Frasnian (Upper Devonian) evidence for multiple origins of seed-like structures

Authors: CHENG-SEN L.¹; HILTON J.²; HEMSLEY A.R.²

Source: Botanical Journal of the Linnean Society, Volume 123, Number 2, 1997 , pp. 133-146(14)

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Abstract:

Reproductive structures of Frasnian (early Late Devonian) age from Wuhan, Hubei province, South China provide evidence for the early emergence of monomegaspory and integumentation in plants of non-progymnosperm affinity. Sphinxia wuhania gen. et sp. nov. pre-dates the occurrence of other reproductive structures exhibiting a similar suite of characters and adds support to the view that evolution towards an ovule may not have been a unique event. Sphinxia possesses a single functional megaspore with associated aborted members of the meiotic tetrad, a distinct, striated sporangial wall, and a sterile envelope bearing proximal spines. The morphology of the structure precludes assignment to any known group of plants in the absence of additional information regarding the parent plant. A progymnospermous affinity is unlikely. Thus, Sphinxia demonstrates that the Devonian progymnosperms did not lack potential competition from similarly specialized reproductive strategies in other plant lineages.

Keywords: China; Lycopsid; monomegaspory; palaeobotany; progymnosperm; seed

Language: English

Document Type: Research article

Affiliations: 1: Institute of Botany, Academia Sinica, Xiangshan, Beijing, 100093, China 2: Department of Earth Sciences, University of Wales Cardiff, Cardiff, CF1 3YE

Publication date: 1997-01-01