Delthyris sulcata from Lockport, NY

Delthyris is a somewhat common brachiopod within Silurian and Devonian rocks but there are several other genera that look similar such as Kozlowskiella and Howella. The specimen below I am calling Delthyris sulcata based on the picture found on this page from the New York Paleontology website.

Pedicle valve

Anterior

Brachial valve

Posterior

Profile

The specimen above came from the Irondequoit limestone Rochester Shale near Lockport, NY. The Irondequoit limestone Rochester Shale is middle Silurian (Sheinwoodian) in age.