Bolboforma n. gen. (Protozoa?) — eine neue stratigraphisch wichtige Gattung aus dem Oligozän/Miozän Nordwestdeutschlands

The Genus Bolboforma Daniels and Spiegler in the Oligocene and Miocene Sediments of the North Atlantic and Northern Europe

“…B. spiralis has not been reported from the lower Miocene of the Antarctic (Rögl and Hochuli, 1976) or from the Norwegian-Greenland Sea. On the other hand, the common occurrence of B. metzmacheri in the upper Miocene sediments of Germany, as described by Daniels and Spiegler (1974), seems to be more typical, as also mentioned by Willems (1976) from Belgium. An acme for this species was also observed in the upper Miocene at Site 400 in the Bay of Biscay.…”

“…The presence of an additional aboral opening has been described by Willems (1976); however, no such opening was observed in the specimens examined in this study. Bolboforma have been described as having no true pores (Daniels and Spiegler, 1974), but some specimens in this study from the Norwegian-Greenland Sea show irregularly arranged perforations that might correspond to pores (PI. 1,Figs.…”

“…Bolboforma spiralis is common in the upper Oligocene sediments of northwest Germany (Daniels and Spiegler, 1974). This species is rare in the lower Miocene sediments of that region.…”

“…Each species seems to have a rather long range, and species abundance seems to be controlled by ecology. Daniels and Spiegler (1974) described spherical forms as more characteristic of older rocks (late Oligocene to early Miocene) and aborally flattened forms as more typical of the middle and late Miocene.…”

“…They introduced the genus Bolboforma and discussed in detail its systematic position. Bolboforma have been regarded as test-forming protozoans (Daniels and Spiegler, 1974;Odrzywolska-Bienkowa, 1976); as cysts of algae (Rögl and Hochuli, 1976); and as incertae sedis (Bizon et al, 1977). Specimens have now been found in other areas (mainly in Miocene sediments): the Antarctic (Rögl and Hochuli, 1976); the Atlantic (Leg 82, Sites 558 and 563); the northern high latitudes like the Norwegian-Greenland Sea (Leg 38); the Bay of Biscay and Rockall Bank (Leg 48); Belgium, Poland, and the Mediterranean; and the Vienna Basin (Rögl, pers.…”