A new genus and species of monofenestratan pterosaur has been identified from partial cranial and post cranial remains found in Chubut Province, Patagonia, Argentina. Named Melkamter pateko, the ancient flying reptile predates the currently oldest member of the clade Monofenestrata by at least 8 and probably 10 million years.
Life reconstruction of Melkamter pateko. Image credit: Pedro Andrade.
Melkamter pateko lived in what is now Argentina during the latest Early Jurassic epoch, between 184 and 174 million years ago.
The ancient species is a member of Monofenestrata, a large clade of pterosaurs consisting of the Darwinoptera, Anurognathidae and Pterodactyloidea.
“Pterosaurs were the first clade of actively flying tetrapods and were highly successful during the Mesozoic, achieving a global distribution from the Triassic to the Cretaceous,” said Dr. Alexandra Fernandes from the Bayerische Staatssammlung für Paläontologie und Geologie and colleagues from Germany and Argentina.
“Over that time, the pterosaur bauplan transitioned from the basal non-monofenestratan ‘non-pterodactyloid’ body style to that of the more derived pterodactyloids.”
“This evolutionary event has become better understood in recent years, with the recognition of the clade Darwinoptera, which have been largely considered as ‘intermediate’ monofenestratans that show a morphological array of attributes during this transition, combining plesiomorphic characters of ‘non-pterodactyloids’ with pterodactyloid features.”
“The Mesozoic pterosaur record is abundant in the northern hemisphere, whereas the record in the southern hemisphere is comparatively more scarce.”
“With the possible exclusion of the Argentinian Allkaruen koi, non-pterodactyloid monofenestratan pterosaurs have thus far only been recovered from the northern hemisphere, namely the UK, Germany and China, where they first appeared during the Bathonian age (168 to 165 million years ago).”
“The apparent success of these monofenestratan forms and their pterodactyloid descendants went on to supplant the rhamphorhynchid body style (which disappeared in the Early Cretaceous), surviving through to the end-Cretaceous extinction.”
“However, there is still a dearth of knowledge about non-pterodactyloid monofenestratans, specifically in terrestrial sedimentary settings.”
The paleontologists found Melkamter pateko’s fossilized remains — a partial cranium, two associated teeth and several postcranial elements — at the locality of Queso Rallado in the Cañadón Asfalto Formation.
They also found an isolated tooth of ctenochasmatid pterodactyloid pterosaur at the same locality.
“The Cañadón Asfalto Formation crops out in the northern central part of Chubut Province, Argentina,” they said.
“It is part of the sedimentary infill of the Cañadón Asfalto Basin, a large semigraben structure on central Patagonia that opened with the beginning of the South Atlantic in the Early Jurassic.”
“The Queso Rallado locality is located approximately 5.5 km northwest of the village of Cerro Cóndor in the area of the mid-course of the Río Chubut.”
“The fossiliferous level is a 0.8 m thick carbonatic and partially silicified mudstone within the lower part of the section of the Cañadón Asfalto Formation.”
According to the researchers, Melkamter pateko marks the earliest worldwide occurrence of a monofenestratan pterosaur, predating the currently oldest member of this clade by at least 8 and probably 10 million years.
The species is also the first and only non-pterodactyloid monofenestratan from the supercontinent Gondwana.
“Melkamter pateko represents the so far most conclusive evidence for the presence of Monofenestrata during the late Early Jurassic, while also contributing to their morphological diversity with the novel traits expressed in this new species,” the scientists concluded.
“Furthermore, if confirmed by future finds, the possible presence of a ctenochasmatid, currently indicated by a single tooth, would not only place the origin of pterodactyloids into the Early Jurassic, but even indicate that their initial diversification already happened during that time.”
“Although the Lagerstätten of the northern hemisphere have traditionally dominated in our understanding of the diversity and dispersion of pterosaurs over time, it is clear now that Gondwana also held a high phylogenetic diversity of Early Jurassic pterosaurs, with the Cañadón Asfalto Formation alone now exhibiting evidence for at least three distinct species.”
“This further highlights our still-lacking knowledge of Jurassic pterosaur faunas from Gondwana, and it is evident that, pending more field sampling and pterosaur fossil recovery, the inherent potential is present for the southern hemisphere to perhaps one day match the abundance of the northern hemisphere.”
The discovery of Melkamter pateko is reported in a paper in the journal Royal Society Open Science.
_____
Alexandra E. Fernandes et al. 2024. The oldest monofenestratan pterosaur from the Queso Rallado locality (Cañadón Asfalto Formation, Toarcian) of Chubut Province, Patagonia, Argentina. R. Soc. Open Sci 11 (12): 241238; doi: 10.1098/rsos.241238
