Equatorial section of Neoschwagerina, from here.

Belongs within: Loeblichiidae.
Contains: Schubertellidae, Boultoniidae, Palaeofusulinidae, Triticitidae, Rugosofusulinidae, Pseudofusulinidae, Polydiexodinidae, Schwagerininae, Pseudoschwagerininae, Paraschwagerininae, Misellinidae, Neoschwagerinidae, Staffellidae, Pseudostaffellidae, Nankinellidae, Aljutovellidae, Profusulinellidae, Fusulinellinae, Pulchrellinae, Fusulininae, Eofusulininae.

The Fusulinida are a group of Foraminifera known from the Ordovician to the Triassic, characterised by a wall ancestrally composed of microgranular calcite, becoming differentiated into two or more layers in some derived subgroups (Loeblich & Tappan 1964). Early species were often simple with tests divided into few chambers or undivided, but some later lineages became complex and multi-chambered.

The Verbeekinidae are a group of fusulinids known from the Permian, with closely spaced foramina through the bases of all septa. The foramina are bordered by parachomata throughout the test in members of the Upper Permian subfamily Neoschwagerininae; in earlier genera of the subfamily Verbeekininae, the parachomata are discontinuous in earlier volutions of the test, becoming continuous only in later volutions (and throughout the test in later genera of this subfamily). Neoschwagerininae are further characterised by the presence of at least transverse septula, and sometimes also axial septula (Loeblich & Tappan 1964).

Fusulinoids: complex forams of the Late Palaeozoic
Published 7 October 2017

Among the most characteristic fossils of the latter part of the Palaeozoic are the group of Foraminifera known as the fusulinoids. These forams, known from around the middle of the Carboniferous to the end of the Permian, can be extremely abundant. Indeed, I get the impression that some fossil deposits are pretty much made of fusulinoids. Fusulinoids did not merely thrive in their environment; they were the environment.

Limestone block dominated by fusulinids, copyright James St John. Field of view is about 3.9 cm across.

Fusulinoids are distinguished from other forams by their test composition, built from minute granules of calcite, and complex internal structure. Externally, fusulinoids (defined here to exclude their forerunners, the endothyroids) were fairly conservative, with a planispiral, usually involute test (that is, each successive whorl covers the last). The last whorl ended on a transverse wall without a defined aperture; instead, the only connection between the interior and exterior of the test was by a series of pores in said wall. Early forms were disc-shaped; later species could be more globular or fusiform. Some of the later fusulinoids also reached gigantic sizes by single-celled organism standards: whereas the earliest fusulinoids were only a fraction of a millimetre across, the late Permian Polydiexodina could be up to six centimetres along their longest axis (Loeblich & Tappan 1964). Internally, fusulinoids had an incredibly complicated and varied structure which I’m not going to go into too much detail about here, primarily because I barely understand a word of it myself. Any description of fusulinoid morphology quickly devolves into madly throwing about terms like chomata, parachomata, spirotheca, tectorium, and the like, and your humble narrator feeling the need to go look at something else.

Cutaway diagram of a fusulinid, showing an example of internal structure, from here.

I have to go into some detail, though, because some features of the fusulinoid wall structure may explain their success. The ancestral state for the fusulinoid test wall involved a thin layer of solid calcite, the tectum. In most species, the inside of the tectum was coated with a thicker, less dense layer. As the test wall becomes more derived, this inner layer becomes more or less translucent, or pierced by tubular alveoli to produce a honeycomb-like appearance. It has been suggested that these modifications may have been adaptations to accomodating symbiotic microalgae, striking a balance between maintaining the protective test and allowing optimal transmission of light. Microalgal associations with fusulinoids may be corroborated by the discovery of minute fossils of probable planktonic relationships such as Ovummuridae preserved within fusulinoid tests (Vachard et al. 2004).

Ecologically, fusulinoids were restricted to off-shore marine habitats, being mostly found preserved in limestones and calcareous shales. They are absent from deposits that would have been formed in brackish water, and while they may be found in sandstones it is debatable whether such occurrences represent life associations or post-mortem transport (Loeblich & Tappan 1964). Fusulinoids would therefore have been ecologically similar to the inhabitants of modern-day photic zone coral reefs, another reflection of their probable co-dependence with photosynthetic microalgae. However, as successful as the advanced fusulinoids were in their time, they did not make it past the massive extinction event at the end of the Permian. This was not the end of giant and complex forams entirely—indeed, some later forms such as the alveolinids would evolve morphologies very similar to those of fusulinoids—but it was the end of these particular giant forams.

Fusulinellidae, -inae, summat like that…
Published 4 July 2018

In the section above, I introduced you all to the fusulinids, a group of complex foraminiferans that were abundant during the later Palaeozoic. Therein, I alluded to the complex array of terminology that can be used when describing fusulinids but said that I would rather not cover it at that time. Well, this time I’m going to be dredging some of it up because I’ve drawn the Fusulinellidae as the topic for today’s post.

Sectioned reconstruction of Fusulinella, from here. Labels: нк = primary chamber, са = septal folds, с = septa, сб = septal furrows, х = chomata, у = septal aperture, т = tunnel.

The Fusulinellidae as recognised by Vachard et al. (2013) are a family of fusulinids with fusiform or oblong tests known from the Middle to Late Pennsylvanian (during the later part of the Carboniferous). One genus, Pseudofusulinella, persists into the early Permian (Ross 1999). They are a part of the larger superfamily Fusulinoidea, a group of fusulinids characterised by what is known as a diaphanotheca. This is a thick, more or less translucent layer in the test wall. As noted in my earlier post, such a test structure may have functioned to allow light through to symbiotic microalgae (or possibly captured chloroplasts from algal prey) sheltered within. Fusulinellids are distinguished from other fusulinoids by the structure of the septa dividing chambers within the test, which are mostly flat except for some folding near the poles of the test (in the Fusulinidae, in contrast, the septal walls were folded throughout). As the test developed, sections of the septa were resorbed to form tunnels connecting adjacent chabers (and presumably allowing the transmission of materials between chambers in life). The course of the tunnels is commonly delimited within the chambers by chomata, discrete ridges of shell material. In other species, the chomata are absent but axial fillings of calcite were formed in the chambers instead.

How fusulinids are more commonly seen: sections of fusulinellid Dagmarella iowensis from Vachard et al. (2013). Image on left = subaxial section (scale bar = 0.1 mm); image on right, larger individual = tangential section (scale = 0.5 mm). The smaller individual on the right is a juvenile Profusulinella cf. fittsi, which depending on the author may or may not be considered a fusulinellid.

Being so widespread and abundant when they lived, fusulinellids are commonly used as index fossils for identifying when a deposit was formed. However, this process is complicated somewhat by ongoing debates about fusulinid systematics. Rauzer-Chernousova et al. (1996) proposed a classification of fusulinids that represented an extensive modification from previous systems. Part of this was simply a question of ranking, with Rauzer-Chernousova et al. recognising many groups at higher ranks than previously (so, for instance, recognising the separate family Fusulinellidae as opposed to its previous recognition as a subfamily of Fusulinidae). Nevertheless, some subsequent authors have felt that Rauzer-Chernousova et al. and their followers attribute too much significance to relatively minor variations. For instance, Kobayashi (2011) synonymised several genera under Profusulinella that Rauzer-Chernousova et al. regarded as belonging to distinct families (and Vachard et al. 2013 even placed in separate superfamilies). Some of the features regarded by Rauzer-Chernousova et al. as indicating separate genera were regarded by Kobayashi as representing variation within a single species. Indeed, there have even been arguments that some ‘significant’ features may represent post-mortem preservation artefacts (I’ve come across the term ‘taphotaxa’ used to refer to taxa based on such features). At present, my impression is that there is something of a geographical divide in preferred systems with eastern European authors following the lead of Rauzer-Chernousova et al. whereas authors from elsewhere may keep to a more conservative arrangement. The Berlin Wall may be down but the Fusulinid Cold War continues.

Systematics of Fusulinoida
<==Fusulinoida [Fusulinaceae, Fusulinidea, Fusulinoidea, Neoschwagerinaceae, Verbeekinacea, Verbeekinidea]M13
| i. s.: Fujimotoella Morikawa 1952LT64
| `--*F. umblicata Morikawa 1952LT64
| Moscoviella Miklukho-Maklay 1952 [=Moscovella Thompson 1954]LT64
| `--*M. mosquensis (Rauzer-Chernousova in Rauzer-Chernousova et al. 1951) (see below for synonymy)LT64
| Praeparafusulina Tumanskaya 1962LT64
| `--*P. pseudojaponica (Dutkevitch in Gorsky 1939) [=Parafusulina pseudojaponica]LT64
| Carbonoschwagerina morikawaiN00
| |--SchubertellidaeK04
| |--BoultoniidaeM13
| |--PalaeofusulinidaeM13
| `--Yangchienia Lee 1933LT64 [=Jangchienia Miklukho-Maklay 1953LT64; YangchieniidaeM13, Yangchieninae]
| |--*Y. iniqua Lee 1933 [=*Jangchienia iniqua]LT64
| |--Y. haydeniDX84
| `--Y. tobleriLT64
| |--TriticitidaeM13
| |--RugosofusulinidaeM13
| |--PseudofusulinidaeM13
| |--PolydiexodinidaeM13
| `--SchwagerinidaeM13
| |--SchwagerininaeM13
| |--PseudoschwagerininaeM13
| `--ParaschwagerininaeM13
| |--MisellinidaeM13
| |--NeoschwagerinidaeM13
| |--Verbeekina Staff 1909 [incl. Paraverbeekina Miklukho-Maklay 1955; Verbeekinidae, Verbeekininae]LT64
| | | i. s.: V. deprati [=Schwagerina deprati]G31
| | | V. grabauiLT64
| | | V. pontica (Miklukho-Maklay 1955) [=*Paraverbeekina pontica]LT64
| | |--*V. (Verbeekina) verbeeki (Geinitz 1876)R-CB96 (see below for synonymy)
| | `--V. (Quasiverbeekina Wang, Sheng & Zhang 1981)R-CB96
| | `--V. (*Q.) pedashanica Wang, Sheng & Zhang 1981R-CB96
| |--Pseudodoliolinidae [Pseudodoliolininae]M13
| | |--Metadoliolina Ishii & Nogami 1961R-CB96
| | | |--*M. gravitesta (Kanmera 1954) [=Pseudodoliolina pseudolepida gravitesta]R-CB96
| | | `--M. lepidaR-CB96
| | `--Pseudodoliolina Yabe & Hansawa 1932R-CB96
| | |--*P. ozawai Yabe & Hansawa 1932R-CB96
| | |--P. lettensis [=Doliolina lettensis, Misellina lettensis]DX84
| | `--P. pseudolepidaLT64
| `--Sumatrinidae [Sumatrininae]M13
| |--Presumatrina Tumanskaya 1950R-CB96 (see below for synonymy)
| | `--*P. schellwieni (Deprat 1913) [=Doliolina schellwieni, *Praesumatrina schellwieni]LT64
| |--Sumatrina Volz 1904 [incl. Pseudolepidolina Tumanskaya 1953]LT64
| | |--*S. annae (Volz 1904) [=Neoschwagerina (*Sumatrina) annae]R-CB96
| | `--S. longissima (Deprat 1914) [=Neoschwagerina (Sumatrina) longissima, *Pseudolepidolina longissima]LT64
| `--Afghanella Thompson 1946R-CB96 [=Avganella Miklukho-Maklay 1953LT64; incl. Pseudosumatrina Tumanskaya 1950LT64]
| |--*A. schencki Thompson 1946 [=*Avganella schencki]LT64
| `--A. sumatrinaeformis (Gubler 1935) (see below for synonymy)LT64
| |--StaffellidaeLT64
| |--PseudostaffellidaeM13
| |--NankinellidaeR-CB96
| |--Cheniidae [Cheniinae]M13
| | |--Chenia Sheng 1963R-CB96
| | | `--*C. kwangsiensis Sheng 1963R-CB96
| | `--Primoriina Sosnina 1981R-CB96
| | `--*P. ovoidea Sosnina 1981R-CB96
| |--Kahlerinidae [Kahlerininae]M13
| | |--Pseudokahlerina Sosnina 1968R-CB96
| | | `--*P. discoidalis Sosnina 1968R-CB96
| | `--Kahlerina Kochansky-Devidé 1955R-CB96 (see below for synonymy)
| | |--*K. pachytheca Kochansky-Devidé 1955R-CB96
| | `--K. ussurica (Sosnina in Kiparisova et al. 1956) [=*Ussuriella ussurica]LT64
| |--Pisolinidae [Pisolininae]M13
| | |--Pisolina Lee 1933LT64
| | | `--*P. excessa Lee 1933LT64
| | |--‘Caspiella’ Gibshman & Sipko 1985 nec Thiele 1928 nec Mandelstam 1956R-CB96
| | | `--*C. volgensis (Ketat 1982) [=Sphaerulina volgensis]R-CB96
| | |--Pamirina Leven 1970R-CB96
| | | `--*P. darvasica Leven 1970R-CB96
| | `--Zarodella Sosnina 1981R-CB96
| | `--*Z. zhamoidai Sosnina 1981R-CB96
| `--PseudoendothyridaeM13
| |--Palaeostaffella Liem 1966R-CB96
| | `--*P. moelleri (Ozawa 1925) [=Staffella moelleri]R-CB96
| |--Parastaffella Rauser 1948R-CB96
| | `--*P. struvei (Moeller 1880) [=Fusulinella struvei]R-CB96
| `--Pseudoendothyra Mikhailov 1939R-CB96
| | i. s.: P. kremenskensisR79
| |--P. (Pseudoendothyra) mikhailovi Rauser 1985 (see below for synonymy)R-CB96
| `--P. (Volgella Reitlinger 1977)R-CB96
| `--P. (*V.) orbiculata Reitlinger 1977R-CB96
| i. s.: Thailandina hongnusonthinae Toriyama & Kanmera 1968ZL04
| |--FusulinellinaeM13
| `--PulchrellinaeM13
|--Hemifusulina Moeller 1877R-CB96 [=Hemifusina (l. c.)LT64; HemifusulinidaeM13, Hemifusulininae]
| | i. s.: ‘Fusulina’ minimaLT64
| |--*H. (Hemifusulina) bocki Moeller 1877R-CB96
| |--H. (Dutkevichella Putrja 1956)R-CB96
| | `--H. (*D.) dutkevichi (Putrja 1937) [=Fusulina dutkevichi]R-CB96
| `--H. (Hemifusulinella Rumjanceva 1962)R-CB96
| `--H. (*H.) djartassenssi Rumjanceva 1962R-CB96
|--Wedekindellinidae [Wedekindellininae]M13
| |--Parawendekindellina Safonova 1951R-CB96
| | `--*P. kamensis Safonova 1951R-CB96 [=Wedekindellina kamensisLT64]
| |--Thompsonella Skinner & Wilde 1965R-CB96
| | `--*T. rugosa Skinner & Wilde 1965R-CB96
| `--Wedekindellina Dunbar & Henbest 1933R-CB96 (see below for synonymy)
| |--*W. euthysepta (Henbest 1928) (see below for synonymy)LT64
| `--W. maturaLT64
| i. s.: Eowedekindellina Ektova 1977HW93
|--Quasifusulina Chen 1934LT64 [=Epifusulina Chen 1936LT64; QuasifusulininaeM13]
| |--*Q. longissima (Moeller 1878)R-CB96 (see below for synonymy)
| `--Q. tenuissimaC40
|--Beedeina Galloway 1933LT64
| `--*B. girtyi (Dunbar & Condra 1927) [=Fusulinella girtyi, Fusulina girtyi]LT64
|--Citronites Solovieva in Rauzer-Chernousova, Bensh et al. 1996R-CB96
| `--*C. citronoides (Manukalova 1948) [=Fusulina citronoides]R-CB96
|--Parabeedeina Solovieva in Rauzer-Chernousova, Bensh et al. 1996R-CB96
| `--*P. elegans (Rauser & Beljaev 1940) [=Fusulina elegans]R-CB96
`--Putrella Rauser 1951R-CB96
`--*P. brazhnikovae (Putrja 1948) [=Pseudotriticites brazhnikovae]R-CB96

Afghanella sumatrinaeformis (Gubler 1935) [=Neoschwagerina sumatrinaeformis, *Pseudosumatrina sumatrinaeformis]LT64

Kahlerina Kochansky-Devidé 1955R-CB96 [incl. Ussuriella Sosnina in Kiparisova et al. 1956 non Paramonov 1929LT64]

*Moscoviella mosquensis (Rauzer-Chernousova in Rauzer-Chernousova et al. 1951) [=Ozawainella mosquensis, *Moscovella mosquensis]LT64

Presumatrina Tumanskaya 1950R-CB96 [=Praesumatrina Miklukho-Maklay, Rauzer-Chernousova & Rozovskaya in Rauzer-Chernousova & Fursenko 1959LT64]

Pseudoendothyra (Pseudoendothyra) mikhailovi Rauser 1985 [=Fusulinella struvei Mikhailov 1939 non Moeller 1880, *Pseudoendothyra struvei]R-CB96

*Quasifusulina longissima (Moeller 1878)R-CB96 [=Fusulina longissimaR-CB96, *Epifusulina longissimaLT64, Schellwienia longissimaG31; incl. S. longissima var. compactaG31, S. longissima var. phaseolusG31, S. longissima var. tenuisG31]

*Verbeekina (Verbeekina) verbeeki (Geinitz 1876)R-CB96 [=Fusulina verbeekiR-CB96, Moellerina verbeekiG31, Schwagerina verbeekiG31]

Wedekindellina Dunbar & Henbest 1933R-CB96 [=Wedekindella Dunbar & Henbest 1930 non Schindewolf 1928LT64, Wedekindia Dunbar & Henbest 1931 non Schindewolf 1925LT64]

*Wedekindellina euthysepta (Henbest 1928) [=Fusulinella euthysepta, *Wedekindella euthysepta, *Wedekindia euthysepta]LT64

*Type species of generic name indicated


[CV01] Cózar, P., & D. Vachard. 2001. Dainellinae subfam. nov. (Foraminiferida du Carbomifère inférieur), révision et nouveaux taxons. Geobios 34 (5): 505–526.

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

[DX84] Ding Y., Xia G., Duan C., Li W., Liu X. & Liang Z. 1984. Study on the early Permian stratigraphy and fauna in Zhesi district, Nei Mongol Zizhiqu (Inner Mongolia). Bulletin Tianjin Institure Geol. Min. Res. 10.

[G31] Grabau, A. W. 1931. The Permian of Mongolia: A report on the Permian fauna of the Jisu Honguer limestone of Mongolia and its relations to the Permian of other parts of the world. American Museum of Natural History: New York.

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

[K04] Kobayashi, F. 2004. Late Permian foraminifers from the Limestone Block in the Southern Chichibu Terrane of west Shikoku, SW Japan. Journal of Paleontology 78 (1): 62–70.

Kobayashi, F. 2011. Two species of Profusulinella (P. aljutovica and P. ovata), early Moscovian (Pennsylvanian) fusulines from southern Turkey and subdivision of primitive groups of the family Fusulinidae. Rivista Italiana di Paleontologia e Stratigrafia 117 (1): 29–37.

[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.

[N00] Niko, S. 2000. Youngest record of tentaculitoids: Hidagaienites new genus from near the Carboniferous–Permian boundary in central Japan. Journal of Paleontology 74 (3): 381–385.

[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”.

[R79] Ross, C. A. 1979. Carboniferous. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A254–A290. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

Ross, C. A. 1999. Classification of the Upper Paleozoic superorders Endothyroida and Fusulinoida as part of the class Foraminifera. Journal of Foraminiferal Research 29 (3): 291–305.

Vachard, D., K. Krainer & S. G. Lucas. 2013. Pennsylvanian (Late Carboniferous) calcareous microfossils from Cedro Peak (New Mexico, USA). Part 2: smaller foraminifers and fusulinids. Annales de Paléontologie 99: 1–42.

Vachard, D., A. Munnecke & T. Servais. 2004. New SEM observations of keriothecal walls: implications for the evolution of Fusulinida. Journal of Foraminiferal Research 34 (3): 232–242.

[ZL04] Zhou, Z., & M. Liengjarern. 2004. Lower Permian perrinitid ammonoid faunas from Thailand. Journal of Paleontology 78: 317–339.

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