Exploring the complex cranial morphology of Tupandactylus imperator (Pterodactyloidea, Tapejaridae) based on a new specimen.

Tupandactylus imperator, a striking tapejarid pterosaur from the Lower Cretaceous (Aptian) Crato Formation (Araripe Basin), is renowned for its extraordinary cranial crest, one of the proportionally largest among pterosaurs and, indeed, also among all living and extinct vertebrates. This species is known from six specimens, showing different degrees of completeness. Here we describe a new material (MN 7852-V) that represents the most complete skull and articulated lower jaw of Tupandactylus imperator to date, presenting an exceptionally well-preserved cranial crest composed of bone and extensive soft-tissue. Uniquely, the soft-tissue portion of the crest has a sinuous dorsoposterior margin, contrasting with previously reconstructions that suggested a convex or concave profile. The new specimen also shows several new anatomical features such as a free descending process of the nasal and several unfused elements of the lower jaw. It further displays a well-developed dentary crest and a pronounced retroarticular process, differing from previous interpretations. The specimen also displays plant material in direct contact with the mandible, which may be taphonomic or could tentatively be seen as an indication of a herbivorous feeding habit for this species.