Nannotax Enabling nannofossil research

Description: Six rayed discoaster with blunt ended complanate rays. It has a very large stellate boss on the proximal side, and a small one on the distal side.

Remarks: A short-ranging and highly distinctive species, most records from the Indo-Pacific.

Original description:

Synonym: D. tristellifer Bukry, 1976. As explained by Young (1998) D. tristellifer and D. altus were described from the same material, DSDP Site 242 Core 3 Section 1, but without reference to each other. Both species were described as 6-rayed discoasters with very large proximal bosses and complanate rays. Re-examination of this material reveals, unsurprisingly, that it contains only one such species. The description of Bukry (1976), based on light microscopy, is much better since it mentions the smaller, but very distinct, distal knob. The description of Muller (1974), however, has priority so the correct name is D. altus.

Original Description: A small six-rayed species with only short rays. The central area is covered by a very high and broad knob. The other side is flat. Dimensions: 7 µ - 8 µ.



Type locality: DSDP 242-3-1, 30 cm. (Western Indian Ocean).



Depository: Senckenberg-Museum, Frankfurt a. Mein. Holotype: fig, 1; SM.B 12599.



Author: Müller C., 1974, p. 592; pl. 9, figs. 1-3. Reference: Calcareous Nannoplankton, Leg 25 (Western Indian Ocean). Initial Reports of the Deep Sea Drilling Project, vol. 25, pp. 579-634, 1 fig., 2 tabs., 19 pls.