The Sinuiju Formation(신의주층) is a geologic formation in North Korea. Formerly of uncertain age, it is now thought to be Early Cretaceous. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation. Compression fossils of insects are also known from the formation. Several bird fossils are found in this formation, including a very large enantiornithine specimen with a long tibia and a long pygostyle. Amphibian fossils, including frogs and lissamphibians, have also been found here.
Fossil content
Fish
Lycoptera sp. Acipenseriformes indet.
Amphibians
Anuran (a frog, might be referred to Liaobatrachus grabaui). Pterosaurs Anurognathidae indet.
Birds
Confuciusornithidae indet. (known colloquially as the Archaeopteryx of Korea) Enantiornithes indet. Ornithurae indet.
Insects
Angarosphex baektoensus
Sinuijuhelorus baektoensis
Sinuijus baektoensis
Stellularis sinuijuensis
Stenophlebia ryonsangensis
Sinuijumantispa ryonsangiensis
Other invertebrates
Eosestheria (a conchostracan)