A new sauropodomorph dinosaur from the Lower Jurassic Fengjiahe Formation of Dali of Yunnan Province, China

Early-diverging sauropodomorph dinosaurs are abundant in the Lower
Jurassic Lufeng Formation of Lufeng area of Yunnan Province, southwestern
China. However, the fossil records of this group remain relatively scarce
in other regions of China. Here we describe a new sauropodomorph,
Xiangyunloong fengming gen. et sp. nov., based on recently collected
material from the Lower Jurassic Fengjiahe Formation of Xiangyun County of
Dali Bai Autonomous Prefecture of Yunnan Province, which is about 200 km
west to the Lufeng dinosaur fossil sites. Xiangyunloong can be diagnosed
by several unique features such as lateral expansion developed at the
middle region of the dorsal end of cervical neural spines, heightened
hyposphene of dorsal vertebrae, and ilium with anteroposteriorly reduced
but laterally and ventrally flaring supracetabular crest. Phylogenetic
analysis recovers Xiangyunloong at a position between Massospondylidae and
Sauropodiformes and within an unresolved clade together with Xingxiulong
chengi and Xingxiulong yueorum. Nonetheless, Xiangyunloong exhibits
significant morphological distinctions from Xingxiulong and other
early-diverging sauropodomorphs, supporting its designation as a new
genus. The discovery of Xiangyunloong not only further expands the known
taxonomic composition of Early Jurassic sauropodomorphs in southwestern
China, but also enhances our understanding of the diversity, distribution,
and evolutionary history of this group.