Hystricina trulla brachiopod from Independence, Iowa

Hystricina trulla is another wavy/spiny surfaced brachiopod like Spinatrypa. I liken it to Pseudoatrypa because it has a similarly deep, convex brachial valve.

Brachial valve

Anterior

Pedicle valve

Posterior

Profile

This specimen is still partially embedded in the matrix.

The specimens shown above came from the Cedar Valley formation (Devonian, Givetian stage) near Independence, Iowa. I purchased both specimens from this seller on E-bay.