This is just neat.
Scientists feared ancient phreatoicids (pronounced "free-at-o-ik-ids") were extinct after they went missing from the scientific record for 60 years.
But a painstaking search has revealed all nine known species - and four new species - were living unnoticed in South Island pools, swamps and drains.
The 2-cm creatures play a major role in cleansing Canterbury's groundwater and keeping Christchurch's drinking water naturally pure.
Read more from The New Zealand Herald >>