Original 1 Department of B iology, Faculty of ScienceMahasarakhamUniversity, Khamrieng, Kantharaw ichai, Mahasarakham , 44150, Thailand 2 S irindhornMuseum , Department of M ineral Resources, Kalasin, Thailand 3 Palaeontological Research and Education Centre, MahasarakhamUniversity, Khamrieng, Kantharaw ichai, Mahasarakham44150, Thailand * Correspondingauthor: sporangium28@gmail.com A new localityof well-preservedsilicifi edEarlyPerm ianbrachiopodsinLoei province, NE Thailand Sakchai Juanngam 1,2* , Mongkol Udchachon 1,3 Received: 30July 2013; Accepted: 15October 2013 Abstract Several localities of brachiopod faunas have been reported in the Loei area found mostly in late Palaeozoic shales andlimestones. S ilicifi edarticulatebrachiopodswereobservedinthePhaDam sectioneast of Loei, intheNam Suay sub-district, Na duang district. This section is part of the NamMahoran Formation according to the geological map publishedbyDMR. It consistsof brownshalesandsiltstonesinterbeddedw ithdarkgreylimestonesandthebrachio- podassemblageincludescf. Chonetinella, Rhipidomella, Phricodothyris, Marginifera, Reticulatia, STROPHOMENIDA fam . indet. , and SPIRIFERIDA fam . indet. . These specimens are relatively small in size, silicifi ed and mostly consist of single-valves. The occurrence and characteristics of the brachiopods in this section differ fromthose reported by previousworkersinthearea. Thislocalityalsocontainsseveral other abundant anddiverseinvertebrategroupssuchas bryozoans, crinoidsandsolitarycorals. Therocksfrom bothsectionsconsist of shaleandlimestone. Thebrachiopods, corals, bryozoans and crinoids are interpreted as having lived in shallowmarine or shelf environments. Prelim inary agedeterm inations arebasedmainly onbrachiopods andsuggest that therocks shouldbereassignedtotheLower Perm ianwhichis compatiblew iththeageassignedinthegeological mapof Thailand. Keywords: silicifi edbrachiopods, invertebratefossils, Loei province Introduction The Perm ian brachiopod faunas of Thailand are both diverse and abundant and are found both on the S ibu- masu and Indochina Terranes. Thai brachiopods are very important for tectonic, palaeoclimatic, stratigraphic and palaeoenvironmental studies 1 . Thai S ibumasu bra- chiopods have been reported in many monographs and papers 2,3,4 but the Indochina faunas of Thailand have only been documented in a fewrelatively brief studies. Yanagida, et al. in1974 5 , 1999 6 andPérez-Huerta, et al. in 2007 7 have described a total of 59 species from49 genera. Thailandbrachiopodshavebeendescribedfrom thefollow inglocalities. Thispaper containsprelim inarydescriptionsand age conclusions which w ill be refi ned in future studies. Specimenswerecollect bythewritersinthedryseasons of 2010 – 2012 in collaboration w ith the staff of the S irindhorn museumand Phuw iang D inosaur museum , Department of M ineralsResourcesandPalaeontological ResearchandEducationCentre, Mahasarakham Universi- ty. Thematerialswerecollectedinsituandanattempt was made to collect all visible specimens, they was cleaned inS irindhornmuseum ’slaboratoryby pneumaticair pen. The brachiopods at this site are not highly - abundant andwell preservedsilicifi edsample. Thebrachiopods at this site are particularly abundant not particularly well preserved.