“Dinosaur” was coined in 1842 by Sir Richard Owen, a pioneering British comparative anatomist. It is from the Greek roots, deinos (terrible, fearfully, great) and sauros (lizard or reptile) and means a fearfully great lizard. Nowadays, there are more than 340 species discovered worldwide.
In Thailand, Dinosaur was found in the northeastern plateau, Khorat Plateau. It might be the land of origin of Dinosaur both sauropod (plant-eating) and theropod (meat-eating) which later evolved and distributed to other territories. The evidence was from a sauropod remains, Isanosaurus attavipachi which is 210 Ma in age and was found in Chaiyaphum province. This fossil is older than the other sauropods fossils that were previously found in the world. Moreover, tyrannosaurid theropod fossils, Siamotyrannus isanensis (130 Ma) was found in Khon Kaen province. It was recognized as the world oldest tyrannosaur compared with other tyrannosaurs which are not over 100 million years old. Siamosaurus suteethorni is the first Thai theropod (130 Ma) that had distinct crocodile-like snout. The most complete sauropod skeleton in Thailand is Phuwiangosaurus sirindhornae (130 Ma) which found in Kalasin provinece. The first Ceratopsia was Psittacosaurus satayaraki (100 Ma) that found in Chaiyaphum province.
In Nakhon Ratchasima, the southwest edge of the Khorat Plateau, especially in Suranaree and Khok Kruat subdistricts, was once a habitat of at least three dinosaurs, allosaurid, iguanodontid, and sauropod, and other associated fauna including pterosaur, hybodont shark (Thaiodus ruchae), lepidotes fish, crocodile, and turtle. The fossils were excavated by the Thailand-Japan Dinosaur Excavation Project (year 2007 to 2009). The identifications of these dinosaurs in specific level are under studied.
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Allosaurid
Allosaurid was meat-eating dinosaur, with a massive head, short neck, and bulky body with three fingered forelimbs. It has a distinctive bony bump over the eyes. It was the most abundant, and probably the largest predator in the Late Jurassic period in the lands. The Khorat allosaurid, a Thailand largest theropod, had reach 10 m in length and probably be a new species.
Iguanodontid
Iguanodont is an ornithischian, plant-eating, that lived during the late Jurassic to Cretaceous period. They had been primarily quadrupedal, but also capable of bipedal walking. Its thick and column-like hind legs and shorter and thinner front legs. The middle three fingers on each hand were jointed together by a pad of skin. The fifth finger could curl to grasp food and the thumb was long spike.
Sauropod
Sauropod was herbivorous (plant-eating), usually long-necked quadrupeds (four-legged), with spatulate (spatula-shaped: broad at the base, narrow at the neck) teeth. They had small heads, huge bodies, and tended to have long tails. Their legs were thick, ending in blunt feet with five toes, though only three bore claws. It was first appeared in the late TriassicPeriod. By the Late Jurassic (150 Ma), sauropods were widespread (especially the diplodocids and brachiosaurids). By the Late Cretaceous, those groups had mainly been replaced by the titanosaurs, which had a near-global distribution. Khorat sauropod, Early Cretaceous, had a tooth form, peg or pencil shape, like that of Phuwiangosaurus and possibly it was primitive to Nemegtosaurus, that once lived during Late Cretaceous in Mongolia. Pterosaur: it was first appeared in the Triassic Period, continued to evolve during the Jurassic, and declined during Late Cretacesous.
Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the legs to a dramatically lengthened fourth finger. Early species had long, fully-toothed jaws and long tails, while later forms had a highly reduced tail, and some lacked teeth. Many sported furry coats made up of hair-like filaments which covered their bodies and parts of their wings. Surprisingly, the teeth of pterosaur were also found during excavation in Khorat.
The age of Khorat dinosaurs
Fossils of the dinosaur from Suranaree and Khok Kruat subdistricts were found in calcareous conglomerate of Khok Kruat Formation which is the upper formation of the Khorat Group. It is Abtian and Albian epochs of late Early Cretaceous (ca. 100 million years ago)
Fossil value
Fossil is “the keys to the past”. The presence of dinosaur and other faunas such as fish, turtles, soft-shell turtles, crocodiles indicate that once the environment were freshwater river and swamp. The disassociation of bone elements indicate the transportation from the original dead site to deposit in the Suranaree and Khok Kruat sites.
Prof. Dong Zhiming and Dr. Yoichi Azuma were examining the Khorat dinosaur fossils. The fossils is important for the study of various sciences, geography, geology, paleontology, and paleobiology, etc. Therefore, the Khorat dinosaur would help to complete the dinosaur history, especially for the history of Asian dinosaur. It could be a learning center for not only researcher, but also students and the public nearby.
Dinosaur is essential to sciences. It would be eternal benefit both for academic and natural heritage. Thus, Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University (NRRU) aims to collect and conserve in the Dinosaur Museum, one of our three museums that you should not miss!
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