Fallen fowl

A prehistoric treasure trove of fossils in Central Otago has helped shape our understanding of New Zealand's fauna.

- Bob Brockie

At last, some good news for these troubling times - a giant duck fossil has been found in Otago.

New Zealand was a very different place 15 to 19 million years ago. It was subtropical, with no mountains - just rolling hills - and a lot of flat land. A lake nine times bigger than Lake Taupo covered most of what is now Central Otago. The prehistoric Lake Manuherikia was edged by marshy swamps, palm trees, eucalypts, proteas, casuarinas, macadamias and cycads.

Fish and mussels thrived in the huge lake before perishing in the muddy sediment. A large river disgorged more animals into the lake, to be fossilised in the silty lake bed.

In 1989, Dr Mike Pole discovered the jawbone of a crocodile in an eroded riverbed near St Bathans, an old gold-mining town. Subsequently, dozens more croc bones have been found, showing the animals were 3m long with blunt snouts.