Paleontologists have identified a new genus and species of titanosaurian dinosaur from the fossilized remains found in the Brazilian state of Minas Gerais.
Life reconstruction of Rinconsaurus, a sister species of Caieiria allocaudata. Image credit: Steveoc 86 / CC BY-SA 3.0.
Titanosaurs were a diverse group of quadrupedal sauropod dinosaurs in the clade Titanosauria.
These creatures lived from the Late Jurassic epoch (163.5-145 million years ago) to the end of the Cretaceous period (145-66 million years ago).
They had small heads, long tails and necks, and included the largest terrestrial animals known.
One of the largest titanosaurs, Patagotitan mayorum, had a body mass estimated to be 69 tons, whereas one of the smallest, Magyarosaurus dacus, had a body mass of 900 kg.
Titanosaurs differed from other sauropods in that their bodies were stockier and their limbs produced a wider stance than other sauropods. Some titanosaurs possessed osteoderms (armored plates).
The newly-identified species, Caieiria allocaudata, lived during the Maastrichtian age of the Late Cretaceous epoch, between 70 and 66 million years ago.
Its fossilized remains were collected from the site known as ‘Caieira,’ or ‘Quarry 1,’ located less than 2 km from the town of Peirópolis in the Brazilian state of Minas Gerais.
The fossil-bearing sandstones belong to the Late Cretaceous Serra da Galga Formation (Bauru Basin).
“Titanosauria currently represents the most species-rich dinosaur group in the Brazilian Cretaceous period, with numerous records coming from the Serra da Galga Formation in the surroundings of Uberaba, Minas Gerais State,” said Universidade de São Paulo paleontologist Julian Silva Junior and colleagues.
“Field work carried-out in that area, from the 1940s to the 1960s, by the Brazilian paleontologist Llewellyn Ivor Price, were especially productive, followed by systemic excavations conducted by the Centro de Pesquisas Paleontológicas Llewellyn Ivor Price and Museu dos Dinossauros since the beginning of the 1990s.”
The fossilized material of Caieiria allocaudata included a set of 10 anterior to middle caudal vertebrae.
It was previously assigned to a different species of titanosaur called Trigonosaurus pricei.
“Its uniqueness among Bauru Group and other South American titanosaurs, including the presence of autapomorphic features, warrants the proposition of a new species to accommodate the specimen,” the paleontologists said.
They suggest that Caieiria allocaudata is a member of Aeolosaurini, a group of titanosaurian dinosaurs known from the Cretaceous period of Argentina and Brazil.
“The affinity of Caieiria allocaudata also to Aeolosaurini reinforces that this clade dominated the Late Cretaceous sauropod fauna of the Bauru Basin,” they said.
The team’s paper ws published online in the journal PeerJ.
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J.C.G. Silva Junior et al. 2022. New specimens of Baurutitan britoi and a taxonomic reassessment of the titanosaur dinosaur fauna (Sauropoda) from the Serra da Galga Formation (Late Cretaceous) of Brazil. PeerJ 10: e14333; doi: 10.7717/peerj.14333
Source link: https://www.sci.news/paleontology/caieiria-allocaudata-11470.html
