Tree biloba". This is considered to be a living fossil because it is virtually unchanged from the fossilised specimens found in Triassic deposits. During the Mesozoic (245 to 66 million years ago) the conifers flourished and became adapted to live in all the major terrestrial habitats. Subsequently, the tree forms of flowering plants evolved during the Cretaceous period. These began to displace the conifers during the Tertiary era (66 to 2 million years ago) when forests covered the globe. When the climate cooled 1.5 million years ago and the first of four ice ages occurred, the forests retreated as the ice
Gangdese batholith Gangdese batholith The Gangdese batholith or Gangdese volcanic arc is a major geological structure in the south of the Lhasa terrane in Tibet, to the north of the Himalayas. The batholith formed around 100 million years ago, and was volcanically active for about 20 million years. It reactivated around 65 million years ago as the Indian plate approached Eurasia, and was active for another 20 million years. The Lhasa terrane moved northward and collided with the Qiangtang terrane along the Bangong-Nujiang suture towards the end of the late Jurassic (). Collision activity continued until the early Late Cretaceous () Ma.