Protozoa - Nassellaria - Eucyrtidiidae
Original description: Test conical, short, with two post-abdominal chamber, without circumferential ridges. Cephalis small, dome-shaped, without horn. Cephalis, thorax, and abdomen closely spaced, sparsely perforate, covered with layer of microgranular silica. Post-abdominal chamber consisting of single layer of pentagonal and hexagonal pore frames. Pore frames increasing in size distally. Bulbous expansion large, subspherical in outline, comprised of nearly two thirds of whole test.
Original remarks: Pseudoristola obesa differs from other Pseudoristola spp. in this report by having an extremely short test with a very large bulbous subspherical final post-abdominal chamber.
Etymology: Obesus-a-um (Latin, adj.) fat. Original description: Test conical, short, with two post-abdominal chamber, without circumferential ridges. Cephalis small, dome-shaped, without horn. Cephalis, thorax, and abdomen closely spaced, sparsely perforate, covered with layer of microgranular silica. Post-abdominal chamber consisting of single layer of pentagonal and hexagonal pore frames. Pore frames increasing in size distally. Bulbous expansion large, subspherical in outline, comprised of nearly two thirds of whole test.
Original remarks: Pseudoristola obesa differs from other Pseudoristola spp. in this report by having an extremely short test with a very large bulbous subspherical final post-abdominal chamber.
Etymology: Obesus-a-um (Latin, adj.) fat. Original description: Test conical, short, with two post-abdominal chamber, without circumferential ridges. Cephalis small, dome-shaped, without horn. Cephalis, thorax, and abdomen closely spaced, sparsely perforate, covered with layer of microgranular silica. Post-abdominal chamber consisting of single layer of pentagonal and hexagonal pore frames. Pore frames increasing in size distally. Bulbous expansion large, subspherical in outline, comprised of nearly two thirds of whole test.
Original remarks: Pseudoristola obesa differs from other Pseudoristola spp. in this report by having an extremely short test with a very large bulbous subspherical final post-abdominal chamber.
Etymology: Obesus-a-um (Latin, adj.) fat. Original description: Test conical, short, with two post-abdominal chamber, without circumferential ridges. Cephalis small, dome-shaped, without horn. Cephalis, thorax, and abdomen closely spaced, sparsely perforate, covered with layer of microgranular
silica. Post-abdominal chamber consisting of single layer of pentagonal and hexagonal pore frames. Pore frames increasing in size distally. Bulbous expansion large, subspherical in outline, comprised of nearly two thirds of whole test.
Original remarks: Pseudoristola obesa differs from other Pseudoristola spp. in this report by having an extremely short test with a very large bulbous subspherical final post-abdominal chamber.
Etymology: Obesus-a-um (Latin, adj.) fat. Original description: Test conical, short, with two post-abdominal chamber, without circumferential ridges. Cephalis small, dome-shaped, without horn. Cephalis, thorax, and abdomen closely spaced, sparsely perforate, covered with layer of microgranular silica. Post-abdominal chamber consisting of single layer of pentagonal and hexagonal pore frames. Pore frames increasing in size distally. Bulbous expansion large, subspherical in outline, comprised of nearly two thirds of whole test.
Original remarks: Pseudoristola obesa differs from other Pseudoristola spp. in this report by having an extremely short test with a very large bulbous subspherical final post-abdominal chamber.
Etymology: Obesus-a-um (Latin, adj.) fat.
Alternative combinations: Pseudoristola obesa, Stichocapsa obesa
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 Lantus according to L. O'Dogherty and H. J. Gawlick 2008
See also Gorican et al. 2006
Sister taxa: Lantus intermedius, Lantus praeobesus, Lantus sixi, Lantus sutnal
Type specimen: NMNS (0001555). Its type locality is Suplee-Izee area, OR-600A, which is in a Toarcian marine tuff/limestone in the Hyde Formation of Oregon.
Ecology: passively mobile planktonic omnivore
Distribution:
• Jurassic of Austria (1 collection), Canada (9: British Columbia), Greece (1), Japan (2), Oman (3), United States (1: Oregon)
Total: 17 collections including 18 occurrences
Specimen images are retrieved through the ePANDDA API.
Click image to enlarge. Click to access iDigBio record.