Crinocheta is a clade of woodlice that includes the majority of described land-dwelling isopods (Oniscidea). Crinocheta is regarded as monophyletic and the sister group of the clade Synocheta. Some researchers refer to the group of the clades Crinocheta, Synocheta, and Microcheta as Orthogonopoda.
Description The plesiomorphic form of Crinocheta has two transverse lines present on the cephalothorax (linea frontalis or the linea supraantennalis), a "marginal line" that can be found on the vertex of the head (linea marginalis) and is a "runner" morphotype. Some families have lost the linea frontalis and/or the linea supraantennalis but all members have retained the linea marginalis.
Crinocheta have a large number of ommatidia compared to other oniscidean clades. Some reports claim up to 200 ommatidia can be present in some genera but many dispute this claim and maximum of 80. The majority of species have no more than 30 ommatidia.
The second antennae of this clade appear to be made of only five articles because the basal-most article is fused with the head capsule. The distal end of these antennae also bare a tuft that acts as a sensory organ.
In almost all Crinocheta the legs of the first thoracic segment have a distal end with a brush for cleaning the antennae.
Many Crinocheta can conglobate but not all.
Etymology This clade was first introduced by Jean-Jacques Legrand in 1946. The origin of the name Crinocheta is not certain but it may refer to the forked penes present in this group.
Families There are currently 31 families that are considered part of this clade.
Agnaridae Schmidt, 2003 Alloniscidae Schmidt, 2003 Armadillidae Brandt in Brandt & Ratzeburg, 1831 Armadillidiidae Brandt, 1833 Balloniscidae Vandel, 1963 Bathytropidae Vandel, 1952 Berytoniscidae Vandel, 1955 Bisilvestriidae Verhoeff, 1938 Cylisticidae Verhoeff, 1949 Delatorreiidae Verhoeff, 1938 Detonidae Budde-Lund, 1904 Dubioniscidae Schultz, 1995 Eubelidae Budde-Lund, 1899 Halophilosciidae Verhoeff, 1908 Hekelidae Ferrara, 1977 Olibrinidae Budde-Lund, 1912 * Oniscidae Latreille, 1802 Paraplatyarthridae Javidkar & King, 2015 Philosciidae Kinahan, 1857 Platyarthridae Verhoeff, 1949 Porcellionidae Brandt in Brandt & Ratzeburg, 1831 Pudeoniscidae Lemos de Castro, 1973 Rhyscotidae Budde-Lund, 1904 Scleropactidae Verhoeff, 1938 Scyphacidae Dana, 1853 Spelaeoniscidae Vandel, 1948 Stenoniscidae Budde-Lund, 1904 Tendosphaeridae Verhoeff, 1930 Thrakosphaeridae Giurginca in Giurginca, Mîrleneanu & Baba, 2025 Trachelipodidae Strouhal, 1953 *These families' places in this clade have been occasionally disputed.
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