Hasandong Formation

The Hasandong Formation is an Early Cretaceous geologic formation in South Korea. It has been dated to the late Aptian and earliest Albian, between 118.0 ± 2.6 Ma and 112.4 ± 1.3 Ma. Fossils including dinosaurs, turtles and pterosaurs are known from this formation.

Fossil content

Invertebrate fossils

Few fragments of insects have been discovered from the formation.

Molluscs

Ostracods

Ostracod carapaces have been discovered from the formation.

Vertebrate fossils

Actinopterygii

Testudines

Shell fragments of testudines have been discovered.

Crocodylomorpha

Several teeth remain have been reported but are not assigned to the specific clade.

Pterosaurs

Dinosaurs

Several indeterminate theropod teeth remains have been reported.

Eggs

Unnamed dinosaur egg fossils have been reported.

Ichnofossils

Tracks of theropods, sauropods and ornithopods have been discovered from the formation. Possible amphibian tracks are also known.

Paleoflora

Consists of 6 genera and 9 species. The assemblage of plant fossils from the Hasandong represents the 'mixed' type of Tetori-type and Ryoseki-type flora.