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Marginocephalia and Coronosauria are node-based clades, indicated by circles. The rest of the clades shown here are stem-based, indicated by half-brackets. See text for definitions and taxonomic authorities. Silhouettes are not to scale (Acrotholus by G. Monger, Psittacosaurus by J. Headden, Triceratops by R. Amos; all others by A. Farke; all images are CC-BY and provided via www.phylopic.org).
