Tapejarid

Tapejaridae (from a Tupi word meaning 'the lord of the ways') is a family of azhdarchoid pterosaurs from the Cretaceous period. Members are currently known from Brazil, England, Hungary, Morocco, Spain, the United States, and China. The most primitive genera were found in China, indicating that the family has an Asian origin.

Description

Tapejarids were small to medium-sized pterosaurs with several unique, shared characteristics, mainly relating to the skull. Most tapejarids possessed a bony crest arising from the snout (formed mostly by the premaxillary bones of the upper jaw tip). In some species, this bony crest is known to have supported an even larger crest of softer, fibrous tissue that extends back along the skull. Tapejarids are also characterized by their large nasoantorbital fenestra, the main opening in the skull in front of the eyes, which spans at least half the length of the entire skull in this family. Their eye sockets were small and pear-shaped. Studies of tapejarid brain cases show that they had extremely good vision, more so than in other pterosaur groups, and probably relied nearly exclusively on vision when hunting or interacting with other members of their species. Tapejarids had unusually reduced shoulder girdles that would have been slung low on the torso, resulting in wings that protruded from near the belly rather than near the back, a "bottom decker" arrangement reminiscent of some planes.

Biology

Tapejarids appear to have been arboreal, having more curved claws than other azhdarchoid pterosaurs and occurring more commonly in fossil sites with other arboreal flying vertebrates such as early birds. Tapejarids have long been speculated as having been frugivores or omnivores, based on their parrot-like beaks. Direct evidence for plant-eating is known in a specimen of '' Sinopterus'' that preserves seeds in the abdominal cavity. The Barremian-
Aptian distribution of some tapejarids may even be partially associated with the first radiation phase of the angiosperms, especially of the genus Klitzschophyllites which represents a more basal angiosperm.

Classification

Tapejaridae was named and defined by Brazilian paleontologist Alexander Kellner in 1989 as the clade containing both '' Tapejara'' and ''Tupuxuara'', plus all descendants of their most recent common ancestor. In 2007, Kellner divided the family: Tapejarinae, consisting of ''Tapejara'' and its close relatives, and Thalassodrominae, consisting of '' Thalassodromeus'' and ''Tupuxuara''. A 2011 study subsumed the family Chaoyangopterinae in as the subfamily Chaoyangopterinae, something not followed by future authors. Kellner's concept of a Tapejaridae consisting of Tapejarinae and Thalassodrominae would be the basis for numerous subsequent phylogenetic analyses.Borja Holgado, Rodrigo V. Pêgas, José Ignacio Canudo, Josep Fortuny, Taissa Rodrigues, Julio Company & Alexander W.A. Kellner, 2019, "On a new crested pterodactyloid from the Early Cretaceous of the Iberian Peninsula and the radiation of the clade Anhangueria", ''Scientific Reports'' 9: 4940

Various opposing studies have arose challenging Kellner's concept of Tapejaridae. The 2003 model of paleontologist David Unwin found ''Tupuxara'' and ''Thalassodromeus'' to be more distantly related to ''Tapejara'' and therefore outside of Tapejaridae, instead being related to Azhdarchidae. Later, in 2006, British paleontologists David Martill and Darren Naish followed Unwin's concept, and provided a revised definition for Tapejaridae was also proposed: the clade containing all species more closely related to ''Tapejara'' than to ''Quetzalcoatlus''. A 2008 study by Lü Junchang and colleagues also corroborated this model, and used the term "Tupuxuaridae" to include both genera. In 2009, British paleontologist Mark Witton also agreed with the Unwin model. However, he noted that the term Thalassodrominae was created before Tupuxuaridae, meaning it had naming priority. He elevated Thalassodrominae to family level, thus creating the denomination Thalassodromidae.

Regarding the core tapejarid clade, American paleontologist Brian Andres and colleagues formally defined Tapejaridae as the clade containing ''Tapejara'' and '' Sinopterus'' in 2014. They also re-defined the subfamily Tapejarinae as all species closer to ''Tapejara'' than to ''Sinopterus'', and added a new clade, Tapejarini, to include all descendants of the last common ancestor of ''Tapejara'' and '' Tupandactylus''. In 2020, in the description of the genus '' Wightia'', an opposing subfamily was named, Sinopterinae, consisting of tapejarids more closely related to ''Sinopterus'' than ''Tapejara''. These studies follow the Unwin model, opposing Kellner's model of Tapejaridae while corroborating the close relationship between thalassodromids, azhdarchids, rather than tapejarids.

In 2023, paleontologist Rodrigo Pêgas and colleagues argued that despite the disagreements about the position of ''Thalassodromeus'' and its relatives, the species in question were consistently related. Therefore, they favored the term Thalassodromidae to have consistency with other studies that used the same name, despite finding them to form a natural grouping with Tapejaridae in their phylogenetic analysis (per the Kellner model). Thus, Thalassodromidae and Tapejaridae would be separate families within Tapejaromorpha.In their 2023 study, Pêgas and colleagues redefined Tapejaridae to be the most recent common ancestor of ''Sinopterus'', ''Tapejara'', and ''Caupedactylus'' in order to preserve the scope of the family in light of finding ''Caupedactylus'', traditionally a tapejarine, outside of the Andres definition of Tapejaridae. They divided this redefined Tapejaridae into the groups Eutapejaria, containing the subfamilies Sinopterinae and Tapejarinae, and Caupedactylia, containing the pterosaurs '' Caupedactylus'' and '' Aymberedactylus''. In 2024, Pêgas rejected this redefinition of Tapejaridae in light of non-compliance with phylocode rules, applying the ''Tapejara'' and ''Sinopterus'' definition and deeming Eutapejaria a synonym. Instead, he created the larger group contain Tapejaridae and Caupedactylia, removing ''Caupedactylus'' and ''Aymberedactylus'' from the family itself.

The cladogram below shows the phylogenetic analysis conducted by paleontologist Gabriela Cerqueira and colleagues in 2021, which uses Kellner's nomenclature of Tapejaridae..

Below are two cladograms representing different concepts of Tapejaridae. The first one shows the phylogenetic analysis conducted by Andres in 2021, in which Tapejaridae consists of the subfamilies Tapejarinae and Sinopterinae. He found the pterosaurs '' Lacusovagus'' and ''Keresdrakon'' as tapejarines, an arrangement that had never been recovered in previous analyses. Regarding the interrelationships of Tapejaridae, Andres follows Unwin's concept. The second cladogram shows the phylogenetic analysis conducted by Pêgas in 2024. He also found Tapejaridae to consist of both Tapejarinae and Sinopterinae, but differed from Andres in recovering the tapejarid '' Bakonydraco'' as a sinopterine instead of tapejarine. He created the new subtribe Caiuajarina within Tapejarini to include '' Caiuajara'' and '' Torukjara''. Additionally, his analysis further differs from that of Andres in finding both Tapejaridae and Thalassodromidae within Tapejaromorpha, which corroborates the close relationship between thalassodromids and tapejarids, similar to Kellner.

Topology 1: Andres (2021).

Topology 2: Pêgas (2024).

Subclades

Summary of the phylogenetic definitions of tapejarid subclades as discussed in the classification section.

References

{{Taxonbar, from=Q134383

Tapejaromorphs
Early Cretaceous first appearances
Late Cretaceous extinctions
Pterosaur families