Helicosphaera consimilis
Set number: 1257
-
1
-
2
-
3
-
4
-
5
-
6
-
7
-
8
-
9
-
10
-
11
-
12
-
13
-
14
10µm
Set number: 1256
-
1
-
2
-
3
-
4
-
5
-
6
-
7
-
8
-
9
-
10
-
11
-
12
10µm
Set number: 1255
-
1
-
2
-
3
-
4
-
5
-
6
-
7
-
8
-
9
-
10
-
11
-
12
10µm
Set number: 1254
-
1
-
2
-
3
-
4
-
5
-
6
-
7
-
8
10µm
Set number: 1253
-
1
-
2
-
3
-
4
-
5
-
6
-
7
-
8
-
9
-
10
-
11
-
12
10µm
Set number: 983
-
1
-
2
-
3
-
4
-
5
-
6
-
7
-
8
10µm
Set number: 450
-
1
-
2
-
3
Fig. 1 Length: 9.80µm; Fig. 2 Length: 9.80µm; Fig. 3 Length: 9.60µm
Helicosphaera consimilis Varol, 2025
A helicolith with a Type III (Helicosphaera carteri type) blanket, an expanded flange termination, and a proximal plate featuring two large elongated pores separated by a conjunct bar. The elongated pore closer to the anterior side is nearly aligned with the long axis of the helicolith, while the other pore is oblique (approximately 21° in the holotype).
The species name consimilis is derived from the Latin word meaning “similar,” referring to its superficial resemblance to Helicosphaera wallichii.
Length = 9.21 μm; width = 5.49 μm (all measurements taken in PC).
Optical Properties: Helicosphaera consimilis exhibits inclined extinction angles of about 60-65° on the blanket on the distal side and shows length-fast (−) elongation.
Helicosphaera consimilis differs from Helicosphaera wallichii in that the pore orientation is closer to the anterior side, which is longitudinal in H. consimilis but obliquely aligned in H. wallichii.
Varol, O. 2025a. A practical guide to optical studies of calcareous nannofossils. Grzybowski Foundation Special Publication. 29: 1-222
Lohmann, H. 1902. Die Coccolithophoridae, eine Monographie der Coccolithen bildenden Flagellaten, zugleich ein Beitrag zur Kenntnis des Mittelmeerauftriebs. Archiv für Protistenkunde. 1: 89-165.
Holotype
Helicosphaera consimilis
Varol, 2025
Middle Pleistocene
DSDP Leg 23, Site 229A, Red Sea