Rare Anataphrus vigilansTrilobites from Iowa

Anataphrus vigilans is an Asaphid trilobite (Order: Asaphida; Family: Asaphidae Subfamily: Isotelinae) coming from the Ordovician Maquoketa Formation dolomitic shale strata of Fayette County, Iowa. This is a fine enrolled example of a trilobite rarely offered for sale that used to be named Vogdesia. Enrollment was a defensive response to predators, and is the way these trilobites are found. It has affinities with both Isotelus and Homotelus (see my other offerings for examples).