Cladoselache, a puzzling ancient shark-like fish

Cladoselache, a puzzling ancient shark-like fish Loren E. Babcock, Professor in the School of Earth Sciences at The Ohio State University, introduces research on Cladoselache, a puzzling ancient shark-like fish. The Devonian Period, ~420 to 359 million years ago, is known in colloquial terms as the “Age of Fishes.” During this time, early cartilaginous and bony fishes experienced substantial diversification and adaptation to varied habitats. One characteristic and commonly illustrated Devonian fish is the shark-like Cladoselache (pronounced “klade-oh-sell-æ-key”), known from numerous specimens, some virtually complete, found in Late Devonian-age (~370 million-year-old) iron-carbonate concretions collected in and around Cleveland, Ohio, U.S. (1-4)