See text Monophyllites is an extinct cephalopod genus belonging to the family Ussuritidae that lived during the Triassic period, from Anisian to Ladinian age.
Whorl low and increasing slowly in height, little embracing and not deeply indented by the inner volution.
Sides somewhat flattened, venter rounded with indistinct abdominal shoulders.
The septa are monophyllic, the saddles rounded entire, contracted at the base and the lobes are digitate.
[2] The following species are recognized in the genus Monophylites[3] Fossils of species within this genus have been found in the Triassic of Afghanistan, Albania, Canada, Hungary, Italy, Japan, New Zealand, Oman, Pakistan, Russia, Switzerland, Turkey, United States.