"Body fossils of true ferns are not common in Hell Creek, but their presence is heavily stated by the fossils of their pollen. Relatives of modern chain ferns (Blechnaceae) are a notable component of the ground flora in forested areas."

― Saurian encylopedia

Blechnaceae, also known as Blechnoideae, is a subfamily of ferns from the family Aspleniaceae. Many genus are known from this subfamily, being the most famous the Blechnum, also known as hard fern. Another one is the closely related Woodwardia, also known as chain fern.