''Ommatoiulus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of millipedes in the family

Julidae Julidae is a family of millipedes in the order Julida, containing more than 600 species in around 20 genera. Its members are largely confined to the Western Palaearctic, with only a few species extending into the Oriental and Afrotropical realms ...

. The

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were described in 2012, and those just from

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

.Akkari, N. and H. Enghoff. (2012)
Review of the genus ''Ommatoiulus'' in Andalusia, Spain (Diplopoda: Julida) with description of ten new species and notes on a remarkable gonopod structure, the fovea.
''Zootaxa'' 3538 1-58. Six new species were described from Portugal in 2017. There are many millipedes known to belong to this genus that do not yet have official names.Bailey, P. T. and T. R. de Mendonça. (1990)
The distribution of the millipede ''Ommatoiulus moreleti'' (Diplopoda, Julida: Julidae) in relation to other ''Ommatoiulus'' species on the south-western Iberian Peninsula.
''Journal of Zoology'' 221(1) 99–111. Ommatoiulus sabulosus 2

This genus is distinguished by the position of the ozopores, the shape of the ocelli and the gonopod legs, the presence of accessory claws on the juveniles, and the presence in males of a large fovea, a cavity where

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...

are stored. Familiar species include the black Portuguese millipede (''Ommatoiulus moreletii''). It is an invasive species in Australia known for its "plagues", when it emerges in swarms so massive that they stop trains, which crush them in huge numbers and make the rails slippery. Like some other millipedes, it produces a secretion with an obnoxious odor and tendency to stain floors when the swarms invade houses.Yuncken, L
Millipede madness.
ABC Science. April 5, 2007. Another well-known species is the striped millipede (''O. sabulosus''), which also swarms. In 2002 it flooded the streets of Dąbrowa Górnicza in

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...

, "causing panic among the inhabitants". Swarms in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

have consisted of "thousands of millions" of individuals, far too many to count. This species has also been known to stop trains. VERHOEFF K. W. (1900)
Wandernde Doppelfüßler, Eisenbahnzüge hemmend
in Zool. Anz., 23, p. 465—473. Species include:
Systema Naturae 2000. *'' Ommatoiulus alacygni'' *'' Ommatoiulus andalusius'' *'' Ommatoiulus aurozonatus'' *''

Ommatoiulus avatar ''Ommatoiulus avatar'' is a species of European millipede in the family Julidae. Individuals are known from Andalusia, southern Spain. Individuals are long. Color in alcohol preserved specimens is brownish with yellowish and black marbling on t ...

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Ommatoiulus baenai ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus baileyi ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus bipartitus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus camurus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus caspius ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus cingulatus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus denticulatus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus diplurus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus dorsovittatus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

'' *'' Ommatoiulus fuentei'' *'' Ommatoiulus fuscounilineatus'' *'' Ommatoiulus hoffmani'' *'' Ommatoiulus ibericus'' *'' Ommatoiulus ilicis'' *'' Ommatoiulus inconspicuus'' *''

Ommatoiulus jaenensis ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The Taxonomy (biology), taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 1 ...

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Ommatoiulus kessleri ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The Taxonomy (biology), taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 1 ...

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Ommatoiulus kimei ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The Taxonomy (biology), taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 1 ...

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Ommatoiulus lapidarius ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The Taxonomy (biology), taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 1 ...

'' *'' Ommatoiulus litoralis'' *'' Ommatoiulus lusitanus'' *''

Ommatoiulus martensi ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

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Ommatoiulus moreletii ''Ommatoiulus moreleti'' (spelt ''moreletii'' in older publications), commonly known as the Portuguese millipede, is a herbivorous millipede native to the western Iberian Peninsula where it shares its range with other ''Ommatoiulus'' species. Fro ...

'' *'' Ommatoiulus navasi'' *'' Ommatoiulus niger'' *'' Ommatoiulus oliveirae'' *'' Ommatoiulus oxypygus'' *'' Ommatoiulus paralellus'' *'' Ommatoiulus porathi'' *'' Ommatoiulus pseudoflagellatus'' *'' Ommatoiulus punicus'' *'' Ommatoiulus recueroi'' *'' Ommatoiulus reipi'' *''

Ommatoiulus rutilans ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

'' *'' Ommatoiulus sabinarensis'' *''

Ommatoiulus sabulosus ''Ommatoiulus sabulosus'', also known as the striped millipede, is a European millipede of the family Julidae. Its common name comes from its two striking bright longitudinal bands on the dorsal surface. ''O. sabulosus'' is widespread and commo ...

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Ommatoiulus schubarti ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The Taxonomy (biology), taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 1 ...

'' *'' Ommatoiulus staglae'' *'' Ommatoiulus stellaris'' *''

Ommatoiulus tetuanus ''Ommatoiulus'' is a genus of millipedes in the family Julidae. The taxonomy of the genus has had a complicated history. As it stands now, there are approximately 60 described species, but this is likely to change. At least 10 new species were ...

'' *'' Ommatoiulus vilnensis''

References

{{Taxonbar, from=Q4298887 Julida