| Khok Kruat Formation | |
|---|---|
| Stratigraphic range: Aptian ~120–113 Ma
| |
| Type | Geological formation |
| Unit of | Khorat Group |
| Underlies | Maha Sarakham Formation |
| Overlies | Phu Phan Formation |
| Lithology | |
| Primary | Sandstone, siltstone |
| Other | Conglomerate, shale |
| Location | |
| Coordinates | 15°54′N 102°00′E / 15.9°N 102.0°E / 15.9; 102.0 |
| Approximate paleocoordinates | 16°18′N 105°18′E / 16.3°N 105.3°E / 16.3; 105.3 |
| Region | Indochina |
| Country |  Thailand |
| Extent | Khorat Plateau |
| Type section | |
| Named by | Ward & Bunnag |
| Year defined | 1964 |
  Khok Kruat Formation (Thailand) | |
The Khok Kruat Formation (Thai: หมวดหินโคกกรวด) 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 fossilsofdinosaurs. It is equivalent to the Gres superieurs FormationofLaos.[2] The group is a fluvial formation consisting primarily of red siltstones and sandstones.[1]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
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]
| Dinosaurs reported from the Khok Kruat Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images |
| cf. Asianopodus | cf. 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".[5] | Theropod tracks. | |
| Ichnogen. et. sp. indet. | "Huai Dam Chum site, Ban Lao Nat, Tha Uthen District, Nakhon Phanom Province".[5] | "Two trackways: T23 composed of 6 consecutive tracks and T35 composed of 3 discontinuous tracks".[5] | Flattened possible theropod tracks. | ||
| Psittacosaurus | P. sattayaraki[6] | Ban Dong Bang Noi | "Well preserved left dentary and an incomplete maxilla."[3] | Aceratopsian | |
| Ratchasimasaurus | R. suranareae | Nakhon Ratchasima province.[7] | Aniguanodontian ornithopod |  | |
| Siamodon | S. nimngami[8] | Ban Saphan Hin | PRC-4, a well-preserved left maxilla, PRC-5, an isolated maxillary tooth and PRC-6, a braincase.[8] | An iguanodontian ornithopod |  |
| Sirindhorna | S. khoratensis | Muaeng Nakhon Ratchasima District, Nakhon Ratchasima Province.[9] | Aniguanodontian ornithopod |  | |
| Siamosaurus | S. sp.[10] | Teeth | Aspinosaurid |  | |
| Siamraptor | S. suwati | Muaeng 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".[11] | Acarcharodontosaur |  |
| Pseudosuchians reported from the Khok Kruat Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images |
| Atoposauridae indet. | Indeterminate | Lam Pao Reservoir, Ban Noi, Sahatsakhan district, Kalasin province.[12] | An isolated lanceolate tooth (PRCMR 282).[12] | May be attributable to Theriosuchus.[12] | |
| Khoratosuchus | K. jintasakuli | Ban Saphan Hin, Nakhon Ratchasima province.[13] | A partial skull (NNRU-A 1803).[13] | An advanced neosuchian. | |
| Turtles reported from the Khok Kruat Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images |
| Kizylkumemys | K. khoratensis | Ban Saphan Hin and Ban Khok Kruat localities, Nakhon Ratchasima province.[14] | Shell material.[14] | Acarettochelyid. | |
| Shachemys | S. sp. | Ban Saphan Hin, Nakhon Ratchasima province.[14] | Shell material.[14] | Anadocid, remains too fragmentary for specific assignment. | |
| Bony fish reported from the Khok Kruat Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images |
| Khoratamia | K. phattharajani | Ban Krok Duean Ha, Nakhon Ratchasima province.[15] | Holotype (NRRU-F01020023), paratype (NRRU-F01020024) and a patch of scales (NRRU-F01020025).[15] | Anamiid. | |
| Lanxangichthys | L. sp. | Khok Pha Suam, Ubon Ratchathani province.[16] | Alepisosteiform. | ||
| Cartilaginous fish reported from the Khok Kruat Formation | |||||
|---|---|---|---|---|---|
| Genus | Species | Location | Material | Notes | Images |
| Acrorhizodus | A. khoratensis | Khok Pha Suam locality, Ubon Ratchathani province.[17] | 5 teeth, most of them incomplete.[17] | Ahybodontiform. | |
| Heteroptychodus | H. aff. steinmanni | Khok Pha Suam locality, Ubon Ratchathani province.[17] | 20 teeth, most incomplete.[17] | Aptychodontid. | |
| Hybodus? | H.? sp. | Khok Pha Suam locality, Ubon Ratchathani province.[17] | 22 incomplete teeth.[17] | Possibly represents a new genus, but the available material is too fragmentary to warrant erecting a new taxon.[17] | |
| Thaiodus | T. ruchae | Khok Pha Suam locality, Ubon Ratchathani province.[17] | One incomplete tooth.[17] | Ahybodontid. | |
