The Graneros Shale is a rock deposited in the Late Cretaceous Western Interior Seaway of North America about 95 million years ago. Many fossil fish remains were collected from the uppermost portion of the Graneros Shale in southeastern Nebraska and were analyzed for their unique characteristics. These collected fish remains consist of at least 24 vertebrate taxa, including 14 cartilaginous fishes and 10 bony fishes. The locality is characterized by the abundance of benthic (bottom-dwelling) taxa, and indicative of a well-oxygenated, shallow marine environment. This is consistent with the paleoenvironmental inference previously made for the Graneros Shale based on lithological and invertebrate evidence that this time period represents a transgressive phase of the Western Interior Seaway.
Jansen, Kevin R.
"Fossil Fish Fauna from the Uppermost Graneros Shale (Upper Cretaceous) in Southeastern Nebraska,"
DePaul Discoveries: Vol. 1
, Article 7.
Available at: http://via.library.depaul.edu/depaul-disc/vol1/iss1/7