Gigantonoclea: An enigmatic Permian plant from North China

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	Gigantonoclea: An enigmatic Permian plant from North China
	Wang, ZQ
刊名	PALAEONTOLOGY
	1999
卷号	42 页码:329-373;PN Part 2
ISSN号	0031-0239
英文摘要	Gigantonoclea is a distinctive and enigmatic plant from the Permian of North China proper, with an unusual frond architecture and a pollen organ and vascular structure which are unique; it demonstrates a sudden rise and a rapid extinction. This paper reviews previous work on Asian gigantopterids and describes new material from the Upper Permian of Shanxi Province, including a new type of pollen organ (Jiaochengia lagrelii) and two new species of frond (Gigantonoclea crenata and G. pubescens). Jiaochengia shows opposite, dissected and rather modified microsporophylls, laxly aggregating into an independent organ, which is markedly different from 'Gigantotheca' from Fujian. This presents evidence of heterogeneity among Asian gigantopterids and partly supports a relationship with the Carboniferous Callistophytales. Jiaochengia sporangia have what may be the first record of a waxy covering on the outer surface of a fossil plant, which is interpreted to have functioned to repel water, to protect against fungal attack and to scatter light. According to Hickey's rule, the venation of true Gigantonoclea fronds consists of three orders of main veins (rachis, midvein and secondary veins) and two orders of anastomosing veins (tertiary veins and veinlets). Certain putative 'Gigantonoclea' species from South China and some peripheral areas of North China do not have this type of venation and are thus excluded from the genus. Frond dimorphism is common among gigantopterids in both North and South China and can be compared with the amphibious variation from submerged to emergent leaves in extant aquatic plants. G. pubescens has a thick, bi-layered adaxial cuticle with an indumentum covering with dense papillae and trichomes bases, and deeply sunken, papillate stomata, suggesting that it favoured more arid conditions. An observed gradient from pubescent to glabrate or even glabrous gigantopterid cuticle structures between North and South China suggests a change from xeric, mesic to humid habitats.
学科主题	古生物学
WOS关键词	ANGIOSPERM CALLITRICHE-HETEROPHYLLA ; LEAF DIMORPHISM ; LEAVES ; ORIGIN ; MORPHOLOGY ; ANATOMY ; TEXAS
WOS研究方向	Paleontology
语种	英语
出版者	BLACKWELL PUBL LTD
WOS记录号	WOS:000080262500008
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37320]
专题	中国地质调查局
作者单位	Chinese Acad Geol Sci, Tianjin Inst Geol & Mineral Resources, Tianjin 300170, Peoples R China.
推荐引用方式 GB/T 7714	Wang, ZQ. Gigantonoclea: An enigmatic Permian plant from North China[J]. PALAEONTOLOGY,1999,42:329-373;PN Part 2.
APA	Wang, ZQ.(1999).Gigantonoclea: An enigmatic Permian plant from North China.PALAEONTOLOGY,42,329-373;PN Part 2.
MLA	Wang, ZQ."Gigantonoclea: An enigmatic Permian plant from North China".PALAEONTOLOGY 42(1999):329-373;PN Part 2.