Wednesday, September 15, 2021

[Paleontology • 2021] Kariridraco dianae • A New Azhdarchoid Pterosaur from the Lower Cretaceous of Brazil and the Paleobiogeography of the Tapejaridae


Kariridraco dianae
Cerqueira, Santos, Marks, Sayão & Pinheiro, 2021

 Artwork by Júlia d’Oliveira 

The Tapejaridae were an apparently worldwide distributed clade of edentulous pterosaurs, being a major component of several Lower Cretaceous terrestrial faunas. Despite their distribution across Gondwana and Laurasia, the oldest tapejarid remains were found in Barremian units from Europe, what led to the assumption that the clade originated in Eurasia and later dispersed southwards. Here we present a new tapejarid pterosaur species (Kariridraco dianae gen. et sp. nov.) from the Lower Cretaceous Romualdo Formation of Brazil. The holotype (MPSC R 1056) comprises an incomplete, three dimensionally preserved skull, lower jaw, and cervical vertebrae. It shows a unique combination of features such as unusually tall and comparatively short nasoantorbital fenestrae, as well as a premaxillary crest forming an angle of about 45° with respect to main skull axis. Phylogenetic analyses recover the new taxon as a Tupuxuara-related Thalassodrominae, a clade of early-diverging tapejarids that were apparently indigenous to central Gondwana. The inclusion of the new taxon in current phylogenetic frameworks, in addition to similarity cluster analyses of Early Cretaceous tapejarid-bearing pterosaur faunas, indicate Gondwana as the most parsimonious origin center for Tapejaridae, and show that pterosaur communities were affected by large scale tectonic-driven vicariant events.

Key words: Pterosauria, Azhdarchoidea, phylogeny, biogeography, Cretaceous, Romualdo Formation, Araripe Basin, Brazil.



Pterosauria Kaup, 1834 
Pterodactyloidea Plieninger, 1901 
Azhdarchoidea Nesov, 1984 (sensu Unwin 2003) 

Tapejaridae Kellner, 1989 
Thalassodrominae Kellner and Campos, 2007 
 
    

Genus Kariridraco nov.  

Etymology: After the Kariris, former indigenous people that lived in the area of the Araripe Plateau, combined with the Latin draco, dragon

Type species: Kariridraco dianae gen. et sp. nov., 

 Kariridraco dianae gen. et sp. nov. 

 Etymology: In reference to Diana Prince, alter ego of the DC fictional character Wonder Woman.

Diagnosis.— Kariridraco dianae gen. et sp. nov. differs from all other pterosaurs for the following combination of characters (characters marked with * represent autapomorphies): presence of a subtle jugal shelf; comparatively short and tall nasoantorbital fenestra; premaxillary crest forming an angle of about 45° with respect to the maxilla*; lacrimal with an anteriorly-directed deep concavity*, and a single elliptic lateral pneumatic foramen in the left lateral surface of cervical IV centrum.


Fig. 11. Life reconstruction of azhdarchoid pterosaur Kariridraco dianae gen. et sp. nov.
 Artwork by Júlia d’Oliveira (Jundiaí, Brazil).
 
 Conclusions:
Kariridraco dianae gen. et sp. nov. (Fig. 11) has a set of diagnostic features that distinguishes it from other azhdarchoid pterosaurs, such as the presence of a concavity in the upper portion of the lacrimal and an angle of about 45° between the maxilla and the premaxillary crest. Kariridraco dianae gen. et sp. nov. was consistently recovered as a thalassodromine tapejarid, closely related to the well-known genus Tupuxuara. Our assessment of tapejarid paleobiogeography recovered Gondwana as the most parsimonious origin center for the Tapejaridae, also suggesting that, similarly to strictly terrestrial animals, pterosaur distribution is marked by tectonic-driven provincialism.


Gabriela M. Cerqueira, Mateus A.C. Santos, Maikon F. Marks, Juliana M. Sayão, and Felipe L. Pinheiro. 2021. A New Azhdarchoid Pterosaur from the Lower Cretaceous of Brazil and the Paleobiogeography of the Tapejaridae. Acta Palaeontologica Polonica. in press. DOI:  10.4202/app.00848.2020