Just 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.
References:
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.
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.
Thanks, Paul! I suppose in some peculiar way they ARE related to the stars, since we’re all ultimately made of star stuff.
I found an amazing little collection of these in a little museum in Kaycee, WY. I can email you a photo if you wish.
I find dark coloured rocks with these stars in, quite often at the beaches here in Wales (UK).
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
How do I send u a picture of my star rocks.
Hi Debbie: You can send me images at mwilson — at — Wooster.edu. Mark