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Normal Faults 34°59′59.6″N 127°55′08.1″E / 34.999889°N 127.918917°E
Hasandong Formation | |
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Stratigraphic range: Aptian-Albian ~ | |
Type | Geological formation |
Unit of | Shindong Group |
Underlies | Jinju Formation |
Overlies | Nakdong Formation |
Thickness | 1200 metres |
Lithology | |
Primary | Mudstone |
Other | Shale, sandstone |
Location | |
Coordinates | 35°06′N 128°00′E / 35.1°N 128.0°E |
Approximate paleocoordinates | 41°18′N 128°06′E / 41.3°N 128.1°E |
Region | Gyeongsang Province |
Country | ![]() |
The Hasandong Formation (Korean: 하산동층; Hanja: 霞山洞層; RR: Hasandong-cheung) is an Early Cretaceous (Aptian to Albian) 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.[1] Dinosaur remains have been discovered from this formation, though no genus is considered valid as of 2016.[2] Other reptiles from the formation include the adocid turtle Proadocus and possibly the pterosaur Dsungaripterus.[3][4][5]
Few fragments of insects have been discovered from the formation.[6]
Molluscs reported from the Hasandong Formation[5] | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Plicatounio | P. naktongensis | |||||
P. okjuni | ||||||
P. yooni | ||||||
Nagdongia | N. soni | |||||
Trigonioides | T. jaehoi | |||||
T. kodairai | ||||||
T. tamurai | ||||||
Brotiopsis | B. kobayashii | |||||
B. naktongensis | ||||||
B. ryohoriensis | ||||||
B. wakinoensis | ||||||
Viviparus[7] | V. sp. | Architaenioglossan gastropod, probably V. keishoensis | ||||
Probaicalia | P. katoensis[8] | Hydrobiidae gastropod; species previously assigned to the genus Micromelania |
Ostracod carapaces have been discovered from the formation.[6]
Ostracods reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Cypridea | C. cf. trita[9][10] |
Ray-finned fish reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Sinamia[11] | S. sp. | Partial Skeleton | ||||
Lepidotes[6] | L. sp. | Partial Skeleton |
Shell fragments of testudines have been discovered.
Turtles reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Proadocus[3] | P. hadongensis | Partial Skeleton | Adocid turtle |
Several teeth remains have been reported but are not assigned to the specific clade.
Crocodylomorphs reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
"Hadongsuchus"[12] | "H. acerdentis" | Skull | nomen nudum |
Pterosaurs reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Pterodactyloidea[13][14][15] | Indeterminate | Teeth and a partial second wing phalanx | Dental remains belong to either Boreopteridae or Anhanguerian | |||
Dsungaripterus | D.? cf. D. weii[4][5] | Incomplete wing phalanx belonging to Dsungaripteridae[16][17] |
Several indeterminate theropod teeth remains have been reported.[18]
Dinosaurs reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Carcharodontosauridae[19][20] | Indeterminate | Teeth | Some dental remains show similarities with Acrocanthosaurus | |||
Hadrosauroidea[21] | Indeterminate | Tooth | ||||
Titanosauriformes[22][23][24] | Indeterminate | A partial skeleton and several teeth showing different morphotypes | Includes Chiayusaurus lacustris and Pukyongosaurus milleniumi, both of which are nomen dubium | |||
Tyrannosauroidea[25] | Indeterminate | Tooth, estimated crown length ~18mm |
Unnamed dinosaur egg fossils have been reported.[26]
Eggs reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Testudoolithus[6] | T. aff. curiosa | Turtle eggs |
Tracks of theropods, sauropods and ornithopods have been discovered from the formation.[6][27]
Ichnofossils reported from the Hasandong Formation | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Pteraichnus[28] | P. koreanensis | Pterosaur tracks | ||||
Sauripes[29] | S. hadongensis | The oldest lizard tracks showing bipedalism | ||||
Diplocraterion[30] | D. luniforme | |||||
Beaconites | B. coronus[27] | |||||
Circulichnus | C. montanus[27] | |||||
Cochlichnus | C. anguineus[27] | |||||
Chondrites | C. isp.[27] | |||||
Helminthopsis | H. abeli & H. hieroglyphica[27] | |||||
Laevicyclus | L. isp.[27] | |||||
Planolites | P. annularius, P. beverleyensis & P. montanus[27] | |||||
Skolithos | S. magnus, S. verticalis & S. isp.[27] | |||||
Spirodesmos | S. isp.[27] | |||||
Taenidium | T. barretti[27] | |||||
Thalassinoides | T. paradoxicus & T. suevicus[27] |
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.
Plants reported from the Hasandong Formation[31] | ||||||
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Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Brachyphyllum | B. japonicum | Araucariaceae conifer | ||||
Cladophlebis | C. denticulata | |||||
C. (Eboracia?) lobifolia | ||||||
C. (Klukia?) koraiensis | ||||||
C. shinshuensis | ||||||
Elatocladus | E. tennerima | Conifer with an unknown systematic position | ||||
Onychiopsis | O. elongata | Leptosporangiate fern | ||||
Taeniopteris | T.? sp. cf. T. auriculata | The specific systematic position of this form genus is unknown. | ||||
Thallites | T. yabei | Liverwort |