23 May 2014
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South Australian Museum Senior Researcher Dr Mike Lee, and Research Associate Trevor Worthy, are part of a team of researchers who have rewritten the evolutionary history of giant flightless birds called ratites, and solved the mystery of how they migrated across the globe after the mass extinction of dinosaurs.
Until now, the closest relatives of the New Zealand Kiwi were thought to be the Australian emu and cassowary. However, a paper published today in the prestigious journal Science reveals that the New Zealand Kiwi’s closest cousin is a giant extinct bird from much further away: Madagascar! The team was led by Mr Kieran Mitchell and Professor Alan Cooper from the Australian Centre for Ancient DNA at the University of Adelaide.
The extinct Madagascan elephant bird was around three metres tall and weighed up to 300 kilograms. They are among the most impressive and enigmatic of birds: the South Australian Museum has real bones of these creatures, that have been in the collection for at least a century. They are kept in the same drawer as bones of another famous extinct bird, the dodo, from Mauritius.
Dr Lee says “The distribution of two bizarre, flightless relatives on islands on opposite sides of the world, which have never been directly connected, implies that they must have evolved from ancestors capable of long-distance flight.
“The ancestors of emus, ostriches, kiwis and elephant birds flew around the world, and then became wingless giants separately on each continent, confounding attempts to understand how they got around.”
Prof. Cooper adds “It’s finally great to set the record straight, as we New Zealanders were shocked and dismayed to find that our national bird appeared to be an Australian immigrant. I can only apologise it has taken so long.”
The team sequenced the complete mitochondrial genomes of two elephant birds and performed phylogenetic analyses which revealed that these birds are the closest relatives of the New Zealand kiwi, and are distant from the basal ratite lineage of ostriches.
Dr Lee says the publication of the research in Science is a major coup for the Museum. “The research team included ornithologists, palaeontologists, molecular biologists and bioinformaticians, and their complementary skills were vital to solve this avian mystery. Museum scientists have unique expertise required to answer some of the biggest questions in science.”