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Actinopterygii

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