Xystodesmidae is a family of millipedes in the suborder Leptodesmidea within the order Polydesmida (the "flat-backed" or "keeled" millipedes).[1] The family Xystodesmidae was created by the American biologist Orator F. Cook in 1895 and named after the genus Xystodesmus.[2][3] This family includes more than 390 known species distributed among 62 genera.[1] Many species, however, remain undescribed: for example, it is estimated that the genus Nannaria contains over 200 species, but only 25 were described as of 2006.[4] By 2022, 78 species in Nannaria have been described.[5]

Xystodesmidae
Apheloria virginiensis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Myriapoda
Class: Diplopoda
Order: Polydesmida
Suborder: Leptodesmidea
Superfamily: Xystodesmoidea
Family: Xystodesmidae
Cook, 1895
Subfamilies

Melaphinae
Parafontariinae
Xystodesminae

Diversity
c. 60 genera, 300+ species
Synonyms

Fontariidae Attems, 1926
Eurydesmidae Chamberlin, 1950

Distribution

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Millipedes in this family are found across the northern hemisphere, with peak diversity in the Appalachian Mountains, where one-third of the 300 or so species occur.[4] They are particularly abundant in deciduous broadleaf forests in the Mediterranean Basin, Africa, Asia, Central and North America, and Russia.[4] Species in this family often have very small distributional areas, with many species only known from a single locality.[6]

Description

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Xystodemids are characterized by a relatively broad and compact body shape and one or more spines on the second leg-segments (prefemoral spines) in most species.[7] Millipedes in this family range from 8 mm to 85 mm in length, with moderately convex bodies that taper toward both the front and especially the rear end. The antennae are slender and long. The paranota are normally large and prominent.[1]

Colors range from pitch black to pallid, often with vivid patterns.[1] This family contains many colorful and distinctive species, including Apheloria virginiensis of the eastern U.S. and Harpaphe haydeniana of the western U.S. The Sierra luminous millipedes of the genus Motyxia exhibit the only known examples of bioluminescence in the Polydesmida. Species of Apheloria and Brachoria in the Appalachians exhibit Müllerian mimicry, in which unrelated species resemble one another where they co-occur.[8]

This family also includes the cave-dwelling genus Devillea, notable for having more than the 20 segments (counting the collum as the first segment and the telson as the last) usually found the Polydesmida.[9][10] For example, in the species D. tuberculata, adult females have 22 segments and adult males have 21, with a corresponding increase in the number of leg pairs (35 in adult females and 32 in adult males, excluding the gonopods).[11][9][12] Some species in this genus also exhibit variation in segment number within the same sex, for example, in D. subterranea, adult males can have as few as 19 segments or as many as 23.[9][12] The species D. doderoi has the maximum number of segments recorded in this family (29, including the telson).[9]

Classification

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The family is divided into three subfamilies: the Melaphinae with around 10 species, the Parafontariinae with a dozen species in a single genus, and the Xystodesminae, with many genera and species.[13]

 
Parafontaria tonominea from Japan

Subfamily Melaphinae

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Macellolophini

Melaphini

Subfamily Parafontariinae

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Subfamily Xystodesminae

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Unidentified Xystodesmidae, either Apheloria montana (Bollman) or Cherokia georgiana (Bollman). Purchase Knob, Smokies National Park, Haywood County, North Carolina, USA.

The subfamily Xystodesminae is subdivided into ten tribes,[13][14] each ending in the suffix "-ini", although taxonomist Richard Hoffman stated in his 1999 checklist: "I am by no means satisfied that this is the definitive arrangement, nor that the tribal divisions of the Xystodesminae are entirely satisfactory either."[13]

Apheloriini Hoffman, 1980

Chonaphini Verhoeff, 1941

Devilleini Brölemann, 1916

Nannarini Hoffman, 1964

Orophini Hoffman, 1964

 
Orophe unicus, a species of northern Idaho

Pachydesmini Hoffman, 1980

Rhysodesmini Brolemann, 1916

Sigmocheirini Causey, 1955

Xystocheirini Cook, 1904

Xystodesmini Hoffman, 1980

 
Harpaphe haydeniana, a species of the Pacific Northwest of the U.S. and Canada

See also

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References

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  1. ^ a b c d Enghoff, Henrik; Golovatch, Sergei; Short, Megan; Stoev, Pavel; Wesener, Thomas (2015). "Diplopoda — Taxonomic Overview". In Minelli, Alessandro (ed.). The Myriapoda. Vol. 2. Leiden, The Netherlands: Koninklijke Brill NV. p. 399. ISBN 978-90-04-15612-8.
  2. ^ Cook, O.F. (1895). "Introductory note on the families of Diplopoda". In Cook, O.F.; Collins, G.N. (eds.). The Craspedosomatidae of North America. Annals of the New York Academy of Sciences. Vol. 9. New York: New York Academy of Sciences. pp. 1–9 [5].
  3. ^ "MilliBase - Xystodesmidae Cook, 1895". www.millibase.org. Retrieved 2024-08-03.
  4. ^ a b c Paul E. Marek & Jason E. Bond (2006). "Phylogenetic systematics of the colorful, cyanide-producing millipedes of Appalachia (Polydesmida, Xystodesmidae, Apheloriini) using a total evidence Bayesian approach". Molecular Phylogenetics and Evolution. 41 (3): 704–729. doi:10.1016/j.ympev.2006.05.043. PMID 16876439.
  5. ^ Hennen, Derek A.; Means, Jackson C.; Marek, Paul E. (2022). "A revision of the wilsoni species group in the millipede genus Nannaria Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae)". ZooKeys (1096): 17–118. doi:10.3897/zookeys.1096.73485. PMC 9033750. PMID 35837667.
  6. ^ Richard L. Hoffman (1995). "Laurel Creek Xystodesmid Milliped Sigmoria whiteheadi". In Karen Terwilliger, John R. Tate & Susan L. Woodward (ed.). A Guide to Endangered and Threatened Species in Virginia. University of Tennessee Press. p. 58. ISBN 978-0-939923-31-1.
  7. ^ Hoffman, R L (1978). "The Taxonomic and Nomenclatorial Status of the Milliped Generic Names Parafontaria Verhoeff, Caphonaria Verhoeff, and Japonaria Attems (Polydesmida, Xystodesmidae)". Spixiana. 1. München :Zoologische Staatssammlung München: 215–224 [217].
  8. ^ Marek, P. E.; Bond, J. E. (2009). "A Mullerian mimicry ring in Appalachian millipedes". Proceedings of the National Academy of Sciences. 106 (24): 9755–9760. Bibcode:2009PNAS..106.9755M. doi:10.1073/pnas.0810408106. PMC 2700981. PMID 19487663.
  9. ^ a b c d Enghoff, Henrik; Dohle, Wolfgang; Blower, J. Gordon (1993). "Anamorphosis in Millipedes (Diplopoda) — The Present State of Knowledge with Some Developmental and Phylogenetic Considerations". Zoological Journal of the Linnean Society. 109: 103–234.
  10. ^ Mesibov, Robert. "External Anatomy of Polydesmida: Body plans". myriapodology.org. Retrieved 2022-02-20.
  11. ^ Brölemann, H.-W. (1902). "Myriapodes Cavericoles". Annales de la Société Entomologique de France (in French). 71: 448–460 – via Biodiversity Heritage Library.
  12. ^ a b Minelli, Alessandro (2015-01-01). "Diplopoda — development". Treatise on Zoology - Anatomy, Taxonomy, Biology. The Myriapoda, Volume 2: 267–302. doi:10.1163/9789004188273_012.
  13. ^ a b c Hoffman, R. 1999. Checklist of the millipeds of North and Middle America. Virginia Museum of Natural History Special Publications 8, 1–553
  14. ^ Marek, P., et al. (2014) A Species Catalog of the Millipede Family Xystodesmidae (Diplopoda: Polydesmida). Archived 2017-01-24 at the Wayback Machine Special Publication 17. Virginia Museum of Natural History. 140 p.
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