After Hou & Bergström, 1997, and Edgecombe & Ramsköld, 1999
<==o †Petalopleura Hou & Bergström, 1997 |-- †Sinoburius lunaris Hou, Ramsköld & Bergström, 1991 [Sinoburiida Hou & Bergström, 1997: Sinoburiidae Hou & Bergström, 1997] |--o †Xandarellida Chen, Ramsköld, Edgecombe & Zhou in Chen et al., 1996 | `--o †Xandarellidae Hou & Bergström, 1997 [incl. Almeniidae Hou & Bergström, 1997] | |-- †Xandarella spectaculum Hou, Ramsköld & Bergström, 1991 | `-- †Cindarella eucalla Chen, Ramsköld, Edgecombe & Zhou in Chen et al., 1996 [Almenia spinosa Hou & Bergström, 1997] `--o †Cheloneillida Broili, 1933 `--o †Cheloniellidae Broili, 1932 |?- †Paraduslia Dunlop, 2002; E.Dev. EEu. |-- †Neostrabops martini Caster & Macke, 1952; L.Ord. NAm. `--+-- †Pseudoarthron Selden & White, 1984; L.Sil. |-- †Cheloniellon calmani Broili, 1932; E.Dev. CEu. `--+-- †Triopus Barrande, 1872; L.Ord. `-- †Duslia Jahn, 1893; L.Ord. CEu.
Reference(s):
- Edgecombe, G. D. & Ramsköld, L., 1999: Relationships of Cambrian Arachnata and the systematic position of Trilobita.
–Journal of Paleontology: Vol. 73, #2, pp. 263-287 - Hou X. & Bergström, J., 1997: Arthropods of the Lower Cambrian Chengjiang fauna, southwest China.
–Fossils & Strata, Number 45, 22nd December 1997, pp. 1-116