Meet Xingxiulong yueorum, a new species of early-diverging sauropodomorph dinosaur that lived in what is now China during the Early Jurassic epoch.
Xingxiulong yueorum belongs to Massopoda, a large group of sauropodomorph dinosaurs described in 2007.
The new species is only the second member of the previously monospecific genus Xingxiulong.
“Xingxiulong yueorum is distinguished from Xingxiulong chengi by possessing a pendant-shaped fourth trochanter with distal termination, an astragalus with almost straight dorsal margin of the posterior surface, and pedal digit V with two phalanges,” said Dr. Xiang-Yuan Chen, a paleontologist with the Institute of Vertebrate Paleontology and Paleoanthropology and the University of Chinese Academy of Sciences, and colleagues.
A partial postcranial skeleton of Xingxiulong yueorum was found in 2015 near Lufeng city in the Chinese province of Yunnan.
The specimen came from a sedimentary rock formation called the Lufeng Formation.
“The Lufeng Formation is one of the most important sedimentary units for understanding the evolution of the Early Jurassic sauropodomorph dinosaurs,” the paleontologists said.
Xingxiulong yueorum is estimated to have reached a length of 8 to 10 m (26-33 feet) — twice the size of Xingxiulong chengi.
“Both the two species of Xingxiulong have four sacral vertebrae, which are typically associated with the late-diverging sauropodiforms and sauropods, suggesting a complex early evolution within the sauropodomorphs,” the researchers said.
According to the team, the discovery of Xingxiulong yueorum adds to the diversity of the sauropodomorph dinosaurs from the Lufeng Formation.
“The discovery contributes to our understanding of the intricate patterns characterizing the early evolution of sauropodomorphs in Asia,” the authors concluded.
Their paper was published on February 3, 2025 in the journal Historical Biology.
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Xiang-Yuan Chen et al. A new species of Xingxiulong (Dinosauria, Sauropodomorpha) from the lower Jurassic Lufeng formation of Yunnan Province, China. Historical Biology, published online February 3, 2025; doi: 10.1080/08912963.2025.2458130
