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New research in the Chatham Islands has underpinned arguments for the whole of New Zealand's terrain being submerged about 23 million years ago, says a Wellington scientist.
Biologists and geologists carrying out the Chathams research extended their scrutiny to mainland New Zealand - 800km to the west - and examined evidence for assuming that there has been continuous land in the area since it separated from Gondwanaland 85 million years ago.
"The research produced a startling conclusion," said Dr Hamish Campbell, a palaeontologist at GNS Science.
"The geological evidence for continuous land is so weak that it can no longer be assumed.
"A strong argument can be made for complete submergence of land in the New Zealand region about 23 million years ago".
The conclusion was likely to initiate a raft of new research into the origins of the New Zealand flora, fauna and other organisms.
"If it is correct, then it implies that the entire endemic biology of New Zealand is less than 23 million years old," Dr Campbell said.
The Chatham Islands Emergent Ark Research Survey, co-led by Dr Campbell and Massey University molecular biologist Dr Steve Trewick, set out to investigate the idea that the Chathams may have been totally submerged under the sea until only about 3.5 million years ago.
The islands have only 10 native species of tree, and for most other groups of native organisms such as insects, lizards, freshwater fish, and birds and flowering shrubs, the diversity is less than 10 per cent of similar species on the mainland. go.
"The entire land area of the Chatham Islands must have been under the sea until about 2 million years ago," the team said in a report released by the Marsden Fund.
- NZPA
