CP crinoid stem in north China

[blackmoth]

It is in Yangquan, Shanxi province, which is a known for its CP coal mine ( the best in China) and fossils. This is the well known Taiyuan Formation (late philadelphian, late C early P) .

Tons of marine stuff, you have to literally walk on the crinoids and brachiopods calcite, yet a few dozen meters away you see the land plant fossils like cordaits.

I saw crinoid stem pieces in all shaps, round rings, roud rings with radiant rays, eclips rings, penta rings, and square and rectangle pieces ( one in the foto), as well as internal molds. They are every where scattered.

I have little knowledge about it.  I wonder if I could get any help here, like possible ID, or if there is any on-line place to learn.  I only have some generic paleotology book and a small chapter on crinoids fossils, and only a few sketchy words for crinoid stem in CP period.

[blackmoth]

BTW , the rectangle piece has diagonal groove on both sides, but they go the oppsite way, as shown here

[blackmoth]

the weird thing is this crinoid stem that looks like a "double stem". If I do not rember wrongly,  it is not a rare thing there. Could it be possibel that it is not the stem, but the "arm"?

[blackmoth]

even the pavement of remote country road has fossils. In making this particular plate, people may have destroyed a rare 3-D piece in its natural state.

[blackmoth]

and this is a holdfast?

[abyssunder]

14 hours ago, blackmoth said:

the weird thing is this crinoid stem that looks like a "double stem". If I do not rember wrongly,  it is not a rare thing there. Could it be possibel that it is not the stem, but the "arm"?

Doesn't looks like a biserial arm to me, rather it could be an imploded stem.

[abyssunder]

17 hours ago, blackmoth said:

BTW , the rectangle piece has diagonal groove on both sides, but they go the oppsite way, as shown here

I haven't checked the possible crinoid fauna of the region you mentioned, but the columnal in question might be close to Platyplateium, at least it would be a starting point in the research.

 

" Genus PLATYPLATEIUM Moore & Jeffords, new genus

 

Stem composed of strongly compressed, elongate elliptical internodals, with or without cirrus scars at their extremities, and subquadrate nodals bearing divergently oriented elliptical facets on opposite sides and commonly bearing at least one cirrus scar, sides of nodals sloping strongly in region of their angles but subvertical and longitudinally convex like internodals along middle parts of nodal sides. Crown unknown.

 

Type species.-Platyplateium *texanum MOORE & JEFFORDS,
new species; designated herein.

 

Discussion.-The large angular divergence of fulcral ridges on the opposite articula of nodals is much the same as in the Devonian Platystela and is comparable also to many columnals of Platyparallelus and Platyclonus, even though very unlike these latter in appearance. Internodals of Platystela are unknown. If columnals of the other two mentioned genera that have subparallel fulcral ridges on opposite facets are interpreted as internodals, no perceptible differences in shape separate nodals and internodals. In Platyplateium the contrast between internodals and nodals is very marked. Available pluricolumnals consisting of internodals attached to nodals indicate that noditaxes of Platyplateium probably contain not more than 6 or 7 columnals. Platycrinites and Eucladocrinus lack nodals and the fulcral ridges on opposite facets of columnals diverge only slightly in orientation.

 

Occurrence.-Lower Mississippian-Middle Pennsylvanian. "

 

excerpts from R. C. Moore & R. M. Jeffords. 1968. Classification and nomenclature of fossil crinoids based on studies of dissociated parts of their columns. Univ. Kansas Paleontol. Contrib. Serial number 46, Echinodermata, Article 9: 1-114

 

[blackmoth]

13 hours ago, abyssunder said:

Doesn't looks like a biserial arm to me, rather it could be an imploded stem.

 

I took a pic for a side view

[blackmoth]

14 hours ago, abyssunder said:

I haven't checked the possible crinoid fauna of the region you mentioned, but the columnal in question might be close to Platyplateium, at least it would be a starting point in the research.

 

" Genus PLATYPLATEIUM Moore & Jeffords, new genus

 

Stem composed of strongly compressed, elongate elliptical internodals, with or without cirrus scars at their extremities, and subquadrate nodals bearing divergently oriented elliptical facets on opposite sides and commonly bearing at least one cirrus scar, sides of nodals sloping strongly in region of their angles but subvertical and longitudinally convex like internodals along middle parts of nodal sides. Crown unknown.

 

Type species.-Platyplateium *texanum MOORE & JEFFORDS,
new species; designated herein.

 

Discussion.-The large angular divergence of fulcral ridges on the opposite articula of nodals is much the same as in the Devonian Platystela and is comparable also to many columnals of Platyparallelus and Platyclonus, even though very unlike these latter in appearance. Internodals of Platystela are unknown. If columnals of the other two mentioned genera that have subparallel fulcral ridges on opposite facets are interpreted as internodals, no perceptible differences in shape separate nodals and internodals. In Platyplateium the contrast between internodals and nodals is very marked. Available pluricolumnals consisting of internodals attached to nodals indicate that noditaxes of Platyplateium probably contain not more than 6 or 7 columnals. Platycrinites and Eucladocrinus lack nodals and the fulcral ridges on opposite facets of columnals diverge only slightly in orientation.

 

Occurrence.-Lower Mississippian-Middle Pennsylvanian. "

 

excerpts from R. C. Moore & R. M. Jeffords. 1968. Classification and nomenclature of fossil crinoids based on studies of dissociated parts of their columns. Univ. Kansas Paleontol. Contrib. Serial number 46, Echinodermata, Article 9: 1-114

 

Thanks a lot. I downloaded the article.

[abyssunder]

3 hours ago, blackmoth said:

I took a pic for a side view

Thank you for the picture. That may confirm my thought.

 

Type species.-Cyphostelechus claudus MOORE & JEFFORDS, new species, from Middle Pennsylvanian of Texas
Plate 14, figure 4a,b, facetal and side views of type specimen showing straight, even crenulae, very large collapsed axial canal

excerpt from the same document mentioned before