Jiangjunding Formation

The Jiangjunding Formation is a geological formation in Shandong, China whose strata date back to the Campanian-Maastrichtian stages of the Late Cretaceous.[1] Dinosaur remains are among the fossils that have been recovered from the group.[2]

Jiangjunding Formation
Stratigraphic range: Campanian-Maastrichtian
~72.9–68.5 Ma
TypeGroup
Unit ofWangshi Group
UnderliesJingangkou Formationn
OverliesHongtuya Formation
Lithology
PrimaryConglomerate, sandstone, siltstone
OtherMarl
Location
Coordinates36°54′N 120°42′E / 36.9°N 120.7°E / 36.9; 120.7
Approximate paleocoordinates37°18′N 111°00′E / 37.3°N 111.0°E / 37.3; 111.0
RegionShandong
Country China
Jiangjunding Formation is located in China
Jiangjunding Formation
Jiangjunding Formation (China)
Jiangjunding Formation is located in Shandong
Jiangjunding Formation
Jiangjunding Formation (Shandong)

The Jiangjunding formation consists purpley-grey or reddy-brown sandstones or various consistencies, siltstones and conglomerates. The Jiangjunding Formation was deposited in a fluvial to lacustrine environment. The climate was warm and humid during the majority of the timespan, although it was beginning to dry out after the Jiangjunding.[3]

Paleofauna edit

Dinosaur eggs are known from this formation.[4]

Paleofauna of the Jiangjunding Formation
Genus Species Location Stratigraphic position Material Notes Images
Cheloniidae aff. Nanhsiungchelyidae[5] Indeterminate[6]
Coelurosauria indet.[5] Indeterminate[6]
Micropachycephalosaurus[7] M. hongtuyanensis[7] "Partial mandible, associated postcranial fragments."[5]
 
Pinacosaurus[8] P. cf. grangeri[8]
 
Sauropoda indet.[5] Indeterminate[5]
Shantungosaurus[6] S. giganteus[6] Xingezhuang Formation
 
Tanius[6] T. sinensis[6]  

Age of the formation edit

The Wangshi group of geologic formations is generally considered to be from the Late Cretaceous, although some regions are older. Based on the discovery of Pinacosaurus, only known elsewhere in the Djadokhta Formation or regions of the same age, the Wangshi Group was presumed to be a similar age of 75–71 million years old. The specific age for the Hongtuya Formation has been identified as 73.5–72.9 mya. As the Hongtuya is directly older than the Jiangjunding, it was identified that the Jiangjunding must be of latest Campanian to earliest Maastrichtian age, according to Borinder (2015).[3]

References edit

  1. ^ Wangshi Group in the Paleobiology Database
  2. ^ Weishampel et al., 2004, pp.593–600
  3. ^ a b Borinder, N.H. (2015). Postcranial Anatomy of Tanius Sinensis Wiman, 1929 (Dinosauria; Hadrosauroidea) (PDF) (Report). Examensarbete vid Institutionen för geovetenskaper. Uppsala University. ISSN 1650-6553.
  4. ^ Zhang, J.L.; Wang, Q; Jiang, S.X.; Cheng, X.; Li, N.; Qiu, R.; Zhang, X.J.; Wang, X.L. (2017). "Review of historical and current research on the Late Cretaceous dinosaurs and dinosaur eggs from Laiyang, Shandong" (PDF). Vertebrata PalAsiatica. 55 (2): 187–200.
  5. ^ a b c d e "Table 21.1," in Weishampel, et al. (2004). Page 466.
  6. ^ a b c d e f "48.9 Shandong, People's Republic of China; 1. Wangshi Group," in Weishampel, et al. (2004). Page 598.
  7. ^ a b Z. Dong. (1978). [A new genus of Pachycephalosauria from Laiyang, Shantung]. Vertebrata PalAsiatica 16(4):225–228.
  8. ^ a b Listed as "Pinacosaurus cf. grangeri" in "48.9 Shandong, People's Republic of China; 1. Wangshi Group," in Weishampel, et al. (2004). Page 598.