Open Paleo

Qianjiangsaurus

Dai et al., 2024 chee-EN-jyahng-SOR-us

Named for Qianjiang District, Chongqing Municipality, China, where the type locality is located, combined with Greek 'sauros' meaning 'lizard'; meaning 'Qianjiang lizard.'

85.7–66.0 million years ago Santonian–Maastrichtian, Late Cretaceous
Late Cretaceous stages

Qianjiangsaurus is an extinct genus of hadrosauroidean ornithopod dinosaurs from the Late Cretaceous Zhengyang Formation of China. The genus contains a single species, Q. changshengi, known from a partial skeleton. Qianjiangsaurus is one of the few hadrosauroids named from south China, and it indicates important fauna connections between similarly aged formations in Mongolia.

Diagnosis

  1. Fan-shaped prepubic process of pubis greatly anteroposteriorly shortened and dorsoventrally expanded, length/height ratio ~0.79
  2. Transversely wide U-shaped predentary with smoothly arcuate anterolateral edges
  3. Right-angled coronoid process relative to dorsal margin of dentary body
  4. Dentary tooth crown with slightly distally offset primary ridge, short secondary ridge mesially, slender faint ridge distally
  5. Sacrum consisting of seven fused vertebrae
  6. Strongly concave posterodorsal margin of iliac central plate above supraacetabular process
  7. Ischial shaft nearly parallel with long axis of pubic peduncle of ischium

Species

Qianjiangsaurus changshengi Dai et al., 2024

Type species

Named for Changsheng Wang, the discoverer of the Chongqing fossil locality where the holotype was found.

Holotype
CLGPR V00016 , Chongqing Laboratory of Geoheritage Protection and Research
Material
Incomplete, partially articulated skeleton: predentary, left dentary, dorsal vertebrae, sacrum, caudal vertebrae with chevrons, right ilium, left pubis, paired ischia, left femur, tibiae, fibula, astragalus, metatarsals
Horizon
upper Zhengyang Formation, Santonian–Maastrichtian, Late Cretaceous , 85.7–66.0 million years ago
Locality
Small quarry in the southeast of the Zhengyang area, Chongqing, China

Notable specimens

  • CIP V0002

    Chongqing Institute of Paleontology Found 2024 complementary

    Referred partial skull preserving cranial anatomy absent in the holotype, including a hollow helmet-like nasal crest. It is the first ornithopod to bear such a structure outside Lambeosaurinae. An associated braincase found about 80 meters away likely belongs to the same individual.

    Ma et al. (2026)

References

  1. Ma, Q.; Ma, Y.; Tan, C.; Chen, J.; Lin, Y.; Xiao, M.; Dai, H.; Wei, G.; Mallon, J. C.; Wang, J.; Yao, H.; Zou, Z.; Xing, H. (2026). First report of a hollow cranial crest in an early-diverging duck-billed dinosaur, with implications for convergent evolution of acoustic signaling. Biology 15(8): 615. MDPI AG. doi:10.3390/biology15080615 ma2026a
  2. Dai, H.; Ma, Q.; Xiong, C.; Lin, Y.; Zeng, H.; Tan, C.; Wang, J.; Zhang, Y.; Xing, H. (2024). A new late-diverging non-hadrosaurid hadrosauroid (Dinosauria: Ornithopoda) from southwest China: Support for interchange of dinosaur faunas across East Asia during the Late Cretaceous. Cretaceous Research 166. Elsevier BV. doi:10.1016/j.cretres.2024.105995 dai2024a