Bulletin of the Geological Society of Malaysia, Volume 43, Dec. 1999, pp. 467 – 475
1Department ·of Earth and Planetary Sciences, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan
2Geological Survey Division, Department of Mineral Resources (DMR), Rama VI Rd., Bangkok 10400, Thailand
Abstract: The Carboniferous cephalopods are abundantly recognized at “Barite Mine”, northern part of Loei-city, northern Thailand. The fauna of “Barite Mine” consists of various taxa such as cephalopods, brachiopods, corals, bivalves and gastropods etc. More than three hundreds specimens of cephalopods consisting of ammonoids, nautiloids and orthoceratids are collected and are replaced by barite minerals. Five genera of ammonoids and five genera of nautiloids are identified at present. In addition to these, one new genus and two new species of ammonoid are included. The identified cephalopod species are as follows; Branneroceras branneri, Diaboloceras involutum, Syngastrioceras sp., Neogastrioceras sp., Bisatoceras sp., Catastroboceras subsulcatifomae, Epidomatoceras doohylense, Gzheloceras sp, Temnocheilus sp., and Epistroboceras sp. These cephalopod fauna indicates the age from Namurian to Moscovian of the Middle Carboniferous. This fauna is very important to construct the biostratigraphy based upon the Paleozoic ammonoid zones in Southeast Asia.