combined with postcrania; CP.V 1023: a snout and postcrania; CP.V 1024: a skull and postcrania of at least three juveniles; CP.V 1025: a thighbone; CP.V 1026: a thighbone; CP.V 1450: a slab containing at least fourteen juveniles; CP.V 2003: a skull with lower jaws and articulated wing elements; UEPG/DEGEO/MP-4151: a slab with two skulls and postcrania; and UEPG/DEGEO/MP-4152: a snout with postcrania. Most specimens are part of the collection of the Centro Paleontológico of the Universidade do Contestado. Description The largest individuals of Caiuajara had an estimated wingspan of . The species had a large toothless head with, in adult individuals, an enormous shark fin-shaped crest on the snout. The describing authors established several distinguishing unique traits, autapomorphies. The tip of the snout is strongly oriented to below, at 142 to 149°, relative to the edge of the upper jaw. The rear ascending branches of the premaxillae on their midline form an elongated bony rim projecting to below into the nasoantorbital fenestra, the large skull opening in the side of the snout. In the concave upper rear of the symphysis, the fronts of the lower jaws grown together, a rounded depression is present. The front outer edge of the quadrate shows a longitudinal groove. Below the front part of the nasoantorbital fenestra, a depression is present in the upper jaw edge. Additionally, Caiuajara shows a unique combination of traits that are themselves not unique. The lower edge of the eye socket is rounded. At a maximal occlusion, the gap between the upper and lower jaw is wider than with other tapejarines. The pteroid on its bottom surface shows a conspicuous depression lacking a pneumatic opening. Phylogeny Caiuajara was assigned to the Tapejaridae, more precisely the Tapejarinae. It shares several traits with the tapejarids, such as a crest running from the front snout to the back of the head; an elongated nasoantorbital fenestra occupying over 40% of total skull length; and a large boss on the front edge of the coracoid. A typical tapejarine trait is the down-turned snout tip. A cladistic analysis showed that Caiuajara is a possible sister species of Tupandactylus. In 2014, Caiuajara was the geologically youngest known tapejarid (aside from the possible tapejarid Bakonydraco galaczi) and also the most southern one known. This expansion of their known range was seen as an indication that tapejarids had a global distribution. Moreover, Caiuajara is the first pterosaur found in