Bold claim first: a single fossil goose reshapes our view of New Zealand bird history, showing a much more dynamic evolutionary past than we thought. And this is where it gets intriguing—the tale isn’t just about one ancient bird, but about how NZ’s avifauna moved, mixed, and changed through time.
Aotearoa New Zealand’s bird story just got a fresh chapter from the University of Otago’s Ōtākou Whakaihu Waka research team. Associate Professor Nic Rawlence, who directs the Otago Palaeogenetics Laboratory, is a co-author of a new study that examines a rare fossil goose found in an ancient Central Otago lake and traces its origins.
The study, published in Historical Biology, is an international collaboration among Otago, Te Papa Tongarewa (the Museum of New Zealand), and the University of Cambridge. It centers on fossils uncovered near St Bathans and re-examines bones previously labeled as geese, comparing them with other waterfowl bones from the site and a wide set of bird skeletons for context.
Rawlence explains that while many waterfowl fossils from the area are common, some remain unusual or underrepresented. Through careful re-identification and comparison, the team discovered an undescribed goose species comparable in size to a small modern goose.
To honor the find, the researchers named the St Bathans goose Meterchen luti. The name draws from Old Mother Goose: Meterchen means “mother goose” in ancient Greek, and luti translates to “of the mud” in Latin, nodding to how the ancient bird appears to rise from the muddy fossil deposit.
Importantly, the St Bathans goose is not closely related to the giant, flightless NZ geese (the Cnemiornis species) or their Australian cousin, the Cape Barren goose. This finding, together with other recent genetic work, suggests that New Zealand’s bird evolution has been more dynamic and interconnected than previously appreciated.
Lead author Alan Tennyson of Te Papa notes that birds have arrived in Zealandia through waves of colonization over deep time, but some of our large-beaked and large-bodied birds show up surprisingly recently—within roughly the last four to five million years. This includes takahē, Forbes’ harrier, and the famed Haast’s eagle.
Tennyson explains that an earlier hypothesis posited the St Bathans goose as a direct ancestor of the giant flightless Cnemiornis geese, implying a line that stretched back at least 14 million years in Zealandia. However, genetic data indicate that the ancestors of Cnemiornis likely arrived from Australia about seven million years ago, a claim that the older theory had dismissed. The team’s careful reassessment supports the later arrival model.
Thus, while the St Bathans goose’s ancestors existed in Zealandia before 14 million years ago, no descendants from that lineage survived into the present. Rawlence emphasizes that combining DNA analysis with fossil evidence lets researchers reconstruct how Zealandia’s shifting geology, climate, and human history shaped its fauna in ever more detail. The giant, flightless Cnemiornis geese illustrate rapid morphological change that can occur on islands within relatively short timescales, with these geese reaching up to one meter tall and weighing as much as 18 kilograms—the largest geese known in the world.
Publication details: A review of fossil goose (Aves: Anserinae) records from the Miocene St Bathans deposits, New Zealand, with the description of a new species. Authors include Alan J. D. Tennyson, Elizabeth M. Steell, Pascale Lubbe, Amy L. Adams, Liam Greer, Alex H. Brown, Laura J. E. Wilson, Timothy C. Campbell, Tobia C. Dale, and Nicolas J. Rawlence. Public release from Mirage.News summarizes the study and its implications, while noting that the material reflects the point-in-time nature of the research and is presented with clarity and context for broader audiences. A link to the full publication is provided in the original release.
If you’re curious to dive deeper, you can explore the published article here: https://doi.org/10.1080/08912963.2025.2601236.
