Bear Gulch Coelacanth

Cardiosuctor populosum

Coelacanth

late Mississippian 

Bear Gulch Limestone 

The matrix of this specimen is a bit unusual and not typical of what I've seen from most other Bear Gulch fossils, does anyone know why this might be? I'm assuming it might be a specific layer within the Lagerstätte which is also rich in Coelacanths as the only other fossils I've been able to find online in similar dark colored matrix from Bear Gulch with the same type of preservation are also Cardiosuctor specimens. 

The dark color of both matrix and fossil make it a bit difficult to distinguish some of the features, but there's some good preservation of skull elements, the vertebral column, fins and some scales around the specimen.

generously gifted to me by my friend @Dean Ruocco