Coordinates: 35°06′N 135°06′E / 35.1°N 135.1°E / 35.1; 135.1

Ohyamashimo Formation

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Ohyamashimo Formation
Stratigraphic range: Albian
~112.1–106.4 Ma
File:Tamba Site01JH.jpg
Type locality of the Tambatitanis, currently covered by concrete for protection.
TypeGeological formation
Unit ofSasayama Group
UnderliesSawada Formation
OverliesBasement (Unconformity)
Thickness1300 metres
Lithology
PrimaryConglomerate, Sandstone, Mudstone
OtherTuff
Location
CoordinatesLua error in Module:Coordinates at line 489: attempt to index field 'wikibase' (a nil value).
Approximate paleocoordinatesLua error: callParserFunction: function "#coordinates" was not found.
RegionHyōgo Prefecture
CountryJapan
Type section
Named forOhyamashimo, Tamba-Sasayama
Named byHayashi et al., 2017[1]

The Ohyamashimo Formation(大山下層) is an Early Cretaceous (Albian) geologic formation, distributed in Tamba and Tamba-Sasayama, Hyogo Prefecture, Japan. It has been dated to the early-mid Albian, between 112.1 ± 0.4 Ma and 106.4 ± 0.4 Ma. The depositional environment represents a fluvial system with a subhumid to semi-arid climate. The Ohyamashimo Formation was called the 'Lower Formation' of the Sasayama Group before it was named in 2017.[1]

Fossil content

[edit | edit source]
Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Dinosaurs

[edit | edit source]

Ornithischians

[edit | edit source]
Ornithischians of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Ankylosauria Indet.[2] Indeterminate Kamitaki Bonebed Quarry, Tamba Albian Dental remains.
Iguanodontia Indet.[2] Indeterminate Kamitaki Bonebed Quarry, Tamba Albian Dental remains.
Sasayamagnomus[3] S. saegusai Miyada microvertebrate site, Tamba-Sasayama Albian Skull elements and partial postcranial remains. A neoceratopsian; closely related to Aquilops americanus.
File:Sasayamagnomus saegusai.png

Saurischians

[edit | edit source]
Sauropods
[edit | edit source]
Sauropods of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Tambatitanis[2] T. amicitiae Kamitaki Bonebed Quarry, Tamba Albian A single partial skeleton. A titanosauriform sauropod
File:Tambatitanis Palaeotaku 24.png
Theropods
[edit | edit source]

Indeterminate theropod dental remains are known from the Kamitaki Bonebed Quarry, Tamba.[2]


Theropods of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Hypnovenator[4] H. matsubaraetoheorum Nishikosa, Tamba-Sasayama Albian A single partial skeleton. A troodontid theropod; closely related to Gobivenator mongoliensis.
File:Hypnovenator matsubaraetoheorum.png
Therizinosauria Indet.[2] Indeterminate Kamitaki Bonebed Quarry, Tamba Albian Dental remains.
Tyrannosauroidea Indet.[2] Indeterminate Kamitaki Bonebed Quarry, Tamba Albian Dental remains.

Squamates

[edit | edit source]
Squamtes of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Morohasaurus[5] M. kamitakiensis Kamitaki Egg Quarry, Tamba Albian A nearly complete left dentary. A monstersaurian lizard
File:Morohasaurus HolotypeJH.jpg
Pachygenys[6] P. adachii Miyada microvertebrate site, Tamba-Sasayama Albian A single, partially broken right mandible A scincomorphan lizard
File:Pachygenys adachii holotypeJH.jpg

Amphibians

[edit | edit source]
Amphibian of the Ohyamashimo Formation[7]
Genus Species Location Stratigraphic position Material Notes Images
Hyogobatrachus H. wadai Kamitaki Bonebed Quarry, Tamba Albian A nearly complete skeleton. A frog
File:Hyogobatrachus HolotypeJH.jpg
Tambabatrachus T. kawazu Kamitaki Bonebed Quarry, Tamba Albian An articulated skeleton lacking the anterior part of the skull, most of the pectoral girdle, manus, and feet. A frog
File:Tambabatrachus HolotypeJH.jpg

Mammals

[edit | edit source]
Mammals of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Sasayamamylos[8] S. kawaii Miyada microvertebrate site, Tamba-Sasayama Albian Three dentaries. A asioryctitherian eutherian
File:Sasayamamylos HolotypeJH.jpg

Crustaceans

[edit | edit source]
Crustaceans of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Mongolocypris M. sp. Albian A ostracod
Conchostraca Indet. Indeterminate Albian A clam shrimp

Molluscs

[edit | edit source]

Bivalves

[edit | edit source]
Bivalves of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Sphaerium S. coreanicum Albian A sphaeriid bivalve

Gastropods

[edit | edit source]
Gastropods of the Ohyamashimo Formation
Genus Species Location Stratigraphic position Material Notes Images
Viviparus V. cf. keishoensis Albian A viviparid gastropod

Oofossils

[edit | edit source]
Eggs of the Ohyamasimo Formation[9][10]
Genus Species Location Stratigraphic position Material Notes Images
Elongatoolithus E. sp. Kamitaki Bonebed Quarry, Tamba Likely laid by oviraptorosaur.
Himeoolithus H. murakamii Kamitaki Egg Quarry, Tamba Likely laid by a small theropod.
Nipponoolithus N. ramosus Kamitaki Bonebed Quarry and Kamitaki Egg Quarry, Tamba Likely laid by non-avian maniraptoran theropod.
Prismatoolithus P. sp. Kamitaki Bonebed Quarry and Kamitaki Egg Quarry, Tamba Likely laid by either troodontids or birds.
Subtiliolithus S. hyogoensis Kamitaki Bonebed Quarry and Kamitaki Egg Quarry, Tamba Likely laid by a small theropod.
Spheroolithus S. sp. Kamitaki Bonebed Quarry, Tamba Likely laid by hadrosaurs or other ornithopods.

References

[edit | edit source]
  1. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  2. ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  3. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  4. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  5. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  6. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  7. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  8. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  9. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  10. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).