中国大羽羊齿植物分叉蕨叶的首次发现——兼论亚洲与北美大羽羊齿植物之异同

东亚与北美大羽羊齿植物间的主要差异在于蕨叶的结构 :北美大羽羊齿植物的蕨叶为单叶或二歧分叉叶 ,而东亚的大羽羊齿植物以往只知为羽状复叶或不分叉的单叶。因之 ,二歧分叉蕨叶在中国的发现具有十分重要的意义 ,它使东亚与北美大羽羊齿植物之间的关系变得更为密切 ,虽然其间仍存在不少实质性的差异。同时 。

The main difference between the Asian and the American gigantopterids lies in the frond: the fronds of the American gigantopterids are dichotomously bifurcated or simple, while the Asian plants are hitherto only known bearing pinnate or simple fronds that do not fork. The discovery of dichotomously bifurcated fronds of Gigantonoclea from the late Early Permian Tongtseyan Formation in Fujian Province is thus a matter of vital importance, for it brings a much closer relationship between the Asian and the American gigantopterids, although there are still many substantial differences between them. Meanwhile, the resemblance and the differences between the Asian and the American species of Cathaysiopteris are discussed in some length.