Citation: Phormacantha Jørgensen 1905Taxonomic rank: genusBasionym: PhormacanthaType species: Peridium hystrix Jørgensen 1900Taxonomic discussion: Recent. [rather minimal development of cephalic lattice wall but Jörgensen considered this to be closely related to Plectacantha, which is in the Lophophaenidae-dbl]
Original description: Has the same four primary spines and the same three primary arches as Plectacantha. There is, however, also a ventral, sagittal spine, which is less strongly developed than the others (""der secundäre Mittelstachel Jørgensen, 1900, p. 77). The network, as in Plectacantha, is at a late stage and only imperfectly closed beneath.
Description
Biogeography and Palaeobiology
Biostratigraphic distribution
Geological Range: Last occurrence (top): Extant. Data source: Total of ranges of the species in this database First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Lophophaenidae
References:
Jørgensen, E (1905). The protist plankton and diatoms in bottom samples: Radiolaria. In, Nordgaard (ed.) Hydrographical and biological investigation in Norwegian Fjord. 49-151. gsO
Phormacantha compiled by the radiolaria@mikrotax project teamviewed: 8-7-2025