A recently identified sauropod dinosaur, Mamenchisaurus, was discovered in China, originating from the late Jurassic period.
Reconstruction of the life of Mamenchisaurus species, Mamenchisaurus sinocanadorum. Image credit: Júlia d’Oliveira.
Mamenchisaurus sanggensis existed during the early Oxfordian stage of the Jurassic period, approximately 160 million years ago.
This dinosaur belonged to the divergent Mamenchisauridae family, sharing a close relationship with other Mamenchisaurus species.
“The diversity of sauropod dinosaurs peaked in the Late Jurassic, encompassing numerous geographically widespread non-neosauropod eusauropod lineages (like Mamenchisaurs and turiasaurs) alongside a broad array of globally distributed neosauropod members (Diplodocoidea and Macronaria),” stated Dr. Hui Dai, a paleontologist at the Chongqing Institute of Paleontology.
“Late Jurassic sedimentary formations in China preserve a rich sauropod fossil record, predominantly featuring mamenchisaurids, although precise neosauropod remains are largely recognized from the Middle Early Jurassic period.”
“The dominance of sauropod faunas in Asia contrasts sharply with that of contemporary European and North and South American strata.”
“Additionally, most of the late Jurassic Asian sauropod diversity is traced back to deposits from the lower section, particularly around the transition from the Middle to Late Jurassic.”
A partial skeleton of Mamenchisaurus sanggensis was uncovered at a fossil site in Chongqing, located in southwest China.
“The remains were found in reddish-purple silty mudstone near the upper layer of the Shaximyo formation,” paleontologists noted.
“While a general Callovian-Oxford age for this formation has traditionally been assumed, the exact age remains a subject of debate.”
The discovery of Mamenchisaurus sanggensis adds to the diversity of early-branching sauropod dinosaurs and offers further insights into the evolutionary history of sauropods in northwestern China.
“A deeper understanding of the evolutionary relationships among mid to late Jurassic Chinese eusauropods may have implications for testing theories regarding the isolation of East Asia from western Laurasia and Gondwana during this era and for the paleobiogeographic history of early diverging sauropods and more broadly, eusauropods,” the researchers remarked.
“Nonetheless, our knowledge of this evolutionary transition is incomplete, and a reexamination of specimens is essential to bridge the existing ‘gap’ in East Asian lineages.”
The study was published in the Journal on November 25, 2025 in Scientific Reports.
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H. Dai et al. A new mamenchisaurid sauropod dinosaur from the Late Jurassic of southwestern China reveals fresh insights into the evolution of East Asian eusauropods. Scientific Reports, published online on November 25, 2025. doi: 10.1038/s41598-025-29995-z
Source: www.sci.news
