Sactorthceras is an orthoceratoid genus (subclass Nautiloidea s.l.) known from the Middle Ordovician of eastern North America (NY), Norway and Korea and is the type genus of the Sactorthoceratidae.

Sactorthceras was named by Kobayashi in 1934 to include smooth or striated, straight or slightly curved longicones with short camerae and slender, subcentral, suborthochoanitic siphuncles with segments slightly inflated and no cameral deposits.

Sactorthocras has also been recognized in the Silurian Racine Formation of Wisconsin

Wisconsin

Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...

, and from the Ordovician of China and Iran. Related genera include Centroonoceras

Centroonoceras

Centroonoceras is a middle Ordovician cyrtoconic nautiloid cephalopod, otherwise similar to the orthoconic Sactorthoceras and also included in the Sactorthoceratidae...

and Sigmocycloceras

Sigmocycloceras

Sigmocycloceras is a nautiloid cephalopod discovered in the Middle Ordovician of Korea, said to be similar to Sactorthoceras, and included in the Sactorthoceratidae, but unique in being longitudinally sigmoid and sculpted with transverse annuli....

-References-

• Sweet, Walter C. 1964. Nautiloidea -Orthocerida. Treatise on Invertebrate Paleontology
  Treatise on Invertebrate Paleontology
  The Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and...
  
  , Part K. Geological Soc. of America and Univ of Kansas press.
• Sactorthoceras ref Paleodb