Khok Kruat Formation Explained

Khok Kruat Formation
Type:Geological formation
Age:Aptian
~
Period:Aptian
Prilithology:Sandstone, siltstone
Otherlithology:Conglomerate, shale
Namedby:Ward & Bunnag
Year Ts:1964
Region:Indochina
Coordinates:15.9°N 102°W
Paleocoordinates:16.3°N 105.3°W
Unitof:Khorat Group
Underlies:Maha Sarakham Formation
Overlies:Phu Phan Formation
Extent:Khorat Plateau

The Khok Kruat Formation is a rock formation found in northeastern Thailand. It is the uppermost formation of the Khorat Group.[1] It is dated to the Aptian stage of the Early Cretaceous period, and is notable for its fossils of dinosaurs. It is equivalent to the Gres superieurs Formation of Laos.[2] The group is a fluvial formation consisting primarily of red siltstones and sandstones.

Vertebrate paleofauna

The Khok Kruat Formation has yielded remains of sharks, fishes, turtles, crocodilians and pterosaurs. Phuwiangosaurus-like teeth, Siamosaurus teeth, and fragmentary postcranial remains of spinosaurids have also been recovered from it.[3] Fukuiraptor-like teeth have also been recovered from the formation.[4]

Reptiles

Dinosaurs

Dinosaurs reported from the Khok Kruat Formation
Genus Species Location Material Notes Images
cf. Asianopoduscf. A. isp."Huai Dam Chum site, Ban Lao Nat, Tha Uthen District, Nakhon Phanom Province".[5] "At least 79 trackways composed of 341 consecutive tracks in total".Theropod tracks.
Ichnogen. et. sp. indet."Huai Dam Chum site, Ban Lao Nat, Tha Uthen District, Nakhon Phanom Province"."Two trackways: T23 composed of 6 consecutive tracks and T35 composed of 3 discontinuous tracks".Flattened possible theropod tracks.
PsittacosaurusP. sattayaraki[6] Ban Dong Bang Noi"Well preserved left dentary and an incomplete maxilla."A ceratopsian
RatchasimasaurusR. suranareaeNakhon Ratchasima province.[7] An iguanodontian ornithopod
SiamodonS. nimngami[8] Ban Saphan HinPRC-4, a well-preserved left maxilla, PRC-5, an isolated maxillary tooth and PRC-6, a braincase.An iguanodontian ornithopod
SirindhornaS. khoratensisMuaeng Nakhon Ratchasima District, Nakhon Ratchasima Province.[9] An iguanodontian ornithopod
SiamosaurusS. sp.[10] TeethA spinosaurid
SiamraptorS. suwatiMuaeng Nakhon Ratchasima District, Nakhon Ratchasima Province.[11] "A composite cranial and postcranial skeleton comprising premaxilla, maxilla, jugal, surangular, prearticular, articular, vertebrae, manual ungual, ischium, tibia, and pedal phalanx".A carcharodontosaur

Pseudosuchians

Pseudosuchians reported from the Khok Kruat Formation
Genus Species Location MaterialNotes Images
Atoposauridae indet.IndeterminateLam Pao Reservoir, Ban Noi, Sahatsakhan district, Kalasin province.[12] An isolated lanceolate tooth (PRCMR 282).May be attributable to Theriosuchus.
KhoratosuchusK. jintasakuliBan Saphan Hin, Nakhon Ratchasima province.[13] A partial skull (NNRU-A 1803).An advanced neosuchian.

Turtles

Turtles reported from the Khok Kruat Formation
Genus Species Location MaterialNotes Images
KizylkumemysK. khoratensisBan Saphan Hin and Ban Khok Kruat localities, Nakhon Ratchasima province.[14] Shell material.A carettochelyid.
ShachemysS. sp.Ban Saphan Hin, Nakhon Ratchasima province.Shell material.An adocid, remains too fragmentary for specific assignment.

Fish

Bony fish

Bony fish reported from the Khok Kruat Formation
Genus Species LocationMaterialNotes Images
KhoratamiaK. phattharajaniBan Krok Duean Ha, Nakhon Ratchasima province.[15] Holotype (NRRU-F01020023), paratype (NRRU-F01020024) and a patch of scales (NRRU-F01020025).An amiid.
LanxangichthysL. sp.Khok Pha Suam, Ubon Ratchathani province.[16] A lepisosteiform.

Cartilaginous fish

Cartilaginous fish reported from the Khok Kruat Formation
Genus Species Location MaterialNotes Images
AcrorhizodusA. khoratensisKhok Pha Suam locality, Ubon Ratchathani province.[17] 5 teeth, most of them incomplete.A hybodontiform.
HeteroptychodusH. aff. steinmanniKhok Pha Suam locality, Ubon Ratchathani province.20 teeth, most incomplete.A ptychodontid.
Hybodus?H.? sp.Khok Pha Suam locality, Ubon Ratchathani province.22 incomplete teeth.Possibly represents a new genus, but the available material is too fragmentary to warrant erecting a new taxon.
ThaiodusT. ruchaeKhok Pha Suam locality, Ubon Ratchathani province.One incomplete tooth.A hybodontid.

See also

Notes and References

  1. Book: Eric Buffetaut. Late Palaeozoic and Mesozoic Ecosystems in SE Asia. 2009. Geological Society of London. 978-1-86239-275-5. 146.
  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. .
  3. Eric Buffetaut . Varavudh Suteethorn . Jean Le Loeuff . Sasidhorn Khansubha . Haiyan Tong . Kamonlak Wongko . 2005 . New dinosaur species from the Upper Triassic Upper Maleri and Lower Dharmaram formations of central India . International Conference on Geology, Geotechnology and Mineral Resources of Indochina (GEOINDO 2005) . 575–581 .
  4. Chokchaloemwong. Duangsuda. Azuma. Yoichi. Shibata. Masateru. Jintasakul. Pratueng. 2015. The Carcharodontosaurid Teeth from the Lower Cretaceous Khok Kruat Formation of Nakhon Ratchasima, Thailand. 2nd International Symposium on Asian Dinosaurs 2015 Bangkok.
  5. Kozu . Shohei . Sardsud . Apsorn . Saesaengseerung . Doungrutai . Pothichaiya . Cherdchan . Agematsu . Sachiko . Sashida . Katsuo . 2017-11-01 . Dinosaur footprint assemblage from the Lower Cretaceous Khok Kruat Formation, Khorat Group, northeastern Thailand . Geoscience Frontiers . en . 8 . 6 . 1479–1493 . 10.1016/j.gsf.2017.02.003 . 2017GeoFr...8.1479K . 1674-9871. free .
  6. Buffetaut, Eric & Suteethorn, Varavudh. (1992). A new species of the ornithischian dinosaur Psittacosaurus from the Early Cretaceous of Thailand. Palaeontology 35: 801-812.
  7. Masateru . Shibata . Pratueng . Jintasakul . Yoichi . Azuma . 2011 . A New Iguanodontian Dinosaur from the Lower Cretaceous Khok Kruat Formation, Nakhon Ratchasima in Northeastern Thailand . Acta Geologica Sinica . en . 85 . 5 . 969–976 . 10.1111/j.1755-6724.2011.00230.x.
  8. Eric . Buffetaut . Varavudh . Suteethorn . 2011 . A new iguanodontian dinosaur from the Khok Kruat Formation (Early Cretaceous, Aptian) of northeastern Thailand . Annales de Paléontologie . 97 . 1–2 . 51–62 . 10.1016/j.annpal.2011.08.001 . 2011AnPal..97...51B .
  9. Shibata . Masateru . Jintasakul . Pratueng . Azuma . Yoichi . You . Hai-Lu . 2015-12-30 . A New Basal Hadrosauroid Dinosaur from the Lower Cretaceous Khok Kruat Formation in Nakhon Ratchasima Province, Northeastern Thailand . PLOS ONE . 10 . 12 . e0145904 . 10.1371/journal.pone.0145904 . 1932-6203 . 4696827 . 26716981. 2015PLoSO..1045904S . free .
  10. Milner. Angela. Buffetaut. Eric. Suteethorn. Varavudh. 2007. A tall-spined spinosaurid theropod from Thailand and the biogeography of spinosaurs. Journal of Vertebrate Paleontology. 27 (supplement 3). 118A. 2020-06-08. 2019-09-23. https://web.archive.org/web/20190923012213/http://vertpaleo.org/Annual-Meeting/Future-Past-Meetings/MeetingPdfs/JVP_07.aspx. dead.
  11. Chokchaloemwong . Duangsuda . Hattori . Soki . Cuesta . Elena . Jintasakul . Pratueng . Shibata . Masateru . Azuma . Yoichi . 2019-10-09 . A new carcharodontosaurian theropod (Dinosauria: Saurischia) from the Lower Cretaceous of Thailand . PLOS ONE . en . 14 . 10 . e0222489 . 10.1371/journal.pone.0222489 . 1932-6203 . 6784982 . 31596853. 2019PLoSO..1422489C . free .
  12. 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 . 10.1007/s12542-010-0071-z . 128623617 . 0031-0220.
  13. Lauprasert . K. . Cuny . G. . Thirakhupt . K. . Suteethorn . V. . May 2009 . Khoratosuchus jintasakuli gen. et sp. nov., an advanced neosuchian crocodyliform from the Early Cretaceous (Aptian-Albian) of NE Thailand . Geological Society, London, Special Publications . 315 . 1 . 175–187 . 10.1144/sp315.13 . 2009GSLSP.315..175L . 131412579 . 0305-8719.
  14. 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 . 10.1144/sp315.11 . 2009GSLSP.315..141T . 130709324 . 0305-8719.
  15. Deesri . Uthumporn . Naksri . Wilailuck . Jintasakul . Pratueng . Noda . Yoshikazu . Yukawa . Hirokazu . Hossny . Tamara El . Cavin . Lionel . April 2023 . A New Sinamiin Fish (Actinopterygii) from the Early Cretaceous of Thailand: Implications on the Evolutionary History of the Amiid Lineage . Diversity . en . 15 . 4 . 491 . 10.3390/d15040491 . 1424-2818 . free .
  16. Cavin . Lionel . Deesri . Uthumporn . Veran . Monette . Khentavong . Bounsou . Jintasakul . Pratueng . Chanthasit . Phornphen . Allain . Ronan . 2019-03-04 . A new Lepisosteiformes (Actinopterygii: Ginglymodi) from the Early Cretaceous of Laos and Thailand, SE Asia . Journal of Systematic Palaeontology . 17 . 5 . 393–407 . 10.1080/14772019.2018.1426060 . 2019JSPal..17..393C . 90886053 . 1477-2019.
  17. Cappetta . Henri . Buffetaut . Eric . Cuny . Gilles . Suteethorn . Varavudh . May 2006 . A New Elasmobranch Assemblage From The Lower Cretaceous of Thailand . Palaeontology . en . 49 . 3 . 547–555 . 10.1111/j.1475-4983.2006.00555.x . 2006Palgy..49..547C . 129380407 . 0031-0239. free .