Xinminbao_Group Knowpia

Xīnmínbǎo Group
新民堡群
Xīnmínbǎo Group; 新民堡群
Stratigraphic range: Late Barremian-Aptian
Type	Geological formation
Sub-units	Chijinbao Formation, Digou Formation, Xiagou Formation, Zhonggou Formation
Lithology
Primary	Conglomerate, siltstone, mudstone
Other	Sandstone
Location
Region	East Asia
Country	China; Mongolia

The Xīnmínbǎo Group (Chinese: 新民堡群; pinyin: Xīnmínbǎo qún) is a group of geological formations in north central China. They occur across a large depression between the Altai mountains of Mongolia to the north and the Qilian mountains of the Qinghai Plateau to the south, in the Gōngpóquán (公婆泉) and Suànjǐngzi (算井子) basins, and also in the neighbouring Jiuquan Basin.

Both of these areas are inland basins consisting of fluvial (river), lacustrine (lake), and intermontane (between mountains) alluvial fan (floodplain) sediments that were deposited during the Early Cretaceous, probably during the Aptian or possibly late Barremian stage, when the climate was semi-arid and subtropical.

The group has been visited by many expeditions including the Silk Road dinosaur expedition of 1992 which concentrated on the area around Mazong Shan.

Geology edit

The group is made up of three main formations.^{[citation needed]}

Chijinbao Formation edit

This consists of a lower red unit of coarse conglomerates grading to fine sandstones representing river channel to alluvial fan deposits, and an upper unit of red clastic sediments from either overbank deposits in a meandering fluvial environment, or accumulation in a shallow lacustrine or paludal (marsh) environment.^{[citation needed]}

Digou Formation edit

This consists of grey siltstones and calcareous mudstones comprising two sequences of fluvio-lacustrine sedimentation with some alluvial fan and littoral (lake-shore) deposits.^{[citation needed]}

Zhonggou Formation edit

This consists of red siltstones and mudstones in a series of upwardly coarsening cycles of lacustrine sediments.^{[citation needed]}

Vertebrate fauna edit

Ceratopsians edit

Ceratopsians reported from the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Archaeoceratops	Archaeoceratops oshimai			"[Two] individuals lacking forelimbs."^[1]		Archaeoceratops Auroraceratops
Auroraceratops	Auroraceratops rugosus
Microceratus	Microceratus gobiensis
Microceratus	Microceratus sulcidens
Psittacosaurus	Psittacosaurus mazongshanensis			"One individual lacking caudal and hindlimb."^[1]

Crocodilians edit

Indeterminate crocodilian remains are known from the group.

Crocodilians reported from the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Chiayusuchus	Chiayusuchus cingulatus

Fish edit

Ray-finned fishes reported from the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Xixiaichthys	Xixiaichthys tongxinensis

Ornithopods edit

Color key

Taxon	Reclassified taxon	Taxon falsely reported as present	Dubious taxon or junior synonym	Ichnotaxon	Ootaxon	Morphotaxon

Notes
Uncertain or tentative taxa are in small text; ~~crossed out~~ taxa are discredited.

Ornithopods reported from the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Equijubus	Equijubus normani			"Skull and partial postcranial skeleton."^[2]	(both this and Probactrosaurus are properly hadrosauroids rather than hadrosaurids)
Gongpoquansaurus^[3]	Gongpoquansaurus mazongshanensis			"Partial skull and postcranial skeleton."^[4]
Siluosaurus	Siluosaurus zhangqiani			"Teeth."^[5]	Nomen dubium, tentatively classified as a Hypsilophodontid.

Pterosaurs edit

Pterosaurs reported from the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Noripterus	Indeterminate					Noripterus

Saurischians edit

Saurischians reported from the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Asiatosaurus	Asiatosaurus mongoliensis					Beishanlong Sinornithoides
Beishanlong	Beishanlong grandis				A deinocheirid ornithomimosaur.
Chiayusaurus	C. lacustris
Gobititan	Gobititan shenzhouensis
"Nanshiungosaurus"	"Nanshiungosaurus bohlini"			"[Sixteen] cervical and dorsal vertebrae."^[6]^[7]	This species does not belong to Nanshiungosaurus.^[7]^[8]
Sinornithoides	Indeterminate

Thyreophorans edit

Indeterminate ankylosaur remains are known from the group.

Color key

Taxon	Reclassified taxon	Taxon falsely reported as present	Dubious taxon or junior synonym	Ichnotaxon	Ootaxon	Morphotaxon

Notes
Uncertain or tentative taxa are in small text; ~~crossed out~~ taxa are discredited.

Thyreophorans of the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Abundance	Notes
Stegosaurides	Stegosaurides excavatus				(nomen dubium)

Turtles edit

Turtles of the Xinminbao Group
Genus	Species	Location	Stratigraphic position	Abundance	Notes
Tsaotanemys	Tsaotanemys rugosus

References edit

^ ^a ^b "Table 22.1," in Weishampel, et al. (2004). Page 479.
^ "Table 19.1," in Weishampel, et al. (2004). Page 415.
^ H.-l. You et al. (in press). "Gongpoquansaurus mazongshanensis (Lü, 1997) comb. nov. (Ornithischia: Hadrosauroidea) from the Early Cretaceous of Gansu Province, northwestern China". In David A. Eberth and David C. Evans (eds). Hadrosaurs: Proceedings of the International Hadrosaur Symposium. Indiana University Press. ISBN 978-0-253-01385-9. Check date values in: |date= (help)
^ "Table 19.1," in Weishampel, et al. (2004). Page 417.
^ "Table 18.1," in Weishampel, et al. (2004). Page 396.
^ Dong, Z.; You, H. (1997). "A new segnosaur from Mazhongshan Area, Gansu Province, China". In Dong, Z. M. (ed.). Sino-Japanese Silk Road Dinosaur Expedition. Beijing: China Ocean Press. pp. 90−95.
^ ^a ^b Zanno, L. E. (2010). "A taxonomic and phylogenetic re-evaluation of Therizinosauria (Dinosauria: Maniraptora)". Journal of Systematic Palaeontology. 8 (4): 503−543. doi:10.1080/14772019.2010.488045.
^ You, H.; Morschhauser, E. M.; Li, D.; Dodson, P. (2018). "Introducing the Mazongshan Dinosaur Fauna". Journal of Vertebrate Paleontology. 38 (sup. 1): 1−11. doi:10.1080/02724634.2017.1396995.