Crinoids from Gilmore City

Class Crinoidea is from the Phylum Echinodermata, and first appears abundantly in the fossil record in the Ordovician Period.  Crinoids consist of a flexible stem made of interlocking ossicles with a calyx (cup)
attached to the top.  Coming off of the cup are arms, which are visible in the pictures below.  The focus of this page is the calyx of the crinoids, which are needed for identification, and besides we found quite a few of
them on this year's field trip.  Most of the ones shown on this page were found in a Gilmore City rock quarry by the Dordt 2000 Paleontology class, on a field trip taken November 3 and 4, 2000. A description of this
first stop can be found on the web (restricted to Dordt students).  The students on the trip were:  Greg Le Mahieu, Sharla Zwart, Janna Leusink, Becky Van Ee, and Marissa Moncur, and the professor, Dr. James Mahaffy.   We found them in the Gilmore City Formation of the Mississippi Period.  Also shown on the page is a calyx found by Florence Mahaffy (wife of Dr. Mahaffy) in the same formation, but a different site on a different date.
A number of the unidentified were identifed with the help of some crinoid experts.

Aorocrinus iola Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected on:  November 3 ,2000 by: Becky Van Ee

Aorocrinus iola Gilmore City Fm.  Mississippian Period  Gilmore City, IA Collected on:  November 3 ,2000 by: Becky Van Ee

Aorocrinus iola Gilmore City Fm.   Mississippian Period  Gilmore City, IA  Collected on: November 3 ,2000 by Greg Le Mahieu

Aorocrinus iola Gilmore City Fm. Mississippian Period   Gilmore City, IA  Collected on:  November 3 ,2000 by Janna Leusink

Aorocrinus iola Gilmore City Fm.  Mississippian Period  Gilmore City, IA Collected on:  November 3 ,2000 by Greg Le Mahieu

Aorocrinus iola Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected on:  November 3 ,2000  by: Janna Leusink

Cusacrinus imperator  Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected on: November 3, 2000 by: Sharla Zwart

Eretmocrinus tentor  Gilmore City Fm.  Mississippian Period  Gilmore City, IA Collected on: November 3, 2000 by: Dr. Mahaffy

Eretmocrinus tentor  Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected on:  November 3, 2000 by Greg Le Mahieu

Eretmocrinus tentor Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected on: November 3, 2000 by: Dr. Mahaffy  Same as picture above but lacking top.

Aorocrinus iola Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected on: November 3, 2000 by: Janna Leusink

Unidentified # 2 ?Eretmocrinus tentor Gilmore City Fm.  Mississippian Period  Gilmore City, IA Collected on: 1990 by: James Mahaffy

Unidentified # 3 ?Eretmocrinus tentor Gilmore City Fm.  Mississippian Period  Gilmore City, IA  Collected Fall of 1988 by: Florence Mahaffy

Unidentified # 4 ?Eretomo Gilmore City Fm.   Mississippian Period  Gilmore City, IA  Collected 1988 by James Mahaffy