Hyolitha - Orthothecida - Circothecidae
Synonym: Larawidae Kruse 1990 [replaced name]
Full reference: A. Y. Rozanov, V. V. Missarzhevsky, N. A. Volkova, L. G. Voronova, I. N. Krylov, B.M. Keller, I. K. Korolyuk, K. Lendzion, R. Mikhnyar, N. G. Pykhova, and A. D. Sidorov. 1969. Tommotskiu jarus i problema nizhney granisty kembriya [The Tommotian Stage and the Cambrian lower Boundary problem]. Trudy Geoligske Institut Leningrad 206:1-379
Parent taxon: Orthothecida according to P. Y. Parkhaev and Y. Demidenko 2010
See also Azmi and Pancholi 1983, Kruse 2002 and Rozanov et al. 1969
Sister taxa: Aldanothecidae, Allathecidae, Ancheilotheca, Bolitheca, Brevitheca, Bucanotheca, Carinitheca, Chelsonella, Cupitheca, Curtitheca, Ebianotheca, Eogloborilus, Eonovitatus, Girvanolithes, Gracilithecidae, Grandicornus, Hexitheca, Inflaticornus, Isititheca, Khetatheca, Kotuyitheca, Lophotheca, Minitheca, Mooritheca, Neobactrotheca, Nikatheca, Novitatidae, Orthothecidae, Panitheca, Paragloborilus, Petasotheca, Plicitheca, Probactrotheca, Renitheca, Sysoievia, Tchuranitheca, Tetratheca, Tetrathecidae, Triplicatellidae, Turcutheca
Subtaxa: Circotheca Conotheca Crossbitheca Guduguwan Laratheca Larawa
Ecology: stationary epifaunal suspension feeder
Distribution:
• Ordovician of the Czech Republic (1 collection), Sweden (1)
• Cambrian of Antarctica (1), Australia (38), Canada (11: New Brunswick, Nova Scotia, Quebec), China (137), France (3), Germany (1), Greenland (13), India (5), Iran (3), Kazakhstan (9), Mongolia (1), the Russian Federation (32), Turkey (1), the United Kingdom (3), United States (7: Massachusetts, New York, Pennsylvania)
• Solvan of Morocco (1)
• Ordian of Australia (2)
• Caerfai of Canada (1: Nunavut)
• Placentian of United States (2: Massachusetts)
• Ediacaran of Mexico (1)
Total: 274 collections including 368 occurrences