Posted April 3, 2014
Several readers correctly pointed out that these could be used as beads! These are discs from the stem of a crinoid. You might remember that we featured the odd-looking “holdfast” that some species of crinoids used as a way to anchor to the sea floor, in a Freak of the Week from last November. To refresh your memory, and to learn more about crinoids, click here.
The stem of a crinoid is made up of many individual columnals, or discs, which are linked together by ligaments. After the animal dies they usually become disarticulated and are preserved as short stems or individual pieces. These were brought to us from Bill Pickard of OHS Archaeology and were screened from a large amount of soil at a historic site in western Ohio. The archaeologists said these weren’t associated with other artifacts at the site and are probably just naturally occurring in the soil. Crinoids are relatively common in the exposed bedrock of western Ohio, and stem fragments often weather out and are found in gravel or soil.
And they certainly have been used as beads! This is true in the midwestern of the United States, where they are fairly common, and in other parts of the world. In medieval Northumberland, England the discs would erode from sea cliffs and end up on the beaches of the small island of Lindisfarne, where St. Cuthbert was a monk. They were strung together as necklaces or rosaries and became known as St. Cuthbert’s Beads, a term that is still used today. In other parts of England the round columnals were called “fairy money”.
Keep your eye out for these ancient fossils on your next outing! In fact, a well known site for collecting invertebrate fossils is right here in Ohio! Hueston Woods State Park, just north of Oxford attracts people from all over the world because of the large number and quality of the fossils that can be found.