Wednesday, July 16, 2008

Star of David or Hexagonalis Crinoid

I like to call this the star of David crinoid piece even though it has 7 points. Maybe 4 mm wide from point to point on this piece. Looking on the internet I have not found anything that looks like it but it might not be crinoid stem but maybe a piece of a calyx.

The second picture shows the small rock that the little star fossil is embedded in.

Revised: At a KYANA fossil study session, I was shown a set of articles from the University of Kansas on crinoid stem classification. It had a series of shapes and names for them. One shape was a six pointed star labeled hexagonalis (hex - Greek for six and gonia - Greek for corner or angle). Since this shape has 7 corners, it could be called a heptagonalis (hepta - Greek for seven).

Also since there is a dot in the middle of the shape, you add a prefix to this word above so if the shape in the middle is a circle, cyclohexagonalis or cycloheptagonalis; if ellipse shape in middle then Ellipsahexagonalis or Ellipsoheptagonalis.

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