Meng-Yin Formation
Stratigraphic range: Berriasian-Valanginian ~145–133 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Lithology
Primary	Sandstone
Other	Siltstone
Location
Coordinates	35°54′N 118°00′E / 35.9°N 118.0°E / 35.9; 118.0
Approximate paleocoordinates	36°54′N 120°12′E / 36.9°N 120.2°E / 36.9; 120.2
Region	Shandong
Country	China
Meng-Yin Formation (China) Show map of China Meng-Yin Formation (Shandong) Show map of Shandong

The Meng-Yin or Mengyin Formation (simplified Chinese: 蒙阴组; traditional Chinese: 蒙陰組; pinyin: Méngyīn Zǔ) is a geological formation in Shandong, China, whose strata date back to the Berriasian and Valanginian stages of the Early Cretaceous.^[1][2]

Dinosaur remains are among the fossils that have been recovered from the formation.^[3] The type material for the titanosauriform dinosaur Euhelopus was excavated at this formation by Otto Zdansky in 1923, in green/yellow sandstone and green/yellow siltstone that were deposited during the Barremian or Aptian stages of the Cretaceous period, approximately 129 to 113 million years ago.^[4]

Both the genus and species of Mengyinaia mengyinensis were named after the formation.

Indeterminate stegosaurid remains have been found in Shandong, China.^[3]

Vertebrates from the Meng-Yin Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Euhelopus[3]	E. zdanskyi[3]	Shandong[3]		"Skull and partial postcranial skeleton, additional fragmentary skeleton."[5]
Mengshanosaurus	M. minimus			A single juvenile skull	A choristodere belonging to Neochoristodera

• Mengyinaia mengyinensis^[6]

Fish

Reptiles

• List of dinosaur-bearing rock formations

• Fang, Z. J.; Chen, J. H.; Chen, C. Z.; Sha, J. G.; Lan, X.; Wen, S. Z. (2009), "Supraspecific taxa of the Bivalvia first named, described, and published in China (1927-2007)", The University of Kansas Paleontological Contributions, New Series, 17: 1–157
• Wilson, Jeffrey A.; Upchurch, Paul (2009), "Redescription and reassessment of the phylogenetic affinities of Euhelopus zdanskyi (Dinosauria:Sauropoda) from the Early Cretaceous of China", Journal of Systematic Palaeontology, 7 (2): 199–239, Bibcode:2009JSPal...7..199W, doi:10.1017/S1477201908002691
• Young, C.-C (1961), "On a new crocodile from Chuhsien, E. Shantung", Vertebrata PalAsiatica, 5: 6–10
• Wiman, C (1929), "Die Kreide-Dinosaurier aus Shantung - The Cretaceous dinosaurs of Shantung", Palaeontologia Sinica, Series C, 6: 1–67
• T'an, H. C. (1923), "New research on the Mesozoic and early Tertiary geology in Shantung", Geological Survey of China Bulletin, 5: 95–135