The Kuwajima Formation is an Early Cretaceous geologic formation in Japan. Its precise age is uncertain due to a lack of identifying fossils, and it was previously considered likely Valanginian to Hauterivian in age.[1] However, it is now considered to probably be Barremian in age.[2] Dinosaurs and other vertebrates has been recovered from the Kaseki-kabe "Fossil-bluff" locality in the uppermost part of the formation.[3]

Kuwajima Formation
Stratigraphic range: Barremian
Unit ofTetori Group
Sub-unitsLower Member, Upper Member
UnderliesAkaiwa Formation
OverliesGomijima Formation
Lithology
PrimarySandstone, Mudstone
Location
Country Japan

The multituberculate mammals Hakusanobaatar matsuoi and Tedoribaatar reini are known from the Kuwajima Formation.[4] A member of Tritylodontidae, Montirictus kuwajimaensis, has also been recovered from the unit.[5]

Vertebrate Paleobiota

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Fish

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Fish reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Sinamia S. kukurihime Mostly complete skeleton An amiiform fish related to bowfins
Tetoriichthys T. kuwajimaensis The oldest record of Osteoglossiform

Amphibians

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Amphibians reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Shirerpeton[6] S. isajii Kaseki-kabe Facies III Partial disarticulated skull Albanerpetontid
Anura Indeterminate Isolated longbone, as well as a partial skeleton "composed of a few skull elements and several postcranial bones, including the femur, ilium, and vertebrae"[7] Partial skeleton belongs to a basal frog that lies outside of Neobatrachia.[7]

Choristoderes

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Choristoderes reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Monjurosuchus Indeterminate Kaseki-kabe Facies III
 
Monjurosuchus
Neochoristodera[8] Indeterminate Facies I The first report of a neochoristodere from Japan
Choristodera Indeterminate Kaseki-kabe Facies III

Squamates

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Squamates reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Asagaolacerta A. tricuspidens Kaseki-kabe Facies III "An association of skull, jaws and postcranial bones of a small lizard with facetted tricuspid teeth, possibly a right maxilla"
 
Kaganaias
Hakuseps H. imberis Kaseki-kabe Facies III An almost complete left dentary
Kaganaias K. hakusanensis Kaseki-kabe Facies III "Part and counterpart of articulated partial skeleton comprising parts of the dors. vert. series and parts of the tail, pelvis, and hind limbs"
Kuroyuriella K. mikikoi Kaseki-kabe Facies III "A disarticulated skull on four originally conjoined blocks, an association on two small blocks"
Kuwajimalla[9] K. kagaensis Kaseki-kabe Facies III
Sakurasaurus Indeterminate Kaseki-kabe Facies III "Small block with disarticulated association of skull bones, vertebrae, ribs, pelvis and hindlimb bones"
Paramacellodidae Indeterminate Kaseki-kabe Facies III
Squamata Indeterminate Kaseki-kabe Facies III Five distinct taxa

Dinosaurs

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Dinosaurs reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Albalophosaurus[3] A. yamaguchiorum Kaseki-kabe Facies III Partial skull and lower jaws
Dromaeosauridae Indeterminate Kaseki-kabe Facies III
Enantiornithes Indeterminate Kaseki-kabe Facies III
Ornithischia[10] Indeterminate Right dentary, left maxilla, isolated teeth Distinct from Albalophosaurus
Sauropoda ("Oharasisaurus") Indeterminate Kaseki-kabe Facies III Tooth[11]
Styracosterna[10] Indeterminate Maxillary and dental teeth

Mammaliamorphs

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Mammaliamorphs reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Hakusanobaatar[4] H. matsuoi Kaseki-kabe Facies III Dentary fragments and teeth Eobaatarid
Hakusanodon[12] H. archaeus Kaseki-kabe Facies III Eutriconodont
Montirictus[5] M. kuwajimaensis Kaseki-kabe Facies III Tritylodontid
Tedoribaatar[4] T. reini Kaseki-kabe Facies III "Fragment of right lower jaw with p4" Eobaatarid
Multituberculata Indeterminate Kaseki-kabe Facies III

Invertebrate Paleobiota

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Invertebrates reported from the Kuwajima Formation
Genus Species Location Stratigraphic position Material Notes Images
Nipponoridium B. matsuoi Kaseki-Kabe Mimarachnid hemipteran
Nipponohagla N. kaga Prophalangopsid
Kagapsychops K. araneus Psychopsid

See also

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References

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  1. ^ Fujita, M. (2003). "Geological age and correlation of the vertebrate-bearing horizons in the Tetori Group". Memoir of the Fukui Prefectural Dinosaur Museum. 2: 3–14.
  2. ^ 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". Journal of Asian Earth Sciences. 205: 104602. Bibcode:2021JAESc.20504602A. doi:10.1016/j.jseaes.2020.104602. ISSN 1367-9120.
  3. ^ a b Ohashi, T.; Barrett, P. M. (2009). "A new ornithischian dinosaur from the Lower Cretaceous Kuwajima Formation of Japan". Journal of Vertebrate Paleontology. 29 (3): 748–757. Bibcode:2009JVPal..29..748O. doi:10.1671/039.029.0306. S2CID 128546047.
  4. ^ a b c Kusuhashi, Nao (September 2008). "Early Cretaceous Multituberculate Mammals from the Kuwajima Formation (Tetori Group), Central Japan". Acta Palaeontologica Polonica. 53 (3): 379–390. doi:10.4202/app.2008.0302. ISSN 0567-7920.
  5. ^ a b Hiroshige Matsuoka, Nao Kusuhashi and Ian J. Corfe (2016). "A new Early Cretaceous tritylodontid (Synapsida, Cynodontia, Mammaliamorpha) from the Kuwajima Formation (Tetori Group) of central Japan". Journal of Vertebrate Paleontology. Online edition:
  6. ^ Matsumoto, Ryoko; Evans, Susan E. (2018-01-03). "The first record of albanerpetontid amphibians (Amphibia: Albanerpetontidae) from East Asia". PLOS ONE. 13 (1): e0189767. Bibcode:2018PLoSO..1389767M. doi:10.1371/journal.pone.0189767. ISSN 1932-6203. PMC 5752013. PMID 29298317.
  7. ^ a b Mizukami, Ayano; Matsumoto, Ryoko; Wani, Ryoji; Evans, Susan E. (2023-01-04). "A Three-Dimensionally Preserved Frog (Amphibia, Anura) from the Lower Cretaceous Kuwajima Formation, Tetori Group, Ishikawa Prefecture, Japan". Paleontological Research. 27 (3). doi:10.2517/PR210031. ISSN 1342-8144.
  8. ^ Matsumoto, Ryoko; Manabe, Makoto; Evans, Susan E. (2015-07-04). "The first record of a long-snouted choristodere (Reptilia, Diapsida) from the Early Cretaceous of Ishikawa Prefecture, Japan". Historical Biology. 27 (5): 583–594. Bibcode:2015HBio...27..583M. doi:10.1080/08912963.2014.898296. ISSN 0891-2963.
  9. ^ Evans, Susan E.; Manabe, Makoto (March 2008). "An early herbivorous lizard from the Lower Cretaceous of Japan". Palaeontology. 51 (2): 487–498. Bibcode:2008Palgy..51..487E. doi:10.1111/j.1475-4983.2008.00759.x. ISSN 0031-0239.
  10. ^ a b Barrett, Paul M.; Ohashi, Tomoyuki (October 2015). "Ornithischian dinosaur material from the Kuwajima Formation (Tetori Group: Lower Cretaceous) of Ishikawa Prefecture, Japan". Historical Biology. 28 (1–2): 280–288. doi:10.1080/08912963.2015.1032273. ISSN 0891-2963. S2CID 128909019.
  11. ^ MATSUOKA H. (2000). Fossils of the Kuwajima "Kasekikabe" (Fossil Bluff): a scientific report on a Neocomian (Early Cretaceous) fossil assemblage of the Kuwajima Formation, Tetori Group, Ishikawa, Japan.
  12. ^ Rougier, Guillermo W.; Isaji, Shinji; Manabe, Makoto (2007). "An Early Cretaceous Mammal from the Kuwajima Formation (Tetori Group), Japan, and a Reassessment of Triconodont Phylogeny". Annals of Carnegie Museum. 76 (2): 73. doi:10.2992/0097-4463(2007)76[73:aecmft]2.0.co;2. ISSN 0097-4463.