning with Artec Space Spider. Meshes were processed in MeshLab and compared to global specimens. Historical archives, including Spry's notes and 1906 cave sketches, corroborated provenance.

The palate's shallow arch and rostrum taper matched M. owenii, ruling out Zaglossus (wedge-shaped) and Tachyglossus (shorter beak). Models are available on MorphoSource for further study.Read the full paper here.

Implications for Pleistocene Victoria

This find extends M. owenii's range, suggesting continuous southeastern distribution. It challenges prior Zaglossus attributions, urging re-examination of Victorian fossils. The species likely navigated forests and woodlands, competing with megafauna before climate shifts and humans altered ecosystems.

Extinction tied to aridification; modern parallels warn of habitat loss threats to short-beaked echidnas.

From Past Giants to Modern Conservation

Today's echidnas face roads, predators (foxes, dogs), and habitat fragmentation in Victoria. EchidnaCSI citizen science aids tracking. Lessons from giants underscore protecting monotreme diversity amid climate change.

Explore the specimen page at Museums Victoria.

Future Frontiers in Australian Palaeontology

Museums Victoria's work exemplifies collection-based science. With Victoria's fossil record underexplored, more caves and archives hold secrets. Collaborations with Traditional Owners enhance ethical research, promising richer Ice Age narratives.

For palaeontologists, this underscores re-curation's power. Careers in research thrive; see opportunities at Australian universities.

Photo by Jacob Dyer on Unsplash

Broader Evolutionary Insights

Monotremes bridge reptiles and mammals. Giants like M. owenii show adaptive radiation post-dinosaur extinction. Their loss reflects megafauna patterns globally, informing biodiversity conservation today.