Читать книгу Hadrosaurs - David A. Eberth - Страница 44

Phylogenetic Definition The stem-based definition of Clypeodonta (“shield-tooths”) is Parasaurolophus walkeri and all taxa positioned more closely to P. walkeri than to Thescelosaurus neglectus. However, the topology of more basal stem taxa falls outside the scope of this account, and Clypeodonta in this analysis occurs at the node that includes Hypsilophodon foxii, Parasaurolophus walkeri, their common ancestor, and all of its descendants.