Rhynchonellata - Rhynchonellida - Hemithirididae
Alternative spelling: Hemithyridae
Synonym: Hemithyrididae Rzhosnitskaya 1956 [replaced name]
Parent taxon: Hemithiridoidea according to C. C. Emig et al. 2013
See also Chiesa et al. 1995, Cooper 1959, Craig 2000 and Williams et al. 2002
Sister taxa: Cyclothyrididae, Notosariidae, Septirhynchiidae, Tetrarhynchiidae
Subtaxa: Hemithiris Paraplicirhynchia Patagorhynchia
Distribution:
• Quaternary of Canada (2: Newfoundland and Labrador, Quebec collections), Greenland (5), Japan (7), United States (3: Alaska, Oregon)
• Pliocene to Pleistocene of Japan (1)
• Pliocene of Japan (1)
• Miocene of Argentina (2), Chile (1), Japan (4)
• Oligocene of United States (5: Washington)
• Eocene of Antarctica (2), United States (4: Washington)
• Paleogene of Antarctica (2)
Total: 39 collections including 45 occurrences