Hercostrophia robusta brachiopod from the Silica Shale

Hercostrophia robusta is a new Strophomenid brachiopod for me. It was part of a lot of fossils from the Silica Shale of Paulding, Ohio but only had the partail, single valve. It has a superficial resemblance to Strophodonta demissa but the valve of H. robusta appears to be flatter and more like Protoleptostrophia perplana. The Silica Shale is Devonian in age (Givetian stage).

Pedicle valve exterior

Pedicle valve interior

Posterior hinge