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

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

Abdomen beneath yellow, each segment margined with brown, the pygidium yellow, with two largish oblique black spots.

From Discoveries in Australia, Volume 1. With an Account of the Coasts and Rivers Explored and Surveyed During The Voyage of H.M.S. Beagle, in the Years 1837-38-39-40-41-42-43. By Command of the Lords Commissioners of the Admiralty. Also a Narrative Of Captain Owen Stanley's Visits to the Islands in the Arafura Sea. by Stokes, John Lort

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.

Dorsal gland orifices: in Diaspinae, oval orifices arranged in more or less distinct rows on the surface of the pygidium, through which is discharged the material of which the dorsal scale is formed.

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