†family Sphaeragnostidae Kobayashi 1939 (artiopod)
Artiopoda - Agnostida - Sphaeragnostidae
Parent taxon: Agnostida according to H. B. Whittington et al. 1997
Sister taxa: Agnostina, Ceragnostus, Eodiscina, Formagnostus, Glyptagnostidae, Lavsanodiscus, Pleurinodus, Quadrahomagnostinae
Subtaxa: Sphaeragnostus
Ecology: slow-moving epifaunal detritivore
Distribution:
• Dobrotivian of the Czech Republic (1 collection)
• Ordovician of Canada (2: Quebec), China (7), the Czech Republic (1), Denmark (1), Poland (1), Sweden (3), the United Kingdom (3), United States (1: Maine)
Total: 20 collections each including a single occurrence