The Sao Khua Formation (Thai: หมวดหินเสาขัว) is a middle member of the Khorat Group. It consists of an alteration of pale red to yellowish-gray, fine to medium-grained sandstone and grayish-reddish brown siltstone and clay. Rare pale red to light gray conglomerates, containing carbonate pebbles, are also characteristic of this formation. This geological formation in Thailand dates to the Early Cretaceous age, specifically the Valanginian through Hauterivian stages.[1]

Sao Khua Formation
Stratigraphic range: late Valanginian-early Hauterivian
~133.6–132.1 Ma
Restoration of Siamosaurus, Sunosuchus and Phuwiangosaurus in the Sao Khua Formation palaeoenvironment.
TypeGeological formation
Unit ofKhorat Group
UnderliesPhu Phan Formation
OverliesPhra Wihan Formation
Thickness~120 m (390 ft)
Lithology
PrimarySandstone, conglomerate
OtherSiltstone, claystone
Location
Coordinates16°42′N 102°18′E / 16.7°N 102.3°E / 16.7; 102.3
Approximate paleocoordinates14°18′N 112°24′E / 14.3°N 112.4°E / 14.3; 112.4
RegionIndochina
Country Thailand
ExtentKhorat Plateau
Type section
Named byWard & Bunnag
Year defined1964
Sao Khua Formation is located in Thailand
Sao Khua Formation
Sao Khua Formation (Thailand)

Dinosaur remains are among the fossils that have been recovered from the formation.[2]

Depositional environment

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Baser on paleosols and lithostratigraphy, the Sao Khua Formation is believed to have been deposited in a warm to slightly cool semi-arid climate by a meandering river system.[citation needed] Geochemistry is indicative of a stable humid subtropical climate regime, and sedimentation is thought to have occurred in a floodplain setting which was fed by bedload-rich large meandering channels.[1] Paleocurrent analysis suggests the sand channels at the time of deposition of the formation probably formed a braided channel environment.[3]

Fossil content

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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.

Amphibians

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Amphibians reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Anura indet. Indeterminate Nong Bua Lamphu province.[4] Humeri (SHM-PT 529 and SHM-PT 530) and a pelvic girdle (SHM-HY 231).[4] A frog.

Reptiles

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Dinosaurs

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Dinosaurs reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Brachiosauridae Indeterminate Phu Wat B Locality, Phu Kao Mountain range A tooth.[5] Similar to other brachiosaurid teeth.
Carcharodontosauridae Locality Phu Wiang 1a, Khon Kaen province.[6] "Fragment of the posterior part of a right maxilla".[6] A carcharodontosaur.
Compsognathidae? Indeterminate [6][7][8] A very small theropod form.[6][7]
Kinnareemimus K. khonkaenensis Locality Phu Wiang 5, Phu Wiang district, Khon Kaen province.[9] Vertebral, pelvic and limb elements.[9] An ornithomimosaur.
 
Ornithurae? Khok Kong, Kalasin province.[10] A humerus fragment.[10] May represent an early ornithurine, and probably is not an enantiornithine.
Phuwiangosaurus P. sirindhornae Khon Kaen province.[11] Nong Bua Lamphu Province.[5] "Partial skeletons, juvenile - adult", & 2 additional vertebrae.[11][12] A scapula and a partial skeleton have also been referred.[5] A titanosaur.
 
Phuwiang spinosaurid B Indeterminate PW9 ‘Hin Lad Yao’ locality site A and site B, Phu Wiang district, Khon Kaen province.[13] Caudal vertebrae.[13] A spinosaur.
Phuwiangvenator P. yaemniyomi Phu Wiang Site 9B, Phu Wiang Mountain, Khon Kaen province.[14] A megaraptoran.
Siamosaurus S. suteethorni Isolated teeth.[15][16] A potentially dubious spinosaur.
 
Siamotyrannus S. isanensis "Pelvis, dorsal, sacral, and caudal vertebrae."[17][18] An avetheropodan of uncertain position
 
Vayuraptor V. nongbualamphuensis Phu Wat Site A1 Locality, Nong Sang, Nong Bua Lamphu province.[14] A megaraptoran.
  • Sauropoda indet. 1 and 2

Lizards

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Lizards reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Anguimorpha indet. Phu Phok (SK1), Sakhon Nakhorn Province.[19] Fossilized eggs containing embryos.[19] Eggs originally thought to be of theropods like Epidendrosaurus.[20]

Pseudosuchians

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Pseudosuchians reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Goniopholis G. phuwiangensis Phu Wiang district.[21] A dentary.[21][22] Reassigned to Sunosuchus.
Siamosuchus S. phuphokensis Phu Phok, Kok Prasil Sub-district, Phu Phan district, Sakon Nakhon province.[23] A partly articulated skeleton (PPC-1).[23] A goniopholidid.
Sunosuchus S. phuwiangensis Phu Wiang district.[21] A dentary.[22] Originally reported as Goniopholis phuwiangensis.
Theriosuchus T. grandinaris Phu Phok, Kok Prasil Sub-district, Phu Phan district, Sakon Nakhon province.[24] "PPC-2, a nearly complete rostrum and dentary".[24] An atoposaurid.
Varanosuchus V. sakonnakhonensis Phu Sung locality near Mueang Sakon Nakhon district, Sakon Nakhon province.[25] A nearly complete skull and skeleton (SM-2021-1-97/101), a nearly complete skull (SM-2023-1-16), and a partial skull table (SM-2023-1-17).[25] An atoposaurid.

Pterosaurs

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Pterosaurs reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Ornithocheiridae Phu Phok, Sakon Nakhon province.[26] An isolated tooth crown (SMP25).[26] Most comparable to ornithocheirid teeth from the Cambridge Greensand and Kem Kem beds.[26]

Turtles

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Turtles reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Isanemys I. srisuki Kalasin, Khon Kaen and Sakon Nakhon provinces.[27] Over 20 shells & additional isolated shell plates.[27] An adocid.
Kizylkumemys K. sp. Khon Kaen, Kalasin and Nong Bua Lamphu provinces.[27] Abundant but very fragmentary shell plates.[27] A carettochelyid.
Protoshachemys P. rubra Phu Din Daeng, Nakhon Phanom province.[28] Shell material.[28] An adocid.

Fish

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Bony fish

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Bony fish reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Siamamia S. naga Phu Phok.[29] A bowfin.

Cartilaginous fish

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Cartilaginous fish reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Heteroptychodus H. steinmanni Over 130 fragmentary teeth.[30] A hybodont
Hybodontiformes Incertae sedis 2 dermal denticles and a cephalic spines.[30] Indeterminate hybodontiform remains
Hybodus "H." sp. A 18 fragmentary crowns.[30] A hybodontid
H. sp. B Over 170 incomplete teeth.[30] A hybodontid
Isanodus I. paladeji Phu Phan Thong, Nong Bua Lamphu province.[30] 185 incomplete teeth.[30] A hybodont
Lonchidion L. khoratensis Phu Phan Thong, Nong Bua Lamphu province.[30] 25 teeth.[30] A hybodont
Mukdahanodus M. trisivakulii Nong Sung district, Mukdahan province.[30] 11 isolated crowns.[30] A hybodont
Parvodus P. sp. 19 teeth.[30] A hybodont
Sclerorhynchidae Base of Phu Kum Khao hill in Sahatsakhan, Kalasin province.[31] A rostral tooth (SM2012-1-021).[31] A sawskate

Invertebrates

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Bivalves

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Bivalves reported from the Sao Khua Formation
Genus Species Presence Material Notes Images
Pseudohyria P. (Matsumotoina) somanai South of Phu Noi, Khon Kaen province.[32]

See also

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References

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  1. ^ a b Tucker, Ryan T.; Hyland, Ethan G.; Gates, Terry A.; King, M. Ryan; Roberts, Eric M.; Foley, Elliot K.; Berndt, David; Hanta, Rattanaphorn; Khansubha, Sasa-on; Aswasereelert, Wasinee; Zanno, Lindsay E. (September 2022). "Age, depositional history, and paleoclimatic setting of Early Cretaceous dinosaur assemblages from the Sao Khua Formation (Khorat Group), Thailand". Palaeogeography, Palaeoclimatology, Palaeoecology. 601: 111107. Bibcode:2022PPP...60111107T. doi:10.1016/j.palaeo.2022.111107. ISSN 0031-0182. S2CID 249702713.
  2. ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. ISBN 0-520-24209-2.
  3. ^ Chenrai, Piyaphong (2012-01-01). "Paleocurrent Analysis of the Sao Khua Formation, Khorat Group, Nong Bua Lamphu region, NE Thailand". Arabian Journal for Science and Engineering. 37 (1): 115–120. doi:10.1007/s13369-011-0144-7. ISSN 2191-4281. S2CID 136504980.
  4. ^ a b Nonsrirach, Thanit; Manitkoon, Sita; Lauprasert, Komsorn (2021). "First occurrence of brachyopid temnospondyls in Southeast Asia and review of the Mesozoic amphibians from Thailand". Fossil Record. 24 (1): 33. Bibcode:2021FossR..24...33N. doi:10.5194/fr-24-33-2021. ISSN 2193-0074. S2CID 233147622.
  5. ^ a b c Samathi, Adun; Suteethorn, Suravech; Boonjarern, Tanachot; Sutcha, Krishna; Suteethorn, Varavudh (April 2024). "Dinosaur fauna from the Lower Cretaceous of Phu Kao-Phu Phan Kham, northeastern Thailand: a review and update". Palaeoworld. 33 (2): 420–438. Bibcode:2024Palae..33..420S. doi:10.1016/j.palwor.2023.03.007. ISSN 1871-174X.
  6. ^ a b c d Buffetaut, Eric; Suteethorn, Varavudh (January 2012). "A carcharodontosaurid theropod (Dinosauria, Saurischia) in the Sao Khua Formation (Early Cretaceous, Barremian) of Thailand". 2012 EAVP Abstracts: 27–30.
  7. ^ a b Buffetaut, Eric; Suteethorn, Varavudh (1999-06-15). "The dinosaur fauna of the Sao Khua Formation of Thailand and the beginning of the Cretaceous radiation of dinosaurs in Asia". Palaeogeography, Palaeoclimatology, Palaeoecology. 150 (1): 13–23. Bibcode:1999PPP...150...13B. doi:10.1016/S0031-0182(99)00004-8. ISSN 0031-0182.
  8. ^ Buffetaut, Eric; Suteethorn, Varavudh; Le Loeuff, Jean; Khansubha, Sasa-On; Tong, Haiyan; Wongko, K. (January 2005). "The dinosaur fauna from the Khok Kruat Formation (Early Cretaceous) of Thailand". International Conference on Geology, Geotechnology and Mineral Resources of Indochina (GEOINDO 2005): 575–581.
  9. ^ a b Buffetaut, Eric; Suteethorn, Varavudh; Tong, Haiyan (May 2009). "An early 'ostrich dinosaur' (Theropoda: Ornithomimosauria) from the Early Cretaceous Sao Khua Formation of NE Thailand". Geological Society, London, Special Publications. 315 (1): 229–243. Bibcode:2009GSLSP.315..229B. doi:10.1144/sp315.16. ISSN 0305-8719. S2CID 128633687.
  10. ^ a b Buffetaut, Eric; Dyke, Gareth; Suteethorn, Varavudh; Tong, Haiyan (2005-12-01). "First record of a fossil bird from the Early Cretaceous of Thailand". Comptes Rendus Palevol. 4 (8): 681–686. Bibcode:2005CRPal...4..681B. doi:10.1016/j.crpv.2005.06.002. ISSN 1631-0683.
  11. ^ a b Suteethorn, Suravech; Loeuff, Jean Le; Buffetaut, Eric; Suteethorn, Varavudh (2010). "Description of topotypes of Phuwiangosaurus sirindhornae, a sauropod from the Sao Khua Formation (Early Cretaceous) of Thailand, and their phylogenetic implications". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 256 (1): 109. doi:10.1127/0077-7749/2010/0036. ISSN 0077-7749.
  12. ^ "Table 13.1," in Weishampel, et al. (2004). Page 268.
  13. ^ a b Samathi, Adun; Sander, P. Martin; Chanthasit, Phornphen (February 2021). "A spinosaurid from Thailand (Sao Khua Formation, Early Cretaceous) and a reassessment of Camarillasaurus cirugedae from the Early Cretaceous of Spain". Historical Biology. 33 (4): 3480–3494. Bibcode:2021HBio...33.3480S. doi:10.1080/08912963.2021.1874372. S2CID 233884025.
  14. ^ a b Samathi, Adun; Chanthasit, Phornphen; Sander, P. Martin (2019). "Two new basal coelurosaurian theropod dinosaurs from the Lower Cretaceous Sao Khua Formation of Thailand". Acta Palaeontologica Polonica. 64 (2): 239–260. doi:10.4202/app.00540.2018.
  15. ^ Bertin, Tor (December 2010). "A catalogue of material and review of the Spinosauridae". PalArch's Journal of Vertebrate Palaeontology. 7 (4): 1–39.
  16. ^ "Table 4.1," in Weishampel, et al. (2004). Page 78.
  17. ^ "Table 4.1," in Weishampel, et al. (2004). Page 74.
  18. ^ Buffetaut, Eric; Suteethorn, Varavudh; Tong, Haiyan (June 1996). "The earliest known tyrannosaur from the Lower Cretaceous of Thailand". Nature. 381 (6584): 689–691. Bibcode:1996Natur.381..689B. doi:10.1038/381689a0. ISSN 1476-4687. S2CID 7350556.
  19. ^ a b Fernandez, Vincent; Buffetaut, Eric; Suteethorn, Varavudh; Rage, Jean-Claude; Tafforeau, Paul; Kundrát, Martin (2015-07-15). "Evidence of Egg Diversity in Squamate Evolution from Cretaceous Anguimorph Embryos". PLOS ONE. 10 (7): e0128610. Bibcode:2015PLoSO..1028610F. doi:10.1371/journal.pone.0128610. ISSN 1932-6203. PMC 4503689. PMID 26176757.
  20. ^ Buffetaut, Eric; Grellet-Tinner, Gerald; Suteethorn, Varavudh; Cuny, Gilles; Tong, Haiyan; Košir, Adrijan; Cavin, Lionel; Chitsing, Suwanna; Griffiths, Peter J.; Tabouelle, Jérôme; Le Loeuff, Jean (2005-09-13). "Minute theropod eggs and embryo from the Lower Cretaceous of Thailand and the dinosaur-bird transition". Naturwissenschaften. 92 (10): 477–482. Bibcode:2005NW.....92..477B. doi:10.1007/s00114-005-0022-9. ISSN 0028-1042. PMID 16158273. S2CID 26168801.
  21. ^ a b c Buffetaut, Eric; Ingavat, Rucha (1983-01-01). "Goniopholis phuwiangensis nov. sp., a newmesosuchian crocodile from the Mesozoic of north-eastern Thailand". Geobios. 16 (1): 79–91. Bibcode:1983Geobi..16...79B. doi:10.1016/S0016-6995(83)80048-5. ISSN 0016-6995.
  22. ^ a b De Andrade, M. B.; Edmonds, R.; Benton, M. J.; Schouten, R. (2011). "A new Berriasian species of Goniopholis (Mesoeucrocodylia, Neosuchia) from England, and a review of the genus". Zoological Journal of the Linnean Society. 163: S66–S108. doi:10.1111/j.1096-3642.2011.00709.x. S2CID 83181094.
  23. ^ a b Lauprasert, Komsorn; Cuny, Gilles; Buffetaut, Eric; Suteethorn, Varavudh; Thirakhupt, Kumthorn (2007). "Siamosuchus phuphokensis, a new goniopholidid from the Early Cretaceous (ante-Aptian) of northeastern Thailand". Bulletin de la Société Géologique de France. 178 (3): 201. doi:10.2113/gssgfbull.178.3.201. ISSN 1777-5817.
  24. ^ a b Lauprasert, Komsorn; Laojumpon, Chalida; Saenphala, Wanitchaphat; Cuny, Gilles; Thirakhupt, Kumthorn; Suteethorn, Varavudh (2010-06-12). "Atoposaurid crocodyliforms from the Khorat Group of Thailand: first record of Theriosuchus from Southeast Asia". Paläontologische Zeitschrift. 85 (1): 37–47. doi:10.1007/s12542-010-0071-z. ISSN 0031-0220. S2CID 128623617.
  25. ^ a b Pochat-Cottilloux, Yohan; Lauprasert, Komsorn; Chanthasit, Phornphen; Manitkoon, Sita; Adrien, Jérôme; Lachambre, Joël; Amiot, Romain; Martin, Jeremy E. (2024-01-09). "New Cretaceous neosuchians (Crocodylomorpha) from Thailand bridge the evolutionary history of atoposaurids and paralligatorids". Zoological Journal of the Linnean Society. In press: 1–27. doi:10.1093/zoolinnean/zlad195.
  26. ^ a b c Cuny, Gilles; Suteethorn, V. (2003-01-01). "A Pterodactyloid tooth from the Sao Khua Formation (Early Cretaceous) of Thailand". Mahasarakham University Journal. 22: 92–98.
  27. ^ a b c d Tong, Haiyan; Claude, Julien; Suteethorn, Varavudh; Naksri, Wilailuck; Buffetaut, Eric (May 2009). "Turtle assemblages of the Khorat Group (Late Jurassic-Early Cretaceous) of NE Thailand and their palaeobiogeographical significance". Geological Society, London, Special Publications. 315 (1): 141–152. Bibcode:2009GSLSP.315..141T. doi:10.1144/sp315.11. ISSN 0305-8719. S2CID 130709324.
  28. ^ a b Tong, Haiyan; Buffetaut, Eric; Suteethorn, Varavudh; Suteethorn, Suravech; Cuny, Gilles; Cavin, Lionel; Deesri, Uthumporn; Martin, Jeremy E.; Wongko, Kamonrak; Naksri, Wilailuck; Claude, Julien (2019-07-01). "Phu Din Daeng, a new Early Cretaceous vertebrate locality on the Khorat Plateau, NE Thailand". Annales de Paléontologie. Palaeobiodiversity of Southeast Asia, issue 1. 105 (3): 223–237. Bibcode:2019AnPal.105..223T. doi:10.1016/j.annpal.2019.04.004. ISSN 0753-3969. S2CID 189968031.
  29. ^ Cavin, Lionel; Suteethorn, Varavudh; Buffetaut, Eric; Claude, Julien; Cuny, Gilles; Le Loeuff, Jean; Tong, Haiyan (2007-12-12). "The first sinamiid fish (Holostei: Halecomorpha) from Southeast Asia (Early Cretaceous of Thailand)". Journal of Vertebrate Paleontology. 27 (4): 827–837. doi:10.1671/0272-4634(2007)27[827:tfsfhh]2.0.co;2. ISSN 0272-4634. S2CID 85325978.
  30. ^ a b c d e f g h i j k M., Cuny, Gilles Guy Roger Suteethorn, V. Buffetaut, E. Philippe (2003). Hybodont sharks from the Mesozoic Khorat Group of Thailand. OCLC 842608080.{{cite book}}: CS1 maint: multiple names: authors list (link)
  31. ^ a b Khansubha, Sasa-On. "A Sclerorhynchoid (Chondrichthyes: Batomorphii) in the Lower Cretaceous of Thailand?". {{cite journal}}: Cite journal requires |journal= (help)
  32. ^ Tumpeesuwan, Sakboworn; Sato, Yoshio; Nakhapadungrat, Somchai (2010). A New Species of Pseudohyria (Matsumotoina) (Bivalvia: Trigonioidoidea) from the Early Cretaceous Sao Khua Formation, Khorat Group, Northeastern Thailand.