These pictures show Upper Devonian Period brachiopods called Spinatrypa. They were found in the Fort Simpson Formation (Frasnian) in the Northwest Territories of Canada. Thanks to Howard in Alberta, Canada for providing the images and information for today's post.
The brachiopod in the left of the first picture is considered large while the other is about the average size found.
Close up view of the larger brachiopod shown earlier of its brachial valve.
I have included a picture of a Devonian brachiopod I found here in Louisville, Kentucky with one found in the Northwest Territories of Canada.