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St. Cuthbert's beads
St. Cuthbert's beads (or Cuddy's beads) are fossilised portions of the "stems" of Carboniferous crinoids. Crinoids are a kind of marine echinoderm which are still extant, and which are sometimes known as "sea lilies". These bead-like fossils are washed out onto the beach and in medieval Northumberland were strung together as necklaces or rosaries, and became associated with St Cuthbert.
In other parts of England, circular crinoid columnals were known as "fairy money." Pentagonal crinoid columnals were known as "star stones", and moulds of the stems left impressions which were known as screwstones. In Germany, the columnals were known as "Bonifacius pfennige" (St Boniface's pennies).
==Palaeontology==
The "beads" are thick discs or short cylinders, which, when the crinoid was still alive, were articulated to form a branched structure, linked by soft tissue, nerves and ligaments which occupied the central hole (lumen).
The columnals usually became disarticulated after the animal died. Articulated crinoid fossils are relatively rare, but disarticulated columnals are quite common in the fossil record. They may be extracted from their matrix (often limestone) or, in the case of exposures in coastal cliffs, they can sometimes be found washed out of the matrix and deposited on the foreshore, as if from the sea.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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