浙江白垩系两种掌鳞杉科化石微细结构及其古环境意义

利用扫描电镜和生物光学显微镜对采自浙江新昌镜岭馆头组的两种已绝灭的松柏类掌鳞杉科植物Pseudofrenelopsis papillosa Chow and Tsao和Pseudofrenelopsis parceramosa Watson细微结构进行了观察研究。其中P.papillosa无论从宏观形态还是表皮构造都与模式标本完全一致；而定为Pseudofrenelopsis parceramosa的标本节间角质层较为光滑，气孔排列规则，副卫细胞上未见乳突，此外该标本气孔器大小、自由叶大小、节间长度等方面都与Pseudofrenelopsis中的其他种不太相同。并利用化石P.parceramosa的气孔比率通过最近现生亲缘种法恢复了早白垩世晚期大气CO2浓度为861~1047ml/L，得出用本种恢复早白垩世晚期CO2浓度时应用石炭纪标准较为准确，说明本种可以作为环境指标。

Microstructures of Two Species of Cheirolepidiaceae from Cretaceous in Zhejiang, China and Its Paleoenvironmental Significance

Cuticular characteristics of two species of Cheirolepidiaceae conifer collected from the Cretaceous Guantou Formation, in Jingling of Xinchang County, Zhejiang Province, Pseudofrenelopsis papillosa Chow and Tsao and Pseudofrenelopsis parceramosa Watson, are studied with SEM and LM. They had been extinct by the Tertiary. Of them, morphological and epidermal characteristics of the former species P.papillosa are completely consistent with those of the holotype ( Chow and Tsao,1977). However, pseudofrenelopsis parceramosa is characterized by smooth internode cuticle and regular stomatal arrangement. Besides, papillae are not found in the subsidiary cells, and size of stomatal apparatus and free leaf and internode length etc. are not the distinctly same as those of other species of the genus Pseudofrenelopsi. CO2 concentration in the late epoch of the Early Cretaceous is estimated by stomatal ratio of P.parceramosa (NLRs), which is from 861 to 1047ml/L. It is suggested that the climate in the Xinchang Basin, Zhejiang Province, was warm or hot and arid or semiarid.