title: Sequoia maguanensis, a new Miocene relative of the coast redwood, Sequoia sempervirens, from China: implications for paleogeography and paleoclimate.
abstract: •
  
  
  OBJECTIVE
  The paleogeographical origin of the relict North American Sequoia sempervirens is controversial. Fossil records indicate a Neogene origin for its foliage characteristics. Although several fossils from the Miocene sediments in eastern Asia have been considered to have close affinities with the modern S. sempervirens, they lack the typical features of a leafy twig bearing linear as well as scale leaves, and the fertile shoots terminating by a cone. The taxonomic status of these fossils has remained unclear.•
  
  
  METHODS
  New better-preserved fossils from the upper Miocene of China indicate a new species of Sequoia. This finding not only confirms the former presence of this genus in eastern Asia, but it also confirms the affinity of this Asian form to the modern relict S. sempervirens.•
  
  
  RESULTS
  The principal foliage characteristics of S. sempervirens had already originated by the late Miocene. The eastern Asian records probably imply a Beringian biogeographic track of the ancestor of S. sempervirens in the early Neogene, at a time when the land bridge was not too cool for this thermophilic conifer to spread between Asia and North America.•
  
  
  CONCLUSIONS
  The climatic context of the new fossil Sequoia in Southeast Yunnan, based on other floristic elements of the fossil assemblage in which it is found, is presumed to be warm and humid. Following the uplift of the Qinghai-Tibet Plateau, this warm, humid climate was replaced by the present monsoonal climate with dry winter and spring. This change may have led to the disappearance of this hygrophilous conifer from eastern Asia.
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Mengla 666303, China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Zhang
authors.affiliation: Department of Botany, Narasinha Dutt College, 129 Bellilious Road, Howrah 711101, India.
authors.forename: Ashalata
authors.initials: A
authors.lastname: D'Rozario
authors.affiliation: The college of Natural Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Adams
authors.affiliation: Institute of Geology, the Chinese Academy of Geological Sciences, 26, Baiwanzhuang Road, Beijing 100037, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Mengla 666303, China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Liang
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Mengla 666303, China.
authors.forename: Frédéric M
authors.initials: FM
authors.lastname: Jacques
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Mengla 666303, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Su
authors.affiliation: Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Mengla 666303, China.
authors.forename: Zhe-Kun
authors.initials: ZK
authors.lastname: Zhou
mesh_terms: D005075:Biological Evolution; D002681:China; D057231:Climate Change; D005580:Fossils / Q000033:anatomy & histology; D010802:Phylogeny; D063148:Plant Dispersal; D018515:Plant Leaves / Q000033:anatomy & histology; D032487:Sequoia / Q000033:anatomy & histology / Q000145:classification* / Q000502:physiology
keywords: China; Cupressaceae; North America; Sequoia sempervirens; comparative morphology; fossil; late Miocene; monsoon climate; phytogeography