A team led by China University of Geosciences has described a new species of sauropod, Jinchuanloong niedu, from a partial skeleton and nearly complete skull found in northwestern China, adding a rare non-neosauropod eusauropod to the Middle Jurassic record of East Asia.
Eusauropods are the clade that includes nearly all long-necked dinosaurs beyond the earliest forms. They became the only surviving sauropod lineage after a global extinction in the late Early Jurassic.
Many later branching forms belong to Neosauropoda, such as the iconic giants Apatosaurus and Brachiosaurus. Several non-neosauropod eusauropods also persisted through the Middle Jurassic, dominating faunas in that interval.
Fossils preserving complete skulls remain rare among non-neosauropod eusauropods, leaving major gaps in the Middle Jurassic fossil record.
In the study, “A new eusauropod (Dinosauria, Sauropodomorpha) from the Middle Jurassic of Gansu, China,” published in Scientific Reports, researchers describe the anatomy and evolutionary placement of a previously unknown specimen.
Recovered from the lower part of the Xinhe Formation in Jinchuan District, Gansu Province, the Jinchuanloong niedu holotype consists of a nearly complete skull with mandible, five articulated cervical vertebrae, and 29 articulated caudal vertebrae. Site sedimentary beds date to the late Bathonian of the Middle Jurassic, around 165 to 168 million years ago.
Detailed anatomical comparisons with other East Asian sauropods revealed a combination of primitive and derived features. Researchers examined the specimen’s cranial and postcranial anatomy through comparative morphological description and scored it in two phylogenetic datasets to evaluate its placement within Eusauropoda.
In both analyses, Jinchuanloong was resolved as a diverged non-neosauropod eusauropod, sister to the clade comprising Turiasauria and Neosauropoda. Unique diagnostic traits include a foramen at the base of the maxillary ascending process, an aperture on the anterodorsal surface of the prefrontal, and a robust postorbital with a height-to-length ratio. Maxillary teeth are described as spoon-like in labial view, a shape shared with taxa such as Shunosaurus and Turiasaurus.
Unfused neural arches in the posterior caudal vertebrae and a large pineal foramen feature suggest a juvenile or subadult individual—something to keep in mind when assessing the estimated body length of approximately 10 meters.
According to the researchers, Jinchuanloong anatomy contributes to broader discussions about Middle Jurassic sauropod diversification and ecological partitioning in East Asia. The near-complete cranial remains offer an exceptional glimpse into the craniofacial evolution of early eusauropods.
“The discovery of Jinchuanloong niedu enriches the diversity of early diverging sauropods and provides additional information to help understand the evolutionary history of sauropods in northwest China,” the authors write.
More information: Ning Li et al, A new eusauropod (Dinosauria, Sauropodomorpha) from the Middle Jurassic of Gansu, China, Scientific Reports (2025). DOI: 10.1038/s41598-025-03210-5
Journal information: Scientific Reports
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