A new genus and species of anatid bird has been identified from a fossilized wing bone found in Central Otago, New Zealand.
The wing bone of the Bannockburn swan (Notochen bannockburnensis). Scale bars – 20 mm. Image credit: Worthy et al., doi: 10.11646/zootaxa.5168.1.3.
The newly-identified bird species belonged to Anatidae, a family of water birds that includes ducks, geese, and swans.
Named the Bannockburn swan (Notochen bannockburnensis), it lived between 16 and 19 million years ago (early Miocene epoch) on Lake Manuherikia, a huge lake covering most of modern Central Otago.
Like today’s swans, it would have foraged for food in the water, but also probably spent some of its time grazing on land.
“Today, the southern hemisphere’s only native swans are Australasia’s black swan (Cygnus atratus) and the Coscoroba swan (Coscoroba coscoroba) of South America — the Bannockburn swan’s closest living relative,” said Flinders University paleontologist Trevor Worthy and colleagues.
“These birds are a separate group from northern hemisphere swans.”
The fossilized wing bone of the Bannockburn swan was found near St Bathans in a layer of prehistoric mud called the Bannockburn Formation.
“This bone is rather damaged but it clearly belonged to a member of the geese and swans group of waterfowl,” Dr. Worthy said.
“We can’t say with total certainty what sort of giant waterfowl this bird was, but we think a swan is most likely which is why we’ve called it the Bannockburn swan.”
“The discovery of the Bannockburn swan provides a clearer picture of how swans, geese and their close relatives evolved,” added Dr. Paul Scofield, senior curator at Canterbury Museum.
“This swan and another goose-like bird we’ve found at St Bathans are the oldest members of the subfamily Anserinae, which contains swans and geese, found in the southern hemisphere.”
“They show a long history of the group in the southern half of the world.”
“This is another example of finds from St Bathans helping us understand bird evolution.”
The team’s paper appears in the journal Zootaxa.
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Trevor H. Worthy et al. A swan-sized fossil anatid (Aves: Anatidae) from the early Miocene St Bathans Fauna of New Zealand. Zootaxa, published online July 20, 2022; doi: 10.11646/zootaxa.5168.1.3
