Nomenclatural revision of Ornithischia

Ornithischians represent one of the three major radiations of dinosaurs. Throughout their evolutionary history, exceeding 134 million years, ornithischians evolved considerable diversity and morphological disparity, expressed especially through the cranial and osteodermal features of their most distinguishable representatives. The new study provides detailed nomenclatural revision of Ornithischia; it reviews the recent and historical use of 76 ornithischian clade names and establishes their phylogenetic definitions in accordance with the newly implemented International Code of Phylogenetic Nomenclature. Additionally, it introduces five new clade names: two for robustly supported clades of later-diverging hadrosaurids and ceratopsians, one uniting heterodontosaurids and genasaurs, and two for clades of nodosaurids. The study marks a key step towards a formal phylogenetic nomenclature of ornithischian dinosaurs.