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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.
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 among them. Meanwhile, the resemblance and the differences between the Asian and the American species of Cathaysiopteris are discussed in some length.