Opilioacaridae

{{Short description|Order of mites}}

{{Automatic taxobox

| image = Opilioacarus baeticus (cropped).png

| image_caption =

| image2 = Opilioacarus baeticus 2 (cropped).png

| image2_caption = Specimens of Opilioacarus baeticus

| fossil_range = {{fossil range|Cenomanian|Recent}}

| parent_authority = Johnston, 1968

| taxon = Opilioacaridae

| authority = With, 1902

| display_parents = 3

| synonyms = * Notostigmata

• Onychopalpida
• Opilioacariformes

| synonyms_ref =

}}

File:Neocarus proteus.jpg]]

Opilioacaridae is the sole family of mites in the order Opilioacarida, made up of about 13 genera. The mites of this family are rare, large (1.5 to 2.5 mm) mites, and are widely considered primitive, as they retain six pairs of eyes, and abdominal segmentation. They have historically been considered separate from other mites belonging to Acariformes and Parasitiformes, but are now generally considered a subgroup of Parasitiformes based on molecular phylogenetics.{{Cite journal|last1=Vázquez|first1=Maria Magdalena|last2=Ávila Herrera|first2=Ivalú Macarena|last3=Just|first3=Pavel|last4=Reyes Lerma|first4=Azucena Claudia|last5=Chatzaki|first5=Maria|last6=Heller|first6=Tim Lukas|last7=Král|first7=Jiří|date=2021-09-30|title=A new opilioacarid species (Parasitiformes: Opilioacarida) from Crete (Greece) with notes on its karyotype|url=https://www1.montpellier.inrae.fr/CBGP/acarologia/article.php?id=4449|journal=Acarologia|volume=61|issue=3|pages=548–563|doi=10.24349/acarologia/20214449|s2cid=236270478 |doi-access=free}}

The first member of the Opilioacarida to be discovered was the Algerian species Opilioacarus segmentatus, which was described by Carl Johannes With in 1902, followed by the Sicilian Eucarus italicus and Eucarus arabicus from Aden, both in 1904. Two fossil specimens are known, one of which was discovered in Baltic amber from the Eocene,{{cite journal |author=Jason A. Dunlop |author2=Jörg Wunderlich |author3=George O. Poinar Jr. |name-list-style=amp |year=2003 |journal=Transactions of the Royal Society of Edinburgh: Earth Sciences |volume=94 |issue=3 |pages=261–273 |doi=10.1017/S0263593300000663 |title=The first fossil opilioacariform mite (Acari: Opilioacariformes) and the first Baltic amber camel spider (Solifugae)|s2cid=85646963 |url=http://edoc.hu-berlin.de/18452/22505 }} while the other one was discovered in the Burmese amber from the Late Cretaceous (Cenomanian) around 99 million years old, tentatively assigned to the living genus Opilioacarus.{{cite journal |author=Jason A. Dunlop |author2=Leopoldo Ferreira de Oliveira Bernardi |name-list-style=amp |year=2014 |title=An opilioacarid mite in Cretaceous Burmese amber |journal=Naturwissenschaften |volume= 101|issue= 9|pages= 759–763|doi=10.1007/s00114-014-1212-0 |pmid=25027588|s2cid=253637881 }}

Members of the group live in semi-arid and tropical environments in leaf-litter, under rocks and in caves. Their diet is known to include arthropod carcasses, fungal spores, and pollen.{{Cite journal |last1=Moraza |first1=María L. |last2=Prieto |first2=Carlos E. |last3=Balanzategui |first3=Iñaki |date=2021-03-30 |title=A new species of the genus Opilioacarus With, 1902 (Acari: Opilioacarida) for the Iberian Peninsula |url=https://www1.montpellier.inrae.fr/CBGP/acarologia/article.php?id=4422 |journal=Acarologia |volume=61 |issue=1 |pages=128–147 |doi=10.24349/acarologia/20214422|s2cid=233786254 |doi-access=free }}