Aerotitan is a genus of azhdarchid pterosaur that lived during the Maastrichtian age of the Late Cretaceous period in what is now Argentina. Its only remains, which consist of a partial snout, were found in the Allen Formation of the Neuquén Basin in northern Patagonia. This specimen was made the holotype of Aerotitan sudamericanus by paleontologist Fernando Novas and colleagues. The genus combines the Greek word ἀήρ, meaning "air" and Titan, alluding to the pterosaur's large size. The specific name is a reference to its origin, South America.
Aerotitan is the first pterosaur belonging the family Azhdarchidae that was found in South America. A wingspan of at least has been estimated for this pterosaur. Within Azhdarchidae, the genus Mistralazhdarcho from France seems to have been the closest relative of Aerotitan, based on numerous phylogenetic analyses that have recovered them together in a clade.
Discovery and naming
The only specimen of
Aerotitan is MPCN-PV 0054, which has been recovered near the Bajo de Arriagada site from a layer of the upper
Allen Formation in
Patagonia, Argentina. It consists of a partial rostrum (snout). In 2012, it was made the
holotype specimen of the new
genus and
type species Aerotitan sudamericanus, named and described by paleontologists
Fernando Novas, Martin Kundrat, Federico Agnolín, Martin Ezcurra, Per Erik Ahlberg, Marcelo Isasi, Alberto Arriagada and Pablo Chafrat. The generic name
Aerotitan is a combination of the Greek word ἀήρ,
aer, meaning "air", and Titan, in reference to the fact that the species represents a large flying reptile. The specific name
sudamericanus refers to its provenance from South America.
Description
The only specimen of
Aerotitan that has been described is an incomplete snout, which has a preserved length of . It is elongated and transversely compressed, the jaws being toothless. Based on this specimen, the
wingspan of
Aerotitan has been estimated to be at least .
In 2021, a thorough analysis by paleontologist Rodrigo Pêgas and colleagues concluded that this specimen represented the lower jaw, contrasting with a few previous studies that have concluded it as an upper jaw. Comparing it with specimens of other azhdarchids, they deduced that the genus
Mistralazhdarcho from France shared the most features, especially the mandibular tip.
Classification
In its description,
Aerotitan was assigned to the family Azhdarchidae. This would make it the first unambiguous azhdarchid found in South America.
However, in 2018, a study published by paleontologist Nicholas Longrich and colleagues classified
Aerotitan as a member of the family
Thalassodromidae, being the sister taxon of
Alanqa (a pterosaur also assigned as an azhdarchid in its initial description). Such assignment is stated as only tentative and is not well-supported.
As is the case, in their 2021 analysis, Pêgas and colleagues noted dissimilarities between
Aerotitan and pterosaurs belonging to the Thalassodromidae (referred to as Thalassodrominae in the analysis, based on its placement within
Tapejaridae at the time). They supported an azhdarchid identity for
Aerotitan, reverting back to its original classification during its initial description.
In the same year, a phylogenetic analysis by American paleontologist Brian Andres placed
Aerotitan in Azhdarchidae, further corroborating its initial placement. Within Azhdarchidae, it is recovered in the subfamily Azhdarchinae, as the sister taxon of
Mistralazhdarcho.
Its close relationship with
Mistralazhdarcho would later be demonstrated again in various subsequent analyses.
One such example is the 2023 study by Pêgas and colleagues. In their phylogenetic analysis, they found
Aerotitan forming a trichotomy with both
Mistralazhdarcho and
Arambourgiania. However, instead of finding it within Azhdarchinae, they recovered it within the subfamily Quetzalcoatlinae.
Cladogram by Andres (2021).
Cladogram by Pêgas and colleagues (2023).
See also
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Timeline of pterosaur research
