Protozoa - Nassellaria - Williriedellidae
Original description: Shell of five segments, ovoidal. Cephalis spherical; thorax and abdomen truncate conical. The proximal three segments form a conical proximal part. The distal two segments form a cylindrical to ovoidal distal part. The last segment hemispherical without aperture. Segmental joints generally indistinct externally; joint between abdomen and fourth segment faintly marked by change in contour from the conical proximal part to the cylindrical to ovoidal distal part. Pores circular to subcircular, rather densely spaced and set in tetragonal to hexagonal pore frames. Pores on the distal part tend to be arranged longitudinally. Pores around distal end slightly larger than those on the rest of the shell; these pores surrounded by circular rims. Small nodes or spines situated at the pore frame vertices.
Original remarks: This species differs from Minocapsa globosa, n. sp. by consisting of five segments rather than four, by possessing a more slender distal part and by the pores of the distal part tending to be longitudinally arranged.
Etymology: The specific name comes from the Latin cylindricus-a-um (cylindrical).
Full reference: A. Matsuoka. 1991. Early Jurassic Radiolarians from the Nanjo Massif in the Mino Terrane, central Japan. Part 1. Tricolocapsa, Stichocapsa, and Minocapsa, n. gen. Transactions and Proceedings of the Paleontological Society of Japan, N.S. 161:720-738
Belongs to Minocapsa according to A. Matsuoka 1991
Sister taxa: Minocapsa globosa, Minocapsa megaglobosa
Type specimen: NU MR 0039. Its type locality is Mino Terrane, Nanjo Massif, Imajo Unit, sample MNA-10, which is in a Toarcian basinal (siliceous) mudstone in Japan.
Ecology: passively mobile planktonic omnivore
Distribution:
• Jurassic of Japan (3 collections), Slovenia (1)
Total: 4 collections each including a single occurrence
Specimen images are retrieved through the ePANDDA API.
Click image to enlarge. Click to access iDigBio record.