Torosaurus and Monoclonius, Cretaceous period, chromolithograph, published in 1900 - stock illustration

Torosaurus (genus of herbivorous ceratopsid dinosaur that lived during the late Maastrichtian stage of the Cretaceous period) and Monoclonius (dubious genus of herbivorous ceratopsian dinosaur found in the Late Cretaceous layers). Chromolithograph after a drawing by Francis John, published in 1900.