Prior to human settlement, the mammals of New Zealand consisted entirely of several species of bat, and several dozen marine mammal species (though the Miocene Saint Bathans Mammal shows that at some point there were terrestrial, "archaic" mammal species). The Māori brought the kurī (Polynesian dog) and kiore (Polynesian rat) in about 1250 CE, and Europeans from 1769 onwards brought the pig, mice, two additional species of rats, weasels, stoats, ferrets and possums and many other species, some of which cause conservation problems for indigenous species.