Lacusovagus

Abstract: A partial pterosaur skull from the Nova Olinda Member of the Crato Formation (Lower Cretaceous, Aptian?) represents a new edentulous pterodactyloid, Lacu- sovagus magnificens gen. et sp. nov. The absence of teeth and a large nasoantorbital fenestra suggest assignment to Azhdar- choidea, and the combination of a particularly short, crestless and shallow rostrum and laterally flared jaw margins distin- guish it from other azhdarchoid taxa. The position of the new form within Azhdarchoidea is problematic: Lacusovagus is distinguished from Tapejaridae in its straight, as opposed to ventrally displaced, jaw tip and absence of a premaxillary crest; from thalassodromids by the absence of a premaxillary crest; and from Azhdarchidae by the short length of the ros- trum and shallow posterodorsal extension of the premaxilla. Lacusovagus shares a shallow, crestless rostrum and a slender posterodorsal premaxillary extension with Jiufotang Forma- tion azhdarchoids such as Chaoyangopterus and Jidapterus. The position of these genera within Azhdarchoidea is contro- versial, but the suite of plesiomorphic and derived azhdarch- oid characters in each suggests a placement between Tapejaridae and Neoazhdarchia. Further research is required, however, to determine the relationships of these genera both to each other and to other azhdarchoids. The new taxon ele- vates the faunal similarity found between the roughly con- temporaneous Jiufotang and Crato formations and continues the pattern of Crato Formation azhdarchoids being much larger than those from the Jehol Group. It also has jaws at least 67 and 55 per cent longer, respectively, than those of the largest azhdarchoids and ornithocheirids from the Crato pterosaur assemblage, making Lacusovagus the largest ptero- saur known from this unit.