Xystodesmidae

{{Automatic taxobox

| image = Apheloriavirginiensis.jpg

| image_caption = Apheloria virginiensis

| taxon = Xystodesmidae

| authority = Cook, 1895

| display_parents = 2

| subdivision_ranks = Subfamilies

| subdivision = Melaphinae

Parafontariinae
Xystodesminae

| diversity = c. 60 genera, 300+ species

| synonyms = Fontariidae Attems, 1926

Eurydesmidae Chamberlin, 1950

}}

Xystodesmidae is a family of millipedes in the suborder Leptodesmidea within the order Polydesmida (the "flat-backed" or "keeled" millipedes). The family Xystodesmidae was created by the American biologist Orator F. Cook in 1895 and named after the genus Xystodesmus.{{Cite book |last=Cook |first=O.F. |url=https://www.biodiversitylibrary.org/page/35260543#page/19/mode/1up |title=The Craspedosomatidae of North America |publisher=New York Academy of Sciences |year=1895 |editor-last=Cook |editor-first=O.F. |series=Annals of the New York Academy of Sciences |volume=9 |location=New York |pages=1–9 [5] |chapter=Introductory note on the families of Diplopoda |editor-last2=Collins |editor-first2=G.N.}}{{Cite web |title=MilliBase - Xystodesmidae Cook, 1895 |url=https://www.millibase.org/aphia.php?p=taxdetails&id=888805 |access-date=2024-08-03 |website=www.millibase.org |language=en}} This family includes more than 390 known species distributed among 62 genera.{{Cite book |last1=Enghoff |first1=Henrik |title=The Myriapoda |last2=Golovatch |first2=Sergei |last3=Short |first3=Megan |last4=Stoev |first4=Pavel |last5=Wesener |first5=Thomas |publisher=Koninklijke Brill NV |year=2015 |isbn=978-90-04-15612-8 |editor-last=Minelli |editor-first=Alessandro |volume=2 |location=Leiden, The Netherlands |pages=399 |chapter=Diplopoda — Taxonomic Overview}} 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. By 2022, 78 species in Nannaria have been described.{{cite journal |last1=Hennen |first1=Derek A. |last2=Means |first2=Jackson C. |last3=Marek |first3=Paul E. |date=2022 |title=A revision of the wilsoni species group in the millipede genus Nannaria Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae) |url=https://zookeys.pensoft.net/article/73485/element/4/463// |journal=ZooKeys |issue=1096 |pages=17–118 |doi=10.3897/zookeys.1096.73485 |pmc=9033750 |pmid=35837667 |doi-access=free}}

Distribution

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.{{cite journal |author=Paul E. Marek & Jason E. Bond |year=2006 |title=Phylogenetic systematics of the colorful, cyanide-producing millipedes of Appalachia (Polydesmida, Xystodesmidae, Apheloriini) using a total evidence Bayesian approach |journal=Molecular Phylogenetics and Evolution |volume=41 |issue=3 |pages=704–729 |doi=10.1016/j.ympev.2006.05.043 |pmid=16876439}} They are particularly abundant in deciduous broadleaf forests in the Mediterranean Basin, Africa, Asia, Central and North America, and Russia. Species in this family often have very small distributional areas, with many species only known from a single locality.{{cite book |author=Richard L. Hoffman |title=A Guide to Endangered and Threatened Species in Virginia |publisher=University of Tennessee Press |year=1995 |isbn=978-0-939923-31-1 |editor=Karen Terwilliger, John R. Tate & Susan L. Woodward |page=58 |chapter=Laurel Creek Xystodesmid Milliped Sigmoria whiteheadi |chapter-url=https://books.google.com/books?id=ZDHL6f2SAuMC&pg=PA58}}

Description

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.{{cite journal |author=Hoffman, R L |year=1978 |title=The Taxonomic and Nomenclatorial Status of the Milliped Generic Names Parafontaria Verhoeff, Caphonaria Verhoeff, and Japonaria Attems (Polydesmida, Xystodesmidae) |url=https://www.biodiversitylibrary.org/part/66272 |journal=Spixiana |publisher=München :Zoologische Staatssammlung München |volume=1 |pages=215–224 [217]}} 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.

Colors range from pitch black to pallid, often with vivid patterns. 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.{{cite journal|last=Marek|first=P. E.|author2=Bond, J. E. |title=A Mullerian mimicry ring in Appalachian millipedes|journal=Proceedings of the National Academy of Sciences|year=2009|volume=106|issue=24|pages=9755–9760|doi=10.1073/pnas.0810408106|pmid=19487663|pmc=2700981|bibcode=2009PNAS..106.9755M|doi-access=free}}

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.{{Cite journal |last=Enghoff |first=Henrik |last2=Dohle |first2=Wolfgang |last3=Blower |first3=J. Gordon |date=1993 |title=Anamorphosis in Millipedes (Diplopoda) — The Present State of Knowledge with Some Developmental and Phylogenetic Considerations |url=https://academic.oup.com/zoolinnean/article-abstract/109/2/103/2646268?redirectedFrom=fulltext |journal=Zoological Journal of the Linnean Society |volume=109 |pages=103–234}}{{Cite web |last=Mesibov |first=Robert |author-link=Robert Mesibov|title=External Anatomy of Polydesmida: Body plans |url=https://myriapodology.org/polydesmida/plans.html |access-date=2022-02-20 |website=myriapodology.org}} 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).{{Cite journal |last=Brölemann |first=H.-W. |date=1902 |title=Myriapodes Cavericoles |url=https://www.biodiversitylibrary.org/item/34158#page/458/mode/1up |journal=Annales de la Société Entomologique de France |language=French |volume=71 |pages=448–460 |via=Biodiversity Heritage Library}}{{Cite journal |last=Minelli |first=Alessandro |date=2015-01-01 |title=Diplopoda — development |url=https://brill.com/view/book/edcoll/9789004188273/B9789004188273_012.xml |journal=Treatise on Zoology - Anatomy, Taxonomy, Biology. The Myriapoda, Volume 2 |language=en |pages=267–302 |doi=10.1163/9789004188273_012|url-access=subscription }} 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. The species D. doderoi has the maximum number of segments recorded in this family (29, including the telson).

Classification

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.

File:Midoribaba yasude 02.jpg from Japan]]

=Subfamily Melaphinae=

Macellolophini

Macellolophus

Melaphini

Melaphe
Ochridaphe

= Subfamily Parafontariinae =

Parafontaria

= Subfamily Xystodesminae =

File:Xystodesmidae sp.jpg

The subfamily Xystodesminae is subdivided into ten tribes,Hoffman, R. 1999. Checklist of the millipeds of North and Middle America. Virginia Museum of Natural History Special Publications 8, 1–553Marek, P., et al. (2014) [http://www.vmnh.net/content/File/Research_and_Collections/VMNHSpecialPub17.pdf A Species Catalog of the Millipede Family Xystodesmidae (Diplopoda: Polydesmida).] {{Webarchive|url=https://web.archive.org/web/20170124163441/http://www.vmnh.net/content/File/Research_and_Collections/VMNHSpecialPub17.pdf |date=2017-01-24 }} Special Publication 17. Virginia Museum of Natural History. 140 p. 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."

Apheloriini Hoffman, 1980