| A (0 species) |
| B (1 species) |
| Boreaspis - Pragian-Emsian |
| C (1 species) |
| Cephalaspis - Early Devonian 415-398 Ma |
| D (1 species) |
| Dartmuthia - Late Silurian |
| E (0 species) |
| F (0 species) |
| G (0 species) |
| H (1 species) |
| Hemicyclaspis - Early Devonian |
| I (0 species) |
| J (0 species) |
| K (0 species) |
| L (0 species) |
| M (0 species) |
| N (0 species) |
| O (0 species) |
| P (0 species) |
| Q (0 species) |
| R (0 species) |
| S (0 species) |
| T (1 species) |
| Tremataspis - Late Silurian |
| U (0 species) |
| V (0 species) |
| W (0 species) |
| X (0 species) |
| Y (0 species) |
| Z (1 species) |
| Zenaspis - Early Devonian |