Seeking Pics Of Ordovician Species From Oh/in/ky

[Shamalama]

I'm trying to ID some Platystrophia that I found in the various Cincinnattian formations of the Ordovician of OH/KY/IN. Specifically I need Platystrophia acutiliriata, Platystrophia annieana and Platystrophia foersti. These are all from the Whitewater fm. and specifically the Richmond roadcut along US 27.

Platystrophia ponderosa and cypha are easy to ID, the rest I'm finding out are much harded to find info online for. Even the "Fossils of Ohio" book has just those two and clarksvillensis and they don't even give good descriptions!

Thanks!

[MikeD]

You can find Platystrophia acutiliriata HERE at the bottom of the page.

[Guest solius symbiosus]

Sorry I can't help. I rare pick up anything but trilobites and crinoids anymore.

I'll see if I can find anything online.

[Guest solius symbiosus]

This is from Jillison's Paleontology of Kentucky(1931)

GENUS PLATYSTROPHIA. KING

A spiriferoid Orthid with long straight hingeline and strongly plicated biconvex shell. Brachial valve with strong median fold, pedicle valve with corresponding sinus. Cardinal area about equally developed on each valve. Hinge teeth thick and prominent.

On the basis of the development of the plications of the fold and sinus Cumings (1903, p. 40) has grouped the species into the uniplicable, biplicate, and triplicate groups. All species described below are included in the Triplicata which has been further subdivided by McEwan (1919, p. 390) into—

A. Low fold subgroup

P. colbiensis

P. precursor

P. clarksvillensis

P. acutilirata

B. Ponderosa subgroup

P. ponderosa

P. ponderosa auburnensis

P. preponderosa

C. High fold subgroup

P. laticosta

P. unicostata

P. cypha

PLATYSTROPHIA COLBIENSIS. FOERSTE

Pl. IV, figs. 3, 4; Pl. VII, figs. 4-6

A small Platystrophia with only moderately elevated and not strongly compressed fold and shallow sinus. Plications 4 on the fold, 3 in the sinus, subequal in size. Lateral plications 8-10. Hinge line usually a little less than greatest width of shell. Width 21-22 mm., length about 0.8 width. The Woodburn specimens average somewhat smaller.

Common in the Woodburn and Cynthiana (Greendale) of Central Kentucky, also in the Rogers Gap.

PLATYSTROPHIA LATICOSTA (MEEK)

Pl. XI, figs. 1, 2

Shell transverse, with high, moderately compressed fold and deep sinus; cardinal angles seldom less than seventy degrees. Lateral slopes flatly-convex with 5-7 broad, angular plications. Fold with four, sinus three plications, the lateral ones much reduced. Width commonly around 30 mm., length, 0.6-0.7 width.

Common throughout the Maysville, typically developed in the Fairmount. Similar specimens are found in the Waynesville.

PLATYSTROPHIA CYPHA. JAMES

Pl. XV, fig. 14

The characteristic features of P. cypha are the high compressed fold and deep sinus with a tendency toward the disappearance of the lateral plications leaving two prominent plications on the fold and one in the sinus. James’ type is a form with extended hinge. Such forms have from 10-12 plications on the lateral slopes. On the other extreme are forms with more or less rectangular cardinal angles and 6-8 plications laterally. A contrast with P. laticosta is one of the degree of compression of the fold and reduction of the lateral plications. An extreme is a form with the general contour of P. laticosta, i. e. more or less rectangular cardinal angles and 5-6 plications on the lateral slopes, but with the lateral plications almost or entirely obsolete. For this "uniplicate P. laticosta" from the Bellevue, Cumings has given the name P. unicostata.

Foerste has recognized the variety P. cypha conradi, (Arnheim), a shell with the prolonged hinge, numerous plications on the lateral slopes, and stronger lateral plications on the fold and sinus.

McMillan—Richmond.

PLATYSTROPHIA CLARKSVILLENSIS. FOERSTE

Pl. XIV, figs. 4, 7

A species of the P. laticosta type but, with narrower and more numerous plications on the lateral slopes (7-9), the plications of the fold and sinus of more nearly equal size with the resulting relatively broader and less angular fold and sinus. The lateral slopes are somewhat fuller, giving less prominence to the fold.

Arnheim, Waynesville, and Liberty formations.

PLATYSTROPHIA ACULTILIRATA. CONRAD

Typical P. acutilirata is a strongly ventricose shell, characterized by a low, broad, rounded fold with four approximately equal plications, and numerous plications along the convex lateral slopes. There is every variation in hinge line from long, with spine-like cardinal extremities, to shorter than greatest width. The following varieties have been recognized:

var. prolongata—forms with spine-like cardinal extremities. The typical form of P. acutilirata has the very extended hinge and acute cardinal angles, but not spinelike; and var. senex—a gerontic form with greatly thickened shell, thickness often in excess of length and a tendency toward the more rectangular cardinal angle.

Liberty and Whitewater of Ohio and Indiana. The var. prolongata and var. senex are from the Whitewater.

PLATYSTROPHIA PONDEROSA. FOERSTE

Pl. XIV, fig. 15; Pl. XII, fig. 3

Characterized by the large size, greatly thickened valves, and quadrangular outline. Fold prominent, though rounded, with usually four plications. Plications on the lateral slopes 7-9.

Common from the Fairmount through the Arnheim, rare at higher levels.

PLATYSTROPHIA PONDEROSA VAR. AUBURNENSIS. FOERSTE

Pl. XIII, fig. 4

A variety with hinge line much shorter than greatest width of shell resulting in fewer plications on the lateral slopes (5 or 6) and a more globose form.

Very common in and characteristic of the Mount Auburn in the region around Cincinnati.

PLATYSTROPHIA PREPONDEROSA. MCEWAN

This species is based on specimens from the Catheys near Nashville, Tennessee. It is smaller than P. ponderosa and has a more compressed and elevated fold, these constituting the only differences. Greatest width 26-27 mm., width along hinge 24 mm., length 20 mm., thickness 20 mm.

Specimens of what may be this species were found at the top of a railroad cut about five miles southeast of Winchester on the Ruckersville road, just above the crinoidal limestone marking the introduction of abundant Plectambonites rugosus.

The plates can be found HERE.

[Shamalama]

MikeD: How'd I miss that! *smacks self in head* I was looking through those pages and didn't pay attention. Thanks!

Solius: Perfect! It even has a few of the other species that I'm trying to figure out. Thanks!