许氏创孔海百合Traumatocrinus hsui的形态定量分析和个体发育过程

Quantitative morphological analysis and ontogeny of Traumatocrinus hsui

Traumatocrinus hsui Mu,1949是关岭生物群的重要组成成员,以数量众多、保存精美、营假浮游生活闻名于世。笔者等通过对5件群体保存标本中的127个大小不同个体的系统描述和形态定量分析,认为T.hsui萼部与整个冠部存在异速生长的特征,个体发育过程中腕的级数和数目逐渐增加;T.hsui的个体发育可分为3个时期6个阶段,即幼年期(Ⅰ、Ⅱ)、少年期(Ⅰ、Ⅱ、Ⅲ)、成年期;幼年期:个体较小,冠高小于26 mm,腕分枝至4级;少年期:个体中等,冠高26~130 mm,腕分枝至7级;成年期:个体较大,冠高大于130 mm,腕分枝至8级。前人在关岭生物群中研究命名的Traumatocrinus hsui enormis Mu,1949,Traumatocrinus kueichouensis Mu,1949,Traumatocrinus uniformis Mu,1949,Traumatocrinus sp.Mu,1949,Traumatocrinus guanlingensis Yu et al.,2000和Traumatocrinus xinpuensis Wang et al.,2002等均为T.hsui的同种异名,其命名标本为个体发育的不同阶段或局部特征。

Objectives:Traumatocrinus hsui is an indispensable part of Guanling Biota.Traumatocrinus hsui with various sizes from the black—dark gray argillaceous limestone of the Wayao Member of the Upper Triassic Falang Formation in Guanling County(South China,Guizhou Province)were discovered,indicating changes of characters in Traumatocrinus hsui from different periods.Methods:Morphological observation and quantitative morphological analysis were conducted in the ontogeny of Traumatocrinus hsui.Different forms of Traumatocrinus hsui were observed and compared in morphological observation,and traditional morphometry was performed in quantitative morphological analysis,in which scatterplot linear regression analysis was principally applied.Results:With crown height increasing,the ratio of cup height to crown height continuously decreased and finally stabilized.Each third-grade arm branches into about 30 fourth-grade arms,some of which even branch to eighth-grade arms.The proximal columns grades increasingly and 4 grades was counted at most.Conclusions:①There are three ontogenetic stages during the ontogeny of Traumatocrinus hsui including infancy,juvenile,and adult.Infancy can be divided into two stages:ⅠandⅡand juvenile can be divided into three stages:Ⅰ,Ⅱ,andⅢ.②Traumatocrinus hsui enormis Mu,1949,Traumatocrinus kueichouensis Mu,1949,Traumatocrinus uniformis Mu,1949,Traumatocrinus sp.Mu,1949,Traumatocrinus guanlingensis Yu et al.,2000 and Traumatocrinus xinpuensis Wang et al.,2002 all should be treated as synonyms for Traumatocrinus hsui Mu,1949.