Isistius
| Isistius Temporal range: Thanetian to Present | |
|---|---|
| Cookiecutter shark (I. brasiliensis) | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Division: | Selachii |
| Order: | Squaliformes |
| Family: | Dalatiidae |
| Genus: | Isistius T. N. Gill, 1865 |
| Type species | |
| Isistius brasiliensis | |
Isistius is a genus of dogfish sharks in the family Dalatiidae. They are commonly known as cookiecutter sharks. Members of the genus are known for their unusual behaviour and dentition.