Article · Wikipedia archive · Last revised Jul 10, 2026

Sinuiju Formation

The Sinuiju Formation(신의주층) is a geologic formation in North Korea. Formerly of uncertain age, it is now thought to be Early Cretaceous. A variety of fossils are known from the formation, including those of anurognathid pterosaurs and birds such as the specimen of a very large enantiornithine with a 5 cm (2.0 in) long tibia and a 3.5 cm (1.4 in) long pygostyle. Frogs have also been found in the formation. Numerous compression fossils of insects have also been found.

Last revised
Jul 10, 2026
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≈ 3 min
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Sinuiju Formation
Stratigraphic range: Barremian-Aptian
TypeGeological formation
Sub-units8 members
OverliesPrecambrian basement
Thickness>500 metres (1,600 ft)
Lithology
PrimarySandstone, siltstone, mudstone
OtherAndesite
Location
Coordinates40°06′N 124°24′E / 40.1°N 124.4°E / 40.1; 124.4
Approximate paleocoordinates43°48′N 125°48′E / 43.8°N 125.8°E / 43.8; 125.8
CountryNorth Korea
Type section
Named forSinuiju city
Sinuiju Formation (North Korea)

The Sinuiju Formation(신의주층) is a geologic formation in North Korea. Formerly of uncertain age, it is now thought to be Early Cretaceous. A variety of fossils are known from the formation, including those of anurognathid pterosaurs (possibly Jeholopterus) and birds such as the specimen of a very large enantiornithine with a 5 cm (2.0 in) long tibia and a 3.5 cm (1.4 in) long pygostyle. Frogs have also been found in the formation.12 Numerous compression fossils of insects have also been found.3

Fossil content

Fish

Fish from the Sinujiu Formation
Genus Species Material Notes Member Images
Lycoptera L. sp.12
Acipenseriformes Indeterminate 12

Amphibians

Amphibians from the Sinujiu Formation
Genus Species Material Notes Member Images
Anura Anura indet. (Possibly Liaobatrachus grabaui).4

Pterosaurs

Pterosaurs from the Continental Teriminal Formation
Genus Species Material Notes Member Images
Jeholopterus J. cf. ningchengensis5 Specimen CKGP 19960828, formerly PS19892256
Pterosauria Indeterminate Specimen PS1999217

Dinosaurs

Birds

Birds from the Sinujiu Formation
Genus Species Material Notes Member Images
Confuciusornithidae Confuciusornithidae indet.12 (Includes the fossil known colloquially as the Archaeopteryx of Korea)
Enantiornithes Indeterminate 12
Ornithurae Indeterminate 2

Non-avian dinosaurs

Dinosaurs from the Sinujiu Formation
Genus Species Material Notes Member Images
Dinosauria Indeterminate A single tooth7

Mammals

Proboscideans from the Continental Teriminal Formation
Genus Species Material Notes Member Images
Multituberculata Indeterminate8

Insects

Insects from the Sinujiu Formation9
Genus Species Material Notes Member Images
Angarosphex A. baektoensus
Ephemeropsis E. sp
Karataus K. ryonsangensis
Sinuijumantispa S. ryonsangiensis10
Stenophlebia S. ryonsangensis11
Stellularis S. sinuijuensis
Sinuijus S. baektoensis
Sinuijuhelorus S. baektoensis
Pompilopterus P. ryonsangensis
Zygadenia Z. liui12

Conchostracans

Conchostracans from the Sinujiu Formation
Genus Species Material Notes Member Images
Eosestheria E. sp. A conchostracan2

Uncertain

Uncertain fossils from the Sinujiu Formation
Genus Species Material Notes Member Images
"Proornis" P. coreae Nomen nudum; assigned to Osteichthyes by the original describer in 1993 but assigned to Aves in 199613
source ↗
See also

See also

References

References

  1. Gao, K.; Li, Q.; Wei, M.; Pak, H.; Pak, I. (2009). "Early Cretaceous birds and pterosaurs from the Sinuiju Series, and geographic extension of the Jehol Biota into the Korean Peninsula" (PDF). Journal of the Paleontological Society of Korea. 25 (1): 57–61. ISSN 1225-0929.
  2. Choi, S.; Lee, Y.N. (2017). "A review of vertebrate body fossils from the Korean Peninsula and perspectives". Geosciences Journal. 21 (6): 867–889. Bibcode:2017GescJ..21..867C. doi:10.1007/s12303-017-0040-6. S2CID 133835817.
  3. Jon, SuHyang; Won, CholGuk; So, KwangSik; Nam, TuYong (July 2019). "New Mesozoic insect fossils from the Democratic People's Republic of Korea". Cretaceous Research. 99: 240–245. Bibcode:2019CrRes..99..240J. doi:10.1016/j.cretres.2019.02.019. S2CID 134337948.
  4. So, Kwang-Sik; Jong, Tal-Mi; Won, Chol Guk; Jo, Song-Dae (2022-08-05). "A fossil anuran from the Lower Cretaceous Sinuiju Formation, North Phyongan Province, Democratic People's Republic of Korea". Cretaceous Research. 140 105304. Bibcode:2022CrRes.14005304S. doi:10.1016/j.cretres.2022.105304. ISSN 0195-6671. S2CID 251425462.
  5. So, K. S.; Kim, P. H.; Won, C. G. (2024). "First Articulated Rhamphorhynchoid Pterosaur from the Early Cretaceous of the Democratic People's Republic of Korea". Paleontological Journal. 57 (1 supplement): S90–S94. doi:10.1134/S003103012360018X.
  6. Won, C.G. (2022). Kim, K.C. (ed.). Sinuiju Biota of the Mesozoic in Korea (PDF). Foreign Languages Publishing House. p. 83.
  7. Won, Chol Guk; So, Kwang-Sik; Pak, Un Song; Ju, Il Yop; Ri, Chol Jun; Jon, Su Hyang; Ma, Jun (November 2022). "Discovery of Early Cretaceous Sinuiju Biota in the Democratic People's Republic of Korea and comparison with Jehol Biota in China". Cretaceous Research. 139 105303. Bibcode:2022CrRes.13905303W. doi:10.1016/j.cretres.2022.105303.
  8. Won, C. G.; So, K. S.; Jon, S. H. (December 2023). "The First Known Mesozoic Mammal in the Democratic People's Republic of Korea". Paleontological Journal. 57 (7): 826–832. Bibcode:2023PalJ...57..826W. doi:10.1134/S0031030123070122. ISSN 0031-0301.
  9. Paektodong, Sinuiju City at Fossilworks.org
  10. So, Kwang- Sik; Won, Chol-Guk (2022-02-16). "A new fossil mantis fly (Insecta: Neuroptera: Mantispidae) from the Lower Cretaceous of the Democratic People's Republic of Korea". Cretaceous Research. 135 105175. Bibcode:2022CrRes.13505175S. doi:10.1016/j.cretres.2022.105175. ISSN 0195-6671. S2CID 246936524.
  11. Won, Chol-Guk; So, Kwang-Sik; Kim, Hui-Chol (March 2022). "A new odonatan (Stenophlebiidae) from the Lower Cretaceous Sinuiju Formation of North Phyongan Province, the Democratic People's Republic of Korea". Palaeoworld. 31 (1): 116–120. doi:10.1016/j.palwor.2021.02.002.
  12. Won, CholGuk; Jon, SuHyang; So, KwangSik; Hyon, LiJong (October 2020). "First record of a beetle (Coleoptera: Cupedidae) from the Lower Cretaceous of the Democratic People's Republic of Korea". Cretaceous Research. 114 104276. doi:10.1016/j.cretres.2019.104276.
  13. "†Proornis Lim 1993 (bird)". Paleobiology Database. Retrieved 2026-04-17.