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A New Lycopsid, Zhenglia radiata gen. et sp. nov., from the Lower Devonian Posongchong Formation of Southeastern Yunnan, China, and Its Evolutionary Significance
Author(s) -
Shougang HAO,
Deming WANG,
Qi WANG,
Jinzhuang XUE
Publication year - 2006
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.2006.tb00789.x
Subject(s) - sporangium , devonian , selaginella , botany , strobilus , biology , fern , lamina , radiata , perianth , scape , paleontology , stamen , pollen , vigna , spore
A new plant, Zhenglia radiata gen. et sp. nov., from the Posongchong Formation (Early Devonian, Pragian age) of the Wenshan District of southeastern Yunnan Province, China is a small herbaceous lycopsid. The aerial branches divide into foliar and fertile stems. The arrangement of the leaf bases on the stem shows lepidodendroid‐like phyllotaxy. Possibly the leaf base bears a ligulate pit The microphyll consists of a swollen, decurrent base, and an entire, linear lamina. The fertile axis is composed of sporophylls arranged helically, forming a compact area similar to cone‐like structure. Each sporophyll consists of a widened lateral extension and a distal lamina. The ovoid‐elongate sporangia are attached adaxially on the surface of sporophylls. Based on morphological similarities, especially the undivided microphylls, the style of phyllotaxy, the form of the cone‐like structures and sporangia, the new lycopsid Zhenglia radiata is placed in the order Protolepidodendrales and a possible evolutionary relationship with the arborescent lycopsids of the Late Devonian and Carboniferous is considered.