Wednesday, July 3, 2013

Meristella haskinsi (?) from the Centerfield limestone

The Centerfield member of the Ludlowville formation has a rich and varied fauna that I am still exploring and trying to ID specimens from with every new visit. A recent trip yielded this brachiopod specimen that may be a Meristella haskinsi. Superficially it looks similar to a Nucelospira concinna, like these from the Kashong shale, but this shell lacks the spines that normally ornament the latter. Another feature that indicates this is a different genus is that there is clearly a circular foramen opening (where the pedicle muscle emerged) on the umbo (beak shape) of the pedicle valve.

With that settled I'm able to examine the details of the specimen better like the faint radial lines and concentric growth lines on the surface of the shell. What really draws the eye is the obvious predation mark on the pedicle valve. This brachiopod met it's end when a snail drilled through the shell and digested the animal inside.

Pedicle valve


Brachial valve

Posterior - note the foramen opening


The Centerfield member of the Ludlowville formation is Devonian in age (Givetian stage).

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