Biogeographic disjunction along the Alpine fault, New Zealand



Eighty taxa (subspecies, species, species groups, genera and families) showing disjunction along the New Zealand Alpine fault (Australian/Pacific plate boundary) are documented and mapped. Four plant divisions, including 14 seed plant families, and four animal phyla, including 13 orders of insects, are represented. The disjunction has usually been explained by glaciers having wiped out central populations. However, the gap is often occupied by a related taxon and many alpine taxa are involved, and so extinction by glaciation seems unlikely as an explanation. It is proposed that the disjunction has been caused by the 480 km of lateral displacement on the fault.