内蒙古晚侏罗世一个新的杉科球果  

A new permineralized taxodiaceous cone from the Upper Jurassic of Inner Mongolia

作　　者：郑月娟[1] 郑少林[1] 陈树旺[1] 寇林林[1] 张建[1] 黄欣[1] 

机构地区：[1]沈阳地质矿产研究所,沈阳110034

出　　处：《科学通报》2013年第S1期178-184,共7页Chinese Science Bulletin

基　　金：中国地质调查局(1212010782001;121011121086)资助项目

摘　　要：一个全矿化的杉科种子球果Cunninghamiostrobus minor sp.nov.被描述于内蒙古科尔沁右翼中旗上侏罗统满克头鄂博组.种子球果为同带叶小枝着生或联合.每个种子球果呈卵圆形至椭圆形,并由一个粗壮的球果轴和很多呈螺旋状着生于轴上的苞片-鳞片复合体组成.苞片呈桃形,体积较大,彼此呈覆瓦状排列,成熟后向外伸展,并在近轴面的基部处同退缩的珠鳞(鳞片)局部融合.珠鳞较小,呈三瓣状,在每个株鳞基部的近轴面有3枚反转的胚珠/种子.球果的轴和带叶小枝的茎的内部构造由一个木质部圆筒组成.木质部圆筒包括一个中央的异质的髓,髓的外侧依次是内始式的初生木质部、次生木质部、韧皮部和皮层.次生木质部管胞径向壁上的纹孔呈多角形或圆形,排成1~2列,两列时互生或单列时互相接触,纹孔式为过渡式.在一般的外部形态和内部解剖构造特征方面,新种的种子球果和带叶小枝与化石Cunninghamiostrobus yubariensis Stopes et Fujii和C.huberi Miller,以及现生Cunninghamia lanceolata(Lamb.)Hook的相似.但后者属种球果轴内部的髓是同质的,次生木质部管胞径向壁的纹孔式是现代式的,而且在种子球果的其他解剖构造方面与前者也有重要区别.Permineralized taxodiaceous seed cones of Cunninghamiostrobus minor sp. nov. are described from the Upper Jurassic(Manketouebo Formation)of Kharcin Right Wing Middle Banner,Inner Mongolia,China. They are either organically attached to or associated with leafy shoots. Each seed cone is ovate to elliptic,and consists of a stout axis and numerous helically arranged bract-scale complexes. The peach-shaped bract protrudes beyond,and is partially fused with the reduced ovuliferous scale at near base. The ovuliferos scale is a small trilobate scale with three reversed ovules/seeds. Pitting of radial wall of tracheids in secondary xylem of the cone axis and leafy twig is either alternate biseriate or crowded uniseriate. Morphological,structural features of seed cones and leafy shoots of the new species are compared with those of the fossil Cunninghamiostrobus yubariensis Stopes et Fujii,and C. huberi Miller and extant seed cones of the Cunninghamia lanceolata(Lamb.) Hook but different from them in its more plesiomorphic transitional pitting pattern.

关 键 词：全矿化 杉科 种子球果 Cunninghamiostrobus MINOR sp. nov. 晚侏罗世 内蒙古 

分 类 号：Q914[天文地球—古生物学与地层学]