Kathleen Walker

Doctor of Philosophy, (Zoology)
Study Completed: 2018
College of Sciences


Thesis Title
Systematics and Phylogeography of the large
land snail: Powelliphanta

Powelliphanta land snails are morphologically diverse and comprise an important but threatened part of New Zealand's invertebrate fauna. Conservation management for the genus has been inhibited by uncertainties as to the taxonomic status of many newly discovered populations and the reliability of previously described taxa. Ms Walker used molecular and morphological approaches to examine variation within the genus. She found morphology and genetics largely supported taxonomic status for the late-discovered groups and for previously described species and subspecies. On the strength of these findings, a new classification for Powelliphanta was suggested. This research provided useful insights as to the extent to which external morphology in molluscs, often considered environmentally shaped, can also reflect evolutionary history. More practically, it paved the way for urgent conservation measures to be instigated to protect the diversity identified by the study.

Professor Steven Trewick
Dr Rod Hitchmough