Didymoceras is an extinct genus of ammonitecephalopod from the Late Cretaceous epoch (approximately 76 Ma). It is one of the most bizarrely shaped genera, with a shell that spirals upwards into a loose, hooked tip. It is thought to have drifted in the water vertically, moving up and down. The generic name is Greek for "paired horns".
Its taxonomic place is often in flux, being placed in either Turrilitidae, Nostoceratidae, or its own family, Didymoceratidae. Species included in the genus are the following:[1][2]
