For other uses, see Pachycormus. For the species of plant, see Pachycormus discolor.

Pachycormus is an extinct genus of pachycormiform from the Toarcian (about 185–182 million years ago) of Europe. This fish had no pelvic fins.

Pachycormus superficially resembled a giant tuna. It was able to grow 1 m (3.5 ft) in length. It is characterized by falciform pectoral fins. The teeth are short and designed for grasping.

The caudal fin was deeply forked, just like a modern-day tuna. The body was covered with small scales equipped with ganoine.

The type species P. macropterus was first named as a species of Elops by Henri Marie Ducrotay de Blainville in 1818. However, this species was placed into Pachycormus by Louis Agassiz in 1833.

Pachycormus is the second most basal pachycormiform after Euthynotus.

Fossils have been found in marine deposits from France, Germany, and England.

• Pleuropholis
• Amblypterus
• Orthocormus
• Bonnerichthys

1. Roberts, George (1839). An etymological and explanatory dictionary of the terms and language of geology. p. 129. Retrieved 31 December 2021.