pygidium

American  

[pahy-jid-ee-uhm] / paɪˈdʒɪd i əm /

noun

Zoology.

plural

pygidia

1. any of various structures or regions at the caudal end of the body in certain invertebrates.

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pygidium British  

/ -ˈɡɪd-, paɪˈdʒɪdɪəm /

noun

1. the terminal segment, division, or other structure in certain annelids, arthropods, and other invertebrates

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Other Word Forms

• pygidial adjective

Etymology

Origin of pygidium

1840–50; < New Latin < Greek pȳg ( ḗ ) rump + -idion diminutive suffix

Example Sentences

The trilobite spans 146 meters from cephalon to pygidium, or head to tail, and is carved into the shape of a spiny Ceraurus trilobite instead of the plainer state fossil, Calymene.

From Science Magazine • Sep. 22, 2017

Spine: a sharp process: in Coccidae there are two, one each side of each segment of the pygidium.

From Explanation of Terms Used in Entomology by Smith, John. B.

Lobe: any prominent rounded process or excrescence on a margin: specifically, the rounded, tooth-like processes on the margin of the pygidium of the Diaspinae: also applied to lateral expansions of the abdominal segments.

From Explanation of Terms Used in Entomology by Smith, John. B.

The relation in size between the flea and its pygidium.

From Scientific American Supplement, No. 470, January 3, 1885 by Various

M. Barrande pointed out that these primordial trilobites have a peculiar facies of their own dependent on the multiplication of their thoracic segments and the diminution of their caudal shield or pygidium.

From The Student's Elements of Geology by Lyell, Charles, Sir