A rare goose fossil discovered at the remains of an ancient lake in Central Otago is changing scientists’ understanding of how New Zealand’s unique bird species evolved. Researchers from the University of Otago’s Otakou Whakaifu Waka say the discovery adds to growing evidence that the origin of Aotearoa’s birds was far more dynamic than previously thought.
Associate Professor Nick Lawrence, director of the Otago Institute of Paleogenetics, is a co-author of a new study investigating the relationship between fossils and their evolution.
This study historical biologycarried out by an international team from the University of Otago, Te Papa Tongarewa Museum, New Zealand, and the University of Cambridge (UK). Scientists examined fossil material recovered from the well-known St. Bathans fossil deposit.
New species hidden among fossils
Lawrence explained that while waterfowl fossils are abundant at St. Bathsans, there are far fewer goose fossils.
To investigate further, the research team reexamined all fossil bones previously identified as belonging to geese. They compared these fossils with other waterfowl fossils from the site and with an extensive collection of skeletons of living and extinct birds.
“We determined that the bones contained an undescribed species about the size of a small goose,” he says.
Newly confirmed bird has been named meters. Its name is inspired by the nursery rhyme “Old Mother Goose” and reflects the idea of an ancient goose emerging from the mud of fossil deposits. meters Means “Mother Goose” in ancient Greek. Ruti It means “mud” in Latin.
“The St. Bathan goose is not closely related to the recently extinct giant flightless New Zealand goose,” Lawrence said.Nemiornis species) or its Australian cousin the Cape Barren goose. ”
Rethinking the evolution of New Zealand birds
Combined with recent genetic evidence, this discovery suggests that New Zealand’s bird history is far more complex than scientists once assumed.
Alan Tennyson, lead author of Te Papa, said that while many bird species had taken millions of years to reach New Zealand, the ancestors of some of the country’s best-known large birds had arrived surprisingly recently. More recent arrivals, dating back just 4-5 million years, include the Forbes harrier, the takahe, and the giant Haast’s eagle.
“Previous theories argued that the St. Bathan goose represented a direct ancestor of the flightless giant goose. Nemiornis “This suggests that this lineage had a very long history in Zealandia (at least 14 million years),” he says.
“However, this contradicts genetic evidence suggesting an ancestry of. Nemiornis It arrived from Australia only about 7 million years ago, but proponents of the earlier theory abandoned it.
“Our rigorous reassessment supports the late arrival theory.”
DNA and fossils reveal a more dynamic past
Lawrence said the ancestors of the St. Basangan arrived in Zealandia more than 14 million years ago, but the lineage eventually died out without leaving any descendants.
“Using all the tools in our toolbox, including DNA and fossils, we can reconstruct in greater detail how Zealandia’s dynamic geological, climatological and human history has shaped the evolution of Aotearoa’s fauna,” he says.
He added that the flightless giant: Nemiornis Geese provide another remarkable example of how rapidly island species change.
“Relatively recent evolution of giant flightless creatures” Nemiornis Geese provide another striking example of the rapid morphological changes that can occur over short periods of time on islands. At one meter tall and weighing up to 18 kilograms, these geese were the largest in the world. ”
