A Beginners Guide To Identifying Cincinnatian Crinoids

By Jack Kallmeyer

Additional Stem Sketches 
Some Stem Photos
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Stem Identification

Illustrations by Jack Kallmeyer

Cincinnaticrinus variabrachialus
Cincinnaticrinus pentagonus


Most common stems found throughout the Cincinnnatian.

Stems up to a meter in length. Shape shown is consistent through most of that lengh. Shape changes to pentagonal near the cup.
Cincinnaticrinus Stems Photo
More Cincinnaticrinus stem sketches

Merocrinus


Round very smooth stems found in the lower Kope.
Merocrinus Stems Photo

Ectenocrinus simplex


One of the most common stems found in the Kope and into the Maysvillian. Stems up to a meter long.

The stem changes below the cup rapidly tapering with very thin columnals.
Ectenocrinus stems photo

More Ectenocrinus stem sketches

Gaurocrinus nealli

Stem is pentagonal with very rounded corners.  On some columnals the corners project more than in this drawing but remain rounded.  Columnal diameter varies with position as shown.  The articulating ridges are always perpendicular to the sides of the pentagon. The central opening is rounded pentagonal.  Found in the Waynesville and Liberty.
 

Glyptocrinid


Species not determined. Crinoid found in the Kope. Largest diameter columnals bear ten nodes around the perimeter from holdfast to the cup.

Iocrinus subcrassus


Species found throughout the Cincinnatian. Stem varies from pentagonal to star shaped.
Iocrinus Stem photo

Plicodendrocrinus casei


Star shaped stem with only faint articulating ridges on the columnals. The column tapers beneath the cup. Found in the Waynesville and Liberty of the Richmondian.
Plicodendrocrinus casea stem photo

Pychnocrinus dyeri
Glyptocinus decadactylus


Stem round in cross section. Larger diameter columnals are smooth. Found in the Maysvillian and lower Richmondian.

Glyptocrinus fornschelli


Stem pentagonal with sharp corners. Columnals become thinner below the cup. Found in the upper Richmondian.

Rhaphanocrinus sculptus

The external shape of this stem can be described as broadly pentalobate.  The articulating ridges are radially arranged in a narrow ring.  The central opening is circular.  The stem diameter varies with position.  The smallest diameter columnals are circular externally but still retain the same articulating ridge pattern.  Found in the Waynesville and Liberty.  

Xenocrinus baeri


Stem is four sided. The corners somtimes have rounded lobes. Found in the Liberty and Whitewater. 
Xenocrinus stem photo
More Xenocrinus stem sketches

Pentameric Stem


The stems of some crioids have columnals made of individual plates called meres. This form is most often seen near the holdfast.

Other Crinoid Identifications

General Identification
Holdfast Identification

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