A new genus and species of gnathosaurine pterosaur that lived during the Jurassic period has been identified from fossils found in Portugal.
Reconstruction of Lusognathus almadrava and its paleoenvironment. Image credit: Jason Brougham.
Lusognathus almadrava lived in what is now Europe approximately 149 million years ago (Late Jurassic epoch).
The flying reptile belonged to Gnathosaurinae, a small subgroup of pterosaurs within the family Ctenochasmatidae.
“The known global distribution and diversity of pterosaurs reinforces their success as a group, as they are found in all continents including Antarctica, and yet their relatively sparse fossil record and often incomplete preservation can pose a challenge for further understanding their paleobiology, when compared with other vertebrates,” said Dr. Octávio Mateus, a researcher at the Museu da Lourinhã and the GEOBIOTEC at the Universidade Nova de Lisboa, and his colleagues.
“Accordingly, the Jurassic of Portugal is a very productive and taxonomically diverse period concerning vertebrate fossils, especially for plesiosaurs, ichthyosaurs, mosasaurs, dinosaurs, crocodylomorphs, and mammals.”
“However, despite this abundance, up to now, pterosaur material recovered from this deposit has been restricted to scant and often fragmentary isolated bones and teeth, hindering any confident taxonomic assignments.”
“This is likely due to the physical bone fragility of pterosaurs, making their remains particularly susceptible to deterrent or destructive fossilization factors such as carcass scavenging or later taphonomic duress.”
The fossilized remains of Lusognathus almadrava — an incomplete rostrum and associated partial vertebrae — were found in November 2018 in the Lourinhã Formation at Praia do Caniçal, the municipality of Lourinhã, central west Portugal.
The new species is one of the largest Jurassic pterosaurs known, the largest known Jurassic gnathosaurine pterosaur, and the first named pterosaur species found within Portugal.
“Portrayals of pterosaurs throughout the Triassic and Jurassic have traditionally been as relatively small animals, with wingspans constrained to around 1.6-1.8 m or less, whereas Cretaceous pterosaurs reached well above 3 m,” the paleontologists said.
“Of late, it has been increasingly postulated that Jurassic pterosaurs have been previously underestimated for their size range (and particularly when considering the larger end of the spectrum).”
“Notwithstanding these larger size estimates, the pterosaurs of the Jurassic of Portugal are especially remarkable for the time period (i.e., the 4 m estimated wingspan of the fossil femur described in 2021), with Lusognathus almadrava being no exception in corroborating the evidence of large Jurassic pterosaurs.”
“The minimum overall length of the preserved rostrum of Lusognathus almadrava begins at 20.2 cm but could potentially be even larger.”
“This means that if we scale the specimen with the overall skull dimensions of Gnathosaurus subulatus, where the calculated total minimum skull length of the new species would be 60.8 cm, then Lusognathus almadrava would have achieved a minimum wingspan starting at 3.6 m.”
According to the researchers, Lusognathus almadrava inhabited a fluvio-deltaic lagoonal environment.
“The paleobiological implications of such an exceptionally large-sized pterosaur in the Jurassic of Portugal denote and reinforce a thriving ecosystem, abundant with prey, in this case perhaps fish, as indicated by the robust teeth of Lusognathus almadrava,” they said.
“Although it has been generally agreed upon that pterosaur body size steadily increased throughout and up to the end of the Cretaceous, Lusognathus almadrava adds more evidence for body sizes already having increased substantially by the end of the Late Jurassic, when compared with earlier forms; this growth having potentially been a response to filling a different ecological niche than their competitors, the birds.”
The team’s work was published online in the journal PeerJ.
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A.E. Fernandes et al. 2023. A new gnathosaurine (Pterosauria, Archaeopterodactyloidea) from the Late Jurassic of Portugal. PeerJ 11: e16048; doi: 10.7717/peerj.16048
