pygidium

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pygidium

(pī-jĭd′ē-əm)
n. pl. pygid·ia (-ē-ə)
The posterior body region or segment of certain invertebrates.

py·gid′i·al (-ē-əl) adj.
References in periodicals archive ?
The affiliation of this specimen to Colpocoryphe bohemica is, in comparison with the previous sample, more reliable because the pygidium has 7-8 rings and a distinct postaxial elevation reaching the pygidial margin.
fabiani Dorsal idiosoma Pilose setae absent present Pygidial shield absent present Oval pits in present absent anterior area of dorsal shield Ventral idiosoma Sternal setae all setae short two pairs of them longer Short setae on one pair three pairs ventral shield Poststigmatid part absent present of peritremes
4) heart-shaped, with short, somewhat transverse lateral carinae; pygidial plate triangular (Fig.
Surface of pygidial disc punctate, with abundant erect setae; strongly prominent pre-apically, rounded.
Peng (1990a) considered the cephalic morphology of his specimens to completely match the holotype of Geragnostus yangtzeensis, but mentioned some pygidial differences such as a tapered axis and a less rounded and somewhat longer posterior segment, so he left his specimens in open nomenclature.
Frons and vertex finely punctate, vertex without transverse ridges; petiole longer than hind tibia; in female, pygidial area broad, with dense, fine punctures (Fig.
Pygidial plate moderately convex, 2 times wider than long, punctulated, triangular, setose, with apical margin weakly reflexed; 4/5 of pygidial plate exposed beyond elytral apex.
Tapinoma melanocephalum workers effectively utilize their pygidial gland secretions as an alarm-defense system during aggressive encounters with other invaders (Tomalski et al.
A species of Serrodiscus with a long, stout, upward and backwardly directed glabellar spine, and 11 pygidial axial rings with prominent median spines directed upwards and slightly backwards.
The arrangement of region A segments after relaxation, the form of pygidial tissue ventral to the anus, the lack of dorsal-ventral flattening of region A, the lack of elongation of the entire body, and the pelagic habitat are additional similarities shared with larval chaetopterids.