The Okurodani Formation is an Early Cretaceous geologic formation in central Honshu, Japan. Part of the Tetori Group, it primarily consists of freshwater continental sediments deposited in a floodplain environment, with occasional volcanic tuffite horizons. It has an uncertain age, probably dating between the Hauterivian and Aptian.[1] An indeterminate iguanodontian dinosaur tooth has been recovered from the formation. Many other fossil vertebrates are known from the KO2 locality[2]

Okurodani Formation
Stratigraphic range: Hauterivian–Aptian
TypeGeological formation
Unit ofTetori Group
UnderliesAmagodani Formation
OverliesOtaniyama Formation
Lithology
PrimaryMudstone, Siltstone, Sandstone
OtherTuffite
Location
RegionGifu Prefecture
CountryJapan

Vertebrate Paleobiota

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Amphibians

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Amphibians reported from the Okurodani Formation
Genus Species Location Stratigraphic position Material Notes Images
Anura Indeterminate KO2 Discoglossid grade
Caudata Indeterminate KO2

Squamates

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Squamates reported from the Okurodani Formation
Genus Species Location Stratigraphic position Material Notes Images
Sakurasaurus[3] S. shokawensis KO2
?Anguimorpha Indeterminate KO2
Scincomorpha Indeterminate KO2 new taxon
Squamata Indeterminate KO2 2 distinct taxa

Turtles

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Turtles reported from the Okurodani Formation
Genus Species Location Stratigraphic position Material Notes Images
cf. Sinemys Indeterminate KO2
Sinochelys Indeterminate KO2 Sinochelyidae
Adocidae Indeterminate KO2
Trionychidae Indeterminate KO2

Choristoderes

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Choristoderes reported from the Okurodani Formation
Genus Species Location Stratigraphic position Material Notes Images
Monjurosuchus Indeterminate KO2 "Association of right squamosal, jugal, quadratojugal, and quadrate"
 
Monjurosuchus
 
Shokawa ikoi
Shokawa S. ikoi KO2 Partial skeleton

See also

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Footnotes

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  1. ^ Amiot, Romain; Kusuhashi, Nao; Saegusa, Haruo; Shibata, Masateru; Ikegami, Naoki; Shimojima, Shizuo; Sonoda, Teppei; Fourel, François; Ikeda, Tadahiro; Lécuyer, Christophe; Philippe, Marc; Wang, Xu (2021-01-01). "Paleoclimate and ecology of Cretaceous continental ecosystems of Japan inferred from the stable oxygen and carbon isotope compositions of vertebrate bioapatite" (PDF). Journal of Asian Earth Sciences. 205: 104602. Bibcode:2021JAESc.20504602A. doi:10.1016/j.jseaes.2020.104602. ISSN 1367-9120.
  2. ^ "KO2 locality, Shokawa Village, Kobudani Valley (Cretaceous to of Japan)". Paleobiology Database.
  3. ^ Evans, Susan E.; Manabe, Makoto (January 1999). "Early Cretaceous Lizards from the Okurodani Formation of Japan". Geobios. 32 (6): 889–899. Bibcode:1999Geobi..32..889E. doi:10.1016/s0016-6995(99)80871-7. ISSN 0016-6995.

References

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  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.