virgatotome

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English

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Etymology

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Ultimately from Latin virga.

Adjective

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virgatotome

  1. (malacology, of the ribs on a shell) Having multiple secondary ribs which branch off successively in front of each primary rib (resulting in a shape like ), like the ribs of Zaraiskites ammonites.
    • 1967, J. C. W. Cope, The Palaeontology and Stratigraphy of the Lower Part of the Upper Kimmeridge Clay of Dorset:
      [...] gyrate furcation, and often a tendency to become fasciculate or virgatotome; secondary ribs obsolescent in some [...] polygyrate ribs and intercalatory secondaries. Microconchs 100-112 mm. in diameter with following rib densities []
    • 1977, Acta geologica polonica:
      ... polygyrate or bidichotomous to fasciculate (rarely virgatotome) ribs, more loosely spaced and coarser. External whorls of macroconch forms with dichotomous to polygyrate ribs []