Open Paleo

Zigongosaurus

Hou et al., 1976 dzuh-GUNG-o-SOR-us Disputed

Named for Zigong City in Sichuan, China, where the fossils were found, combined with Greek 'sauros' meaning 'lizard'.

170.9–154.8 million years ago Bajocian–Oxfordian, Middle Jurassic–Late Jurassic
Middle Jurassic and Late Jurassic stages

Zigongosaurus is a genus of sauropod dinosaur from the Middle-Late Jurassic-aged Shaximiao Formation of Zigong, Sichuan, China. Because of incomplete knowledge of Jurassic Chinese sauropods, it has been hard to interpret, with some sources assigning it to Omeisaurus, some to Mamenchisaurus, and some to its own genus.

Diagnosis

  1. Anterior edge of the maxilla above the tooth row bears a forward-and-downward projecting process contacting the premaxillary suture; maxillary foramen not prominent
  2. Maxilla bearing 12-14 teeth and mandible 15-17 teeth
  3. Prefrontal forming the main component of the dorsal orbital border; posterior part of the temporal bone exceptionally thick (up to 18 mm); upper temporal fenestra oval and narrow anteroposteriorly
  4. Premaxillary teeth largest, with long pointed crowns bearing small apical tubercles but no serrations; cheek-tooth crowns convex externally and concave internally with a prominent internal median ridge
  5. Anterior end of the dentary symphysis projecting downward with a rough external surface; lower margin of the dentary bearing a longitudinal groove extending to the symphysis

Species

Zigongosaurus fuxiensis Hou et al., 1976 Disputed

Type species

Named for Fuxi, a locality in Sichuan Province, China, near the fossil site.

Holotype
CV 02501 , Chongqing Museum of Natural History
Notes
Hou and colleagues designate the type by number alone, their anatomical account being a genus diagnosis drawn from four or more individuals. Dong and colleagues (1983) cite CV00267 for the material.
Horizon
upper Shaximiao Formation, Bajocian–Oxfordian, Middle Jurassic–Late Jurassic , 170.9–154.8 million years ago
Locality
Wujiaba, Ziliujing District, Zigong, Sichuan, China Hou and colleagues (1976) give only Zigong City and spring 1974, naming the species for the Fuxi River. Dong and colleagues (1977, 1978) place the same fauna at Wujiaba, 10 to 15 m above the conchostracan shale.

References

  1. Hou, L. H.; Zhou, S. W.; Chao, S. C. (1976). [New discovery of sauropod dinosaurs from Sichuan]. Vertebrata PalAsiatica 14(3): 160-165.

    In Chinese. Source of the body length, which is the mounted skeleton's.

    hou1976a
  2. Dong, Z.; Zhou, S.; Zhang, H. (1983). [Dinosaurs from the Jurassic of Sichuan]. Palaeontologica Sinica, New Series C, Whole Number 162(23): 1-136.

    Transfers the species to Omeisaurus and gives its material as a basioccipital, a maxilla, a left dentary and an axis under CV00267.

    dong1983a
  3. Dong, Z.; Li, X.; Zhou, S.; Zhang, Y. (1977). On the stegosaurian remains from Zigong (Tzekung), Szechuan province. Vertebrata PalAsiatica 15(4): 307-312.

    Reports the Wujiaba dinosaur fauna of Zigong, noting that its sauropods had already been described, and that Tuojiangosaurus occurs alongside Zigongosaurus.

    dong1977a
  4. Dong, Z.; Zhang, Y.; Li, X.; Zhou, S. (1978). [A new carnosaur from Yongchuan County, Sichuan Province]. Ke Xue Tong Bao [Science Newsletter] 23(5): 302-304.

    Lists Zigongosaurus fuxiensis in the Wujiaba (Zigong) fauna, 10 to 15 m above the conchostracan shale marker bed.

    dong1978a