Cornuspira involvens, from here.

Belongs within: Miliolina.
Contains: Soritidae, Meandropsinidae, Peneroplinae.

The Fischerinidae are a group of porcelaneous Foraminifera known from the Carboniferous to the present, in which the test is undivided after the proloculus (Loeblich & Tappan 1964).

The Rhapydionininae are a group of more or less conical Foraminifera known from the Jurassic to the present, though so far as is known they are extremely rare in the modern fauna (Loeblich & Tappan 1964).

Porcelain fans
Published 23 May 2013
Mature specimen of Rhapydionina deserta, from Loeblich & Tappan (1964).

Calcareous foraminiferans have been featured on this site before: planktic floaters, living stars, microscopic jelly moulds and gigantic reef-formers. All these forms have belonged to the group of calcareous forams known as the rotaliids. Today’s subject is another group of forams, the Rhapydionininae, belonging to a different calcareous group, the Miliolida. Miliolids may have shell walls made of calcite like the rotaliids, but differ in the wall structure: while the walls of rotaliids are glass-like and porous, those of miliolids are structured like porcelain. Phylogenetic studies of forams have not placed the miliolids close to the rotaliids, and the two groups seem to have evolved their secreted shells independently (Sen Gupta 2002).

Rhipidionina liburnica, from Loeblich & Tappan (1964).

The Rhapydionininae were defined by Loeblich & Tappan (1964) as a group of miliolids with a conical test composed of broad chambers stacked one on top of another (the overall shape being kind of like a fan or an ice-cream cone), with each of these chambers subdivided by internal septa into multiple chamberlets (the difference between a ‘chamber’ and a ‘chamberlet’ being that the latter are not completely divided from each other by the walls). The opening of the test took the form of a sieve-like array of pores at the top end. However, subsequent researchers have discovered that Loeblich & Tappan’s definition was inadequate. Rhapydioninines start life growing as a flat spiral, with growth becoming linearised at maturity. However, it turns out that not all Rhapydionininae become linear; some retain their juvenile coiling into maturity (Vicedo et al. 2011). At least some species are believed to have both a linear megalospheric form and a coiled microspheric form. To explain, forams can be divided between microspheric forms, in which the first chambers of a new test are much smaller, and megalospheric forms with larger initial chambers. In those relatively few forams whose life cycles have been studied in detail, these two forms correspond to an alternation of generations, with a mostly microspheric asexually-reproducing generation giving rise to the generally megalospheric sexually-reproducing phase. Loeblich & Tappan’s (1964) concept of rhapydionines, therefore, would have potentially placed members of a single species into separate families.

Diagram of internal structure of two adult chambers of Cuvillierinella, from Vicedo et al. (2011). Key to abbreviations: ap f = apertural face, c chl = cortical chamberlets, flo = floor, m chl = medullar chamberlet, prp = preseptal space, rpi = residual pillars, s = septum, sl = septulum.

Rhapydionines are best known as fossils, with a definite range from the Upper Cretaceous to the mid-Eocene (Loeblich & Tappan 1984). Believe it or not, whether there are still rhapydioninines in the world is something of an open question. Loeblich & Tappan (1964) listed two Recent genera in the Rhapydionininae, each represented by only a single known specimen. Ripacubana conica was originally described from sand deposits in Cuba; however, Loeblich & Tappan (1964) suggested that Ripacubana may actually represent what has been referred to as a ‘zombie taxon’. Some of you may be familiar with the palaeontological concept of a ‘Lazarus taxon’, where a species disappears from the fossil record only to reappear at a later date. What has actually happened in these cases is that the species had only become locally extinct, but survived in some other locality that has not been preserved, subsequently recolonising its old range. A ‘zombie taxon’, however, is one that has genuinely become extinct at the earlier date, but its fossilised remains have since been transported into a younger sediment deposit, giving the impression that it survived later than it did*. In the case of Ripacubana, it is difficult to know just how long a foram shell buried in sand has been lying there.

*Identifications of Lazarus taxa also have to be on the look-out for ‘Elvis taxa’: where the more recent population does not in fact represent the same species, but a different species that has convergently evolved similar features.

Craterites rectus, from Loeblich & Tappan (1964).

Loeblich & Tappan (1964) did not express the same reservations about Craterites rectus, described from a beach on Lord Howe Island east of Australia. Craterites was later separated as its own subfamily by Loeblich & Tappan (1984) on the basis of its being attached to the substrate, and so differing from other free-living Rhapydionininae. Nevertheless, they kept the two subfamilies together as the family Rhapydioninidae, so Craterites may still be the only known survivor of the rhapydioninine lineage. However, with only one known specimen, the details of the internal structure of Craterites remain unknown.

Systematics of Soritida
Soritida [Orbitolinida, Obitolitida, Soritacea, Soritoidea]M13
    |  i. s.: Siphonofera Senowbari-Daryan 1983 [Siphonoferidae]HW93
    |    |--SoritidaeM13
    |    |--CycledomiidaeM13
    |    |--Praerhapydionina Van Vessem 1943B-F08 [PraerhapydionidaeM13]
    |    |    |--*P. cubana van Wessen 1943LT64
    |    |    `--P. delicataB-F08
    |    `--Archaias de Montfort 1808LT64 (see below for synonymy)
    |         |--A. angulatus (Fichtel & Moll 1798) (see below for synonymy)LT64
    |         |--A. aduncus (Fichtel & Moll 1798)C40, LT64 (see below for synonymy)
    |         |--‘Nummulites (Assilina)’ floridanus Conrad 1846 [=*Nemophora floridana]LT64
    |         |--A. kirkukensisB-F08
    |         `--‘Nautilus’ orbiculus Fichtel & Moll 1798 (see below for synonymy)LT64
    |--Meandropsinoidea [Meandropsinidea]M13
    |    |--MeandropsinidaeM13
    |    |--Orduella Sirel 1999B-F08 [OrduellidaeM13, Orduellinidae]
    |    |--Fusarchaias Reichel 1952LT64 [FusarchaiasidaeM13]
    |    |    `--*F. bermudezi Reichel 1952LT64
    |    |--Hottingerina Drobne 1975B-F08 [HottingerinidaeM13]
    |    |    `--H. lukasiB-F08
    |    `--RhapydionidaeM13
    |         |  i. s.: Pseudedomia Henson 1948HW93
    |         |           `--*P. multistriata Henson 1948LT64
    |         |--Craterites Heron-Allen & Earland 1924LT64 [CrateritinaeM13]
    |         |    `--*C. rectus Heron-Allen & Earland 1924LT64
    |         `--RhapydioniaeM13
    |              |--Ripacubana Loeblich & Tappan 1964 [=Conulina d’Orbigny in de la Sagra 1839]LT64
    |              |    `--*R. conica (d’Orbigny in de la Sagra 1839) [=*Conulina conica]LT64
    |              |--Rhipidionina Stache 1913LT64
    |              |    |--*R. liburnica (Stache 1889) [=Pavonina liburnica]LT64
    |              |    |--R. macfadyeniB-F08
    |              |    `--R. williamsoniB-F08
    |              `--Rhapydionina Stache 1913 [=Rhapidionina van den Bold 1946]LT64
    |                   |--*R. liburnica (Stache 1889)LT64 (see below for synonymy)
    |                   |--R. protocaenicaC40
    |                   `--R. urensisLT64
    `--Peneroplidea [Peneroplida, Peneroplideae, Peneroplidee, Peneroplididae, Peneroplidina]M13
         |--Fischerinella Loeblich & Tappan 1962LT64 [FischerinellidaeM13]
         |    `--*F. helix (Heron-Allen & Earland 1915) [=Fischerina helix]LT64
         |--Zoyaella Loeblich & Tappan 1962LT64 [=Ceratina Goës 1894 nec Latreille 1802 nec Menge 1868LT64; ZoyaellidaeM13]
         |    `--*Z. trochamminoides (Goës 1894) [=*Ceratina trochamminoides, Fischerina trochamminoides]LT62
         |--Fischerinidae [Fischerininae, Planispirinellinae, Trisegmentininae]M13
         |    |--Dolosella Danich 1969HW93
         |    |--Planispirinella Wiesner 1931LT64
         |    |    `--*P. exigua (Brady 1879)LT64 [=Hauerina exiguaLT64, Planispirina exiguaC40]
         |    `--Fischerina Terquem 1878 [incl. Planispirina Seguenza 1880, Trisegmentina Wiesner 1920]LT64
         |         |--*F. rhodiensis Terquem 1878LT64
         |         |--F. communis (Seguenza 1880) [=*Planispirina communis]LT64
         |         `--F. compressa (Wiesner 1931) (see below for synonymy)LT64
              |  i. s.: Raoia Matsumaru & Sarma 2008B-F08
              |           `--R. indicaB-F08
              |--Vandenbroeckia Marie 1958LT64 [=VandenbroekiaLT64; VandenbroeckiinaeM13]
              |    `--*V. munieri Marie 1958LT64
              |--Renulina Lamarck 1804LT64 [=Renulites Lamarck 1804LT64, Renulinites (l. c.)LT64; RenulininaeM13]
              |    `--*R. opercularia Lamarck 1804 [=*Renulites opercularia]LT64
              `--Dendritina d’Orbigny 1826LT64 (see below for synonymy)
                   |--*D. arbuscula d’Orbigny 1826 [=Peneroplis (*Dendritina) arbusculus]LT64
                   |--*Meneghinia’ nautiliformis Silvestri 1889LT64
                   |--D. rangiB-F08
                   `--*Neopeneroplis’ sarmaticus Didkovskiy 1958LT64

Archaias de Montfort 1808LT64 [=Archaia Agassiz 1844LT64, Archais (l. c.)LT64; incl. Elenis Agassiz 1844LT64, Helenis de Montfort 1808LT64, Ilotes de Montfort 1808LT64, Nemophora Conrad 1865 nec Illiger 1798 nec Huebner 1825 nec Dahlbom 1854LT64, Orbiculina Lamarck 1816LT64; Archaiadinae, ArchaiasidaeM13, Archaiasinae, Orbiculininae]

Archaias aduncus (Fichtel & Moll 1798)C40, LT64 [=Nautilus aduncusLT64, Orbiculina aduncaLT64; incl. *Helenis spatosus de Montfort 1808LT64, *Elenis spatosusLT64]

Archaias angulatus (Fichtel & Moll 1798) [=Nautilus angulatus, *Archaia angulata; incl. *Archaias spirans de Montfort 1808]LT64

Dendritina d’Orbigny 1826LT64 [incl. Meneghinia Silvestri 1889LT64, Neopeneroplis Didkovskiy 1958LT64; DendritininaeM13]

Fischerina compressa (Wiesner 1931) [=*Trisegmentina compressa; incl. Hauerina compressa Sidebottom 1904 non d’Orbigny 1846, T. sidebottomi Cushman 1933]LT64

‘Nautilus’ orbiculus Fichtel & Moll 1798 [incl. *Orbiculina nummata Lamarck 1816, *Ilotes rotalitatus de Montofort 1808]LT64

*Rhapydionina liburnica (Stache 1889)LT64 [=Peneroplis liburnicaLT64, *Rhapidionina liburnicaLT64; incl. R. liburnica var. laevigataC40, R. liburnica var. strangulataC40]

*Type species of generic name indicated


[B-F08] BouDagher-Fadel, M. K. 2008. The Cenozoic larger benthic foraminifera: the Palaeogene. Developments in Palaeontology and Stratigraphy 21: 297–418.

[C40] Cushman, J. A. 1940. Foraminifera: Their classification and economic use 3rd ed. Harvard University Press: Cambridge (Massachusetts).

[HW93] Hart, M. B., & C. L. Williams. 1993. Protozoa. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 43–70. Chapman & Hall: London.

[LT62] Loeblich, A. R., Jr & H. Tappan. 1962. Six new generic names in the Mycetozoida (Trichiidae) and Foraminiferida (Fischerinidae, Buliminidae, Caucasinidae, and Pleurostomellidae), and a redescription of Loxostomum (Loxostomidae, new family). Proceedings of the Biological Society of Washington 75: 107–114.

[LT64] Loeblich, A. R., Jr & H. Tappan. 1964. 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.

Loeblich, A. R., Jr & H. Tappan. 1984. Suprageneric classification of the Foraminiferida (Protozoa). Micropaleontology 30 (1): 1–70.

[M13] Mikhalevich, V. I. 2013. New insight into the systematics and evolution of the Foraminifera. Micropaleontology 59 (6): 493–527.

Sen Gupta, B. K. 2002. Modern Foraminifera. Springer.

Vicedo, V., G. Frijia, M. Parente & E. Caus. 2011. The Late Cretaceous genera Cuvillierinella, Cyclopseudedomia, and Rhapydionina (Rhapydioninidae, Foraminiferida) in shallow-water carbonates of Pylos (Peloponnese, Greece). Journal of Foraminiferal Research 41 (2): 167–181.

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