云南中新世杉科化石木研究

利用光学显微镜和扫描电镜首次对云南省楚雄州晚中新世石灰坝组石鼓村层的钙化木材进行了解剖学研究.鉴定出两种类型的木材:柳杉型落羽杉型木(Taxodioxylon cryptomeripsoides Schonfeld)和杉木型落羽杉型木(Taxodioxylon cunninghamioides Watari).二者分别与现代柳杉属和杉木属具有最接近的亲缘关系.根据这两种杉科化石木现存最近亲缘种的生态环境,并综合其他资料,推测该地区在晚中新世为温暖湿润的亚热带气候环境.

Late Miocene Woods of Taxodiaceae from Yunnan, China

Late Miocene woods were investigated from the Lühe Basin in Chuxiong Borough, central Yunnan, China. The calcified woods preserved in the Shigucun member of the Shihuiba Formation, are represented by fallen logs and stumps. Two species of fossil wood, Taxodioxylon cryptomeripsoides Schonfeld 1953 and T. cunninghamioides Watari 1948, are described. Their anatomical structure shows striking similarities to the woods of Cryptomeria and Cunninghamia respectively. That the two fossil woods are classed in the Taxodiaceae suggest a subtropical, humid, and warm environment in Lühe during Late Miocene. They compare favorably to other fossil specimens and species reported from localities ranging from Cretaceous to Pliocene. This is the first record of the presence of the species T. cryptomeripsoides and T. cunninghamioides in Late Miocene of Yunnan. Key words: fossil wood; Taxodioxylon cryptomeripsoides; Taxodioxylon cunninghamioides; Late Miocene; Yunnan; palaeoenvironment