Zhoutian Formation

The Zhoutian Formation (Chinese: 周田组; pinyin: zhōu tián zǔ) is a geological formation in Jiangxi, China. It has been dated to the late Cretaceous period, at about 96–90 Ma. Abundant egg fossils are known from the formation, in addition to dinosaurs such as Datai and Gandititan. Invertebrate and plant fossils have also been described from the Zhoutian Formation.

Zhoutian Formation
Stratigraphic range: Late Cretaceous (Turonian–early Coniacian), 96–90 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Ganzhou Group
Underlies	Hekou Formation
Overlies	Maodian Formation
Thickness	Lower unit: 1,435–1,270 metres (4,708–4,167 ft) Upper unit: 1,270–1,100 metres (4,170–3,610 ft)[1]
Lithology
Primary	Reddish siltstone, sandstone
Other	Interbedded halite
Location
Coordinates	25°30′26″N 115°46′34″E
Region	Jiangxi Province
Country	China

Geology

Layers of the Zhoutian Formation are characterized by a consistent sandy lithology, typically with mauve (reddish to purplish) hues. Most of the formation alternates between fine calcic sandstone and siltstone layers. In some places, other minerals are interbedded, such as calcium, gypsum, halite, and mirabilite.^[2][3][4] The Zhoutian Formation dates to around 96–90 million years ago, during the Turonian–early Coniacian ages of the early Late Cretaceous epoch within the Cretaceous period.^[5]

Stratigraphy

The Zhoutian Formation is the upper unit of the Ganzhou Group, overlying the Maodian Formation in that group. The Guifeng Group (beginning with the Hekou Formation) overlies the Zhoutian Formation.^[6] These two groups comprise the Ganzhou Basin.^[7]

Paleoenvironment

The lower unit of the Zhoutian Formation is suggested to have had a predominantly hot-arid climate, punctuated by two cooling events. The upper unit was likely characterized by a predominantly warm-humid climate with frequent climate fluctuations.^[1] The environment has been interpreted as a shallow lacustrine (lake) system.^[8] While oviraptorid body fossils have not been found in the Zhoutian Formation, they are among the most common dinosaur fossils found in other similar localities, in addition to occasional sauropod and hadrosaurid fossils.^[7]

Fossil content

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.

Dinosaurs

Genus	Species	Region	Material	Notes	Images
Datai[5]	D. yingliangis	Jiangxi	YLSNHM 01002 (holotype) and YLSNHM 01003 (paratype), two articulated, associated specimens including both skulls, as well as some cervical, dorsal, and caudal vertebrae, partial pectoral and pelvic girdles, left arm bones, a partial right femur, ribs, and several osteoderms	An ankylosaurine; possibly closely related to Pinacosaurus
Gandititan[4]	G. cavocaudatus	Jiangxi	JXGM-F-V1, a series of cervical, dorsal, sacral, and caudal vertebrae, ribs, and a partial right pelvic girdle	A basal titanosaur; closely related to Abdarainurus

Ootaxa

Genus	Species	Region	Material	Notes	Images
Wormoolithus[9]	W. luxiensis	Jiangxi	PXMV-0021, a small partial clutch with the remains of at least seven eggs	Classified as belonging to the Similifaveoloolithidae
Undulatoolithus[10]	U. pengi	Jiangxi	PXMV-0016, a well-preserved clutch of eight eggs	Classified as belonging to the Elongatoolithidae, possibly laid by an oviraptorosaur
Parafaveoloolithus[10]	P. pingxiangensis	Jiangxi	PXMV-0009-01, a single partial egg	Classified as belonging to the Faveoloolithidae

Invertebrates

Genus	Species	Region	Material	Notes	Images
Nemestheria[11][2]	N. sp.	Jiangxi		A clam shrimp

Plants

Genus	Species	Region	Material	Notes	Images
Euonymus[11]	E. sp.	Jiangxi		A flowering plant within the family Celastraceae
Frenelopsis[11]	F. sp.	Jiangxi		A conifer within the family Cheirolepidiaceae

See also

• Paleontology portal

• List of stratigraphic units with dinosaur body fossils
• List of stratigraphic units with dinosaur trace fossils