Transitional species of duckbilled dinosaurs illuminate relationship between evolution and growth

An emergent field of research in dinosaur paleobiology investigates the relative importance of linear, non-branching evolution (anagenesis) compared with branching evolution (cladogenesis). Increasingly, paleontologists are discovering that many dinosaur species are arranged into anagenetic lineages of rapidly evolving “transitional” species which do not overlap in time. These transitional species usually differ only slightly from their forebears, typically in the shape and size of display structures such as horns or crests. —> Read More