Fusulinida
Fusulinida Temporal range:
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Scientific classification ![]() | |
Domain: | Eukaryota |
Clade: | Diaphoretickes |
Clade: | SAR |
Phylum: | Retaria |
Subphylum: | Foraminifera |
Class: | Globothalamea (?) |
Order: | †Fusulinida |
Superfamilies | |
Archaediscacea |
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/Fusulinid_limestone%2C_Upper_Pennsylvanian%3B_Elk_County_KS.jpg/220px-Fusulinid_limestone%2C_Upper_Pennsylvanian%3B_Elk_County_KS.jpg)
The Fusulinida is an extinct
Taxonomy
Thirteen superfamilies are presently recognised, based on taxa (families) included in the three superfamilies given in the Treatise. Three are based on families in the Parathuramminacea, 1964, and nine families in the Endothyracea, 1964. The Fusulinacea remains the same in both sources (Treatise 1964 and Loeblich and Tappan, 1988).
The term fusulinata has traditionally been used to refer to all palaeozoic foraminifera with multi-chambered tests. However, recent studies based on test microstructure have suggested that fusulinids may be polyphyletic and consist of at least three distinct lineages, and as such are in need of systematic revision.[1]
Test composition
Traditionally, fusulinid tests were considered to have been composed of very small, tightly-packed calcite crystals with no preferred orientation—a so-called microgranular structure. However. a 2017 study using scanning electron microscopy revealed that this supposed structure actually represented tests that had been extensively modified by diagenetic processes. Instead, living fusulinids had low-magnesium hyaline tests with spherical nanograins up to 100 nm across, similar to the tests of the Rotaliida. These factors combined with overall shape of the test led these authors to suggest classification of the fusulinids with the Globothalamea.[2]
A 2021 study further examined test microstructure and suggested instead that the forams examined in the 2017 study were not true fusulinids, but rather considered them their own group containing Nanicella and relatives. These authors considers that true fusulinids did in fact have microgranular tests. A third group consisting of forms related to Semitextularia was also found to have a distinct test microstructure, and was suggested to be a third lineage.[1]
Evolutionary history
The fusulinids are among the earliest calcareous-walled foraminifera; they appear in the fossil record during the
Later species of fusulinids grew to much larger size, with some forms reaching 5 cm in length; reportedly, some specimens reach up to 14 cm in length, making them among the largest foraminifera extant or extinct. Fusulinids are the earliest lineage of foraminifera thought to have evolved symbiosis with photosynthetic organisms.
Fossils of fusulinids have been found on all continents except Antarctica; they reached their greatest diversity during the Visean epoch of the Carboniferous. The group then gradually declined in diversity until finally going extinct during the Permo-Triassic extinction event.[5][6][7]
Terminology
The term "fusulinid" applies to any of the Fusulinida. The Fusulinida are fusulinids (sensu lato). However, the term "fusulinid" is often applied just to the fusiform Fusulinacea and not to the entire order.
Application
Members, especially of the Fusulinacea, are excellent
See also
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f2/Fusulinid_cutaway.gif/220px-Fusulinid_cutaway.gif)
References
- ^ PMID 34155110.
- PMID 29123221.
- ISBN 978-84-300-9949-8.
- ISBN 978-0-226-92537-0. Retrieved 10 January 2023.
- ISBN 978-3-319-14574-7
- JSTOR 1305391.
- ^ "Fusulinids | GeoKansas". geokansas.ku.edu. Retrieved 16 May 2020.
Further reading
- Leppig, Ursula; Forke, Holger C.; Montenari, Michael; Fohrer, Beate (2005). "A three- and two-dimensional documentation of structural elements in schwagerinids (superfamily Fusulinoidea) exemplified by silicified material from the Upper Carboniferous of the Carnic Alps (Austria/Italy): a comparison with verbeekinoideans and alveolinids". Facies. 51 (1–4): 541–553. S2CID 129848257.
- ISBN 978-0-8137-3003-5.
- Alfred R. Loeblich Jr., Helen Tappan, 1988: Foraminiferal genera and their classification, E-Book published by Geological Survey of Iran, 2005, Online Archived 23 March 2012 at the Wayback Machine
- Payne, Jonathan; Jost, Adam; Wang, Steve (March 2013). "A Shift in the Long-Term Mode of Foraminiferan Size Evolution Caused by the End-Permian Mass Extinction". Evolution. 67 (3): 816–827. PMID 23461330.
- Stevens, Calvin H. (September 1995). "A Giant Permian Fusulinid from East-Central Alaska with Comparisons of All Giant Fusulinids in Western North America". Journal of Paleontology. 69 (5): 805–812. S2CID 132061868.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/e/ed/TriticitesPlattsmouthChertRedOakIowaPermian.jpg/350px-TriticitesPlattsmouthChertRedOakIowaPermian.jpg)
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