豫西寒武系第三统张夏组上部保存有大量发育厚壁的遗迹化石。通过野外多剖面多角度观察,结合室内遗迹化石特征统计、宏观一微观结构的分析,发现该遗迹化石的纵切面形态多为I/J形和宽扁u形,且多呈簇状或束状的集群分布,具有厚的衬壁,被深色晕圈所围绕。单个潜穴结构由分界清晰的三部分组成:深灰色亮晶方解石组成的填充物、浅灰白色灰泥质衬壁、深灰色微晶方解石和白云石组成的晕圈。根据这些特征将其定名为Schaubc ylindrichnus heberti,并对其进行形态功能分析,认为S.heberti体现了造迹生物复杂的行为习性:两种摄食方式(建造潜穴时的食沉积物以及居住时的漏斗进食),主动避免环境中的不利因素(建造厚的衬壁),以及快速生长的生存策略(不断废弃旧管、建造新管)。在寒武系张夏组灰岩中发育大量且属种单一的Schaubcylindrichnus,说明寒武纪生物的行为习性已有显著进化,生物应对复杂环境的能力有了很大提升。
Trace fossils with thickly lined tubes are abundantly preserved in the Zhangxia Formation of the Cambrian.Series 3 in western Henan Province. The morphological features are described here by observation from several field sections and microscopic photos~ they are I/J-shaped or flat U- shaped tubes in the vertical cross-section, which are thickly lined, and a bundle of tubes are usually packed by an irregular aureola. A single tube is made of three distinct parts: sparry calcite fillings, packstone linings, and microerystalline calcite and dolomite aureola. Based on these morphological features, we propose that this trace fossil should be re-assigned to Schaubcylindrichnus heberti. According to the functional morphologic analysis, we hypothesize that the trace maker was capable of complex behaviors and survival strategies as follows: various feeding modes-deposit feeding during building burrow and filter feeding after completed construction~ actively avoid adverse factors by constructing thick lining~ and rapid growth strategy-building new tubes and abandoned the little ones unceasingly forming a bundle of tubes. Intensive bioturbation by the single ichnos- pecies of Schaubcylindrichnus found in Cambrian limestones shows that significantly improvement of biological behavior evolution and adaptation for hostile habitat.