The first discovery of coelacanth fossils in Thailand
Coelacanths are a group of ancient fish that have lived since the Paleozoic Era, in the middle of the Devonian period, approximately 393-382 million years ago, and have survived to the present day. This group of fish is characterized by four large, fleshy tufted fins.Recently, there was a report of the discovery of a coelacanth fossil at Ban Kham Pok, Kham Cha-i District, Mukdahan Province, in the upper Phu Kradueng Formation, Early Cretaceous, it is a bone behind the lower jaw, sample code PRC 160. Researchers from the Paleontology Research and Education Center, together with a foreign research team, were able to identify that the fossil found is a coelacanth in the Mawsonid group. However, due to the limitation of only one bone found, more details cannot be specified. However, this is the first fossil evidence of coelacanth in Southeast Asia.Mawsonid coelacanths are freshwater fish that lived in the early Mesozoic Era, in the Triassic period, approximately 251-201 million years ago. Later, when it changed to the late Jurassic period, approximately 163-145 million years ago, it was found that this group of fish changed their habitat to the sea and changed their habitat back to freshwater when entering the Cretaceous period, approximately 145-66 million years ago.This Thai coelacanth once swam in the ancient river together with the Hybodont freshwater sharks, the Thaiichthys buddhabutrensis freshwater fish, the giant tortoise Basilochelys macrobios, and the Chalawan crocodile (Chalawan thailandicus). In addition, fossils of the carnivorous dinosaur group Metriacanthosaurid were also found. This discovery therefore adds to the biodiversity of vertebrate fossils in the Phu Kradueng area of Thailand and further increases the paleogeographic distribution of this ancient fish group