The Khok Kruat Formation is a rock formation found in northeastern Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

. It is one of the formations of the Khorat Group. It is of Aptian

Aptian

The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...

 stage (Early Cretaceous

Early Cretaceous

The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

), and is notable for its fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s of dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s. It is equivalent to the Gres superieurs Formation

Gres superieurs Formation

The Gres superieurs Formation is a geological formation in Laos whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. It is equivalent to the Khok Kruat Formation of Thailand....

 of Laos

Laos

Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...

.

Vertebrate fauna

The Khok Kruat Formation has yielded remains of sharks, fishes, turtles, crocodilians and pterosaurs. Phuwiangosaurus

Phuwiangosaurus

Phuwiangosaurus is the name given to a genus of dinosaur from the Early Cretaceous. It was a titanosaur which lived in Thailand. The type species, P. sirindhornae, was described by Martin, Buffetaut, and Suteethorn in 1994, it was named to honour Princess Maha Chakri Sirindhorn of Thailand on her...

-like teeth, Siamosaurus

Siamosaurus

Siamosaurus is a genus of theropod dinosaur from Early Cretaceous Thailand. The size of the animal is unknown, but it may have reached a length of about 9.1 meters . The type species, Siamosaurus suteethorni, was formally described by Buffetaut and Ingavat in 1986...

-like teeth, and fragmentary remains of spinosaurids have also been recovered from it.

Dinosaur Dinosaur Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of... s reported from the Khok Kruat Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Psittacosaurus Psittacosaurus Psittacosaurus is a genus of psittacosaurid ceratopsian dinosaur from the Early Cretaceous Period of what is now Asia, about 130 to 100 million years ago. It is notable for being the most species-rich dinosaur genus...	P. sattayaraki	Ban Dong Bang Noi		"Well preserved left dentary and an incomplete maxilla Maxilla The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper... ."	A ceratopsia Ceratopsia Ceratopsia or Ceratopia is a group of herbivorous, beaked dinosaurs which thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7... n.
Ratchasimasaurus Ratchasimasaurus Ratchasimasaurus is a genus of non-hadrosaurid iguanodontian ornithopod dinosaur from Early Cretaceous Khok Kruat Formation of Nakhon Ratchasima Province in northeastern Thailand. One autapomorphy of Ratchasimasaurus is its elongated and flat ramus of the dentary...	R. suranareae				An iguanodontian ornithopod Ornithopod Ornithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American... .
Siamodon Siamodon Siamodon is a genus of iguanodontian ornithopod dinosaur from Early Cretaceous deposits of northeastern Thailand. Siamodon is known from the holotype PRC-4, a well-preserved left maxilla and from the referred materials PRC-5, an isolated maxillary tooth and PRC-6, a braincase...	S. nimngami	Ban Saphan Hin		PRC-4, a well-preserved left maxilla Maxilla The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper... , PRC-5, an isolated maxillary tooth Tooth Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...  and PRC-6, a braincase.	An iguanodontian ornithopod.