Stratigraphy
Era:
System:
Series:
Stage:
Substage:
Site and situation
City:
Site:

Identification
  Major shell forms
  Shell outline
  Ubbilicus
  Whorl cross section
  Ventral outlook
  Rib orientation
  Ribs, distance and combination
  Ribs, rib type
  Ribs, rib spreading
  Growthlines
  Decoration
  Position decoration

 
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