The Jinju Formation () is an

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

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 ...

in South Korea.Jinju Formation
in the Paleobiology Database Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. The depositional age of this formation spans from approximately 112.4 ± 1.3 to 106.5 million years ago ( Albian) based on detrital zircon U-Pb dating. It predominantly consists of black shale, with sandstone packets, deposited in a fluvial-lacustrine setting. A diverse spider fauna is known from the formation, including indeterminate

mygalomorphs The Mygalomorphae, or mygalomorphs, are an infraorder of spiders, and comprise one of three major groups of living spiders with over 3000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to th ...

and palpimanoids as well as two species of lagonomegopid belonging to the genera '' Koreamegops'' and '' Jinjumegops''. Other compression fossils known from the formation include a species of the zhangsolvid fly '' Buccinatormyia'', the elaterid beetle '' Koreagrypnus'', and the

ichthyodectiform Ichthyodectiformes is an extinct order of marine stem-teleost ray-finned fish. The order is named after the genus '' Ichthyodectes'', established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest ...

fish '' Jinjuichthys''. This formation has also "attracted global ichnological attention" for the variety of important ichnofossils. Columnar and rod-shaped stromatolites have also been found here.

Fossil content

Flora

Spiders

Insects

Jinju formation consists of a diverse order of insects:

Orthoptera Orthoptera () is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects, such as the bush crickets or katydids and wētā. The order is subdivided into two suborders: Caelifera – grassho ...

, Homoptera, Mantodea,

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

Coleoptera Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

Hymenoptera Hymenoptera is a large order (biology), order of insects, comprising the sawfly, sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are Par ...

, Dermaptera,

Neuroptera The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera can be grouped together with the Megaloptera and Raphidioptera in th ...

Blattoidea Blattoidea is a superfamily of cockroaches and termites in the order Blattodea. There are about 17 families and more than 4,100 described species in Blattoidea. The 12 families of termites are sometimes considered members of the suborder Isopte ...

Hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

, Odonata, Mecoptera, etc. A larvae fossil of aquatic insect has also been discovered.

Orthoptera

Odonata

Raphidioptera

Blattodea

Coleoptera

Diptera

Dermaptera

Neuroptera

Termites

Crustaceans

Isopoda

Ostracoda

Spinicaudata

Vertebrates

Actinopterygii

Archosauria

Mollusks

Bivalvia

Gastropoda

Ichnofossils

References

Bibliography

* * {{cite book , editor-last=Weishampel , editor-first=David B. , editor-link=David B. Weishampel , editor-last2=Dodson , editor-first2=Peter , editor-link2=Peter Dodson , editor-last3=Osmólska , editor-first3=Halszka , editor-link3=Halszka Osmólska , year=2004 , title=The Dinosauria , edition=2nd , url=https://books.google.com/books?id=vtZFDb_iw40C , publisher=Berkeley: University of California Press , access-date=2019-02-21 , isbn=0-520-24209-2 Geologic formations of South Korea Lower Cretaceous Series of Asia Cretaceous South Korea Albian Stage Sandstone formations Shale formations Fluvial deposits Lacustrine deposits Paleontology in South Korea