Chernyshinella glomiformis, copyright François Le Coze.

Belongs within: Endothyroida.

Teardrops in the Palaeozoic
Published 29 July 2022

Among the early major radiations of foraminiferans in the Palaeozoic era was the assemblage known as the endothyroids, regarded by most researchers as the fore-runners of the iconic fusulinoids*. Like fusulinoids, endothyroids had test walls constructed of microgranular calcite, but generally had a simpler internal structure (Loeblich & Tappan 1964). The classification of endothyroids was reviewed in Rauzer-Chernousova et al. (1996) and among the various assemblages recognised therein was the superfamily Chernyshinelloidea.

*Though, as is all too common in summary depictions of palaeontology, describing them as ‘fore-runners’ is arguably somewhat misleading. It is true that fusulinoids probably derived from ancestors that would be classed as endothyroids, but endothyroid-type forams did not disappear as soon as the fusulinoids were on the scene. Indeed, they remained a diverse component of the fauna right to the end of the Palaeozoic, and may have even outlasted their more renowned scions.

Cross-sections and external views of Chernyshinella glomiformis, from Loeblich & Tappan (1987).

Chernyshinelloids formed part of the marine fauna from the late Devonian to the mid-Carboniferous, being diverse enough in this time that some species are significant biostratigraphic markers. The test began development as a flat or plectogyral spiral (a ‘plectogyral’ pattern is one in which the plane of the spiral changes between subsequent volutions). In at least some species, the mature test would then straighten out with ‘chambers’ in one or two rows. I’ve put ‘chambers’ in inverted commas because, though the test appears divided into sections, they are not always divided internally by properly developed septa. These pseudo-chambers are asymmetrically inflated towards one end so they appear teardrop-shaped in cross section.

These distinctively shaped chambers appear to have been the primary factor for Rauzer-Chernousova et al.(1996) in recognising Chernyshinelloidea. Their concept has not been universally accepted; Brenckle & Hance (2005), for instance, criticised their inclusion of taxa with different wall micro-structures in the superfamily. Once again, the question of chemistry vs morphology remains a critical one in foram classification.

Systematics of Chernyshinelloidea
<==Chernyshinelloidea [Chernyshinellacea]M13
|--Palaeospiroplectamminidae [Palaeospiroplectammininae]M13
| |--Rectochernyshinella Lipina 1960 [incl. Birectochernyshinella Lipina 1965]R-CB96
| | `--*R. mirabilis (Lipina 1948) [=Spiroplectammina mirabilis, Endothyranella mirabilis]LT64
| `--Palaeospiroplectammina Lipina 1965R-CB96
| |--*P. tchernyshinensis (Lipina 1948) [=Spiroplectammina tchernyshinensis]R-CB96
| `--P. parvaE03
| |--DarjellinaeM13
| |--Eotextularia Mamet 1970R-CB96 [EotextulariinaeM13]
| | `--*E. diversa (Tchernysheva 1948) [=Palaeotextularia diversa]R-CB96
| `--MstiniinaeM13
| |--Globochernella Hance 1983R-CB96
| | `--*G. braibanti Hance 1983R-CB96
| |--Granuliferelloides McKay & Green 1963R-CB96
| | `--*G. jasperensis McKay & Green 1963R-CB96
| |--Nevillea Conil & Lys 1980R-CB96
| | `--*N. dytica (Conil & Lys 1977) [=Georgella dytica]R-CB96
| |--Haplophragmina Reitlinger 1950R-CB96
| | |--*H. kashirica Reitlinger 1950R-CB96 [=Haplophragmella kashiricaLT64]
| | `--H. beschevensisR-CB96
| `--Mstinia Dain 1953R-CB96
| |--*M. (Mstinia) bulloides Dain 1953R-CB96 [=Cribrospira bulloidesLT64]
| `--M. (Condrustella Conil & Longerstaey 1977)R-CB96
| `--M. (*C.) modavensis Conil & Lys 1967R-CB96
| |--‘Lipinella’ Loeblich & Tappan 1985 non Malakhova 1975R-CB96
| | `--*L. kinelensis (Lipina 1965) [=Chernyshinella (Rectochernyshinella) kinelensis]R-CB96
| |--Eomstinia Lipina 1989R-CB96
| | `--*E. shirokensis Lipina 1989R-CB96
| |--Endochernella Conil & Lys 1977R-CB96
| | `--*E. quaesita (Ganelina 1966) [=Plectogyra (Latiendothyra) quaesita]R-CB96
| `--Chernyshinella Lipina 1955LT64
| |--*C. (Chernyshinella) glomiformis (Lipina 1948) [=Endothyra glomiformis]LT64
| |--C. (Nodochernyshinella Conil & Lys 1977)R-CB96
| | `--C. (*N.) tumulosa Lipina 1955R-CB96
| `--C. (Prochernyshinella Reitlinger in Rauzer-Chernousova, Bensh et al. 1996)R-CB96
| `--C. (*P.) disputabilis Dain 1957R-CB96
|--Rectotournayellina Lipina 1965R-CB96
| `--*R. elegans Lipina 1965R-CB96
|--Rectochernella Vachard 1980R-CB96
| `--*R. distorta (Lipina 1965) [=Chernyshinella (Rectochernyshinella) distorta]R-CB96
|--Tournayellina Lipina 1955LT64
| |--*T. (Tournayellina) vulgaris Lipina 1955 [=Septabrunsiina vulgaris]LT64
| `--T. (Eotournayellina Lipina 1965)R-CB96
| `--T. (*E.) primitiva Lipina 1965R-CB96
`--Eochernyshinella Lipina 1965R-CB96
|--*E. crassitheca (Lipina 1965) [=Chernyshinella (*Eochernyshinella) crassitheca]R-CB96
|--E. disputabilisR-CB96
`--‘Septaglomospiranella’ nana Reitlinger 1961R-CB96

*Type species of generic name indicated


[E03] Edgell, H. S. 2003. Upper Devonian Charophyta of Western Australia. Micropaleontology 49 (4): 359–374.

[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.

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

[R-CB96] Rauzer-Chernousova, D. M., F. R. Bensh, M. V. Vdovenko, N. B. Gibshman, E. Y. Leven, O. A. Lipina, E. A. Reitlinger, M. N. Solovieva & I. O. Chedija. 1996. Spravočnik po Sistematike Foraminifer Paleozoâ (Èndotiroidy, Fuzulinoidy). Rossijskaâ Akademiâ Nauk, Geologičeskij Institut, Moskva “Nauka”.

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