Article: Permian Supaia fronds and an associated Autunia fructification from Shanxi, China
Publication: Palaeontology
Volume:
40
Part:
1
Publication Date:
March
1997
Page(s):
245
–
277
Author(s):
Zi-Qiang Wang
Abstract
Three new species of bipartite Supaia frond, one associated with an Autunia ovuliferous organ have been identified. S. shanxiensis sp. nov. from Central Shanxi is roughly similar in gross morphology to Supaia species from the Permian Hermit Shale of North America, but differs in the size, shape and othe features of the frond. It can also be distinguished by the pinnules having an entire margin, a faintly decurren base and being more closely spaced, and the venation consisting of a weak mid-vein. S. contracta sp. nov., fron North Shanxi, is characterized by pinnules with a markedly constricted base and distinctive cuticles, and compares closely with some of the Upper Permian Tatarina species from the Urals. The Southern Shanxi species, S. yuanquensis sp. nov., is distinguishable from both the above in its smaller frond with a delicate primary rachis, its strongly decurrent and elongate pinnules, and its thin lamina texture. Autunia shanxiensi sp. nov. shows individual cones consisting of bilaterally symmetrical megasporaphylls in spiral attachment, in contrast to the lax, modified, fertile pinnae of A. milleryensis. Although not found in attachment, the close association of S. shanxiensis fronds and A. shanxiensis ovuliferous organs suggests that, at least in North China, the Supaia-type frond may have belonged to the Peltaspermaceae. It is argued that the names Autunii and Peltaspermum, originally proposed as ' organ'-genera, should not be used for natural genera based on partly reconstructed fossil plants. Abundant fungal-spots on or within Supaia fronds in North China are evidence of the increasing deterioration of the environment during the Permian.