by their high nasoantorbital fenestrae and the bony part of their crests beginning at the front of the skull and continuing further back than in other pterosaurs. The interrelationship of these clades within the larger clade Azhdarchoidea remained disputed, and the clade containing Thalassodromeus and Tupuxuara had received different names from different researchers (Thalassodrominae and Tupuxuaridae). Palaeontologist Mark Witton attempted to resolve the naming issue in 2009, noting that the name "Tupuxuaridae" (first used in the vernacular form "tupuxuarids" by palaeontologist Lü Junchang and colleagues in 2006) had never been validly established and Thalassodrominae should be the proper name (although it was bestowed a year later). Witton further converted the subfamily name Thalassodrominae into the family name Thalassodromidae, and considered the clade part of Neoazhdarchia. A 2011 analysis by palaeontologist Felipe Pinheiro and colleagues upheld the grouping of the clades Tapejarinae and Thalassodrominae in the family Tapejaridae, joined by the Chaoyangopterinae. A 2014 study by palaeontologist Brian Andres and colleagues instead found thalassodromines to group with dsungaripterids, forming the clade Dsungaripteromorpha within Neoazhdarchia (defined as the most inclusive clade containing Dsungaripterus weii but not Quetzalcoatlus northropi). Cladogram based on Pinheiro and colleagues, 2011: Cladogram based on Andres and colleagues, 2014: Pêgas and colleagues kept Tapejarinae and Thalassodrominae as part of Tapejaridae in 2018, but acknowledged that the subject was still controversial. Palaeobiology Crest function Possible functions for Thalassodromeuss cranial crest were proposed by Kellner and Campos in 2002. They suggested that the network of blood vessels on its large surface was consistent with use for thermoregulation, which had also been suggested for the crests of some dinosaurs. Kellner and Campos thought that the crest was used for cooling (enabling the animal to dissipate excess metabolic heat through convection), while heat transfer was controlled byand depended onthe network of blood vessels. The ability to control its body temperature would have aided Thalassodromeus during intense activity (such as hunting), and they suggested that, when in flight, heat would have been dispelled more effectively if the crest was aligned with the wind, while the head was intentionally moved to the sides. Kellner and Campos posited that the crest could have had additional functions, such as display; aided by colour, it could have been used in species recognition, and could also have been a sexually dimorphic feature (differing according to sex), as has been proposed for Pteranodon. In 2006, Martill and Naish found that