Open Paleo

Jintasaurus

You & Li, 2009 JEEN-tah-SOR-us

Named for Jinta County in Gansu, China, where the fossils were discovered, combined with Chinese 'long' meaning 'dragon', hence 'Jinta County dragon'.

121.4–113.2 million years ago Aptian, Early Cretaceous
Early Cretaceous stages

Jintasaurus is a genus of hadrosauriform dinosaur that lived during the Early Cretaceous of what is now Jiuquan, Gansu, northwestern China. The type species is J. meniscus, described by Hai-Lu You and Da-Qing Li in 2009. The holotype and only known specimen includes the postorbital skull, lacking the jugal and quadratojugal, whose discovery supports the theory that hadrosaurs originated in Asia.

Under dispute

Jintasaurus meniscus was recovered as the sister of Hadrosauroidea by its describers (You and Li, 2009) and as a basal hadrosauroid by You and colleagues (2014), and Madzia and colleagues (2021) list it in Hadrosauromorpha. It is based on a partial skull, and Norman (2015) doubts its validity as a taxon separate from the sympatric Xuwulong.

Diagnosis

  1. Extremely long pendant and crescentic paroccipital processes with ventral tips projecting far beyond occipital condyle level
  2. Relatively long squamosal process of postorbital
  3. Vertical posterior surface of supraoccipital (not steeply forward-inclined)
  4. Paroccipital process directs ventrally (not anteriorly curved)

Species

Jintasaurus meniscus You & Li, 2009

Type species

From Ancient Greek 'meniskos' meaning 'crescent', referring to the crescentic paroccipital process and occipital condyle of the specimen.

Holotype
FRDC GJ 06-2-52 , The Fossil Research and Development Center of the Third Geology and Mineral Resources Exploration Academy of Gansu Provincial Bureau of Geo-exploration and Mineral Development
Material
Articulated posterior portion of the skull, including elements of the skull roof (postorbitals, squamosals, frontals, fused parietals) and almost complete braincase
Horizon
upper Xiagou Formation, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Yujingzi Basin, Gansu, China

References

  1. You, H. L.; Li, D. Q. (2009). A new basal hadrosauriform dinosaur (Ornithischia: Iguanodontia) from the Early Cretaceous of northwestern China. Canadian Journal of Earth Sciences 46(12): 949-957. Canadian Science Publishing. doi:10.1139/e09-067 you2009a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length estimate.

    jones2026a
  3. Madzia, D.; Arbour, V. M.; Boyd, C. A.; Farke, A. A.; Cruzado-Caballero, P.; Evans, D. C. (2021). The phylogenetic nomenclature of ornithischian dinosaurs. PeerJ 9: e12362. doi:10.7717/peerj.12362

    Lists Jintasaurus in Hadrosauromorpha.

    madzia2021a
  4. Norman, D. B. (2015). On the history, osteology, and systematic position of the Wealden (Hastings group) dinosaur Hypselospinus fittoni (Iguanodontia: Styracosterna). Zoological Journal of the Linnean Society 173: 92-189. doi:10.1111/zoj.12193

    Questioned the validity of Jintasaurus as distinct from the sympatric Xuwulong.

    norman2015a
  5. You, H. L.; Li, D. Q.; Dodson, P. (2014). Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. (Ornithischia: Hadrosauroidea) from the Early Cretaceous of Gansu Province, northwestern China. Hadrosaurs 73-76. Indiana University Press.

    Places the Mazongshan dinosaur beds in the Zhonggou Formation on a personal communication, and names this locality under that formation in a figure caption.

    you2014a
  6. Tanaka, T.; Chiba, K.; Ikeda, T.; Ryan, M. J. (2024). A new neoceratopsian (Ornithischia, Ceratopsia) from the Lower Cretaceous Ohyamashimo Formation (Albian), southwestern Japan. Papers in Palaeontology 10(5). Wiley. doi:10.1002/spp2.1587

    Assigns Archaeoceratops yujingziensis, from the same basin, to the Xiagou Formation.

    tanaka2024a
  7. Suarez, M. B.; Milder, T.; Peng, N.; Suarez, C. A.; You, H.; Li, D.; Dodson, P. (2018). Chemostratigraphy of the Lower Cretaceous dinosaur-bearing Xiagou and Zhonggou formations, Yujingzi Basin, northwest China. Journal of Vertebrate Paleontology 38(sup1): 12-21. doi:10.1080/02724634.2018.1510412

    Assigns the gray-variegated beds of the Yujingzi Basin to the uppermost Xiagou Formation.

    suarez2018a