Actinopterygii

Overview

Class Actinopterygii are the ray-finned fishes which date back to the explosion of all fishes during the Devonian Period (+400 million years ago), aptly named 'the age of fishes'. Although the Late Cretaceous Western Interior Seaway was home to a variety of fish, one of the most famous fossils was of Xiphactinus audax (aka X-fish) a 4 meter (13ft) long predatory fish that had an undigested smaller fish, Gillicus arcuatus, in its stomach. This is known as the famous 'fish-in-a-fish' fossil now on display in the Sternberg Museum of Natural History.

Orders of Actinopterygii present in the Creteacous of the Western Interior Seaway

Acanthomorphata

Albuliformes

Amiiformes

Beryciformes

Crossognathiformes

Elopiformes

Ichthyodectiformes

Pachycormiformes

Pycnodontiformes

Salmoniformes

Siluriformes