A new ‘duck-billed’ dinosaur (Ornithischia: Hadrosauridae) from the upper Campanian of Texas points to a greater diversity of early hadrosaurid offshoots

Abstract

We describe a previously unrecognized genus and species of basally-branching hadrosaurid dinosaur, Malefica deckerti, from the middle- to upper Campanian upper shale member of the Aguja Formation in Big Bend National Park, southwestern Texas, USA. This taxon is represented by a partial left maxilla. The hadrosaurid maxilla is particularly useful in differentiating species, and, despite the incomplete nature of the material, this new taxon is diagnosable by several autapomorphies and a unique combination of character states. Phylogenetic analysis places M. deckerti within Hadrosauridae but outside Saurolophidae, the major hadrosaurid clade consisting of the solid-crested or unadorned Saurolophinae and the hollow-crested Lambeosaurinae. When considered with the other known non-saurolophid hadrosaurids, this species adds to the growing evidence a hitherto unrecognized diversity of early hadrosaurid offshoots spanning the upper Santonian through the Maastrichtian and widespread throughout Eurasia and North America.