Genus
Sphenoecium Chapman et Thomas, 1936
List of species
2. Sphenoecium mesocambricus (Öpik, 1933) | Middle Cambrian (old nomenclature)
Luokittelu
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Hemichordata |
| Class | Pterobranchia |
| Subclass | Graptolithina |
| Order | Rhabdopleuridae |
| Genus | Archaeolafoea |
| Chaunograptus | |
| Chitinodendron | |
| Epigraptus | |
| Haplograptus | |
| Kystodendron | |
| Palaeotuba | |
| Rhabdohydra | |
| Rhabdopleura | |
| Rhabdopleurites | |
| Rhabdopleuroides | |
| Sokoloviina | |
| Sphenoecium | |
| Species | discoidalis |
| filicoides | |
| johanssoni | |
| mesocambricus | |
| obuti | |
| robustus | |
| tubularis | |
| wheelerensis | |
| Genus | Stolonodendrum |
| unranked | Cylindrotheca |