Massetognathus
| Massetognathus Temporal range: early Late Triassic ~ | |
|---|---|
| Skeleton | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Clade: | Synapsida | 
| Clade: | Therapsida | 
| Clade: | Cynodontia | 
| Family: | †Traversodontidae | 
| Subfamily: | †Massetognathinae | 
| Genus: | †Massetognathus Romer 1967 | 
| Type species | |
| †Massetognathus pascuali Romer 1967 | |
| Species | |
| 
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Massetognathus (/ˌmæsɪˈtɒɡnəθəs/ MASS-ə-TOG-nə-thəss; Greek for "chewing muscle jaw") is an extinct genus of plant-eating traversodontid cynodonts. They lived during the Triassic Period about 235 million years ago, and are known from the Chañares Formation in Argentina and the Santa Maria Formation in Brazil.