| Hystricognathi Temporal range: | |
|---|---|
| Desmarest's hutia (Capromys pilorides) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Suborder: | Hystricomorpha |
| Infraorder: | Hystricognathi Tullberg, 1899 |
| Families | |
|
Abrocomidae | |
| Synonyms | |
|
Eucaviomorpha | |
The Hystricognathi are an infraorder of rodents. They have a unique bone structure in their skulls. Their masseter medialis (jaw muscle) goes through a hole below each eye (called the infraorbital foramen). The muscle then connects through the bone on the opposite side. The name Hystricognathi name comes from Ancient Greek ὕστριξ (hústrix, or porcupine), and γνάθος (gnáthos, or "jaw").
There are 18 families in Hystricognathi. Hystricognathi is divided into two parvorders: the Phiomorpha and the Caviomorpha. The Caviomorpha are mostly from South America. A few species are in the Caribbean and North America. The Phiomorpha are in the Old World.
