Dalejina (?) from the Waldron Shale

At a recent Fossil & Mineral show put on by the Delaware Mineralogical Society (DMS), I purchased a couple of pieces of Silurian aged Waldron Shale. I'd bought them as they had Crinoid "roots" preserved but while cleaning them off a number of small Brachiopods came loose. One of them looks almost like a Rhipidomella brachiopod but further study, and conversations with Mike at Lousiville Fossils and Beyond, have led me to think this might be Dalejina instead.

Brachial Valve


Front


Pedicle Valve


Rear


Profile


The reason for my hesitance to name this fossil a Rhipidomella is that the shape and size of the shell don't seem to correspond to what I've found elsewhere. Rhipidomella is more rectangular in shape while Dalejina is rounder. Dalejina is in the same family as Rhipidomella and is known from the Rochester Shale of New York which is often seen as analogous to the Waldron Shale of Indiana and Kentucky.

I found a plate in the book Brachiopods of the Bois Blanc Formation in New York by A.J. Boucott and J.G. Johnson that shows Dalejina. Plate 1, figures 11-27 show both internal and external pictures of the shell.

The website for Primitive Worlds, a group who quarry the Rochester Shale, has a picture of Dalejina that seems to fit my specimen as well.