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 ...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.展开更多
Protolepidodendralean lycopsids are characteristic of morphologically complex leaves.Most taxa of this group are herbaceous and widely distributed in global Devonian sediments,with exceptions of a few members,such as ...Protolepidodendralean lycopsids are characteristic of morphologically complex leaves.Most taxa of this group are herbaceous and widely distributed in global Devonian sediments,with exceptions of a few members,such as Frenguellia eximia from the Lower Carboniferous of Argentina.In this study,we focus on the morphology of Frenguellia eximia and emend its generic and specific diagnoses,based on new materials from the Upper Devonian Hongguleleng Formation of West Junggar,Xinjiang Uygur Autonomous Region,Northwest China,within the fossil-bearing bed palynologically dated as a latest Famennian age.This is the first finding of Frenguellia eximia out of Gondwana.Frenguellia eximia bears planate leaf with three upward pairs of lateral tips,isomorphic sporophyll to the leaf,and elongated,oval sporangium.Leaf morphology of the members of the Order Protolepidodendrales is summarized and classified into lateral-tip and distal-tip types.Lateral-tip type leaf consists of an obvious main body and several paired lateral tips,whereas distal-tip type leaf shows a petiole and a distal lamina with several planate or three-dimensional segments.Two leaf types probably indicate two independent evolutionary routes of microphylls evolving from simple leaf of prelycopsids during the Devonian period.The new occurrence of Frenguellia eximia further shows paleophytogeographical similarities between West Junggar and northwestern Gondwana.展开更多
基金This work was supported by the National Natural Science Foundation of China （No. 40232019 No. 40302001）.
文摘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.
基金supported by the National Key R&D Program of China(Grant No.2022YFF0800200)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDA19050101 and XDB26000000)。
文摘Protolepidodendralean lycopsids are characteristic of morphologically complex leaves.Most taxa of this group are herbaceous and widely distributed in global Devonian sediments,with exceptions of a few members,such as Frenguellia eximia from the Lower Carboniferous of Argentina.In this study,we focus on the morphology of Frenguellia eximia and emend its generic and specific diagnoses,based on new materials from the Upper Devonian Hongguleleng Formation of West Junggar,Xinjiang Uygur Autonomous Region,Northwest China,within the fossil-bearing bed palynologically dated as a latest Famennian age.This is the first finding of Frenguellia eximia out of Gondwana.Frenguellia eximia bears planate leaf with three upward pairs of lateral tips,isomorphic sporophyll to the leaf,and elongated,oval sporangium.Leaf morphology of the members of the Order Protolepidodendrales is summarized and classified into lateral-tip and distal-tip types.Lateral-tip type leaf consists of an obvious main body and several paired lateral tips,whereas distal-tip type leaf shows a petiole and a distal lamina with several planate or three-dimensional segments.Two leaf types probably indicate two independent evolutionary routes of microphylls evolving from simple leaf of prelycopsids during the Devonian period.The new occurrence of Frenguellia eximia further shows paleophytogeographical similarities between West Junggar and northwestern Gondwana.
