Megalograptidae
| Megalograptidae Temporal range: Middle Ordovician - Late Ordovician,  | |
|---|---|
| Megalograptus | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Arthropoda | 
| Subphylum: | Chelicerata | 
| Order: | †Eurypterida | 
| Infraorder: | †Diploperculata | 
| Superfamily: | †Carcinosomatoidea | 
| Family: | †Megalograptidae Caster & Kjellesvig-Waering, 1955 | 
| Genera | |
Megalograptidae are a family of eurypterids, an extinct group of chelicerate arthropods commonly known as "sea scorpions".
The megalograptids were likely the first major successful group of eurypterids, evidenced by a Late Ordovician radiation. All known members of the Megalograptidea are from the Late Ordovician of Laurentia with the exception of the large Pentecopterus from the Middle Ordovician.