Texas Crinoid Stems - Winchell Fm.

[LanceH]

Does anyone know the genus (or even species) of these Texas crinoid stems. I found them in some loose limestone layers in what maybe the Winchell formation near Jacksboro, Texas. If Winchell the age would be 303-304 mya.

Also what about the crinoid cup bottom also found there?

[Rain1950]

Can you send me about 40' of that outcrop?

[Archimedes]

Does anyone know the genus (or even species) of these Texas crinoid stems. I found them in some loose limestone layers in what maybe the Winchell formation near Jacksboro, Texas. If Winchell the age would be 303-304 mya.

Also what about the crinoid cup bottom also found there?

The Crinoid cup has a strong resembalence to

Sciadiocrinus Moore and Plummer, 1938

Pennsylvanian of Texas

can you post a picture of a side view of the anal plate side

[LanceH]

sorry, don't want to tear it out of the matrix at this point.

[jkfoam]

Lance,

I have a publication "Classification and Nomenclature of Fossil Crinoids Based on Studies of Dissociated Parts of Their Columns" by Raymond C. Moore and Russell M. Jeffords, The University ofKansas Publications, January 26, 1968, Article 9, Serial No. 46. In this publication the a crinoid, Blothronagma cinctutum is described that resembles your specimen. It was described as a crinoid from the middle Pennsylvanian in southern Oklahoma.

The publication listed above along with Articles 8 and 10 by the same authors will tell you more than you ever wanted to know about crinoid columnals.

JKFoam

[Mike Murphy]

Lnace:

Archimedes is close with his statement concerning the resemblance of the dorsal cup to Sciadocrinus sp. The dorsal cup, however, is probably Plaxocrinus sp due to the broad, very shallow basal concavity. In addition, the first primibrachs are moderately spinose. Sciadocrinus sp has a deeper and narrower basal concavity. The first primibrachs are not spinose. Both are members of the family Pirasocrinidae (Inadunata, Cladida). The presence of a very low profile (saucer-like) dorsal cup with a shallow to deep basal concavity is characteristic of the family. There are 3 anal plates in the dorsal cup of pirasocrinids. The family is almost exclusively Pennsylvanian, although there is one upper Mississippian genus and a couple of earliest Permian (Wolcampian) genera. The genus Plaxocrinus extends throughout the Pennsylvanian. There are a number of genera in the family. For specific identification, exposure of the anal plates would be necessary.

I cna't help you with identifying the stem sections. I don't think that you will be able to generate much of an identification of the stem sections despite the unusual pattern of nodals and internodals.

Regards,

Mike