Incertae sedis (Latin for 'of uncertain placement')[2] or problematica is a term used for a taxonomic group where its broader relationships are unknown or undefined.[3] Alternatively, such groups are frequently referred to as "enigmatic taxa".[4] In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by incertae familiae (of uncertain family), incerti subordinis (of uncertain suborder), incerti ordinis (of uncertain order) and similar terms.[5]
New World vultures, such as the California condor, were placed incertae sedis within the class Aves until the recognition of the new order Cathartiformes.Plumalina plumaria Hall, 1858 (6.3 cm tall), Upper Devonian of western New York State, US. Workers usually assign this organism to the hydrozoans (phylum Cnidaria, class Hydrozoa) or the gorgonarians (phylum Cnidaria, class Anthozoa, order Gorgonaria), but it is probably safest to refer to it as incertae sedis.[1]The varanopids, a mysterious family of tetrapods, had controversial relationships with many other land tetrapods. Paleolontologists have mostly assigned them in the past as eupelycosaurian synapsids. Others have placed them as basalneodiapsids. A compromise is to place them as Amniotaincertae sedis.
The fossil plant Paradinandra suecica could not be assigned to any family, but was placed incertae sedis within the order Ericales when described in 2001.[6]
The fossil Gluteus minimus, described in 1975, could not be assigned to any known animal phylum.[7] The genus is therefore incertae sedis within the kingdom Animalia.
While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves incertae sedis.[8] It was later agreed to place them in a separate order, Cathartiformes.[9]
Bocage's longbill, Motacilla bocagii, previously known as Amaurocichla bocagii, is a species of passerine bird that belongs to the superfamily Passeroidea. Since it was unclear to which family it belongs, it was classified as Passeroidea incertae sedis, until a 2015 phylogenetic study placed it in Motacilla of Motacillidae.[10][11]
Metallogenium is a bacterium that can form star-shaped minerals.[13]
Circothecidae are a family of Cambrian animals, sometimes attributed to the Hyolitha, though some authors suggest (on the basis of no specified evidence) that they are definitely not.
In formal nomenclatureedit
When formally naming a taxon, uncertainty about its taxonomic classification can be problematic. The International Code of Nomenclature for algae, fungi, and plants, stipulates that "species and subdivisions of genera must be assigned to genera, and infraspecific taxa must be assigned to species, because their names are combinations", but ranks higher than the genus may be assigned incertae sedis.[14]
...the removal of many genera from new and existing families into a state of incertae sedis. Their reduced status was attributed largely to poor or inadequate descriptions but it was accepted that some of the vagueness in the analysis was due to insufficient character states. It is also evident that a proportion of the characters used in the analysis, or their given states for particular taxa, were inappropriate or invalid. Additional complexity, and factors that have misled earlier authorities, are intrusion by extensive homoplasies, apparent character state reversals and convergent evolution.
Not included in an analysisedit
If a formal phylogenetic analysis is conducted that does not include a certain taxon, the authors might choose to label the taxon incertae sedis instead of guessing its placement. This is particularly common when molecular phylogenies are generated, since tissue for many rare organisms is hard to obtain. It is also a common scenario when fossil taxa are included, since many fossils are defined based on partial information. For example, if the phylogeny was constructed using soft tissue and vertebrae as principal characters and the taxon in question is only known from a single tooth, it would be necessary to label it incertae sedis.[5]
Controversyedit
If conflicting results exist or if there is not a consensus among researchers as to how a taxon relates to other organisms, it may be listed as incertae sedis until the conflict is resolved.[5]
Phylogenetic vs. nomenclatural uncertaintyedit
The term incertae sedis refers to uncertainty about phylogenetic position of a taxon, which may be expressed, among others, by using a question mark after or before a taxon name. This should be distinguished from the situation where either it is uncertain how to use a name, often because the types have been lost (nomen dubium, species inquirenda), or whether a poorly preserved specimen should be included within a given species or genus, which is often expressed using a 'cf.' (from Latin confer, compare, before a taxon name); such a convention is especially widespread in palaeontology.[16]
In zoological nomenclatureedit
In zoological nomenclature, "incertae sedis" is not a nomenclatural term at all per se, but is used by taxonomists in their classifications to mean "of uncertain taxonomic position".[2]Glossary In botany, a name is not validly published if it is not accepted by the author in the same publication.[14]Article 36.1 In zoology, a name proposed conditionally may be available under certain conditions.[2]Articles 11 and 15 For uncertainties at lower levels, some authors have proposed a system of "open nomenclature", suggesting that question marks be used to denote a questionable assignment.[5] For example, if a new species was given the specific epithetalbum by Anton and attributed with uncertainty to Agenus, it could be denoted "Agenus? album Anton (?Anton)"; the "(?Anton)" indicates the author that assigned the question mark.[5] So if Anton described Agenus album, and Bruno called the assignment into doubt, this could be denoted "Agenus? album (Anton) (?Bruno)", with the parentheses around Anton because the original assignment (to Agenus) was modified (to Agenus?) by Bruno.[5] This practice is not included in the International Code of Zoological Nomenclature, and is used only by paleontologists.[5]
^Allaby, M. (1999). A Dictionary of Zoology. Oxford University Press. p. 704. Retrieved 5 January 2013.
^ abcdefgS. C. Matthews (1973). (PDF). Palaeontology. 16 (4): 713–719. Archived from the original (PDF) on 27 July 2011.
^Jürg Schönenberger; Else Marie Friis (March 2001). "Fossil flowers of ericalean affinity from the Late Cretaceous of Southern Sweden". American Journal of Botany. 88 (3): 467–480. doi:10.2307/2657112. JSTOR 2657112. PMID 11250825.
^Richard Arnold Davis; Holmes A. Semken Jr. (24 January 1975). "Fossils of uncertain affinity from the Upper Devonian of Iowa". Science. 187 (4173): 251–254. Bibcode:1975Sci...187..251A. doi:10.1126/science.187.4173.251. JSTOR 1739069. PMID 17838783. S2CID 39189634.
^J. V. Remsen Jr.; C. D. Cadena; A. Jaramillo; M. Nores; J. F. Pacheco; M. B. Robbins; T. S. Schulenberg; F. G. Stiles; D. F. Stotz; K. J. Zimmer (2007). . South American Classification Committee. American Ornithologists' Union. Archived from the original on 10 October 2007. Retrieved 15 October 2007.
^J. V. Remsen Jr.; C. D. Cadena; A. Jaramillo; M. Nores; J. F. Pacheco; M. B. Robbins; T. S. Schulenberg; F. G. Stiles; D. F. Stotz; K. J. Zimmer (2011). . South American Classification Committee. American Ornithologists' Union. Archived from the original on 2 March 2009. Retrieved 12 June 2011.
^Per Alström; Knud A. Jønsson; Jon Fjeldså; Anders Ödeen; Per G. P. Ericson; Martin Irestedt (2015). "Dramatic niche shifts and morphological change in two insular bird species". Royal Society Open Science. 2 (3): 140364. Bibcode:2015RSOS....240364A. doi:10.1098/rsos.140364. PMC4448822. PMID 26064613.
^Rebecca B. Harris; Per Alström; Anders Ödeen; Adam D. Leaché (2018). "Discordance between genomic divergence and phenotypic variation in a rapidly evolving avian genus (Motacilla)". Molecular Phylogenetics and Evolution. 120: 183–195. arXiv:1707.03864. doi:10.1016/j.ympev.2017.11.020. PMID 29246816. S2CID 3592799.
^Yamaguchi, Masashi; et al. (28 September 2012). "Prokaryote or eukaryote? A unique microorganism from the deep sea". Microscopy. 61 (6): 423–431. doi:10.1093/jmicro/dfs062. PMID 23024290.
^Joachim Reitner (2011). "Metallogenium". In Joachim Reitner & Volker Theil (ed.). Encyclopedia of Geobiology. Encyclopedia of Earth Sciences Series. Springer. pp. 563–565. Bibcode:2011enge.book.....R. doi:10.1007/978-1-4020-9212-1_220. ISBN978-1-4020-9211-4.
^ abMcNeill, J.; Barrie, F.R.; Buck, W.R.; Demoulin, V.; Greuter, W.; Hawksworth, D.L.; Herendeen, P.S.; Knapp, S.; Marhold, K.; Prado, J.; Prud'homme Van Reine, W.F.; Smith, G.F.; Wiersema, J.H.; Turland, N.J. (2012). International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011. Vol. Regnum Vegetabile 154. A.R.G. Gantner Verlag KG. ISBN978-3-87429-425-6. Retrieved 28 July 2013.
The dictionary definition of incertae sedis at Wiktionary
Media related to incertae sedis at Wikimedia Commons
February 16, 2024
incertae, sedis, latin, uncertain, placement, problematica, term, used, taxonomic, group, where, broader, relationships, unknown, undefined, alternatively, such, groups, frequently, referred, enigmatic, taxa, system, open, nomenclature, uncertainty, specific, . Incertae sedis Latin for of uncertain placement 2 or problematica is a term used for a taxonomic group where its broader relationships are unknown or undefined 3 Alternatively such groups are frequently referred to as enigmatic taxa 4 In the system of open nomenclature uncertainty at specific taxonomic levels is indicated by incertae familiae of uncertain family incerti subordinis of uncertain suborder incerti ordinis of uncertain order and similar terms 5 New World vultures such as the California condor were placed incertae sedis within the class Aves until the recognition of the new order Cathartiformes Plumalina plumaria Hall 1858 6 3 cm tall Upper Devonian of western New York State US Workers usually assign this organism to the hydrozoans phylum Cnidaria class Hydrozoa or the gorgonarians phylum Cnidaria class Anthozoa order Gorgonaria but it is probably safest to refer to it as incertae sedis 1 The varanopids a mysterious family of tetrapods had controversial relationships with many other land tetrapods Paleolontologists have mostly assigned them in the past as eupelycosaurian synapsids Others have placed them as basal neodiapsids A compromise is to place them as Amniota incertae sedis Contents 1 Examples 2 In formal nomenclature 3 Reason for use 3 1 Poor description 3 2 Not included in an analysis 3 3 Controversy 4 Phylogenetic vs nomenclatural uncertainty 5 In zoological nomenclature 6 See also 7 References 8 External linksExamples editThe fossil plant Paradinandra suecica could not be assigned to any family but was placed incertae sedis within the order Ericales when described in 2001 6 The fossil Gluteus minimus described in 1975 could not be assigned to any known animal phylum 7 The genus is therefore incertae sedis within the kingdom Animalia While it was unclear to which order the New World vultures family Cathartidae should be assigned they were placed in Aves incertae sedis 8 It was later agreed to place them in a separate order Cathartiformes 9 Bocage s longbill Motacilla bocagii previously known as Amaurocichla bocagii is a species of passerine bird that belongs to the superfamily Passeroidea Since it was unclear to which family it belongs it was classified as Passeroidea incertae sedis until a 2015 phylogenetic study placed it in Motacilla of Motacillidae 10 11 Parakaryon myojinensis a single celled organism that is apparently distinct from prokaryotes and eukaryotes 12 Metallogenium is a bacterium that can form star shaped minerals 13 Circothecidae are a family of Cambrian animals sometimes attributed to the Hyolitha though some authors suggest on the basis of no specified evidence that they are definitely not In formal nomenclature editWhen formally naming a taxon uncertainty about its taxonomic classification can be problematic The International Code of Nomenclature for algae fungi and plants stipulates that species and subdivisions of genera must be assigned to genera and infraspecific taxa must be assigned to species because their names are combinations but ranks higher than the genus may be assigned incertae sedis 14 Reason for use editPoor description edit This excerpt from a 2007 scientific paper about crustaceans of the Kuril Kamchatka Trench and the Japan Trench describes typical circumstances through which this category is applied in discussing 15 the removal of many genera from new and existing families into a state of incertae sedis Their reduced status was attributed largely to poor or inadequate descriptions but it was accepted that some of the vagueness in the analysis was due to insufficient character states It is also evident that a proportion of the characters used in the analysis or their given states for particular taxa were inappropriate or invalid Additional complexity and factors that have misled earlier authorities are intrusion by extensive homoplasies apparent character state reversals and convergent evolution Not included in an analysis edit If a formal phylogenetic analysis is conducted that does not include a certain taxon the authors might choose to label the taxon incertae sedis instead of guessing its placement This is particularly common when molecular phylogenies are generated since tissue for many rare organisms is hard to obtain It is also a common scenario when fossil taxa are included since many fossils are defined based on partial information For example if the phylogeny was constructed using soft tissue and vertebrae as principal characters and the taxon in question is only known from a single tooth it would be necessary to label it incertae sedis 5 Controversy edit If conflicting results exist or if there is not a consensus among researchers as to how a taxon relates to other organisms it may be listed as incertae sedis until the conflict is resolved 5 Phylogenetic vs nomenclatural uncertainty editThe term incertae sedis refers to uncertainty about phylogenetic position of a taxon which may be expressed among others by using a question mark after or before a taxon name This should be distinguished from the situation where either it is uncertain how to use a name often because the types have been lost nomen dubium species inquirenda or whether a poorly preserved specimen should be included within a given species or genus which is often expressed using a cf from Latin confer compare before a taxon name such a convention is especially widespread in palaeontology 16 In zoological nomenclature editIn zoological nomenclature incertae sedis is not a nomenclatural term at all per se but is used by taxonomists in their classifications to mean of uncertain taxonomic position 2 Glossary In botany a name is not validly published if it is not accepted by the author in the same publication 14 Article 36 1 In zoology a name proposed conditionally may be available under certain conditions 2 Articles 11 and 15 For uncertainties at lower levels some authors have proposed a system of open nomenclature suggesting that question marks be used to denote a questionable assignment 5 For example if a new species was given the specific epithet album by Anton and attributed with uncertainty to Agenus it could be denoted Agenus album Anton Anton the Anton indicates the author that assigned the question mark 5 So if Anton described Agenus album and Bruno called the assignment into doubt this could be denoted Agenus album Anton Bruno with the parentheses around Anton because the original assignment to Agenus was modified to Agenus by Bruno 5 This practice is not included in the International Code of Zoological Nomenclature and is used only by paleontologists 5 See also editGlossary of scientific naming Nomen dubium a name of unknown or doubtful application Species inquirenda a species that in the opinion of the taxonomist requires further investigation Wastebasket taxon Sui generis biology Unclassified languageReferences edit Plumalina plumaria JSJ Geology Retrieved 20 January 2021 a b c Glossary International Code of Zoological Nomenclature International Commission on Zoological Nomenclature Retrieved 12 June 2011 Frequently Asked Questions PLANTS database United States Department of Agriculture Retrieved 12 June 2011 Allaby M 1999 A Dictionary of Zoology Oxford University Press p 704 Retrieved 5 January 2013 a b c d e f g S C Matthews 1973 Notes on open nomenclature and synonymy lists PDF Palaeontology 16 4 713 719 Archived from the original PDF on 27 July 2011 Jurg Schonenberger Else Marie Friis March 2001 Fossil flowers of ericalean affinity from the Late Cretaceous of Southern Sweden American Journal of Botany 88 3 467 480 doi 10 2307 2657112 JSTOR 2657112 PMID 11250825 Richard Arnold Davis Holmes A Semken Jr 24 January 1975 Fossils of uncertain affinity from the Upper Devonian of Iowa Science 187 4173 251 254 Bibcode 1975Sci 187 251A doi 10 1126 science 187 4173 251 JSTOR 1739069 PMID 17838783 S2CID 39189634 J V Remsen Jr C D Cadena A Jaramillo M Nores J F Pacheco M B Robbins T S Schulenberg F G Stiles D F Stotz K J Zimmer 2007 A classification of the bird species of South America South American Classification Committee American Ornithologists Union Archived from the original on 10 October 2007 Retrieved 15 October 2007 J V Remsen Jr C D Cadena A Jaramillo M Nores J F Pacheco M B Robbins T S Schulenberg F G Stiles D F Stotz K J Zimmer 2011 A classification of the bird species of South America South American Classification Committee American Ornithologists Union Archived from the original on 2 March 2009 Retrieved 12 June 2011 Per Alstrom Knud A Jonsson Jon Fjeldsa Anders Odeen Per G P Ericson Martin Irestedt 2015 Dramatic niche shifts and morphological change in two insular bird species Royal Society Open Science 2 3 140364 Bibcode 2015RSOS 240364A doi 10 1098 rsos 140364 PMC 4448822 PMID 26064613 Rebecca B Harris Per Alstrom Anders Odeen Adam D Leache 2018 Discordance between genomic divergence and phenotypic variation in a rapidly evolving avian genus Motacilla Molecular Phylogenetics and Evolution 120 183 195 arXiv 1707 03864 doi 10 1016 j ympev 2017 11 020 PMID 29246816 S2CID 3592799 Yamaguchi Masashi et al 28 September 2012 Prokaryote or eukaryote A unique microorganism from the deep sea Microscopy 61 6 423 431 doi 10 1093 jmicro dfs062 PMID 23024290 Joachim Reitner 2011 Metallogenium In Joachim Reitner amp Volker Theil ed Encyclopedia of Geobiology Encyclopedia of Earth Sciences Series Springer pp 563 565 Bibcode 2011enge book R doi 10 1007 978 1 4020 9212 1 220 ISBN 978 1 4020 9211 4 a b McNeill J Barrie F R Buck W R Demoulin V Greuter W Hawksworth D L Herendeen P S Knapp S Marhold K Prado J Prud homme Van Reine W F Smith G F Wiersema J H Turland N J 2012 International Code of Nomenclature for algae fungi and plants Melbourne Code adopted by the Eighteenth International Botanical Congress Melbourne Australia July 2011 Vol Regnum Vegetabile 154 A R G Gantner Verlag KG ISBN 978 3 87429 425 6 Retrieved 28 July 2013 Graham J Bird 2007 Family incertae cedis PDF Zootaxa 1599 121 149 doi 10 11646 zootaxa 1599 1 8 Bengtson Peter January 1988 Open Nomenclature PDF Palaeontology 1 31 223 227 External links edit nbsp The dictionary definition of incertae sedis at Wiktionary nbsp Media related to incertae sedis at Wikimedia Commons Retrieved from https en wikipedia org w index php title Incertae sedis amp oldid 1193312699, wikipedia, wiki, book, books, library,
