Megamastax

Megamastax
Temporal range: Late Silurian,
Megamastax fossils and estimated body length charts
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Osteichthyes
Clade: Sarcopterygii
Genus: Megamastax
Choo et al., 2014
Type species
Megamastax amblyodus
Choo et al., 2014

Megamastax (meaning "big mouth") is a genus of lobe-finned fish which lived during the late Silurian period, about 423 million years ago, in China. Before the discovery of Megamastax, it was thought that jawed vertebrates (gnathostomes) were limited in size and variation before the Devonian period. Megamastax is known only from jaw bones and it is estimated that it reached about 1 metre (3 ft 3 in) long.