A well-inflated example of a scarce Asaphid, this is Asaphus
expansus, a name derived from its relatively broad thorax. It
appeared early in the evolution of the Asaphidae, giving
rise to the line of some 30 different as Asaphids that extended all
the way to the dramatically-eyestalked Asaphus
golden Calcite exoskeleton is complemented by the white limestone
matrix, making for a showy display specimen.