Story: When was New Zealand first settled?

Gnawed snail shells

Gnawed snail shells

Researcher Fred Brook in Northland has examined fossil shells of the native land snail Placostylus ambagiosus. If rats had arrived in New Zealand as early as 2,000 years ago, we would expect to find evidence of rat predation on small creatures such as snails over that timespan. As shells can be radiocarbon-dated, it is possible to determine the age at which fossil snail shells were gnawed by rats. The evidence to date is that gnaw marks only appeared on the shells after 1250.

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Photograph by F. J. Brook

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How to cite this page:

Geoff Irwin and Carl Walrond, 'When was New Zealand first settled? - Rat DNA', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/photograph/3626/gnawed-snail-shells (accessed 9 December 2019)

Story by Geoff Irwin and Carl Walrond, published 8 Feb 2005, updated 1 May 2016