The Eubostrychoceras (1967)

Phylum : Mollusca
Class : Cephalopoda
Subclass : Ammonoidea
Order : Ancyloceratida
Superfamily : Turrilitaceae
Family : Nostoceratidae
Genus : Eubostrychoceras
Species : E. japonicum

  • Late Cretaceous (90 - 75 Ma)
  • 15 cm long (size)
  • Antarctica, Japan, Spain, Russia and Germany (map)

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. 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.