Genus
Trigonograptus Nicholson, 1869
Classification
| Organism group | Biota |
| Domain | Eukaryota |
| Kingdom | Animalia |
| Phylum | Hemichordata |
| Class | Pterobranchia |
| Subclass | Graptolithina |
| Order | Graptoloidea |
| Suborder | Dichograptina |
| Family | Didymograptidae |
| Genus | Aulograptus |
| Baltograptus | |
| Cymatograptus | |
| Didymograptus | |
| Expansograptus | |
| Janograptus | |
| Jenkinsograptus | |
| Trigonograptus |