Suining Formation

The Suining Formation (simplified Chinese: 遂宁组; traditional Chinese: 遂寧組; pinyin: Suìníng Zǔ) is a geological formation in China whose strata likely date back to the Late Jurassic.^[3] Dinosaur remains are among the fossils that have been recovered from the formation.^[4]

Suining Formation
Stratigraphic range: ?Late Jurassic, ~145? Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Sichuan Basin
Underlies	Penglaizhen Formation
Overlies	Upper Shaximiao Formation
Thickness	Several hundred meters
Lithology
Primary	Mudstone
Other	Sandstone, siltstone
Location
Region	Asia
Country	China
Type section
Named by	Lee & Chen (1939)[2]

History

The Suining Formation was identified in 1939. The formation was initially dated to the Tithonian (Late Jurassic).^[2][4][5] A 2019 publication described zircons from the Suining Formation that implied a younger age, the average age being around 115.5–113.3 million years ago (Early Cretaceous, upper Aptian age).^[6] Later research suggested that a Late Jurassic age is more likely based on reinterpretations of the previous zircon-based ages and comparisons of the dinosaur and pollen fossils with other more confidently-dated formations.^[3][1]

Paleobiota

Dinosaurs

Sauropods

Genus	Species	Presence	Materials	Notes	Images
Mamenchisaurus[7]	M. anyuensis[7]	Geographically located in Sichuan, China.[7]
Qijianglong[8]	Q. guokr
Tongnanlong[3]	T. zhimingi	Tongnan District in the Sichuan Basin		One of the largest known mamenchisaurids

Fish

Genus	Species	Presence	Notes	Images
Beiduyu[9]	B. qijiangensis
Ceratodus[3]	C. szechuanensis

Turtles

Genus	Species	Presence	Notes	Images
Plesiochelys[3]	P. tatsuensis

See also

• Qijianglong
• List of dinosaur-bearing rock formations