claim: Species distribution can be understood through many factors except glaciation.
evidence: Eulimella is a genus of sea snails , marine gastropod mollusks in the family Pyramidellidae , the pyrams and their allies .. genus. genus. marine. marine ( ocean ). gastropod. gastropod. family. family ( biology ). Pyramidellidae. Pyramidellidae. The subgenus name Ptycheulimella Sacco , 1892 or Turbonilla -LRB- Ptycheulimella -RRB- Sacco , 1892 has been used to describe species whose shells show a weak fold on the columella and frequently a brownish spiral band .. Ptycheulimella. Ptycheulimella. Van Aartsen decided not to subdivide Eulimella s.l. because of the uncertainty of the identification of the type species of this subgenus compared with Tornatella pyramidata Deshayes , 183