Mambetov in Missarzhevsky and Mambetov, 1981 Halkieria desquamata Duan, 1984 Halkieria directa Mostler, 1980 Halkieria elonga Qian et Yin, 1984 Halkieria equilateralis Qian et Yin, 1984 Halkieria folliformis Duan, 1984 Halkieria fordi Landing, 1991 Halkieria hexagona Mostler, 1980 Halkieria lata Mostler, 1980 Halkieria longa Qian, 1977 Halkieria longispinosa Mostler, 1980 Halkieria maidipingensis Qian, 1977 Halkieria mina Qian, Chen et Chen, 1979 Halkieria mira Qian et Xiao, 1984 Halkieria obliqua Poulsen, 1967 Halkieria operculus Qian, 1984 ?Halkieria pennata He, 1981 [=?Halkieria sthenobasis Jiang in Luo et al., 1982] Halkieria phylloidea He, 1981 Halkieria praeinguis Jiang in Luo et al., 1982 Halkieria projecta Bokova, 1985 Halkieria sacciformis Meshkova, 1969 Halkieria solida Mostler, 1980 Halkieria sthenobasis Jiang in Luo et al., 1982 Halkieria stonei Landing, 1989 Halkieria symmetrica Poulsen, 1967 Halkieria terastios Qian, Chen et Chen, 1979 Halkieria uncostata Qian et Yin, 1984 Halkieria undulata Wang, 1994 Halkieria ventricosa Mostler, 1980 Halkieria wangi Demidenko, 2010 Halkieria zapfei Mostler, 1980 At present, the structure of complete scleritome is known only for the single species named Halkieria evangelista from the Lower Cambrian of Greenland (Sirius Passet Formation). Phylogenetic position of Halkieria The evolutionary relationships of the halkieriids are a complex topic which is still being debated. Most of this debate is about their relationship to Wiwaxia and to the three major lophotrochozoan phyla — molluscs, annelids and brachiopods. The question of their relationship to an apparently much more primitive Cambrian group, the chancelloriids is also significant and may raise some difficult questions. Relationship to Molluscs, Annelids and Brachiopods In 1995 Conway Morris and Peel presented a cladogram based both on the fossils' features and on early 1990s research in molecular phylogeny, which is the application of cladistic analysis to DNA and RNA: The siphogonotuchids, a group found in Earliest Cambrian rocks, were the "sister" group to all the rest. These are known only from isolated fragments. The earliest halkieriids were a "sister" group to the molluscs, in other words descendants of a fairly closely related common ancestor. This relationship, they said, was supported by the muscular foot that most researchers assumed halkieriids had. Another halkieriid genus, Thambetolepis / Sinosachites, was a "great aunt" of annelids and Wiwaxia was an "aunt" of annelids. Their claim of a close relationship between halkieriids and Wiwaxia was based on both groups' having sclerites divided into three concentric zones. The close relationship of Wiwaxia to annelids was based on the