A team of paleontologists from Australia, Canterbury and Denmark have concluded New Zealand’s true ancient species are animals like kākāpō, small wrens, bats and freshwater limpets, not recent Aussie immigrants such as kiwi, moa and takahē.
The team has spent two decades excavating a large St Bathans fossil site in Central Otago and recently published their findings in Geobios.
Canterbury Museum senior curator natural history Dr Paul Scofield is one of the researchers who have uncovered more than 9000 fossil bones at St Bathans since 2001.
The site was once at the bottom of a large prehistoric lake and offers the only significant insight into the wildlife that lived in and around lakes, rivers and forests from 20 million years ago, in the Early Miocene period.
Extraordinary and exotic creatures have been identified, including a giant parrot the scientists nicknamed "Squawkzilla", two mystery mammals, flamingos, a 3m crocodile, a giant horned turtle and a giant bat.
Dr Scofield, who got involved in the digs in 2002, said the research had prompted a rethink of New Zealand’s native fauna.
"Until now we thought that birds like kiwi and moa were among the oldest representatives of New Zealand fauna. We are now realising that the kākāpō, tiny New Zealand wrens and bats, and even a bizarre freshwater limpet, are the real ancient New Zealand natives."
The research concludes the menagerie of exotic animals was wiped out by dramatic temperature drops over the last 5 million years or so.
Lead author Associate Prof Trevor Worthy, of Flinders University, said it was exciting to continually be making fresh discoveries about New Zealand animals from a critical period in history.
"Every year we find new specimens, finds that reveal amazing new species that we couldn’t have imagined when we first started working there."
Study co-author Dr Vanesa De Pietri, of the University of Canterbury, said the animals that lived 20 million years ago were very different to what we have now.
"For example, we had another giant eagle that was not related to Haast’s eagle. We had a whole bunch of songbirds that were quite different, crocodiles and even potentially a small mammal that we’ve nicknamed the waddling mouse. We are still in the middle of our research into understanding exactly what that was," she said.
The latest research paper was a collaboration between Flinders University, Canterbury Museum, Te Whare Wānanga o Waitaha University of Canterbury, The University of Queensland, University of Copenhagen and University of New South Wales.
