| abstract | - Euomphalidae is an extinct family of mainly Paleozoic gastropods characterized by a shell that is most commonly discoidal with a wide umbilicus, coiling variable from open with whorls apart to close coiled with whorls in contact. An outer-upper angulation that forms an outer ridge, preserved to be an exhalent channel is generally present, rarely with a short slit or selenizone. Euomphalids are archaeogastropods included in the Macluritina, which with the Helicotomidae and Omphalotrochidae forms the Euomphalacea. The Schizostomatidae Bronn, 1849, Polytropidae Ulrich, 1897, and Poleumitidae Wenz, 1938, are junior synonyms.
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