Columnaodus is an extinct genus of hybodontiform (shark-like cartilaginous fish) that lived during the Mississippian.
Distribution Columnaodus witzkei fossils are known from the Burlington-Keokuk Bonebed on the border between Illinois and Iowa. It may have eaten crinoids, brachiopods and/or other shelled invertebrates. The Burlington-Keokuk Bonebed sits at the boundary between the Burlington and Keokuk Limestone formations, both of which were deposited into the Illinois Basin.
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