A New Aetosaur from the Upper Triassic (adamanian: Carnian) of Arizona

Adamanasuchus eisenhardtae is a new genus and species of aetosaur from the Upper Triassic (Adamanian: late Carnian) Blue Mesa Member of the Petrified Forest Formation (Chinle Group) in the Petrified Forest National Park, east-central Arizona. Known from part of its dorsal armor, caudal vertebrae, and a femur, A. eisenhardtae is distinguished by relatively narrow and arched paramedian osteoderms with sparse pitting and faint ridges distributed in a very limited radial pattern, raised anterior bars, ventral keels, and a ridge or eminence that meets the posterior edge of the osteoderm, and lateral osteoderms with low, pyramidal spikes, sparsely distributed pits and faint ridges and relatively shallow arching. The distinctive characteristics of the dorsal armor of A. eisenhardtae are a mosaic of features, most of which are found singly or doubly in other aetosaur genera. This indicates a much more complex evolution of aetosaur armor than previously understood.