St. Leon Brachiopod

[Tidgy's Dad]

I recently required this lovely little brachiopod from the kindly @connorp

It was found in the 'Butter Shale" layer of the Liberty Formation at the Southgate Hill road cut, St. Leon, Dearborn County, Indiana. 

This is the layer that is famous for the multitude of tiny, usually enrolled, Flexicalymene retrorsa minuens trilobites. But it doesn't contain many brachiopods apart from the occasional lingulid as far as I can ascertain . So this specimen has likely come from a higher level of the Liberty, or possibly from the Lower Whitewater overlying that. Or, conceivably, it comes from the underlying Waynesville Formation which is not necessarily always lower if the beds are dipping and the area searched was nearer to the road. Or it may have been dropped by someone. 

Anyway, I've checked all my literature and can't find a match, unless someone's got a photo or document that shows the posterior view / interarea of Austinella scovillei which is sort of my last faint hope. It closely resembles other brachiopods from the Cincinnatian, but not any from these formations. 

Any help or leads would be most gratefully received. 

The specimen is small; 1.4 cm wide along the hingeline and is subequally biconvex. 

Thanks for looking! 

 

  

[fossilcrazy]

Could you be holding this brachiopod?

[Tidgy's Dad]

1 hour ago, fossilcrazy said:

Could you be holding this brachiopod?

 

A young Glyptorthis insculpta had occurred to me, it does show a little reticulate patterning where the striae are crossed by fine growth lines. But my specimen is widest along the hinge line whereas Glyptortis is not and i don't think there are nearly enough costae. The extreme triangular shape of the interarea and the gulf between the beaks don't match either. 

However, brachiopods can be very diverse within a single species so your suggestion is not impossible., indeed I don't really have a better idea. You may well be right. 

Thank you.

Plaesomys subquadratus is much more quadrate and has a narrow interarea. 

Actually, I am now leaning toward it being a young Hebertella occidentalis.

From Dry Dredgers and there are others similar on that excellent site.

And 

 

 

Edited July 26, 2021 by Tidgy's Dad