Wooster’s Fossil of the Week: Star-shaped crinoid columnals from the Middle Jurassic of southern Utah

Isocrinus nicoleti Kane County 585Just a quick Fossil of the Week post. Above we see isolated columnals (stem units) of the crinoid Isocrinus nicoleti (Desor, 1845) found in the Co-Op Creek Member of the Carmel Formation (Middle Jurassic), Kane County, southern Utah. Greg Wiles recently received them as part of a donation to our department collections. They have such perfect star shapes that I had to share them here. For the full analysis, see my previous entry on columnals like these preserved in a limestone from the same location.


Baumiller, T.K., Llewellyn, G., Messing, C.G. and Ausich, W.I. 1995. Taphonomy of isocrinid stalks: influence of decay and autotomy. Palaios 10: 87-95.

Tang, C.M., Bottjer, D.J. and Simms, M.J. 2000. Stalked crinoids from a Jurassic tidal deposit in western North America. Lethaia 33: 46-54.

About Mark Wilson

Mark Wilson is a Professor of Geology at The College of Wooster. He specializes in invertebrate paleontology, carbonate sedimentology, and stratigraphy. He also is an expert on pseudoscience, especially creationism.
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7 Responses to Wooster’s Fossil of the Week: Star-shaped crinoid columnals from the Middle Jurassic of southern Utah

  1. Paul Taylor says:

    In British folklore such specimens are known as ‘star stones’. The great 17th century Oxford naturalist Robert Plot believed they were in some peculiar way related to the heavenly stars. Those were the days.

  2. Mark Wilson says:

    Thanks, Paul! I suppose in some peculiar way they ARE related to the stars, since we’re all ultimately made of star stuff.

  3. Janice Tate says:

    I found an amazing little collection of these in a little museum in Kaycee, WY. I can email you a photo if you wish.

  4. Rachel Wood says:

    I find dark coloured rocks with these stars in, quite often at the beaches here in Wales (UK).

  5. Jerry Henley says:

    from Jerry Henley
    I have some near perfect stars in southern Utah, much nicer than the ones shown in this article. I would be glad to forward pictures if wanted. thanks

  6. Debbie Berry says:

    How do I send u a picture of my star rocks.

  7. Mark Wilson says:

    Hi Debbie: You can send me images at mwilson — at — Wooster.edu. Mark

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