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南极三叠纪的柏科种子球果。

A taxodiaceous seed cone from the Triassic of Antarctica.

出版信息

Am J Bot. 1997 Mar;84(3):343.

Abstract

A silicified seed cone is described from the lower Middle Triassic of A silicified seed cone is described from the lower Middle Triassic of Antarctica. The cone measures up to 3.4 cm long and 1.4 cm wide, and consists of helically arranged cone scales attached to a eustelic axis. Bract and ovuliferous scale are approximately of equal length and fused at the base. The bract is entire and vascularized by a single trace. The ovuliferous scale contains five distal lobes, each vascularized by a terete strand that divides to form a smaller trace to each of the five inverted ovules. Ovules are small and flattened with the three-parted integument attenuated into oppositely positioned lateral wings. The Triassic specimens are compared with both extant and fossil conifer seed cones and believed to have their closest affinities within the Taxodiaceae.

摘要

本文描述了产自南极洲下三叠统的硅化种子球果。该球果长达 3.4 厘米,宽 1.4 厘米,由螺旋排列的鳞片附着在茎轴上组成。苞片和胚珠鳞片大致等长,基部合生。苞片全缘,由单一迹维管束组成。胚珠鳞片有五个远端裂片,每个裂片由一个圆柱状的维管束组成,该维管束分裂成更小的迹维管束,分别通向五个倒生胚珠。胚珠小而扁平,具三部分的珠被退化形成相对的侧翼。三叠纪标本与现存和化石松柏类种子球果进行了比较,被认为与柏科Taxodiaceae 的亲缘关系最为密切。

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