Halkieria是寒武纪一类躯体上披有骨质鳞片的疑难后生动物, 前后各有一个大壳板, 两侧对称, 其钙质骨片在软躯体上形成几条规律的纵向带。半个世纪以来, 学术界对Halkieria生物系统确切位置的讨论以及Halkieriidae不同属种亲缘关系的探索从未停止。本文总结了Halkieria化石在骨片属种分类、古地理和地层分布、生物系统分类学的研究进展，对当前的生物系统分类归纳出以下几种观点: 1) Halkieria为腕足动物的祖先, 并与托莫特壳类有一定的亲缘关系; 2) Halkieria与Wiwaxia等骨片化石具有单源性, 组成一种新的分类单元Halwaxiidae, 都属于软体动物或冠轮动物的干群; 3) Halkieria为软体动物有刺亚门干群, 与无板纲、多板纲更为亲近; 4) Halkieria为环节动物的祖先。目前, 虽然多数人根据Halkieria与现生多板纲的骨片排列一致将Halkieria归属软体动物有刺亚门的干群, 但新化石材料的发现及壳体发育研究使得Halkieria的系统发育位置出现新的争议。通过对化石分类学的系统厘定和生物分类研究进展的总结梳理, 本文进一步讨论了Halkieria对小壳化石的分类、骨片系重建及冠轮动物各门类的起源和谱系演化关系等方面的重要意义, 并提出当前Halkieria研究存在的问题及今后工作重点。

Halkieria is a kind of Cambrian problematic metazoan with mineralized sclerites covering its body. It possesses a large shell plate on both anterior and posterior parts of the body, and its calcareous sclerites are arranged bilaterially-symmetrically, which form several regular longitudinal bands on the body. For over half a century, the biological affinities of Halkieria or halkieriids have been contentious. This paper summarizes the research progress of Halkieria fossils in aspects of taxonomy, paleogeographical distribution, stratum spanning, and reviews the following viewpoints regarding its biological affinities: 1) Halkieria is a stem group brachiopod, and has a close relationship with tommotiids; 2) The sclerites fossils such as Halkieria and Wiwaxia are monogenic, forming a monophyletic lineage, Halwaxiidae, which belongs to a stem group mollusk or brachiopod and annelid; 3) Halkieria is a stem group of the Aculifera, that includes the class Polyplacophora and Aplacophora; 4) Halkieria is the ancestor of annelids. Of these, it is currently widely accepted that Halkieria is a stem group aculiferan because of the close comparability of scleritome construction between Halkieria and chitons, which, however has been challenged by new fossil materials discovered across the globe and ontogenetic studies of the animal. Through systematical determination of taxonomy and summary of research progress in biological affinities. The paper further discusses the significance of Halkieria in the taxonomy of SSFs, reconstruction of scleritome, origin and evolution of lophotrochozoans. And we further point out the deficiencies of current studies of Halkieria and highlight the research emphasis in future.

国家自然科学基金项目（面上项目，重点项目，重大项目）