Bellusaurus
From Vulgar Latin bellus meaning 'beautiful' + Ancient Greek sauros (σαῦρος) meaning 'lizard'; overall meaning 'beautiful lizard'.
Bellusaurus was a sauropod dinosaur from the Late Jurassic (Oxfordian) known from juvenile specimens that would have measured about 4.8 meters (16 ft) long. Its fossils were found in Shishugou Formation rocks in the northeastern Junggar Basin in China.
Under dispute
Bellusaurus, known only from juveniles, was recovered outside Neosauropoda (grouped with Janenschia and Haestasaurus) by Mannion and colleagues (2019), while Moore and colleagues (2018) found its anatomy consistent with a position near the base of Neosauropoda or Macronaria; Moore and colleagues (2023) instead treat it as a juvenile mamenchisaurid-grade form. Jones (2026) lists it among mamenchisaurids but documents the competing neosauropod placements.
Diagnosis
- Small size with gracile body structure; spoon-shaped teeth with curvature rate of approximately 13 degrees
- Cervical vertebrae opisthocoelous with robust centra, well-developed pleurocoels, and planar ventral surfaces lacking ventral keels
- Neural arches and spines low; cervical and dorsal neural spines unbifid and appearing pseudospinus (vertical plate form)
- Longest cervical vertebra 1.5 times longer than dorsal vertebrae; neck slightly longer than body
- Sacrum composed of four vertebrae; sacricostal lobes present but distal ends not mutually connected (no yoke-like structure)
- Anterior caudals procoelous; first caudal with fan-shaped diapophyses; haemal arch structure simple and unbifurcated
Species
Bellusaurus sui Dong, 1990
Type species
Named for Senior Preparator Youling Sui, a notable restorer of dinosaur remains for whom Bellusaurus was the last restoration undertaken.
- Holotype
- IVPP V8299 , Institute of Vertebrate Paleontology and Paleoanthropology
- Material
- Fragmentary cranial elements and teeth; referred composite skeleton V8300 with minimal cranial elements and portion of caudal vertebrae
- Horizon
- upper Shishugou Formation, Callovian–Oxfordian, Middle Jurassic–Late Jurassic , 165.3–154.8 million years ago
- Locality
- Dinosaur Valley (Konglonggou), Xinjiang, China Moore and colleagues (2018) place the quarry at the base of the upper beds, correlated to a level between the T-1 and T-BW tuffs, which on the ICS chart v2024/12 straddle the base of the Oxfordian.
References
- Dong, Z. (1990). Sauropoda from the Kelamaili region of the Junggar Basin, Xinjiang Autonomous Region. Vertebrata PalAsiatica 28(1): 43-58. dong1990a
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Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.
Source of the mass and hip height estimates.
jones2026b -
Mannion, P. D.; Upchurch, P.; Schwarz, D.; Wings, O. (2019). Taxonomic affinities of the putative titanosaurs from the Late Jurassic Tendaguru Formation of Tanzania: phylogenetic and biogeographic implications for eusauropod dinosaur evolution. Zoological Journal of the Linnean Society 185(3): 784-909. Oxford University Press (OUP). doi:10.1093/zoolinnean/zly068
Recovered Bellusaurus outside Neosauropoda, grouped with Janenschia and Haestasaurus.
mannion2019a -
Moore, A. J.; Mo, J.; Clark, J. M.; Xu, X. (2018). Cranial anatomy of Bellusaurus sui (Dinosauria: Eusauropoda) from the Middle-Late Jurassic Shishugou Formation of northwest China and a review of sauropod cranial ontogeny. PeerJ 6. doi:10.7717/peerj.4881
Argued Bellusaurus's anatomy is consistent with a near-Neosauropoda/basal-Macronaria position, without running a phylogenetic analysis.
moore2018a -
Moore, A. J.; Barrett, P. M.; Upchurch, P.; Liao, C. C.; Ye, Y.; Hao, B.; Xu, X. (2023). Re-assessment of the Late Jurassic eusauropod Mamenchisaurus sinocanadorum Russell and Zheng, 1993, and the evolution of exceptionally long necks in mamenchisaurids. Journal of Systematic Palaeontology 21(1). doi:10.1080/14772019.2023.2171818
Treats Bellusaurus as juvenile mamenchisaurid-grade form.
moore2023a