Palaeozoic Molluscs of Uncertain Systematic Position

(existing only as fossils)

Uncertain position (Gastropoda or Monoplacophora)

• unassigned to superfamily
  • Khairkhaniidae †
  • Ladamarekiidae †
  • Metoptomatidae †
  • Patelliconidae †
  • Protoconchoididae †
     
• Archinacelloidea
  • Archinacellidae †
  • Archaeopragidae †
     
• Pelagielloidea
  • Pelagiellidae †
  • Aldanellidae †
     
• Scenelloidea
  • Scenellidae †
  • Coreospiridae †
  • Igarkiellidae †
     
• Yochelcionelloidea
  • Yochelcionellidae †
  • Stenothecidae †
  • Trenellidae †

With isostrophically coiled shells of uncertain position (Gastropoda or Monoplacophora)

• Bellerophontoidea
  • Bellerophontidae †
  • Bucanellidae †
  • Bucaniidae †
  • Euphemitidae †
  • Pterothecidae †
  • Sinuitidae †
  • Tremanotidae †
  • Tropidodiscidae †

With anisostrophically coiled shells of uncertain position (Gastropoda?)

• Euomphaloidea
  • Euomphalidae †
  • Helicotomidae †
  • Lesueurillidae †
  • Omphalocirridae †
  • Omphalotrochidae †
     
• Macluritoidea
  • Macluritidae †

Basal taxa that are certainly Gastropoda

• unassigned to superfamily
  • Anomphalidae †
  • Codonocheilidae †
  • Crassimarginatidae †
  • Holopeidae †
  • Isospiridae †
  • Opisthonematidae †
  • Paraturbinidae †
  • Planitrochidae †
  • Pragoserpulinidae †
  • Pseudophoridae †
  • Raphistomatidae †
  • Rhytidopilidae †
  • Scoliostomatidae †
  • Sinuopeidae †
     
• Clisospiroidea
  • Clisospiridae †
  • Onychochilidae †
     
• Loxonematoidea
  • Loxonematidae †
  • Palaeozygopleuridae †
     
• Ophiletoidea
  • Ophiletidae †
     
• Straparollinoidea
  • Straparollinidae †
     
• Trochonematoidea
  • Trochonematidae †
  • Lophospiridae †

Return to: Systematics of Gastropoda.