Tupuxuara

''Tupuxuara'' is a genus of thalassodromid pterosaur that lived during the Albian age of the Early Cretaceous, about 112 million years ago. Its remains were found in what is now the Romualdo Formation of the Santana Group in Brazil. ''Tupuxuara'' was named in 1988 by paleontologists Alexander Kellner and Diógenes de Almeida Campos. The name ''Tupuxuara'' means "familiar spirit" referring to a familiar spirit in the mythology of the Tupi people in Brazil. Two species have been named, ''T. longicristatus'', the type species, and ''T. leonardii''. An additional species has been named in 2013, ''T. deliradamus''. However, the validity of this species has been put into question and it may not even belong to ''Tupuxuara''.

''Tupuxuara'' was quite large in size. It had a big crest at the back portion of its head, stemming from the snout. This crest is most likely an indicator of sexual maturity, given that it appears more prominently in mature individuals. The beak of ''Tupuxuara'' was toothless. A wingspan of and a body mass of have been estimated for ''Tupuxuara'', indicating that it had long wings with respect to its mass.

The classification history of ''Tupuxuara'' has been quite controversial. It was initially assigned to the family Tapejaridae, grouped with the closely related ''Thalassodromeus'' in a subfamily called Thalassodrominae. However, several studies have argued against this arrangement and have supported a closer relationship with the families Azhdarchidae and Dsungaripteridae, with Thalassodrominae being elevated to family level, thus creating the term Thalassodromidae. All three families would be grouped in a clade called Neoazhdarchia. More recently, studies that support a tapejarid identity for ''Tupuxuara'' have also favored the denomination Thalassodromidae to have consistency, which would effectively remove the group from Tapejaridae. Nonetheless, they would find thalassodromids and tapejarids to group together in a clade called Tapejaromorpha. Early studies had suggested that ''Tupuxuara'' was piscivorous (a fish eater), with some even suggesting a fruit-based diet. However, based on its azhdarchoid lineage, ''Tupuxuara'' most likely would have been a terrestrial omnivore or carnivore.

Discovery and history

''Tupuxuara'' was named and described by Brazilian paleontologists Alexander Kellner and Diógenes de Almeida Campos in 1988. The type species is ''Tupuxuara longicristatus''. The generic name ''Tupuxuara'' means "familiar spirit", referring to a familiar spirit from the mythology of the Tupi people in Brazil. The specific name ''longicristatus'' means "long-crested" in Latin.Kellner, A.W.A., and Campos, D.A. (1988). "Sobre un novo pterossauro com crista sagital da Bacia do Araripe, Cretaceo Inferior do Nordeste do Brasil. (Pterosauria, Tupuxuara, Cretaceo, Brasil)." ''Anais da Academia Brasileira de Ciências'', 60: 459–469. n Portuguese/ref>

The holotype specimen, MN 6591-V, was found in the Santana Formation (now known as the Romualdo Formation) of Brazil, a rock formation dating back to the Albian stage of the Early Cretaceous period. The holotype consists of a snout and some partial wing bones.

In 1994, Kellner and Campos named a second species, ''Tupuxuara leonardii''. The specific name honors Giuseppe Leonardi, an Italian geologist and paleontologist. The holotype specimen is MN 6592-V, a fragmentary skull with a more rounded crest than the type species ''T. longicristatus''. Other similar material has been referred to ''T. leonardii'' as well.

In 2009, British paleontologist Mark Witton named a purported third species, ''Tupuxuara deliradamus''. The holotype is SMNK PAL 6410, a skull. Another skull is the paratype: KPMNH DL 84. The specific name is derived from Latin ''delirus'', "insane" or "crazy", and ''adamas'', "invincible", but also the word from which "diamond" is derived. The species has a distinctive diamond-shaped skull opening and low eye sockets. The name is a tribute to the song "Shine On You Crazy Diamond" by Pink Floyd, one of Witton's favorite bands. However, this species has been considered as a ''nomen dubium'' (dubious name) by Kellner in 2013. A 2023 study by Brazilian paleontologist Gabriela Cerqueira and colleagues also classified ''T. deliradamus'' as a ''nomen dubium''. It was recovered as an indeterminate member of the subfamily Tapejarinae and as the sister taxon of the species ''Caupedactylus ybaka'', effectively removing it from the genus ''Tupuxuara''.

Description

''Tupuxuara'' was a fairly large pterosaur in terms in size. The most distinguishing characteristic of ''Tupuxuara'' is the large crest that it possessed, which protruded from the back portion its head and originated from its snout. This crest consisted primarily of bone. This feature was more prominent in mature individuals. More recently found fossil material show considerable variation in morphology. Some researchers explain this as intra-specific variability, being caused by a difference in age or sex. Others even assume that it is due to different species being present in the discoveries.

In his 2022 pterosaur book, American paleontologist Gregory S. Paul indicated that ''Tupuxuara'' had a wingspan measuring , a total body length of and a body mass of . Paul noted that ''Tupuxuara'' had long wings relative to its body mass. ''Tupuxuara'' was slightly smaller compared to its closest relative, ''Thalassodromeus'', and it bore a skull that was less heavily built due to its crest having a smaller size.Wilton, Mark P. (2013). ''Pterosaurs: Natural History, Evolution, Anatomy.'' Princeton University Press. . A key difference between the two species of ''Tupuxuara'' is the structure of the crest. The type species, ''T. longicristatus'', featured a more elongated crest, as its name suggests, while ''T. leonardii'' featured a more rounded crest in terms of shape.

Classification

''Tupuxuara'' was initially assigned to the family Tapejaridae in its description by Kellner, closely related to the pterosaur '' Tapejara''. Within Tapejaridae, its closest relative was ''Thalassodromeus'', indicated by their bony crest, a characteristic only shared by them in the family. Meanwhile, other tapejarids bore a crest mostly consisting of soft tissue. In 2007, Kellner and Campos divided Tapejaridae into the subfamilies Tapejarinae and Thalassodrominae, with ''Tupuxuara'' being a member of the latter, alongside ''Thalassodromeus''. Tapejaridae itself was recovered within the superfamily Azhdarchoidea. This arrangement would later be supported by many different studies..

However, conflicting studies also arose. A new group had been named in 2003 by paleontologist David Unwin, the Neoazhdarchia, containing ''Tupuxuara'' and the family Azhdarchidae. This new group, like the Tapejaridae, would be inside Azhdarchoidea. In 2006, this arrangement would be further supported by British paleontologists David Martill