Class
Merostomata Dana, 1852
Klassificering
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Arthropoda |
| Subphylum | Chelicerata |
| Superclass | Euchelicerata |
| Class | Arachnida |
| Merostomata | |
| Pycnogonida | |
| Xiphosura | |
| Order | Eurypterida |
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Arthropoda |
| Subphylum | Chelicerata |
| Superclass | Euchelicerata |
| Class | Arachnida |
| Merostomata | |
| Pycnogonida | |
| Xiphosura | |
| Order | Eurypterida |