rhabdolith

Noun

rhabdolith (plural rhabdoliths)

1. A minute calcareous rodlike structure found at both the surface and the bottom of the ocean, supposed by some to be a calcareous alga.
   • It there forms bold bluffs for many miles, and the name "Chalk" is very properly applied to it, from the fact that, like the chalks of Europe, it is largely composed of Foraminifera and coccoliths, to which, in these formations, is added the more recently discovered rhabdolith.1895, Geology of Minnesota, page 49
2. (broadly) Any Mesozoic and Cenozoic coccolith consisting of a single plate with a stem.
   • There is no doubt that Cruxia mericii designates a sacculiform rhabdolith with a structure related to that of the rhabdoliths in Group 1.1984, Marie-Pierre Aubry, Handbook of Cenozoic Calcareous Nannoplankton, page 88
   • A dithecate coccosphere has two discrete layers of different rhabdolith type, an inner endotheca and an outer exotheca.1992, Annelies Kleijne, Extant Rhabdosphaeraceae, page 11