山东寒武系崮山组褶颊虫类三叶虫Jiulongshania acalla个体发育过程中的头盖形态变化及其生态学意义  

Cranidial Shape Variation during Ontogeny in Ptychopariid Trilobite Jiulongshania acalla from the Cambrian Gushan Formation of Shandong Province and Its Ecological Implication

作　　者：秦树健 董琳[1] QIN Shujian;DONG Lin(School of Earth and Space Sciences,Peking University,Beijing 100871)

机构地区：[1]北京大学地球与空间科学学院,北京100871

出　　处：《北京大学学报（自然科学版）》2024年第4期626-638,共13页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金(41402025)资助。

摘　　要：基于大量采自山东济南唐王寨剖面寒武系崮山组的阿克利九龙山虫Jiulongshania acalla Walcott,1905标本,用传统的形态测量方法和几何形态测量方法,对头盖形态特征进行度量和定量化分析,揭示其在个体发育过程中的形态变化特点。研究结果显示,在个体发育过程中,J.acalla鞍前区的生长速率最快,头盖宽度的生长速率最慢,头盖形态变化主要表现为头盖整体形态由半扁椭圆形向半长椭圆形转变,鞍前区的宽度逐渐增加。推测三叶虫外骨骼形态的变化,特别是头盖形态的变化,可能与三叶虫的取食方式有关;J.acalla头盖标本在个体发育过程中的形态变化,可能指示从幼虫到成虫取食方式的改变。Based on a large number of cranidial specimens of Jiulongshania acalla Walcott,1905 from the Cambrian Gushan Formation at the Tangwangzhai section in Jinan City,Shandong Province,the traditional morphometric method and geometric morphometrics were used to measure and quantify the morphological features of the cranidium,revealing the cranidial shape variation during ontogeny.The results show that the growth rate of preglabellar field is the fastest,and the rate for the cranidial width is the slowest.The cranidial shape variation during ontogeny is mainly characterized by elongation of cranidium and gradual increase in the length of preglabellar field.It is proposed that the variation of trilobite exoskeletal morphology,particularly the cephalon,might be related to the feeding mode of trilobite.The results may suggest that the feeding habits of J.acalla might have changed during development.

关 键 词：Jiulongshania acalla 头盖形态变化 寒武系 崮山组 山东 

分 类 号：Q915[天文地球—古生物学与地层学]