What is "berriasella"

Berriasella is a discoidal evolute perisphinctacean ammonite, and type genus for the neocomitid subfamily Berriasellinae. Its ribbing is distinct, consisting of both simple and bifurcated ribs that extend from the umbilical seam across the venter; its whorl section generally compressed, the venter more or less narrowly rounded.

Berriasella, named by Uhlig, 1905, is known from the late Upper Jurassic, Tithonian, to the early Lower Cretaceous, Berriasian and has a fairly world-wide distribution.