Fossil History
Even though no fossil records of the species Philinopsis Pilbryi as been identified yet, several studies were able to identify fossil records of related order or class.
For instance, Bandel (1988) and Bieler (1992) listed acteonid-fossil shells, probably related to gastropods, from the Carboniferous.
Haas (1953) was also able to illustrate fossils of the more usual "bubble-shell" types similar to Retusa or Acteocina, which are highly related to Philinopsis p. (c.f. Systematics and phylogeny) from Upper Triassic.
Finally, numerous records of fossil opistobranchs from the Tertiary have been recently found (Valdes & Lozouet, 2000). |