After Thomsen, 1978
Eiffelospina bifurcata (Thomsen, 1978) Cavalier-Smith, 2012
basionym Pinaciophora bifurcata Thomsen (1978)
(synonym Rabdiophrys bifurcata Roijackers and Siemensma, 1988)
Diagnosis: Periplast c. 20 X 12 µm when flattened, covered with scales of two kinds. Details of protoplast unknown. Plate-scales circular, 2.0-2.5 µm in diameter. A small number of differently sized larger perforations penetrate the distal plate, mainly clustered around the center of the scales. The major part of the distal scale surface is occupied by hexagonally close-packed fine perforations. A narrow band along the scale edge is patternless. The lower scale plate – visible through the larger distal plate perforations – appears to be patternless. The two scale plates are fused peripherally, elsewhere connected by intercalary material appearing as black dots with some tendency towards a hexagonal arrangement. Spine-scale 2.5-3.0 µm long and 0.8-0.9 µm wide at the distal bifurcate end (0.6-0.7 µm wide proximally and c. 0.2 µm at the narrowest point). The spine-scales are flattened distally into a very conspicuous bifurcation (hence the specific epithet). The triangular area between the branches is the only non-perforated part of the whole spine-scale. Proximally a number of struts attach the spine proper to an oval base plate. Large holes appear between these struts.
Type location: Dybso Fjord (Denmark). Surface water sample.