Protozoa - Spumellaria - Orbiculiformidae
Original description: Test thick, circular in outline, with large, deep central cavity. Test consisting of concentric layers of small irregular polygonal pore frames with circular to elliptical pores. Pore frames slightly larger on rims, smaller in central cavity and median band of margin, Margin slightly concaved with several small peripheral spines. Peripheral spines usually thin, short, circular in cross-section. Diameter of central cavity about half the diameter of test.
Original remarks: Orbiculiforma callosa, differs from 0. trispina, by having a test with larger central cavity and by having several small peripheral spines rather than three massive, elongate spines.
Etymology: Callosus-a-um (Latin, adj.) hard. Description: Test thick, circular in outline, with large, deep central cavity. Test consisting of concentric layers of small irregular polygonal pore frames with circular to elliptical pores. Pore frames slightly larger on rims, smaller in central cavity and median band of margin, Margin slightly concaved with several small peripheral
spines. Peripheral spines usually thin, short, circular in cross-section. Diameter of central cavity about half the diameter of test.
Remarks: Orbiculiforma callosa, differs from 0. () trispina, by having a test with larger central cavity and by having several small peripheral spines rather than three massive, elongate spines.
Etymology: Callosus-a-um (Latin, adj.) hard.
Alternative combination: Orbiculiforma callosa
Synonyms: Orbiculiforma kwunaensis Carter 1988 [objective synonym], Orbiculiformella kwunaensis Carter 1988 [objective synonym]
Full reference: K. Y. Yeh. 1987. Taxonomic Studies of Lower Jurassic Radiolaria from East-Central Oregon. National Museum of Natural Science Special Publications 2:1-169
Belongs to Orbiculiformella according to L. O'Dogherty and H. J. Gawlick 2008
See also Gorican et al. 2006
Sister taxa: Orbiculiformella incognita, Orbiculiformella mediocircus, Orbiculiformella teres, Orbiculiformella trispina
Type specimens:
- Orbiculiformella callosa: NMNS (000039)
- Orbiculiforma kwunaensis: Its type locality is GSC loc. C-080577, Maude Island, which is in a Pliensbachian open shallow subtidal sandstone in the Fannin Formation of Canada.
Ecology: passively mobile planktonic omnivore
Distribution:
• Jurassic of Austria (1 collection), Canada (1: British Columbia), Mexico (6), Oman (1), Slovenia (5), United States (3: Oregon)
Total: 17 collections each including a single occurrence
Specimen images are retrieved through the ePANDDA API.
Click image to enlarge. Click to access iDigBio record.