Crinocheta Legrand, 1946

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Suggested Common Name: Woodlice and Pillbugs
Number of subordinate taxa: over 3100 species in an undetermined amount of families, 233 species in our area.
Etymology: Unknowm, likely refering to the forked penes present in this group. Common name is a standardization of the often-used name for terrestrial isopods. The term Pillbug is also standardized to conglobulating species with reduced telsons and uropods continuing or nearly continuing the body margin, such as members of Armadillidiidae and Armadilidae.
Taxonomic History: Crinocheta Legrand, 1946; Embolophora Verhöeff, 1953
Description: (modified from Tabacaru & Giurginca, 2019) Eyes with 0-+100 ommatidia. Antenna 1 distal segment reduced. Antenna 2 flagellum with 1-4 segments, robust, cylindrical or terminal segments conical, often easy to distinguish from each other. Mandible molar reduced to a spiny lobe. Maxilla 1 endopod with 2 penicils (=tooth setae). Pereopods 1-7 (1-)2-clawed. Stomach superomedianum absent; inferolateralia divided by an oblique bar, limited by strongly chitinized frame. Penes tip forked. Oostegites with brood pouch. ♂ pleopod 1 protopod without water-conducting scales; endopod with sperm channel. ♂ pleopod 2 endopod colinear
Type taxon: none [functionally Oniscoidea Dana, 1852]
Notes: This huge clade contains most described terrestrial woodlice. Many morphological details that often occur in this clade immensely facilitate dispersal into much drier environments than Synochetans, allowing for an immense radiation of terrestrial forms. Most familiar and well-researched land isopods, such as Porcellio scaber and Armadillidium vulgare, are in this clade, although the vast majority of it is poorly studied.

Subordinate Taxa: Detonidae, Oniscoidea, Scyphacidae

Key to lower taxa
1 a. Flagellum long, 7-segmented; uropods robust; tropical seashores --> Olibrinidae*
b. Flagelum shorter, 1-4 segmented; uropods generally not robust; various environments --> 2

*two species of Olibrinus are widespread in the Indopacific, with reports of at least one of them recently coming from Brazil. Although not currently known from our region, it should be watched for along tropical coastlines in the southern parts of the covered area

2 (1) a. Flagellomeres (1-)2-3; coastal or inland --> Oniscoidea
b. Flagellomeres 4 (hard to distinguish but cylindrical in Scyphacidae); coastal --> 3

3 (2) a. Face with very distinct lateral lobes; body generally tuberculated --> Detonidae
b. Face flat or with weak lateral lobes; body smooth --> Scyphacidae


Schmidt, C. (2008). Phylogeny of the terrestrial Isopoda (Oniscidea): a review. Arthropod Systematics Phylogeny, 66(2), 191-226.

Schultz, G. A. (1972). A Review Of Species Of The Family Scyphacidae In The New-World (Crustacea, Isopoda, Oniscoidea). Proceedings of the Biological Society of Washington, 84(56):477-488.

Published: Jan 1, 2023
Edited: Apr 1, 2023