What is "bostrychoceras"

Bostrychoceras is a genus of heteromorph ammonite from the family Nostoceratidae. Fossils have been found in Late Cretaceous sediments in Europe and North America.

The shell of Bostrychoceras begins as a tightly wound helical spire, like that of Nostoceras, from which hangs a U or J shaped body chamber, at least in the adult. The shell is covered with dense, strong, but un-flaired, ribs that are commonly sinuous and oblique. May nor may not have strong constrictions.