A new species of sauropod dinosaur Mamenchisaurus was discovered in China back in the Late Jurassic era.
Reconstruction of another's life Mamenchisaurus variety, Mamenchisaurus sinocanadorum. Image credit: Julia d'Oliveira.
Mamenchisaurus sanjiangensis roamed our planet in the early Oxfordian Jurassic period, about 160 million years ago.
This dinosaur was divergent mamenchisauridhas relatively close relationships with most others Mamenchisaurus variety.
“The diversity of sauropod dinosaurs reached an apparent peak in the Late Jurassic and included many geographically widespread non-neosauropod lineages of eusauropods (e.g. mamenchisaurids, turiasaurids), and most notably a wide range of nearly globally distributed members of the neosauropod clades (Diplodocoidea and Macronaria),” said Dr Hui Dai, a paleontologist from Chongqing Institute of Paleontology and Chongqing Key Laboratory of Paleontology and Paleoenvironmental Coevolution and his colleagues.
“Late Jurassic sediments of China preserve rich sauropod finds, and most are dominated by mamenchisaurids, although definitive neosauropod remains are widely known from the early Middle Jurassic.”
“The dominance of Asian sauropod faunas is very different from the dominance of modern formations in Europe and the Americas.”
“Moreover, much of the Late Jurassic Asian sauropod diversity comes from sediments classified as lower, especially near the Middle-Late Jurassic transition.”
Single partial skeleton Mamenchisaurus sanjiangensis was discovered at a fossil site in Chongqing in southwest China.
“The remains were found in purple-red silty mudstones near the middle part of the Upper Shaximiao Formation,” the paleontologists said.
“Traditionally, a general Callovian-Oxfordian age has been assumed for this formation, while the exact age of this formation is still controversial.”
Opening Mamenchisaurus sanjiangensis enriches the diversity of early divergent sauropod dinosaurs and provides additional information to help understand the evolutionary history of sauropods in northwest China.
“Clarifying the evolutionary relationships of Middle and Late Jurassic Chinese eusauropods is relevant for testing hypotheses regarding the isolation of East Asia from western Laurasia and Gondwana at this time, as well as the paleobiogeographic history of early branching sauropods and eusauropods more broadly,” the researchers said.
“However, our understanding of this stage of evolution is far from complete, and East Asian lineages require re-examination of specimens to fill the gaps.”
study published November 25, 2025 in the magazine Scientific reports.
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H. Dai etc.. A new mamenchisaurid sauropod dinosaur from the Upper Jurassic of southwestern China reveals new evidence for the evolution of East Asian eusuropods. scientific representativepublished online November 25, 2025; doi: 10.1038/s41598-025-29995-z
