Xingxiulong

Xingxiulong Temporal range: Early Jurassic, Hettangian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Photographs of skeletal elements (a-n) and skeletal reconstruction (o) of Xingxiulong chengi
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	†Sauropodomorpha
Clade:	†Massopoda
Genus:	†Xingxiulong Wang et al., 2017
Type species
†Xingxiulong chengi Wang et al., 2017
Other species
Xingxiulong yueorum Chen et al., 2025

Xingxiulong (meaning "Xingxiu Bridge dragon") is a genus of bipedal massopodan sauropodomorph from the Early Jurassic of China. It contains two species; the type species is X. chengi, described by Wang et al. in 2017 from three specimens, two adults and an immature individual, that collectively constitute a mostly complete skeleton. Adults of this species measured 4–5 metres (13–16 ft) long and 1–1.5 metres (3.3–4.9 ft) tall. A second species, X. yueorum, was described by Chen et al. in 2025 based on a partial articulated postcranial skeleton of an adult individual larger than X. chengi. Phylogenetic analysis suggests that Xingxiulong is most closely related to its contemporary Jingshanosaurus, although an alternative position outside of both the Sauropodiformes and Massospondylidae is also plausible.

Despite their close relationship, Xingxiulong prominently differs from Jingshanosaurus—and from most basal sauropodomorphs—in having a number of sauropod-like traits. These include a sacrum containing four vertebrae; a pubis with an exceptionally long top portion; and the femur, the first and fifth metatarsals on the foot, and the scapula being wide and robust. These probably represent adaptations to supporting high body weight, in particular a large gut. Unlike sauropods, however, Xingxiulong may have still been bipedal.