| spirifer | <paleontology> Any one of numerous species of fossil brachipods of the genus Spirifer, or Delthyris, and allied genera, in which the long calcareous supports of the arms form a large spiral, or helix, on each side. Origin: NL, fr. L. Spira a coil + ferreto bear. Source: Websters Dictionary (01 Mar 1998) |
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