• The enigmatic Paleodictyon, from "Something Has Been Making This Mark For 500 Million Years"

• The archaic ungulates Loxolophus, Arctocyon, and Eoconodon, from "How a Mass Extinction Changed Our Brains"

• And the nautilid Aturia, from "When Nautiloids Met Their Match"

———

"The pioneers of the army of milkgivers: Ideal forms of the early Herbivora and Carnivora. In the foreground Paleotherium, Anoplotherium, and Eohippus (this last only restored conjecturally); in the background, Xiphodon and Arctocyon (this last also only an approximation); on the tree, a small lemur; and in front, a hedgehog."

From Winners in life's race, or, The great backboned family by Arabella B. Buckley, 1882