The Hasandong Formation () is an Early Cretaceous ( Aptian to

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0 ...

) geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and sharing a land border with North Korea. Its western border is formed by the Yellow Sea, while its eas ...

. It has been dated to the late Aptian and earliest Albian, between 118.0 ± 2.6 Ma and 112.4 ± 1.3 Ma.

Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

remains diagnostic to the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

level are among the fossils that have been recovered from the formation. Tracks of the pterosaur ichnospecies ''

Pteraichnus ''Pteraichnus'' is an ichnogenus that has been attributed to pterosaurs. It has been found in, among other units, the Lower Jurassic Aztec Sandstone and Lake Ezequiel Ramos Mexia in the Candeleros Formation.Lockley, M.; Harris, J.D.; and Mitchell ...

koreanensis'' have also been recovered from the unit.Y.-N. Lee, H.-J. Lee, J. and Y. Kobayashi. 2008. New pterosaur tracks from the Hasandong Formation (Lower Cretaceous) of Hadong County, South Korea. Cretaceous Research 29:345-353.

Fossil content

Paleofauna

* '' Hadongsuchus acerdentis'' - nomen nudum *

Tyrannosauroidea Tyrannosauroidea (meaning 'tyrant lizard forms') is a superfamily (or clade) of coelurosaurian theropod dinosaurs that includes the family Tyrannosauridae as well as more basal relatives. Tyrannosauroids lived on the Laurasian supercontinen ...

indet. - "Tooth." *

Carcharodontosauridae Carcharodontosauridae (carcharodontosaurids; from the Greek καρχαροδοντόσαυρος, ''carcharodontósauros'': "shark-toothed lizards") is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae ...

indet. * '' Chiayusaurus asianensis''? (possibly a synonym of '' Chiayusaurus lacustris'') - "Tooth.""Table 13.1," in Weishampel, et al. (2004). Page 271. * ''

Pukyongosaurus ''Pukyongosaurus'' (meaning "Pukyong lizard", after the Pukyong National University) is a genus of titanosauriform dinosaur that lived in South Korea during the Early Cretaceous period ( Aptian - Albian). It may have been closely related to ''Euh ...

milleniumi'' - "Cervical and dorsal vertebrae, ribs, limb and girdle elements." *

Hadrosauroidea Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, and all dinosaurs more closely related to them than to ''Iguanodon''. Their remains have been recovered in Asia, Europ ...

indet. - "Tooth." *

Pterodactyloidea Pterodactyloidea (derived from the Greek words ''πτερόν'' (''pterón'', for usual ''ptéryx'') "wing", and ''δάκτυλος'' (''dáktylos'') "finger" meaning "winged finger", "wing-finger" or "finger-wing") is one of the two traditional ...

indet. (belongs to either

Boreopteridae Boreopteridae (meaning "northern wings") is a group of pterodactyloid pterosaurs from the Aptian-age Lower Cretaceous Yixian Formation of Liaoning, China. Classification In 2006, Lü Junchang and colleagues named the clade Boreopteridae for the ...

or Anhanguerian) *

Dsungaripteridae Dsungaripteridae is a group of pterosaurs within the suborder Pterodactyloidea. They were robust pterosaurs with good terrestrial abilities and flight honed for inland settings. Classification In 1964 Young created a family to place the recently ...

indet. * ''

Sinamia ''Sinamia'' is an extinct genus of amiiform fish which existed in China, Japan, and possibly South Korea during the Early Cretaceous period. Like the related bowfin, it has an elongated low-running dorsal fin, though this was likely convergentl ...

'' sp. * ''Sauripes hadongensis'' - an

ichnotaxon An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

(the oldest lizard trackway; shows bipedalism) * ''

koreanensis'' - pterosaur

Paleoflora

*''Thallites'' (''T. yabei'') -

liverwort The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ...

s *''Onychiopsis'' (''O. elongata'') -

leptosporangiate fern The Polypodiidae, commonly called leptosporangiate ferns, formerly Leptosporangiatae, are one of four subclasses of ferns, and the largest of these, being the largest group of living ferns, including some 11,000 species worldwide. The group has ...

s *''

Cladophlebis ''Cladophlebis'' is an extinct form genus of fern, used to refer to Paleozoic and Mesozoic fern leaves that have "fern fronds with pinnules that are attached to the rachis, and have a median vein that runs to the apex of the pinnule, and veins ...

'' (''C. denticulata'', ''C. shinshuensis'', ''C.''/''Eboracia''? ''lobifolia'' and ''C.''/''Klukia''? ''koraiensis'') *''

Brachyphyllum ''Brachyphyllum'' (meaning "short leaf") is a form genus of fossil coniferous plant foliage. Plants of the genus have been variously assigned to several different conifer groups including Araucariaceae and Cheirolepidiaceae. They are known from ...

'' (''B. japonicum'') *''

Elatocladus ''Elatocladus'' is an extinct form genus of Mesozoic sterile conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coni ...

'' (''E. tennerima'') *''Taeniopteris'' (''T.''? sp. and cf. ''T. auriculata'') - cycad

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

References

Bibliography

* {{ISBN, 0-520-24209-2 Geologic formations of South Korea Lower Cretaceous Series of Asia Cretaceous South Korea Albian Stage Aptian Stage Mudstone formations Shale formations Sandstone formations Fluvial deposits Ichnofossiliferous formations Paleontology in South Korea

Fossil content

Paleofauna

Paleoflora

See also

References

Bibliography