Crinocheta


Crinocheta is a clade of woodlice that includes the majority of described land-dwelling isopods. 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, a "marginal line" that can be found on the vertex of the head 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 Oniscidae 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.
*These families' places in this clade have been occasionally disputed.