Cephalopoda - Orthoceratoidea - Sactorthoceratidae

Alternative combination: Orthoceras makkolense

Synonyms: Cycloceras taihakuense Kobayashi 1934, Kawasakiceras densistriatum Kobayashi 1934, Sactorthoceras gonioseptum Kobayashi 1934, Sactorthoceras shimamurai Kobayashi 1934, Sigmorthoceras sigmoidale Kobayashi 1934

Belongs to Sactorthoceras according to C.-S. Yun 1999

Sister taxon: Sactorthoceras banestanensis

Type specimens:

• Sactorthoceras makkolense: UMUT PM6 (lectotoype), a shell. Its type locality is Makkol, which is in a Llanvirn marine shale/limestone in the Jigunsan Formation of South Korea.
• Cycloceras taihakuense: UMUT PM659, a shell. Its type locality is Makkol, which is in a Llanvirn marine shale/limestone in the Jigunsan Formation of South Korea.
• Kawasakiceras densistriatum: UMUT PM634, a shell. Its type locality is Makkol, which is in a Llanvirn marine shale/limestone in the Jigunsan Formation of South Korea.
• Sactorthoceras gonioseptum: UMUT PM650, a shell. Its type locality is Makkol, which is in a Llanvirn marine shale/limestone in the Jigunsan Formation of South Korea.
• Sactorthoceras shimamurai: UMUT PM643, a shell. Its type locality is Makkol, which is in a Llanvirn marine shale/limestone in the Jigunsan Formation of South Korea.
• Sigmorthoceras sigmoidale: UMUT PM652, a shell. Its type locality is Makkol, which is in a Llanvirn marine shale/limestone in the Jigunsan Formation of South Korea.

Ecology: fast-moving nektonic carnivore