Choanoflagellate

Choanoflagellates; Temporal range: Only possible fossils are known from Cretaceous (Cenomanian/Turonian)
	Codosiga sp.
Scientific classification
Domain:	Eukaryota
Clade:	Amorphea
Clade:	Obazoa
(unranked):	Opisthokonta
(unranked):	Holozoa
(unranked):	Filozoa
Clade:	Choanozoa
Class:	Choanoflagellata; Kent, 1880–1882
Type species
	Monosiga brevicollis;
Orders & families
	Craspedida Codonosigidae; Salpingoecidae; ; Acanthoecida Stephanoecidae; Acanthoecidae; ;
Synonyms
	Craspedmonadina Stein, 1878; Craspedomonadaceae Senn, 1900; Craspedophyceae Chadefaud, 1960; Craspédomonadophycidées Bourrelly, 1968; Craspedomonadophyceae Hibberd, 1976; Choanomonadea Krylov et al., 1980; Choanoflagellida Levine et al., 1980, Lee et al., 1985; Choanoflagellea Cavalier-Smith, 1997; Choanomonada Adl et al. 2005; Choanoflagellatea Cavalier-Smith, 1998;

The choanoflagellates are a group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of the animals. Choanoflagellates are collared flagellates, having a funnel shaped collar of interconnected microvilli at the base of a flagellum. Choanoflagellates are capable of both asexual and sexual reproduction.^[9] They have a distinctive cell morphology characterized by an ovoid or spherical cell body 3–10 μm in diameter with a single apical flagellum surrounded by a collar of 30–40 microvilli (see figure). Movement of the flagellum creates water currents that can propel free-swimming choanoflagellates through the water column and trap bacteria and detritus against the collar of microvilli, where these foodstuffs are engulfed. This feeding provides a critical link within the global carbon cycle, linking trophic levels. In addition to their critical ecological roles, choanoflagellates are of particular interest to evolutionary biologists studying the origins of multicellularity in animals. As the closest living relatives of animals, choanoflagellates serve as a useful model for reconstructions of the last unicellular ancestor of animals.

^ Fonseca, Carolina; Mendonça Filho, João Graciano; Reolid, Matías; Duarte, Luís V.; de Oliveira, António Donizeti; Souza, Jaqueline Torres; Lézin, Carine (2023-01-23). "First putative occurrence in the fossil record of choanoflagellates, the sister group of Metazoa". Scientific Reports. 13 (1): 1242. Bibcode:2023NatSR..13.1242F. doi:10.1038/s41598-022-26972-8. ISSN 2045-2322. PMC 9870899. PMID 36690681.
^ Parfrey LW, Lahr DJ, Knoll AH, Katz LA (August 2011). "Estimating the timing of early eukaryotic diversification with multigene molecular clocks". Proceedings of the National Academy of Sciences of the United States of America. 108 (33): 13624–9. Bibcode:2011PNAS..10813624P. doi:10.1073/pnas.1110633108. PMC 3158185. PMID 21810989.
^ Saville-Kent, W. (1880). A manual of Infusoria. London, vol. 1, p. 324, [1].
^ Adl SM, Bass D, Lane CE, Lukeš J, Schoch CL, Smirnov A, Agatha S, Berney C, Brown MW, Burki F, Cárdenas P, Čepička I, Chistyakova L, del Campo J, Dunthorn M, Edvardsen B, Eglit Y, Guillou L, Hampl V, Heiss AA, Hoppenrath M, James TY, Karnkowska A, Karpov S, Kim E, Kolisko M, Kudryavtsev A, Lahr DJG, Lara E, Le Gall L, Lynn DH, Mann DG, Massana R, Mitchell EAD, Morrow C, Park JS, Pawlowski JW, Powell MJ, Richter DJ, Rueckert S, Shadwick L, Shimano S, Spiegel FW, Torruella G, Youssef N, Zlatogursky V, Zhang Q (2019). "Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes". Journal of Eukaryotic Microbiology. 66 (1): 4–119. doi:10.1111/jeu.12691. PMC 6492006. PMID 30257078.
^ King N, Westbrook MJ, Young SL, Kuo A, Abedin M, Chapman J, et al. (February 2008). "The genome of the choanoflagellate Monosiga brevicollis and the origin of metazoans". Nature. 451 (7180): 783–8. Bibcode:2008Natur.451..783K. doi:10.1038/nature06617. PMC 2562698. PMID 18273011.
^ Nitsche F, Carr M, Arndt H, Leadbeater BS (2011). "Higher level taxonomy and molecular phylogenetics of the Choanoflagellatea". The Journal of Eukaryotic Microbiology. 58 (5): 452–62. doi:10.1111/j.1550-7408.2011.00572.x. PMID 21895836. S2CID 2076733.
^ Cavalier-Smith T (1998). "Neomonada and the origin of animals and fungi.". In Coombs GH, Vickerman K, Sleigh MA, Warren A (eds.). Evolutionary relationships among protozoa. London: Kluwer. pp. 375–407.
^ Leadbeater BS (2015). The choanoflagellates: evolution, biology, and ecology. University of Birmingham. ISBN 978-0-521-88444-0.
^ "Bacterial protein acts as aphrodisiac for choanoflagellates".

[1] Fonseca, Carolina; Mendonça Filho, João Graciano; Reolid, Matías; Duarte, Luís V.; de Oliveira, António Donizeti; Souza, Jaqueline Torres; Lézin, Carine (2023-01-23). "First putative occurrence in the fossil record of choanoflagellates, the sister group of Metazoa". Scientific Reports. 13 (1): 1242. Bibcode:2023NatSR..13.1242F. doi:10.1038/s41598-022-26972-8. ISSN 2045-2322. PMC 9870899. PMID 36690681.

[Wegener-Parfrey_et_al._2011-2] Parfrey LW, Lahr DJ, Knoll AH, Katz LA (August 2011). "Estimating the timing of early eukaryotic diversification with multigene molecular clocks". Proceedings of the National Academy of Sciences of the United States of America. 108 (33): 13624–9. Bibcode:2011PNAS..10813624P. doi:10.1073/pnas.1110633108. PMC 3158185. PMID 21810989.

[3] Saville-Kent, W. (1880). A manual of Infusoria. London, vol. 1, p. 324, [1].

[Adl_2019-4] Adl SM, Bass D, Lane CE, Lukeš J, Schoch CL, Smirnov A, Agatha S, Berney C, Brown MW, Burki F, Cárdenas P, Čepička I, Chistyakova L, del Campo J, Dunthorn M, Edvardsen B, Eglit Y, Guillou L, Hampl V, Heiss AA, Hoppenrath M, James TY, Karnkowska A, Karpov S, Kim E, Kolisko M, Kudryavtsev A, Lahr DJG, Lara E, Le Gall L, Lynn DH, Mann DG, Massana R, Mitchell EAD, Morrow C, Park JS, Pawlowski JW, Powell MJ, Richter DJ, Rueckert S, Shadwick L, Shimano S, Spiegel FW, Torruella G, Youssef N, Zlatogursky V, Zhang Q (2019). "Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes". Journal of Eukaryotic Microbiology. 66 (1): 4–119. doi:10.1111/jeu.12691. PMC 6492006. PMID 30257078.

[5] King N, Westbrook MJ, Young SL, Kuo A, Abedin M, Chapman J, et al. (February 2008). "The genome of the choanoflagellate Monosiga brevicollis and the origin of metazoans". Nature. 451 (7180): 783–8. Bibcode:2008Natur.451..783K. doi:10.1038/nature06617. PMC 2562698. PMID 18273011.

[6] Nitsche F, Carr M, Arndt H, Leadbeater BS (2011). "Higher level taxonomy and molecular phylogenetics of the Choanoflagellatea". The Journal of Eukaryotic Microbiology. 58 (5): 452–62. doi:10.1111/j.1550-7408.2011.00572.x. PMID 21895836. S2CID 2076733.

[7] Cavalier-Smith T (1998). "Neomonada and the origin of animals and fungi.". In Coombs GH, Vickerman K, Sleigh MA, Warren A (eds.). Evolutionary relationships among protozoa. London: Kluwer. pp. 375–407.

[Leadbeater-8] Leadbeater BS (2015). The choanoflagellates: evolution, biology, and ecology. University of Birmingham. ISBN 978-0-521-88444-0.

[sciencedaily.com-9] "Bacterial protein acts as aphrodisiac for choanoflagellates".

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Choanoflagellates Temporal range: Only possible fossils are known from Cretaceous (Cenomanian/Turonian)^[1]^[2]

Codosiga sp.
Scientific classification
Domain:	Eukaryota
Clade:	Amorphea
Clade:	Obazoa
(unranked):	Opisthokonta
(unranked):	Holozoa
(unranked):	Filozoa
Clade:	Choanozoa
Class:	Choanoflagellata Kent, 1880–1882^[3]^[4]
Type species
Monosiga brevicollis^[5]
Orders & families
Craspedida Codonosigidae Salpingoecidae Acanthoecida Stephanoecidae Acanthoecidae
Synonyms
Craspedmonadina Stein, 1878 Craspedomonadaceae Senn, 1900 Craspedophyceae Chadefaud, 1960 Craspédomonadophycidées Bourrelly, 1968 Craspedomonadophyceae Hibberd, 1976 Choanomonadea Krylov et al., 1980 Choanoflagellida Levine et al., 1980, Lee et al., 1985 Choanoflagellea Cavalier-Smith, 1997 Choanomonada Adl et al. 2005^[6] Choanoflagellatea Cavalier-Smith, 1998^[7]^[8]