Family Trimusculidae Burch 1945 (button snail)
Gastropoda - Heterostropha - Trimusculidae
Parent taxon: Ellobioidea according to P. Bouchet et al. 2017
See also Abbott 1974 and Bouchet et al. 2005
Sister taxa: Carychiidae, Ellobiidae
Subtaxa: Trimusculus
Type: Trimusculus
Ecology: facultatively mobile low-level epifaunal grazer
Distribution:
• Quaternary of Angola (1 collection), Ecuador (1), Mexico (7), South Africa (1), United States (13: California)
• Pliocene of the Dominican Republic (1)
• Oligocene of Canada (2: British Columbia)
Total: 26 collections each including a single occurrence