地球学报2017，Vol.38Issue(2)：135-143,9.DOI:10.3975/cagsb.2017.02.05
中国首次发现白垩纪桫椤科茎干化石
The First Discovery of a Cretaceous Cyatheaceae Trunk from China
摘要
Abstract
Songliao Basin is one of the largest,thickest and best preserved Cretaceous continental sedimentary basins in China.Palynological studies show that Cyathidites spores are common in the Cretaceous strata in the basin.As Cyatheaceae and Dicksoniaceae are spread in common by means of Cyathidites spores,the discovery of the Cyathidites spores is still considered to be an ambiguous evidence for the existence of Cyatheaceae plants,which hinders further precise analysis of paleoenvironment and paleoclimate in the basin.A series of Cretaceous Cyatheaceae stem fossils,found from Keshan County,Qiqihar City,Heilongjiang Province,provide solid evidence for the presence of Cyatheaceae tree fern in the Songliao Basin.The studied fossils are permineralized stem fragments of Cyatheaceae tree fern,and each piece consists of pith,dictyostele and cortex.Each meristele is S-,U-or W-shaped in transverse section,enclosed by a sclerenchyma sheath.Margins of the meristeles of the main dictyostelic ring curve deeply toward cortex or pith at the distal end of each leaf gap.Pith and cortex are parenchymatous,in which medullary bundles and roots are abundant.Wound tissues often occur in pith.This specimen is the first fossil record of Cyatheaceae trunk found in China,which suggests that ancestor taxa of the extant Cyatheaceae tree fern now living in tropical or subtropical region used to grow near Keshan County in northern Songliao Basin in Cretaceous.The present fossils and their associated petrified fossils of Tempskya and Bennettitales,may indicate that the paleoclimate there might have been tropical or subtropical.关键词
桫椤科/树蕨/茎干/解剖结构/桫椤孢/白垩系/黑龙江Key words
Cyatheaceae/tree fern/trunk/anatomy/Cyathidites spore/Cretaceous/Heilongjiang分类
生物科学引用本文复制引用
程业明,刘风香..中国首次发现白垩纪桫椤科茎干化石[J].地球学报,2017,38(2):135-143,9.基金项目
本文由国土资源部部门预算项目(编号:121113000000160034)和国家自然科学基金项目(编号:31170206)联合资助.This study was supported by Departmental Budget of Ministry of Land and Resources of the People's Republic of China (No.121113000000160034)and National Natural Science Foundation of China (No.31170206). （编号:121113000000160034）
