[1] The living members of the Diplopoda are divided into sixteen orders in two subclasses.[2] The basal subclass Penicillata contains small species whose exoskeleton is not calcified, and which are covered in setae or bristles. All other millipedes belong to the subclass Chilognatha, consisting of two infraclasses: the infraclass Pentazonia containing the short-bodied pill millipedes, and the infraclass Helminthomorpha (worm-like millipedes) containing the great majority of the species.[3][4]
The classification of millipedes from 1758 as new discoveries and methods of analysis.
History
editThe formal science of millipede biology and taxonomy is called diplopodology, the study of diplopods. The history of scientific millipede classification started with Carl Linnaeus, who in his 10th edition of Systema Naturae, 1758, named seven species of Julus as "Insecta Aptera" (wingless insects).[5] In 1802, the French zoologist Pierre André Latreille proposed the name Chilognatha as the first group of what are now the Diplopoda, and in 1840 the German naturalist Johann Friedrich von Brandt produced the first detailed classification. The name Diplopoda itself was coined in 1844 by Henri Marie Ducrotay de Blainville. In the following decades, millipede taxonomy was driven by relatively few researchers at any given time, with major contributions by Carl Attems, Karl Verhoeff and Ralph V. Chamberlin, who each described over 1,000 species, as well as Orator F. Cook, Filippo Silvestri, R. I. Pocock, and Henry W. Brölemann.[6] The 50-year period from 1890 to 1940, when the seven researchers above were working, was a period when the science of diplopodology flourished: rates of species descriptions during this period was on average the highest in history, sometimes exceeding 300 per year.[7]
In 1971, Dutch biologist C. A. W. Jeekel published a comprehensive listing of all known millipede genera and families described between 1758 and 1957 in his Nomenclator Generum et Familiarum Diplopodorum, a work credited as launching the "modern era" of millipede taxonomy.[8][9] In 1980, American biologist Richard L. Hoffman published a classification of millipedes which recognized the the Penicillata, Pentazonia, and Helminthomorpha,[10], and the first phylogenetic analysis of millipede orders using modern cladistic methods was published in 1984 by Henrik Enghoff of Denmark.[11] A 2003 classification by American myriapodologist Rowland Shelley is similar to classification originally proposed by Verhoeff, and remains the currently accepted classification scheme (shown below), despite more recent molecular studies which propose a number of conflicting relationships.[6][12] A 2011 summary of millipede family diversity by William A. Shear placed the order Siphoniulida within the larger group Nematomorpha.
Diplopoda |
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Classification
editThe living members of the class (biology) Diplopoda are divided into sixteen biology|orders in two subclasses.[2] There are also nine extinct orders. The basal subclass Penicillata contains a single order of small species whose exoskeleton is not calcified, and which are covered in setae or bristles. All other millipedes belong to the subclass Chilognatha.[a]
The subclass Chilognatha is divided into two infraclasses.
The infraclass Pentazonia contains the short-bodied pill millipedes, which are capable of rolling themselves into a ball ("volvation"). The infraclass Helminthomorpha (worm-like contains the great majority of millipede species.[13][14]
The higher-level classification of millipedes is presented below, based on Shear, 2011[2], and Shear & Edgecombe, 2010[12] (extinct groups). Recent cladistic and molecular studies have challenged traditional classification schemes (see Phylogeny, below), and in particular the position of the orders Siphoniulida and Polyzoniida is not yet well established[6]. The placement and positions of extinct groups (†) known only from fossils is tentative and not fully resolved.[6][12]
Class Diplopoda de Blainville in Gervais, 1844
- Subclass Penicillata Latrielle, 1831
- Order Polyxenida Verhoeff, 1934
- Subclass †Arthropleuridea (placed in Penicillata by some authors)[12]
- Order †Arthropleurida
- Order †Eoarthropleurida
- Order †Microdecemplicida
- Subclass Chilognatha Latrielle, 1802
- Order †Zosterogrammida Wilson, 2005 (Chilognatha incertae sedis)[12]
- Infraclass Pentazonia Brandt, 1833
- Order †Amynilyspedida Hoffman, 1969
- Superorder Limacomorpha Pocock, 1894
- Order Glomeridesmida Cook, 1895
- Superorder Oniscomorpha Pocock, 1887
- Order Glomerida Brandt, 1833
- Order Sphaerotheriida Brandt, 1833
- Infraclass Helminthomorpha Pocock, 1887
- Order †Pleurojulida Schneider & Werneburg, 1998 (possibly sister to Colobognatha)[6]
- Superorder †Archipolypoda Scudder, 1882
- Order †Archidesmida
- Order †Cowiedesmida
- Order †Euphoberiida
- Order †Palaeosomatida
- Subterclass Colobognatha Brandt, 1834
- Order Platydesmida Cook, 1895
- Order Polyzoniida Cook, 1895
- Order Siphonocryptida Cook, 1895
- Order Siphonophorida Newport, 1844
- Subterclass Eugnatha Attems, 1898
- Superorder Juliformia Attems, 1926
- Order Julida Brandt, 1833
- Order Spirobolida Cook, 1895
- Order Spirostreptida Brandt, 1833
- Superfamily †Xyloiuloidea Cook, 1895 (Sometimes aligned with Spirobolida)[15]
- Superorder Nematophora Verhoeff, 1913
- Order Callipodida Pocock, 1894
- Order Chordeumatida Pocock 1894
- Order Stemmiulida Cook, 1895
- Order Siphoniulida Cook, 1895
- Superorder Merochaeta Cook, 1895
- Order Polydesmida Pocock, 1887
- Superorder Juliformia Attems, 1926
Hoffman 1980
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Shelley 2003
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2003 Phylogeny inferred through morphology
editWhile most millipede orders are considered monophyletic,[6] the relationship of the orders to each other (the so-called higher level phylogeny), has still not been unambiguously resolved, and different phylogenetic hypotheses have been proposed. Common findings include a basal Penicillata, and a monophyletic Helminthomporpha and Pentazonia. The composition of other groups is equivocal.
The cladogram below shows a phylogeny inferred from morphological traits in 2003[16], supplemented with extinct groups (†) from two recent reviews[6][12] The tentative placement of extinct groups (†) is indicated by dotted lines. The orders Siphoniulida,
Siphonocryptida, †Pleurojulida, and †Zosterogrammida are not shown.
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2007 DNA and morphology
editThe cladogram below shows millipede phylogeny inferred from a total-evidence analysis of morphological traits and molecular data published in 2007.[6] The relative placement of several orders differs from previous studies, but the authors caution that it is premature to propose classification changes based on this study alone.[6]
Penicillata | |
Chilognatha | |
Fossil record
editIn addition to the 16 living orders, there are 9 extinct orders and one superfamily known only from fossils. The relationship of these to living groups and to each other is controversial. The extinct Arthropleuridea was long considered a distinct myriapod class, although work in the early 21st century established the group as a subclass of millipedes.[17][18][19] Several living orders also appear in the fossil record. Below are two proposed arrangements of fossil millipede groups.[6][12] Extinct groups are indicated with a dagger (†). The extinct order Zosterogrammida, a chilognath of uncertain position,[12] is not shown.
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Alternate hypothesis of fossil relationships [18][6] |
Diplopoda |
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References
edit- ^ Brewer, Michael S.; Sierwald, Petra; Bond, Jason E. (2012). "Millipede Taxonomy after 250 Years: Classification and Taxonomic Practices in a Mega-Diverse yet Understudied Arthropod Group". PLoS ONE. 7 (5): e37240. doi:10.1371/journal.pone.0037240. PMC 3352885. PMID 22615951.
{{cite journal}}
: CS1 maint: date and year (link) - ^ a b c Shear, W. (2011). "Class Diplopoda de Blainville in Gervais, 1844. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness" (PDF). Zootaxa. 3148: 159–164. doi:10.11646/zootaxa.3148.1.32.
- ^ Julián Bueno-Villegas, Petra Sierwald & Jason E. Bond. "Diplopoda". In J. L. Bousquets & J. J. Morrone (ed.). Biodiversidad, taxonomia y biogeografia de artropodos de Mexico (PDF). pp. 569–599.
- ^ Rowland M. Shelley. "Millipedes". Retrieved October 12, 2013.
- ^ Caroli Linnaei (1758). Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. pp. 639–640.
- ^ a b c d e f g h i j k Sierwald, Petra; Bond, Jason E. (2007). "Current Status of the Myriapod Class Diplopoda (Millipedes): Taxonomic Diversity and Phylogeny". Annual Review of Entomology. 52 (1): 401–420. doi:10.1146/annurev.ento.52.111805.090210. PMID 17163800.
{{cite journal}}
: CS1 maint: date and year (link) Cite error: The named reference "SierwaldBond2007" was defined multiple times with different content (see the help page). - ^ Brewer, Michael S.; Sierwald, Petra; Bond, Jason E. (2012). "Millipede Taxonomy after 250 Years: Classification and Taxonomic Practices in a Mega-Diverse yet Understudied Arthropod Group". PLOS ONE. 7 (5): e37240. doi:10.1371/journal.pone.0037240. PMC 3352885. PMID 22615951.
- ^ Shelley, R. M. (2007). "Taxonomy of extant Diplopoda (Millipeds) in the modern era: Perspectives for future advancements and observations on the global diplopod community (Arthropoda: Diplopoda)" (PDF). Zootaxa. 1668: 343–362. doi:10.11646/zootaxa.1668.1.18.
- ^ Shelley, Rowland M.; Petra Sierwald; Selena B. Kiser; Sergei I. Golovatch (2000). Nomenclator generum et familiarum Diplopodorum II : a list of the genus and family-group names in the class Diplopoda from 1958 through 1999. Sofia, Bulgaria: Pensoft. p. 5. ISBN 9546421073.
- ^ Hoffman, Richard L. (1980). Classification of the Diplopoda. Geneva, Switzerland: Muséum d’Historie Naturelle. pp. 1–237.
- ^ Enghoff, H. (1984). "Phylogeny of millipedes - a cladistic analysis". Journal of Zoological Systematics and Evolutionary Research. 22 (1): 8–26. doi:10.1111/j.1439-0469.1984.tb00559.x.
- ^ a b c d e f g h Shear, William A.; Edgecombe, Gregory D. (2010). "The geological record and phylogeny of the Myriapoda". Arthropod Structure & Development. 39 (2–3): 174–190. doi:10.1016/j.asd.2009.11.002. PMID 19944188.
{{cite journal}}
: CS1 maint: date and year (link) - ^ Julián Bueno-Villegas, Petra Sierwald & Jason E. Bond. "Diplopoda". In J. L. Bousquets & J. J. Morrone (ed.). Biodiversidad, taxonomia y biogeografia de artropodos de Mexico (PDF). pp. 569–599.
- ^ Rowland M. Shelley. "Millipedes". Retrieved October 12, 2013.
- ^ Hoffman, R.L. (1963). "New genera and species of Upper Paleozoic Diplopoda". Journal of Paleontology. 37 (1): 167–174. JSTOR 1301419.
- ^ Sierwald, P.; Shear, W. A.; Shelley, R. M.; Bond, J. E. (2003). "Millipede phylogeny revisited in the light of the enigmatic order Siphoniulida". Journal of Zoological Systematics and Evolutionary Research. 41 (2): 87–99. doi:10.1046/j.1439-0469.2003.00202.x.
{{cite journal}}
: CS1 maint: date and year (link) - ^ Wilson, Heather M.; Shear, William A. (2000). "Microdecemplicida, a new order of minute arthropleurideans (Arthropoda: Myriapoda) from the Devonian of New York State, U.S.A.". Transactions of the Royal Society of Edinburgh: Earth Sciences. 90 (4): 351–375. doi:10.1017/S0263593300002674.
- ^ a b Kraus, O.; Brauckmann, C. (2003). "Fossil giants and surviving dwarfs. Arthropleurida and Pselaphognatha (Atelocerata, Diplopoda): characters, phylogenetic relationships and construction". Verhandlungen des Naturwissenschaftlichen Vereins in Hamburg. 40: 5–50.
- ^ Kraus, O. (2005). "On the structure and biology of Arthropleura species (Atelocerata, Diplopoda; Upper Carboniferous/Lower Permian)". Verhandlungen des Naturwissenschaftlichen Vereins in Hamburg. 41: 5–23.