Belongs within: Rotaliida.
The Cassidulinidae are a group of Foraminifera with biserial, planispirally enrolled chambers, known from the Eocene to the present. Later parts of the test may be uncoiled (Loeblich & Tappan 1964b).
Characters (Loeblich & Tappan 1964b): Test lenticular, subglobular or elongate; chambers biserially arranged, alternating chambers also planispirally enrolled at least in early stage, later may be uncoiled; aperture elongate, comma-shaped, slit extending from basal suture into apertural face.
<==Cassidulinidae [Islandiellidae]
|--Cassidulinella Natland 1940LT64b
| `--*C. pliocenica Natland 1940LT64b
|--Favocassidulina Loeblich & Tappan 1957LT64b
| `--*F. favus (Brady 1877) [=Pulvinulina favus]LT64b
|--Burseolina Seguenza 1880LT64b
| `--*B. calabra Seguenza 1880LT64b
|--Cassidulinoides Cushman 1927LT64b
| `--*C. parkerianus (Brady 1881)LT64b, PHT13, LT64b [=Cassidulina parkerianaLT64b]
|--Stichocassidulina Stone 1946LT64b
| `--*S. thalmanni Stone 1946LT64b
|--Islandiella Nørvang 1958AB19, HW93 [incl. Cassilamellina Voloshinova 1960LT64b]
| |--I. algida (Cushman 1944)H03 [=Cassidulina algidaH03; incl. C. islandica Nøvang 1945H03, *Islandiella islandicaLT64b]
| |--I. californica (Cushman & Hughes 1925) [=Cassidulina californica, *Cassilamellina californica]LT64b
| |--I. japonica (Asano & Nakamura 1937) [=Cassidulina japonica]H03
| |--I. norcrossiLT64a
| `--I. seranensisJW99
|--Globocassidulina Voloshinova 1960 [incl. Cassilongina Voloshinova 1960]LT64b
| |--*G. globosa (Hantken 1875) [=Cassidulina globosa]LT64b
| |--G. arataH90
| |--G. bisecta Nomura 1983H03
| |--G. elegansJW99
| |--G. oblonga (Reuss 1850) [=Cassidulina oblonga, *Cassilongina oblonga]LT64b
| `--G. subglobosaJW99
|--Ehrenbergina Reuss 1850AB19, LT64b [EhrenberginidaeM13, Ehrenbergininae]
| |--*E. serrata Reuss 1850LT64b
| |--E. bicornisH90
| |--E. bradyiC40
| |--E. hystrixLT64a
| |--E. pacificaLT64a
| |--E. pupa [incl. E. hystrix glabra]LT64a
| `--E. undulataJW99
`--Cassidulina d’Orbigny 1826 [incl. Entrochus Ehrenberg 1843 non Hofer 1760, Selenostomum Ehrenberg 1858; Cassidulininae]LT64b
|--*C. laevigata d’Orbigny 1826LT64b
|--C. crassaJW99
|--C. cretaceaC40
|--C. delicataLT64a
|--C. margaretaLJ98
|--C. reniforme Nøvang 1945 (see below for synonymy)H03
|--‘*Entrochus’ septatus Ehrenberg 1843LT64b
`--C. subglobosaB49
Cassidulina reniforme Nøvang 1945 [=C. crassa var. reniforme; incl. C. islandica f. minuta Nøvang 1945, C. islandica var. norvangi Thalmann in Phleger 1952]H03
*Type species of generic name indicated
References
[AB19] Adl, S. M., D. Bass, C. E. Lane, J. Lukeš, C. L. Schoch, A. Smirnov, S. Agatha, C. Berney, M. W. Brown, F. Burki, P. Cárdenas, I. Čepička, L. Chistyakova, J. del Campo, M. Dunthorn, B. Edvardsen, Y. Eglit, L. Guillou, V. Hampl, A. A. Heiss, M. Hoppenrath, T. Y. James, A. Karnkowska, S. Karpov, E. Kim, M. Kolisko, A. Kudryavtsev, D. J. G. Lahr, E. Lara, L. Le Gall, D. H. Lynn, D. G. Mann, R. Massana, E. A. D. Mitchell, C. Morrow, J. S. Park, J. W. Pawlowski, M. J. Powell, D. J. Richter, S. Rueckert, L. Shadwick, S. Shimano, F. W. Spiegel, G. Torruella, N. Youssef, V. Zlatogursky & Q. Zhang. 2019. Revisions to the classification, nomenclature, and diversity of eukaryotes. Journal of Eukaryotic Microbiology 66: 4–119.
[B49] Battey, M. H. 1949. The geology of the Tuakau-Mercer area, Auckland. Transactions and Proceedings of the Royal Society of New Zealand 77 (3): 429–455.
[C40] Cushman, J. A. 1940. Foraminifera: Their classification and economic use 3rd ed. Harvard University Press: Cambridge (Massachusetts).
[H03] Hanagata, S. 2003. Miocene-Pliocene Foraminifera from the Niigata oil-fields region, northeastern Japan. Micropaleontology 49 (4): 293–340.
[HW93] Hart, M. B., & C. L. Williams. 1993. Protozoa. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 43–70. Chapman & Hall: London.
[H90] Hayward, B. W. 1990. Use of foraminiferal data in analysis of Taranaki Basin, New Zealand. Journal of Foraminiferal Research 20: 71–83.
[JW99] Jian, Z.-M., L.-J. Wang, M. Kienast, M. Sarnthein, W. Kuhnt, H.-L. Lin & P.-X. Wang. 1999. Benthic foraminiferal paleoceanography of the South China Sea over the last 40,000 years. Marine Geology 156: 159–186.
[LJ98] Li, Q., N. P. James, B. McGowran, Y. Bone & J. Cann. 1998. Synergetic influence of water masses and Kangaroo Island barrier on foraminiferal distribution, Lincoln and Lacepede shelves, South Australia: a synthesis. Alcheringa 22 (2): 153–176.
[LT64a] Loeblich, A. R., Jr & H. Tappan. 1964a. Sarcodina: chiefly “thecamoebians” and Foraminiferida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt C. Protista 2 vol. 1. The Geological Society of America and The University of Kansas Press.
[LT64b] Loeblich, A. R., Jr & H. Tappan. 1964b. Sarcodina: chiefly “thecamoebians” and Foraminiferida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt C. Protista 2 vol. 2. The Geological Society of America and The University of Kansas Press.
[PHT13] Pawlowski, J., M. Holzmann & J. Tyszka. 2013. New supraordinal classification of Foraminifera: molecules meet morphology. Marine Micropalaeontology 100: 1–10.