This is a timeline of the history of New Zealand that includes only events deemed to be of principal importance – for less important events click the year heading or refer to List of years in New Zealand. Prehistory (to 1000 CE) 85 mya: Around this time New Zealand splits from the supercontinent Gondwana. 5 mya: New Zealand's climate cools as Australia drifts north. Animals that have adapted to warm temperate and subtropical conditions become extinct. 26,500 BP: The Taupō volcano erupts extremely violently, covering much of the country with volcanic ash and causing the Waikato River to avulse from the Hauraki Plains to its current path through the Waikato to the Tasman Sea. 18,000 BP: New Zealand's North and South islands are connected by a land bridge during the last ice age. Glaciers spread from the Southern Alps carving valleys and making fiords in the South Island. The land bridge is submerged around 9,700 BCE. 181 CE: Lake Taupō erupts violently. Pre-colonial time (1000 to 1839) 1000 to 1600 c1280: Earliest archaeological sites provide evidence that initial settlement of New Zealand occurred around 1280 CE. ~1300: Most likely period of ongoing early settlement of New Zealand by Polynesian people (the Archaic Moa-Hunter Culture). ~1400: Rangitoto Island near Auckland is formed by a series of eruptions. 1400~1500: Development of the Classic Māori Material Culture including expansion of Māori settlement from coastal to inland areas, increase in horticulture and development of pā (hillforts) ~1400~1450: Most likely extinction of the moa. 1576: Speculation exists that around this time Spanish explorer Juan Fernández visited New Zealand although this is not generally accepted by most reputable authorities. 17th century 1601 onwards Expansion and migration of Māori groups and formation of classic iwi. (many still existing today) 1642 13 December: Dutch explorer Abel Tasman sights the South Island. He called it Staten Landt but the Dutch East India Company cartographer Joan Blaeu subsequently changed it to Nieuw Zeeland. 18 December: Abel Tasman's expedition sails around Farewell Spit and into Golden Bay. Dutch sailors sight local Māori. 19 December: Four of Tasman's crew are killed at Wharewharangi (Murderers) Bay by a Ngāti Tūmatakōkiri war party. Tasman's ships are approached by 11 waka as he leaves and his ships fire on them, hitting a Māori standing in one of the waka. Tasman's ships depart without landing. The Dutch chart the west of the North Island. 18th century