Superfamily Turrilitaceae Subclass Ammonites | Order Ancyloceratida Rank Genus | |
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Similar Ammonites, Ainoceras, Nostoceras, Ancyloceratina, Turrilites costatus | ||
Eubostrychoceras is a genus of helically wound, corkscew form, heteromorph ammonite which lived during the Upper Cretaceous (M Turonian - Campanian). The genus is included in the ancycleratid family Nostoceratidae.
The shell of Eubostrychoceras is a loosely to tightly wound spiral forming a corkscrew with an open, empty umbilicus in the middle. coiling is commonly dextral (right hand). Coils are covered by moderately strong, straight transverse ribs. The aperture, or apertural end, reverses general direction and points upwards or back towards to apex. Sutures are moderately complex. The siphuncle is located mid flank.
Eubostrychoceras has a widespread distribution in the Upper Createous and has been found in Antarctica, Japan, Spain, the far east of Russia, Alaska, U.S. western interior, Madagascar, Germany, and Madagascar. In 2001 it was reported from Alaska's Matanuska Formation as well. E. japonicum is Turonian, and likely confined to the middle Turonian.
Related genera include Anaklinoceras, Bostychocdras, Didymoceras, and Nostoceras
