乌达早二叠世Sphenophyllum angustifolium(Germar)Geoppert的形态复原与生态习性探讨

MORPHOLOGICAL RECONSTRUCTION AND ECOLOGICAL HABIT OF SPHENOPHYLLUM ANGUSTIFOLIUM(GERMAR)GOEPPERT FROM EARLY PERMIAN OF WUDA,INNER MONGOLIA

基于内蒙古乌达下二叠统太原组火山凝灰岩中保存的标本对窄楔叶Sphenophyllum angustifolium(Germar)Goeppert的形态特征和生态习性进行探讨。标本异叶性明显,不同等级的茎上保存钩状线形叶、二裂叶、三裂叶和四裂叶。孢子叶穗着生于分枝顶端,每轮大约12片孢子叶,每片孢子叶近轴面上直接着生1个孢子囊,未发现孢囊柄的结构。本文对该植物的气生部分进行初步复原。根据本文材料以及已报道的楔叶属化石材料的形态学、解剖学特征和埋藏学的分析,认为该属植物可能是一种可以直立生长的草本植物,生活在三角洲平原、泛滥盆地或岸后湖泊、成煤沼泽及其边缘,适应轻度干旱至淹水环境。根据S.angustifolium(Germar)Goeppert深裂的叶型和表皮细胞特征,推测其可能生活在较长期淹水环境,属于湿性中生植物至湿性植物。

Based on specimens collected from the Early Permian volcanic tuff of the Taiyuan Formation, Wuda, Inner Mongolia, morphological characteris- tics and ecological habit of Sphenophyllurn angus- tifolium （Germar） Goeppert have been studied. This species is obviously heterophyllous with hook-linear leaf, two-toothed leaf, three-toothed leaf and four-toothed leaf attached to various orders of axes. Strobili are attached to the apex of lateral branch, articulated, with about twelve spo- rophylls per whorl. Sporangia are sessile, located on the adaxial side of the sporophyll. A tentative aerial parts reconstruction ed. On the basis of the pre with the morphological, of this plant is provid- sent ana and taphonomic analysis of pu Sp Sp as materials, together tomical characters, blished materials of enophyllum Brongniart, it enophyllum Brongniart may erbaceous plants living in al basin, the shore of lucustrine, their margins, adapting to sligh environment. Accordingly, S is concluded that be self-supported luvial plain, flood coal swamps and tly dry to flooded angusti folium （Germar） Goeppert may have lived in a frequently flooded environment, with respect to its deeply dissected leaves and features of epidermal cells, as a hygrophytic mesophyte to hygrophyte.