Maehary bonapartei is considered to be the most basal of the evolutionary lineage that gave rise to pterosaurs.
(A) location map of the Linha São Luiz site in Brazil and the surface distribution of the geologic units in the area; (B) general view of the Linha São Luiz site; (C) hypothetical reconstruction of the skeleton of Faxinalipterus minimus depicting in orange the preserved elements; (D) hypothetical reconstruction of the skull of Maehary bonapartei depicting some of the preserved elements. Image credit: Kellner et al., doi: 10.7717/peerj.13276.
Maehary bonapartei lived in what is now Brazil during the Norian age of the Triassic period, some 225 million years ago.
“It bears a peculiar anatomy and is regarded as the earliest-diverging member of Pterosauromorpha,” said Dr. Alexander Kellner from the Museu Nacional at the Universidade Federal do Rio de Janeiro and his colleagues.
The fossilized remains of Maehary bonapartei — a partial skull, partial lower jaw, some vertebral centra, and a fragmentary scapula — were found at the Linha São Luiz site, about 1.5 km northeast of the town of Faxinal do Soturno in Rio Grande do Sul State, southern Brazil.
The specimen was originally described as Faxinalipterus minimus, a species of Triassic pterosaur.
“There was always a great doubt whether the two specimens attributed to Faxinalipterus minimus represented the same species, and whether this was a flying reptile,” Dr. Kellner said.
“It was clear to me that this is a primitive reptile that did not belong to pterosaurs, as it did not present any unequivocal features of this lineage,” added Dr. Borja Holgado, a paleontologist in the Museu Nacional at the Universidade Federal do Rio de Janeiro and the Institut Català de Paleontologia Miquel Crusafont at the Universitat Autònoma de Barcelona.
“But the present knowledge of the faunas at the end of the Triassic indicates that the disparity of animals at that time was so great that animals that might resemble pterosaurs at first glance, but really they are not flying reptiles. This is what happened to Faxinalipterus minimus and Maehary bonapartei.”
The researchers also found that Faxinalipterus minimus was a member of Lagerpetidae, a branch considered to be a sister group to Pterosauria.
“That is, Faxinalipterus minimus and Maehary bonapartei are not pterosaurs, but are related to them,” said Dr. Rodrigo Müller, a paleonologist in the Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia at the Universidade Federal de Santa Maria.
“Especially Maehary bonapartei is configured as a key element in the elucidation of how the anatomical characteristics evolved along the lineage of pterosauromorphs to the pterosaurs themselves, fully adapted to the flight.”
The study was published online in the journal PeerJ.
_____
A.W.A. Kellner et al. 2022. Reassessment of Faxinalipterus minimus, a purported Triassic pterosaur from southern Brazil with the description of a new taxon. PeerJ 10: e13276; doi: 10.7717/peerj.13276
Source link: https://www.sci.news/paleontology/maehary-bonapartei-10778.html
