机构地区: 兰州大学资源环境学院
出 处: 《古生物学报》 2009年第4期654-661,共8页
摘 要: 在云南保山羊邑煤矿上新统羊邑组发现了一栎属高山栎组植物压型化石,根据叶形态和表皮微细构造特征,将其鉴定为前灰背栎(Quercus presenescens Z.K.Zhou)。该标本具有之字形中脉,叶最宽处形成一矩形区域,叶缘略反卷的特征,与已报道的前灰背栎化石形态一致,且区别于其它已发现的高山栎组化石。解剖学研究表明,该化石叶片为气孔下生型,上、下表皮均无毛基;上表皮细胞为四边形,垂周壁波状弯曲;下表皮细胞多为四-五边形,垂周壁波状弯曲,气孔器环列型。通过与现生高山栎组植物叶形态相比,当前化石与灰背栎最为接近,且其表皮细胞形态、气孔器类型与现生灰背栎基本一致,二者的主要区别在于前灰背栎无毛基,而现生灰背栎有表皮毛。研究认为,两者被毛的差异,是植物叶形态结构对气候变化的响应。 A compression fossil reported as Quercus sect. Heterobalanus was collected from the Plioeene Yangyi Formation at the Yangyi eoal-mine of Baoshan, Yunnan, and is identified in this study as Quercus presenescens Z. K. Zhou based on morphological and cuticular characters. The typical morphological characters of the fossil are zigzag primary vein, oblong leaf blade and revolute leaf margin; these features are characteristic of Q. presenescens, but different from those of Quercus sect. Heterobalanus. The epidermal characters are as follows,