Original Anewlocalityof well-preservedsilicifiedEarlyPermianbrachiopodsinLoei province, NEThailand Sakchai Juanngam1,2*, Mongkol Udchachon1,3 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. SilicifiedarticulatebrachiopodswereobservedinthePhaDamsectioneast of Loei, intheNamSuay sub-district, Na duang district. This section is part of the NamMahoran Formation according to the geological map publishedby DMR. It consists of brownshales andsiltstones interbeddedwithdark grey limestones andthebrachiopodassemblageincludescf. Chonetinella, Rhipidomella, Phricodothyris, Marginifera, Reticulatia, STROPHOMENIDA fam. indet., and SPIRIFERIDAfam. indet.. These specimens are relatively small in size, silicified 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. Therocksfrombothsectionsconsist of shaleandlimestone. Thebrachiopods, corals, bryozoans and crinoids are interpreted as having lived in shallowmarine or shelf environments. Preliminary age determinations are based mainly on brachiopods and suggest that the rocks should be reassigned to the Lower Permianwhichis compatiblewiththeageassignedinthegeological mapof Thailand. Keywords: silicifiedbrachiopods, invertebratefossils, Loei province Thispaper containspreliminarydescriptionsand The Permian brachiopod faunas of Thailand are both age conclusions which will be refined in future studies. diverse and abundant and are found both on the Sibu- Specimenswerecollect bythewritersinthedryseasons masu and Indochina Terranes. Thai brachiopods are of 2010 – 2012 in collaboration with the staff of the very important for tectonic, palaeoclimatic, stratigraphic Sirindhorn museum and Phuwiang Dinosaur museum, and palaeoenvironmental studies1. Thai Sibumasu bra- Department of MineralsResourcesandPalaeontological chiopods have been reported in many monographs and ResearchandEducationCentre, MahasarakhamUniversipapers2,3,4 but the Indochina faunas of Thailand have ty. Thematerialswerecollectedinsituandanattempt was only been documented in a fewrelatively brief studies. made to collect all visible specimens, they was cleaned Yanagida, et al. in19745, 19996 andPérez-Huerta, et al. inSirindhornmuseum’slaboratoryby pneumaticair pen. in 20077 have described a total of 59 species from49 The brachiopods at this site are not highly - abundant genera. Thailandbrachiopodshavebeendescribedfrom andwell preservedsilicifiedsample. Thebrachiopods at this site are particularly abundant not particularly well thefollowinglocalities. preserved. Introduction 1 Department of Biology, Faculty of ScienceMahasarakhamUniversity, Khamrieng, Kantharawichai, Mahasarakham, 44150, Thailand SirindhornMuseum, Department of Mineral Resources, Kalasin, Thailand 3 Palaeontological Research and Education Centre, MahasarakhamUniversity, Khamrieng, Kantharawichai, Mahasarakham44150, Thailand * Correspondingauthor: sporangium28@gmail.com 2 404 Juanngamet al. Terminologyandclassification Theterminology usedherefollows Williams andRowell, 196510. Thesupraspecificclassificationsfor taxawithinthe order Strophomenida followCocks. and Jia-Yu, 200011. Thesupraspecific classifications for taxawithintheorder ProductidafollowBruntonet al., 200012. Thesupraspecific classificationsfor taxawithintheorder OrthidafollowWilliamsandHarper, 200013. Thesupraspecificclassifications for taxa within the order Spiriferida followCarter et al., 200614. Geological setting ThePhaDamsectionislocatedintheNa-Duangdistrict, Loei province. It is covered by marine sedimentary rock ranginguptotheUpper Permian8,9. It is assignedtothe NamMahoran Formation of the Saraburi Group, which consists predominantly of white to grey, thick-bedded limestoneof algal reef origin, brownishshale, calcareous shaleandinthelowest bedsisreddishbrownsandstone interbeddedwithchert. It outcropsinaNorth–Southbelt East of Muangdistrict Loei provinceextendingtotheEast andSoutheast of WangSaPhungdistrict Loei province. The Pha Damsection is a road-cut section between a small hill in the east of Loei by highway number 3117 (Figure 1), which contains folded brown siliceous shale intercalatedwithdark grey limestone. Systematicpalaeontology Repository Studied specimens are housed in the Sirin dhornMuseum,Department of Mineral Resources, Kalasin, Thailandwithspecimennumbers prefixedhereinSM. PhylumBRACHIOPODADuméril, 1805 SubphylumLINGULIFORMEAWilliamset al., 1996 ClassSTROPHOMENATAWilliamset al., 1996 1. STROPHOMENIDAfam. Indet. Order STROPHOMENIDAÖpik, 1934 Figure3A 1.1 Examinedspecimen Three poorly preserved external pedicle valves. Registeredspecimens SM2014-2-001to SM2014-2-003 J Sci Technol MSU 1.2 Diagnosis SeeCocks. andJia-Yu, 200011page216 1.3 Description Small-sizeshellsareabout 2cm. wide; subtrigonal shell outline; thegreatest widthis at mid-length; weaksulcus; thesurfaceornamentationwithstrongplicae and sparse short spines. Internal structure cannot be observed. 1.4 Measurement (mm.) Specimen Length Width Thickness SM2014-2-001 13.20 19.30 11.05 SM2014-2-002 13.15 18.30 7.45 SM2014-2-003 12.20 19.05 9.50 SubphylumRHYNCHONELLIFORMEAWilliams et al., 1996 2. Chonetinellasp. Order PRODUCTIDA Sarytcheva and Sokolskaya, 1959 Suborder CHONETIDINAMuir –Wood, 1955 Superfamily CHONETOIDEABronn, 1862 FamilyRUGOSOCHONETIDAEMuir –Wood, 1962 SubfamilyRUGOSOCHONETINAEMuir–Wood, 1962 Genus ChonetinellaRamsbottom, 1952 Chonetinellasp. Figure3B 2.1 Examinedspecimen Only one well preserved external pedicle valve. RegisteredspecimenSM2014-2-004. 2.2 Diagnosis See Grant, 19762 page 74 and Brunton et al., 200012page405 2.3 Description Small-size shell is about 2 cm. wide; subtrigonal shell outline; thegreatest widthis at mid-length; weaksulcus; thesurfaceornamentationwithstrongplicae and sparse of short spines. Internal structure cannot be observed. 2.4 Discussion Chonetinellaspisalwayscharacterizedbya distinct sulcus andthebilobatecharacter of lateral sides whichoriginatenear theumbo, remarkably ventral valve Vol 33. No4, July-August 2014 Anewlocality of well-preservedsilicifiedEarly Permianbrachiopods inLoei province, NEThailand convexwithdeepmediansulcus. Our Chonetinellasp. is quiteclosetoChonetinellasp., Yanagida15 (1975, p. 20, pl. 2, figs 8 – 9) fromHuai Luang, Loei – described as “sulcusdistinct, originatingnear beakasadistinct groove, surfaceornamentedbyfineradial capillae”; andit is also are similar to Chonetinella cymatilis, Grant2 (1976, p77, pl.16, figs. 1 – 58) fromKo Muk, Trang in general outline, sulcusandornamentation. Theyalsolooksimilar to Chonetinellaandamanensis, Waterhouse, et al.3 (1981, p. 65, pl. 2, figs. 18–19, pl. 3, figs. 1–18) fromKoYaoNoi, Krabi and Chonetinella cf. andamanensis,Waterhouse Thonnarat, et al.16 (2012, p. 41, pl. 4, figs. B – I) from BanAoNam, Krabi –bisectedbydeepsulcus, verynarrowfloor. 2.5 Measurement (mm.) Specimen Length Width Thickness SM2014-2-004 10.85 19.90 2.65 3. Marginiferasp. Order PRODUCTIDA Sarytcheva and Sokolskaya, 1959 Suborder PRODUCTIDINAWaagen, 1883 Superfamily PRODUCTOIDEAGray, 1840 FamilyPRODUCTELLIDAESchuchert, 1929 Subfamily MARGINIFERINAEStehli, 1954 Genus MarginiferaWaagen, 1884 Marginiferasp. Figure3C 3.1 Examinedspecimens Four well preserved external indeterminate valves and three external pedicle valves. Registered specimeninSM2014-2-005toSM2014-2-011 3.2 Diagnosis See Grant, 19762 page 106 and Thonnarat et al., 201216 page45 3.3 Description Small-size shells are about 2.5 cm. wide; Triangular droplikeshell outline; beakprominent anderect; theventral valveisnot clear sulcus; thegreatest widthis mid-length; shell ornamentedbystrongplicaeandsparse short strong spines, spines normally broken. Internal structurecannot beobserved. 405 3.4 Discussion Marginifera is characterized by its shell outline, costation, andspines. Our specimensaresimilar to MarginiferaarenariaGrant2 (1976, p109, pl.24, figs. 1–34) fromKoMuk, Trangfromtheir spinesand general outline and but it is quite different in ornamentation. While M. drastica Grant2 (1976, p110, pl.26, figs. 1 – 23) fromKo Muk, TrangandMarginiferacf. drasticaThonnarat, et al.16 (2012, p. 45, pl. 7, figs. A–F) fromBanAoNam, Krabi, M. nesiotes Grant2 (1976, p112, pl.27, figs. 1 – 34), M. otaria Grant2 (1976, p115, pl.25, figs. 1 – 24) fromKo Muk, Trang and Marginifera drastica Yanagida6 (1999, p.129, pl.29, figs 2, 3, 5 – 9) fromKhao Hin Kling area near Petchaboon are different in having weak costae. The Huay NamSuay specimens are closely similar to M. banphotensisusingitsexternal characters, Yanagida5 (1964, p.11, pl.3, figs2- 3) fromnear TambonBanPhot of Petchaboonprovince(Indochinaterrane). 3.5 Measurement (mm.) Specimen Length Width Thickness SM2014-2-005 20.10 22.25 1.70 SM2014-2-006 23.15 25.45 14.20 SM2014-2-007 19.20 21.55 11.10 SM2014-2-008 17.45 25.35 8.10 SM2014-2-009 14.90 24.10 6.25 SM2014-2-010 16.20 28.10 SM2014-2-011 12.45 16.40 4. Reticulatiasp.A Order PRODUCTIDA Sarytcheva and Sokolskaya, 1959 Suborder PRODUCTIDINAWaagen, 1883 Superfamily PRODUCTOIDEAGray, 1840 Family PRODUCTIDAEGray, 1840 SubfamilyDICTYOCLOSTINAEStehli, 1954 Genus Reticulatia Muir-Wood and Cooper, 1960 Reticulatiasp.A Figure3D 406 Juanngamet al. 4.1 Examinedspecimens One external both of pedicle and brachial valvesandtenexternal pediclevalves. Registeredspecimens SM2014-2-012toSM2014-2-023 4.2 Diagnosis SeeBruntonet al., 200012 page496 4.3 Description Small to medium - size shells are about 1.4 – 3.5 cm.; transversely subquadrate with hinge line makinggreatest width; sub-trigonal shell outline; Pedicle valvehavestronglyconvexwithslightlybeak; beakprominent rather straight; cardinal extremities quite round to trianglular; thecostae, about 10–12costaein1cm., on surface; strongrugaefoundrarelyonfront tomid-length. Internal structurecannot beobserved. 4.4 Measurement (mm.) Specimen Length Width Thickness SM2014-2-012 17.55 20.05 9.10 SM2014-2-013 8.75 9.70 SM2014-2-014 11.30 11.20 SM2014-2-015 20.05 29.65 15.70 SM2014-2-016 27.70 19.70 SM2014-2-017 16.55 23.20 SM2014-2-018 16.75 21.40 10.80 SM2014-2-019 8.10 11.40 5.60 SM2014-2-020 13.35 22.20 11.35 SM2014-2-021 15.45 23.30 6.45 SM2014-2-022 15.40 20.90 5. Reticulatiasp.B Figure3E 5.1 Examinedspecimens Twoexternal bothof pedicleandbrachial valves andthirty-threeexternal pediclevalves. Registeredspecimens SM2014-2-024toSM2014-2-059 5.2 Diagnosis SeeBruntonet al., 200012 page496 5.3 Description Small-size shells are about 1.4 – 3.5 cm.; transverselysubquadratewithhingelinemakinggreatest J Sci Technol MSU width; sub-trigonal shell outline; Pediclevalveisstrongly convexwithaslight beak; beakprominent rather straight; cardinal extremitiesquiteroundtotriangular; thecostae, about 10 – 12 costae in 1 cm. on surface; strong rugae foundrarelyonfront tomid-length; sulcusandcostaeare weaklydevelopedtoveryclear. Internal structurecannot beobserved. 5.4 Discussion Our Reticulatia sp is always characterized by a distinct sulcus and bilobate character of lateral side which originates near umbo, and a remarkable ventral valve convex with deep median sulcus. The R. sp. Aspecimens aredifferencefromR. sp.Bby welldeveloped to clear sulcus and costae which in R. sp.A cannot be observed. These specimens are similar to Reticulatiaaff. R. huecoensis, Yanagida15 (1975, p. 26, pl. II, figs 16–19; pl. III, Figs. 1- 2) fromHuai Luang, Loei andReticulatiauralica, Yanagida17 (1966, p. 54, pl. XVI, figs 7 - 8; pl. XVII, Figs. 1 - 4) and Reticulatia moelleri, Yanagida17 (1966, p. 56, pl. XXIII, figs 2 - 7) fromNorth – Central Thailand (all Indochina Terrane) in general outline, sizeandornamentation. 5.5 Measurement (mm.) Specimen Length Width Thickness SM2014-2-024 15.80 22.75 12.30 SM2014-2-025 14.35 22.00 9.95 SM2014-2-026 12.70 20.70 9.40 SM2014-2-027 14.50 18.60 7.75 SM2014-2-028 11.60 14.10 6.35 SM2014-2-029 8.55 11.45 SM2014-2-030 14.80 14.35 8.55 SM2014-2-031 11.35 15.75 9.65 SM2014-2-032 12.20 19.40 SM2014-2-033 20.70 26.00 14.60 SM2014-2-034 15.10 19.25 SM2014-2-035 19.80 22.35 11.90 SM2014-2-036 11.35 15.45 SM2014-2-037 8.70 21.40 SM2014-2-038 19.35 SM2014-2-039 45.50 32.65 Vol 33. No4, July-August 2014 Anewlocality of well-preservedsilicifiedEarly Permianbrachiopods inLoei province, NEThailand 5.5 Measurement (mm.) cont. Specimen Length Width SM2014-2-040 8.90 11.30 SM2014-2-041 14.40 19.70 SM2014-2-042 13.00 20.80 SM2014-2-043 12.45 19.95 SM2014-2-044 16.75 21.1 SM2014-2-045 16.00 21.30 SM2014-2-046 12.40 16.10 SM2014-2-047 14.05 15.45 SM2014-2-048 10.10 20.70 SM2014-2-049 20.20 21.00 SM2014-2-050 9.00 13.50 SM2014-2-051 18.45 20.05 SM2014-2-052 16.10 22.70 SM2014-2-053 16.10 22.70 SM2014-2-054 16.30 19.40 SM2014-2-055 12.35 17.95 SM2014-2-056 16.90 19.25 SM2014-2-057 11.25 19.00 SM2014-2-058 19.50 SM2014-2-059 54.90 54.55 Thickness 4.30 6.95 9.05 9.65 14.65 11.65 10.9 10.10 6.50 18.40 13.20 16.25 16.25 7.40 14.90 32.10 6. Rhipidomellasp. Order ORTHIDASchuchert andCooper, 1932 Suborder DALMANELLIDINAMoore, 1952 SuperfamilyDALMANELLOIDEASchuchert, 1913 FamilyRHIPIDOMELLIDAESchuchert, 1913 SubfamilyRHIPIDOMELLINAESchuchert, 1913 Genus RhipidomellaOehlert, 1890 Rhipidomellasp. Figure3F 6.1 Examinedspecimen One incomplete external pedicle valves. RegisteredspecimenSM2014-2-059. 6.2 Diagnosis SeeinGrant, 19762 page37 407 6.3 Description Small-size shells are about 0.5 cm. wide; weakly convex, more convex transversely than longitudinally with largest convexity at mid-length; shell outline elongate sub-round trigonal; hinge line is short; surface ornamented by costellae. Internal structure cannot be observed. 6.4 Discussion ThisspecimenresemblesRhipidomellacf. R. pecosi, Yanagida15 (1975, p. 18, pl. II, figs 5) fromHuai Luang, Loei, Rhipidomella cordialis, Grant2 (1976, p37, pl.2, figs. 31–41; pl.3, figs. 1–53) fromKoMuk, Trang, Rhipidomella cf cordialis, Thonnarat, et al.16 (2012, p. 35, pl. 2, figs. A- F) fromBanAoNam, Krabi ingeneral outline but differs in the sulcus and shell surface of the ventral and dorsal valves. In the Huai Luang specimens the shell surface is finely costellate with a clear sulcus whereas the Ko Muk specimens the shell surface is minutelyroughenedbyacombinationof finegrowthlines and; and in the Ao Namspecimens the shell surface is minutelysmoothwhileour specimenhascoarsecostellae andnosulcus. 6.5 Measurement (mm.) Specimen Length Width Thickness SM2014-2-059 4.25 4.30 7. SPIRIFERIDAfam. Indet. Order SPIRIFERIDAWaagen, 1883 Figure3G 7.1 Examinedspecimen Not well preserved three external pedicle valves. Registered specimens in SM2014-2-060 to SM2014-2-062. 7.2 Diagnosis SeeinCarter et al., 200614page1689 7.3 Description Small-sizeshellsareabout 2cm. wide; oval shell outline with exceeds length; cardinal extremities quitesub-round; sulcusisslightlytonot deep; shell ornament is not clear. Internal structurecannot beobserved. 408 Juanngamet al. 7.4 Measurement (mm.) Specimen Length Width Thickness SM2014-2-060 6.70 14.10 SM2014-2-061 8.65 15.70 6.25 SM2014-2-062 11.10 18.15 8.20 8. Phricodothyrissp. Order SPIRIFERIDAWaagen, 1883 Suborder SPIRIFERIDINAWaagen, 1883 SuperfamilyRETICULARIIDAEWaagen, 13 Family ELYTHIDAEFredericks, 1924 SubfamilyPHRICODOTHYRIDINAECaster, 1939 Genus Phricodothyris George, 1932 Phricodothyris sp. Figure3H 8.1 Examinedspecimen Quitenot well preservedthreevalves; oneof external pediclevalve, oneof brachial valve; andoneof bothof pedicleandbrachial valve. Registeredspecimens SM2014-2-063toSM2014-2-065. 8.2 Diagnosis SeeCarter et al., 200614 page1866 8.3 Description Small to mediumsize shells are about 1 – 4.5cm. wide; sub-roundtrigonal shell outline; wider than high; cardinal extremities round and hinge line shorter than greatest width; beak prominent and strongly incurved; interareanot clear; sulcusabsent except 1sample shownarrowsulcus; maximumwidthclosetomidlength; shell ornamented by rugae; faint growth lines. Internal structurecannot beobserved. 8.4 Discussion The Phricodothyris is always characterized by shell outline and by the remarkable character of the ornamentation. These specimens are similar to Phricodothyris echinata, Yanagida15 (1975, p. 20, pl. 2, figs 8 – 9) fromHuai Luang, Loei, Upper Carboniferous and Phricodothyrissp., Waterhouse, et al.,3 (1981, p. 65, pl. 2, figs. 18–19, pl. 3, figs. 1–18) fromKoYaoNoi, Krabi, Lower Permian but our specimen have stronger growth lines anddiffer frommodeof costae. J Sci Technol MSU 8.5 Measurement (mm.) Specimen Length Width SM2014-2-063 8.80 8.00 SM2014-2-064 31.30 36.45 SM2014-2-065 8.35 17.05 Thickness 8.45 1.45 Discussion The main groups of silicified brachiopods obtained fromshaleinthePhaDamsectionincludecf. Reticulatia, Marginifera, Phricodothyris, STROPHOMENIDA fam. indet., SPIRIFERIDA fam. indet., Chonetinella and Rhipidomela and are illustrated respectively by number, in figure 2. Most of these specimens are small in size and with nearly complete valves. The faunais dominated by Reticulatia which constitute 76%of the total. This we can designate a Reticulatia assemblage Marginifera indicates an Early Permian age which supports the previous work of DMR8. The Reticulatia assemblage sediments, are interpreted as having been deposited in shallow marine conditions, Brachiopods assemblage are generally sessile low-level epifaunal suspension feeders. A low energy environment is indicated. More taxonomic and biostratigraphic work is necessary in order to fully appreciate the palaeogeographic, biogeographic and tectonic significance of this newly discoveredfauna. Acknowledgments It is my pleasure to thank Dr. Suree Teerarungsigul (former director of Sirindhorn Museum) for her support and encouragement, Miss Wilailuck Naksri, Miss Kamonlak Wong-Ko and Dr. Clive Burrett are thanked for their helpinbringingthis paper tocompletionandfor their advice. Grateful appreciation is due to the staff of Sirindhorn Museum(Department of Mineral Resources) and Palaeontological Research and Education Centre (MahasarakhamUniversity) for their encouragement. Vol 33. No4, July-August 2014 Anewlocality of well-preservedsilicifiedEarly Permianbrachiopods inLoei province, NEThailand 409 11. Cocks, LRM, Jia-Yu, Rong. StrophomenidainTreatiseonInvertebratePaleontologyPart HBrachiopoda 1. Shi, GR, Archbold, NW. Permianbrachiopodfaunal RevisedVolume2, 1st ed., USA.: TheUniversityof sequenceof theShan-Thai terrane: biostratigraphy, Kansas Press 2000; 216- 349. palaeobiogeographical affinities and plate tectonic/ palaeoclimatic implications. Journal o/Southeast 12. Brunton, CHCet al. Productida in Treatise on InvertebratePaleontologyPart HBrachiopodaRevised AsianEarthSciences 1995; 11(3): 177- 187. Volume2- 3, 1st ed., USA.: TheUniversityof Kan2. Grant, RE. Permian Brachiopods from southern sas Pres 2000; 350- 642. Thailand, Journal of Paleontology, V. 50(supplement to no.3), Paleontological Society Memoir 9, 1976; 13. Williams, A, Harper, D.A.T. Orthida in Treatise on Invertebrate Paleontology Part H Brachiopoda Re269p., 71pl. vised Volume 3, 1st ed., USA.: The University of 3. Waterhouse, JB, Pitakpaivan, K, Mantajit, N. The Kansas Press 2000; 714- 846. Permian stratigraphy and paleontology of southern Thailand. Thailand Geological Survey Memoir 4, 14. Carter, JLet al. SpiriferidainTreatiseonInvertebrate Paleontology Part H Brachiopoda Revised Volume 1981; 1–213. 5, 1st ed., USA.: The University of Kansas Press 4. Shi, GR, Archbold, NW. Permian marine biogeo 2006; 1689- 1876. graphy of SEAsia Biogeograhy and Geographical 15. Yanagida, J. Upper CarboniferousBrachiopodsfrom Evolutionof SEAsia1998; 57–72. WangSapung, NorthThailand. Contributions toKo5. Yanagida, J. Permian brachiopods from central bayashi, Teiichi. andToriyama, RyuzoGeology and Thailand, Geology andPalaeontology of Southeast Palaeontologyof Southeast AsiaVolume16, Tokyo: Asia., V.1, 1964; 143–165. University of TokyoPress 1975; 1–31. 6. Yanagida, J, Nakornsri, N. Permian brachiopods fromtheKhaoHinKlingAreanear Petchabun, North- 16. Thonnarat, D, et al., Brachiopodsiteof theAoNam Area, LaemSak Subdistrict, Ao Luek District, Krabi central Thailand, Bulletinof theKitakyushuMuseum Province, SouthernThailand. Technical Report No. of Natural History., V.20, 1999; 105 – 136, pls. BFP.3/2012., Bangkok: Bureauof Fossil Protection, 26–32. Department of Mineral Resources 2012; 96 p., 23 7. Pérez-Huerta, A., et al., PermianBrachiopods from pl. newlocalities innortheast Thailand: Implications for paleobiogeographicanalysis. Journal of AsianEarth 17. Yanagida, J. EarlyPermianbrachiopodsfromnorthcentral Thailand. Geology and Palaeontology of Sciences 30., 2007; 504–517. Southeast Asia3, 1966; 46–97. 8. Department of Mineral Resources. Theclassification of Mineral andGeologyResourcesfor Management, Loei. Province, Thailand. Bangkok. 2008; 107p. 9. Chairangsee, C., et al., Geology of the Ban Sup Quadrangle, Geological Survey Report No.0071., Department of Mineral Resources 1987; 35p. 10. Williams, A, Rowell, AJ. Morphological termsapplied to brachiopods in Treatise on Invertebrate Paleonto logy Part HBrachiopoda Volume 1, 1st ed., USA.: TheUniversityof KansasPress1965; H139- H154. References 410 Juanngamet al. J Sci Technol MSU Pha Dam Section Figure1Mapof site(PhaDamSection) fromwherethefossils werecollected. Figure2Distributionpatternof brachiopods diversity fromthePhaDamSection. Vol 33. No4, July-August 2014 Anewlocality of well-preservedsilicifiedEarly Permianbrachiopods inLoei province, NEThailand A B C D E F G 411 H Figure3 A: ventral viewof STROPHOMENIDAfam. Indet., B: ventral viewof cf. Chonetinellasp., C: ventral view of cf. Marginifera sp., D: ventral viewof cf. Reticulatia sp.A, E: anterior viewof cf. Reticulatia sp.B, F: ventral viewof cf. Rhipidomella sp., G: ventral viewof SPIRIFERIDAfam. Indet., H: ventral viewof cf. Phricodothyris sp. , scalebar equal 1cm.