Paleontologists have discovered a new species of plant-eating dinosaur measuring at 39 feet long.
Huashanosaurus qini, discovered in the Guangxi region of China, is part of a new genus and species of early eusauropod from the Jurassic period, according to a paper published in the journal Acta Geologica Sinica.
The partial skeleton was found in the Shiwandashan Basin of the Wangmen Formation — a geological rock unit in southern China that contains fossils from the Jurassic period — near the Mingjiang River, the researchers said. The findings contained fossils of vertebrae, ribs, humerus, ulna, fibula and foot bones.
Measurements of the recovered bones indicate that H. qini was likely about 12 meters, or 39 feet long, and walked on four legs, according to the paper.
Researchers knew they were dealing with a new taxon based on the autapomorphies — distinctive derived characteristics — of several parts of the skeleton.
The posterior process of the ulna — the larger of the forearm bones — is hooked-shaped, the proximal part of the ulna is crescent-shaped, and a groove structure is present at the posterodistal surface of the fibula — traits not seen in other species of sauropods that may have helped with weight distribution on the massive dinosaur, according to the paper.
The dinosaur likely resided in forested river and lakeside environments, which were prevalent in the region at the time, the researchers said.
Also found at the site were some bony fish scales and teeth and incomplete plesiosaurian teeth, indicating a humid climate and complex ecosystem, according to the paper.
Phylogenetic analysis reveals that H. qini is likely the oldest sauropod in South China — dating to the early to middle Jurassic, between 200 million to 162 million years ago, according to the paper. This predates previously known sauropod fossils from the region by about 30 million years.
Illustration of Mamenchisaurus eating leaves of tree branch.
De Agostini Picture Library via Getty Images
The new species is the second eusauropod — a group derived from sauropods — found in Guangxi. Jingia dongxingensis was excavated from the Dongxing Formation and was named a new genus and species in 2024.
Sauropods are herbivores known for their very long necks, long tails, small head and pillar-like legs.
The research team consisted of scientists from the Guangxi Museum of Natural History, the Cultural Relics Administration of Ningming County and the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences.
The finding increases the understanding of the diversity of Jurassic-era eusauropods in China and how they evolved, the researchers said.