Saurostomus is an extinct genus of pelagic pachycormiform from the early Toarcian of Europe. Its only species is S. esocinus. Fossil remains have been found in England, Germany, and France.
The generic name means "lizard mouth." Cladistic analysis retains Saurostomus as sister to a clade comprising Ohmdenia and the suspension-feeding pachycormids.
This fish was large. The model on the right shows that it resembled a small shark, but with a smaller dorsal fin. The robust body had two pectoral fins, particularly elongated.
Saurostomus is is part of the Pachycormiformes, a group of bony fish that first appeared in the Lower Jurassic. In particular, it is a fish with some skull features bringing it closer to the giant filter feeder Leedsichthys.