NNaatitoinaolnScaieln ceSMcusieuemnce Museum N.llv'NFrv l(j4s4u ),2,0061P3E28N Mern.Natn,Sci,Mus,,Ibkyo,(44M)a,rch 28,2006 Bulacanites Gen. Nov, Large LucinidBivalve obtusiplicatus et a (Molluscfrao)mthePlioceneSpC,entralLuzon, Philippines of [Ibmoki Kasei and Yblanda Maac Aguilaff i Department ofGeologyl National Science Museum, 1[bkyo ,3-23-1 Hyakunin-cho, Shiajuku-kuI,bkyo,169-O073Japan E-mail:[email protected] 2Petrolal], Mines and Geoscience Bsureau ,North Aye. ,Diliman ,Quezo CnitM ?hilippines E-inail :[email protected] 'of Abstract . Bulacanite osbtttsiplicatus is describe das a new genus and species the bivalv efam- ily Lucinida eba,sed on the valves collected fror nthe upper Lower Pliocen eTartar oFormation in Bulacan province e,entral Luzon, Philippine Tsh.is new genus has very larg eshells and edentulous hinge plates a,nd is close to Anodontia and Mbganodontia, but diffb risn having very thick shells, anteriorly more incline udmbones, and unique radially divergen rtibs in the shell surface. The sedi- mentary facie sand associated fossi lrseveal that B. obrnsiplicatus sp, nov live din shallow marine, intertid taol subtidal envirerrrnents, Key werds: Bulacanit eosbtusipiicatus, new genus, new species, Lucinidae, Philippin ePsl,iocene, [[lartaFroormation. unpublished report by Melendres and Versoza Introduction (1960 a)l,ong the Madlum River in the vicinity of In an effbrt to strengthen paleontoleg irce- barrio sTartaro and Sibul ,about 10km ENE of search in the Mines and Geoscience sBureau, San Miguel municipality In the typ elocali ttyhle Philippin e(sMGB) ,the Nationa lScienc eMuse- fbrmatio nunconfbrmably overlies marine sedi- um (NSM) ,Tokyo, Japan , and the MGB ments of the Miocene Madlum Formatio nin the Iaunched in 2003 ajoint research program on east, and to it swest it is unconfbrTnably overlain fbssi lcollection bui]din gand natural history by the non-marine Pleistoce nAelat Conglomer- studies in the Philippine sTh.e program aims to ate Member of the Guadalupe Formation (Gon- establish staiidard fossi rleference material in the zales et al., 1971) .Based on it ssedimentary fea- Philippine sg,eared tewards understanding the tures and fbssi lcontent, the Tartar oFormation origin of high biodiversi tiyn the tropica lIndo- represents an interti daandl subtidal, shallow ma- Western Pacifi cS,ince then, the authors have rine setting. It is slightly over 200m thick .The been undertaking fossi lcollection surveys in fbrmatio nconslsts of very gentl ydippin gbeds of Luzon, Cebu, Mindanao, Leyte, and Panay is- clayey sandstone and sandy siltstone that are lands ,and explored a number of younger Ceno- strongly bioturbate odr in place sthinly bedded, zoic fbssi llocalit iyeest unstudied previously It is highly fossilifer othursoughout the succes- One of the targete dareas in this projec tis Bu- sion and contains abundant mollusks and corals, lacan provinc ein central Luzon, where the Benthic fbraminifer sare also abundant in the younger Cenozoic [fartar oFormation crops out matrix, and patchy coral mounds are also present along the east-central 1imb of the Luzon Central mostly in the middle section of the Madlurn Vhlley Basin ,about 100 km north of Manila River succession. Specimens collected from the (Fi g1,) .The best exposures ofthe fartar ocan be Madlum River are not only abundant but also observed at the type sectien, designated in an highly diverse and exquisitely preserve d.Many NII-Electronic Library Service NNaatitoinaolnScaieln ceSMcusieuemnce Museum 176 Tomoki Kase and "folanda M. Aguilar luscan fbssil sH.owever, these age determinations becausebenthicfbraminifers are not reliable and fossi mlollusks are not good age indicato rVsi,l- lanuev aet al. (1995 f)bund namiofossils indica- tive of lat eMiocene to early Pliocen efrom the middle part of the formatio nalong the Madlum River, Recent preliminary nannofbssil analyses by Kameo (per sco.mm., 2005) showed tha tthe Thrtar oFormation along the Madlum River is within the lat eEarly Pliocene, which is defined by the las toccurrences ofE)?henolithus abies and ReticulojZinestprsaeudoumbilica3,.6to 3.75Ma (Sait1o9,99). Kanno et aL (1982 r)eported 55 species of mollusks from the Tartaro Formation. In the cur- rent projec tw,e have been collecting fossi lmol- lusks extensively throughout the fbrrnati oatn the type locali tanyd in other newly discovere adreas. As a result, more divers efbssi lmollusks have been recognized, which tota lup to 200 species. We her einitia rlelpoyrt a remarkably 1arg enew lucini sdpecies from the Tartar oFormation. Fig, 1. Map showing the collecting localit ioefs Bulacanites obtusiplicatus sp. nov in Bulaean Fossi lLocalities province, central Luzon ofthe Philippines. The specimens of the new lucini dspecies de- inthis fromlocality scribed paper were collected still retain thei rpristin eoriginal eolor matkings. AGT. 2 (14057.11 41'2N1e,02.999'E )a, riverbed Because of the almost fla tgeomorphology ofBu- of the Bayabas River in baranga yBanaban, lacan province e,xposures of the [lartar oForma- Angat municipalityL Bulacan provinc e(Fi g1,). tion are limite adnd widely separated. The forma- An additional fragmentar yspecimen was also tion also exposes jn the south of the type area collected at TTR20, a rivert}ed of the Madlum along the Magasawang Mangga Creek, a tribu- River in barri oTartaro of the same province T,he tary of the Salapunga nRiver about 10km SSE beds exposed at locali tAyGT. 2 belong to the of San Ildefonso municipality, and along the lower part of [fartar oFormation, about 15m Bayabas River, about fbur km NE of Angat mu- thick, very gentl ydipping, highly fbssiliferous, nicipality. Here too, abundant and divers emol- and consists mainly of strongly bioturbate dfid- lusca nfbssi losccasionally admixed with coral able, fine-graine dsand and silty sandstone. The fragment shave also been found. specimens were obtained from two beds in the The detaile gdeologic age of the Tartar oFor- middle and upper part sof the succession. The mation has not been well understood. Gonza!es lower bed consists of ill-sort efdine-grained et aL (1971 d)ated it as Pliocen eto Pleistocenesandstone, is not highly fossiliferou san,d bears based on the benthi csmaller foraminife rsI.n many small calcareous concretions. IIWo speci- contrast, Kanno et al. (1982 d)ated a fbssil-bear-mens collected from this bed are articulated ing horizo nofthe middle part of the formatio nin and likel yto be autochthonous in origin. Other the type area as lat eMiocene on the basi sofmol- common mollusks identifi iend thi sbed are large NII-Electronic Library Service NNaatitoinaolnScaieln ceSMcusieuemnce Museum A new Pliocen leucini gdenus and species from Philippines 177 gastropod ssuch as A(felongen agigas (Martin,plicatus sp. nov can be classified under the sub- 1883) and SZrombus maximus Martin, 1882, and famil yMilthinae Chavan, 1959. Among modern many articulated valves ofPtaeuna (llphmpium)lucinid st,he newly introdnce dgenus matches (Retziu1s7,8g) identifiebdy AnodbntiaLink,1807 Megunodon- guadriangularis well with and Kanno et ai. (1982 )[[.Wo disarticula tvaeldves tia Bouchet and von Cosel ,2004 in terms of the are from a highl yfbssilifer ofuisne-grain esadnd- shell size and the edentulous nature ofthe hinge stone bed jus atbove an autochthonous finger- plate ,However, species categorized under tliese coral bea and associated with diver smeollusks two genera are characterized by having much such as Cerithiu mj'onker iMartin ,1884, C. be- thinne rshells, a circular shell outline, without benkiria.n uMma,rtin ,1884, Strombus varinginen- any distin icntterrupti ionn the ventral shell mar- sis Martin ,1899, Pbtema ]'unghuhni (Martin,gin due to the absence of radial sulci that define 1895) ,Pblema sp., several species of Conus, the escutcheon and lunule M,oreover ,Anodontia Circe sp., and Dosinia (Bonartem istsab)itis and Meganodontia have a narrower hinge plate Iredal e1,929. Another common species in this and a shorter but wider anterior adductor scar bed is Smaragdia pauluccian aGasseies ,1870, than in Bulacanites. an interti dtaol subtidal species known in sea- Among known fbssi llucinid so,nly Lucina grass beds in the modern tropica lPacifi eB.ased magameris Dall ,1901 from the upper Eocene of on the assQciated mollusk species and corals, Bu- Jamaica was describe das having an edentulous lacanite sobtusiplicatus sp. noy thrive din an in- hinge and the maximum shell lengt habout twice tertidal to subtidal shallow marine environment. greater than our [farta rspoecimens. Comparison of Dall' s(1901 asp)ec'imens with the 1fartaro Systematics specimens is diMcult because they are represent- Fami]y Lucinidae Fleming ed by intern amlolds that only show the presiennnceer SubfamilyMilthinaeChavan ofalong anterior adductor scar and smooth Genus Bul acanite gs en. nov vmeanrtkraablly sh el1la rmagr egi(n.al mCoo xts h(tre1e 9t4im1 eds)e sgcrreiabte e dart hraen- [fype species. Bulacanites obtusiplicatus sp, the holotyp eof B, obtusiplicatus sp. nov,) and nav well preserve dspecimen of L, magameris also Diagnosis .Shel lvery large v,ery thick, mod- from the Eocene of Jamaica in the collections erately inflate qequivalve, quite inequilateraolf, the Natural History Museum, London. This and subcircular in outline. Umbones small, situ- specimen clearly shows a resemblance to B, ated well in fron tof vertical midline, markedly obtusiplicatus sp, nov, based on the presenc eof hooked forwarq not protruded beyond ventral escutcheon that is depresse dfrom the main sur- margin of shell. Shallow but sharp posterior face .Although information regardmg the shell sulcus presen ton both valves, forrnin gshallow thickness and detai losf hinge and ligamen tareas notch adjunct to ventral margin. Lunule absent, are still poorly known, it can be presumed that L, but depresse dand extended anterior area fbrming ntegameris is closely related to Buftzcanit eDsal.l pseudolunul eS.culptur eof commarginal rugae, (190l bpl)aced L. megameris under the subgenus with thick divergin gradial ribs .Hinge edentu- Ryeudomiltha ,subsequently fbllowe dby Cox lous ,archect with moderately wide and fia ptlate. (194 1)and Wbodring (1982 )w,hile Bretsky Ligament area long ,arched and deeply inse tinto (197 62:90) suggested that it be referred to the valve, Anterior adductor muscle long ,slender, subgenus EDmiltha .These assignments are, how- and eurved almost in accordance with pallial ever, untenable because the hinge is edentulous line I.nner valve margin smooth. in L. megameris. Discussion .Based on the thick shell and the Genus OMptolucina Saul 'et al,, 1996 is also a long anterior adductor scar, Bulaeanites obtusi- larg eand edentulous lucini dthat originally in- NNIII-IE-leEcltreoncitcronic Library Service NNaatitoinaolnScaieln ceScience MMuusesuemum 178 Ibmoki Kase and Y)landa M. Aguilar Cr)Lptolucina Saul cluded megadyseides et aL, Bulacanites obtusiplicatus sp. noM 1996 and C. elassoclyseidles Saul et aL, 1996 (Fig2s-3) from the Eocene cold-seep assemblages of west- ern Washington, USA, Cmptolucina megadysei- T>rpe material. Holotype :reg. no. MGB des attains a shell length of about 180 mm, so fat MFOOO2, complete lef tvalve, lengt h105.3 mm, the second larges tlucinid ever known. This heigh t106.9mm, thickness 31.5 mm, housed in is by theMines GeosciencesBureau(MGB),Que- species represented peorly preserved and and distort esdhells, but ,like B. obtusiplicatus sp. zon Cityl Philippines ,collected from N]G. 2, nov, the shells are thicke r(bu tthinner tha nthose riverbed of Bayal)as River in barangay Banaban, ofB. obtusiplicatus sp. noy), and have a deeply Angat municipalityi 14057.114'N, 121e02.999'E. grooved ligamen tarea that is covered by the ex- TXvo paratype sin the National Science Museum, tended shell of the postero-dorsa lmargin. How- [[bkyo :reg, no, NSM PM14862, fragmentary ever, this species seerns to haye a shell fbrm conioined valves, length 120.5mrn, thicknes isn quit ediffere nftrom B. obtusiplicatus sp. nov, in coajoined valves 57.2mm; reg. no. NSM that the shells are wide, the umbones are more PM14861, complete lef tvalve, lengt h95.8mm, protmded from the dorsa lmargin and not so heigh t98.8mm, thickness in single valve 30.5 strongly prosogyrate ,and the well define des- mm. One paratype: reg. no. MGB MFOO03, ftag- cutcheon and pseudolunule are absent. Cp:Jtptolu-mentary coajoined valves, heigh t98.0 mm, thick- cina elassodyseides is smaller and longer than a ness in both valves 53.5 mm, in the collection of thePresence MGB, fromthetypelocality, magaclyseides and shows ofan elon- all gate anterior addnctor scar ef lucini tdype w,hich Diagnosis .Sameasgenus. otherwise does not extend so long toward the Description Shel lvery larg efbr familM up yertical midline lik eB. obtusiplicatus sp. novL to 120,5 mm long ,slightly higher than wide, very Saxolucina (Mbgaxim usma)tsushitai Mat- thick and solia subcircular in outline, inequilat- sumoto, 1971 from the lower Miocene forearc eral and equivalve, moderately inflate dwith basin deposit osfcentral Japan is also a 1arg eand thicknessAength ratio of ahout O,3 .Umbones edentulous lucini tdhat can be referred to Cizp- small, locate dwell anterior of vertical midline, toiucina. The larges tspecimen (Matsumotoma,rkedly hooked anteriorlM enly slightly pro- 1971, pl .2, fig 1,) has an equivalent shell size to truding beyond dorsa lmatgin, Shel lexterior sur- C megadyseides, and this species is a constituent face with dense, irregularl sypaced, rugose cQm- of a chemosynthetic cold-seep community (Maji-marginal growth 1ines ,and with thick, round- ma et at,, 2005), The type series ofS (IL tmaCt-) toppect somewhat irregularl ydivergin gradial sushitai appears to be an admixture of at least ribs of variable prominence ,numbering les sthan two species, which will necessitate futur etaxo- 20 at ventral margin. Ventral to antero-ventral nomic revision based on additional material. The margin broadl yrounded; anterior margin slightly holotyp e(Matsumo t1o97,1, pl .1, fig .1) shows rostrate and set offby weakly curved radial ridge, an almost complete subquadraiigular shell out- demarcate dby pseudolunule, Posteri ormargin lin echai:acteristic of Cr zptolucina ,which is defi- with relatively larg eand depresse descutcheon differenftromB, from discby distinct nitely obtusiplicatus sp. noy separated main posterior EtymologyL The new genus is named after sulcus, juncti woitnh ventral margin forming a Bulacan ,the name of province where the bi- notch of varial)le prominence .Greates tdorso- valve-bearing formatio nis distribut edg;ender ventral gxtens idoentermine dby rounded pos- mascu]ine. tumbonal dorsa lmargin, Hinge plate wide fbr lucinid sed,entulous; an- terior part broade rthan posterio arl,most fla ta,nd constrictedjust anterior of umbones due to inser- NII-Electronic Library Service NNaatitoinaolnScaieln ceSMcusieuemnce Museum A new Pliocene 1ucini gdenus and speeies fromPhilippines 179 Fig.2 . Holetyp eof Bulacanit eosbtusiplieatzLs sp. noy, MGB MFOO02, from a riverbed of Bayabas nver,same barangay Banaban, Angat municipality in Bulacan province. A, ExteTior of lef tvalve; B, interi oofr the valve. Scale bar :20 mm. NII-Electronic Library Service NNaatitoinaolnScaieln ceSMcusieuemnce Museum 180 Tbmoki Kase and Yblanda M. Aguilar Fig. 3. Paratypes ofBulacanites obtusiplicatus sp. nev from the same locali tofythe holotyp eA, & B, Exterior and interi oofrleft va]ve, respectively, NSM PM14861; C, anterior view ofcoajoined yalves, NSM PM14862, Scal ebar :20 mrn. NII-Electronic Library Service NNaatitoinaolnScaieln ceScience MMuusesuemum A new Plioeen leucini gdenus and species from Philippines 181 tion of sinus; posterior part arched and variably specimen from Solo because their depositories Ligamental long However, concave medially area and are unlenown. an almost complete artic- arched sunken steeply and deepl yint oshell, with ulated specimen (RGM6996 )from the Junghuhn's deep slit on it sdorsa lside; ligameta larea com- locali tOy housed in the Nationa lMuseum of pletel ycovered by extension of postero-dorsalNatural History Naturali sL,eiden, and two other margin of escutcheon when both valves con- vety larg especimens (th meaximum shell diame- joined, ter is 213mm) from the middle Miecene of lmer ventral shell margin almost smoeth and Nyalindung ,west Java, illustra taendd identified varial]ly uneven, but occasionally with irregularb,y Dharma (200 5p,. 282) as Anodonn'a sp., crest-topped radial crenulations. Inner shell sur- seemingly match the descriptio ngsiven to L. face uneven, with manM -random]y distributedmaxima. If this identificat iiso cnorrect, L. mcLxi- pit sof unknown functio nA,nterio radductor scar ma can be referable to Anodontia ,which evident- very long ,slender, pointed at dista elnct and ex- ly diffe rfsrom B. obtusiplicatus sp. nov tending close to vertical midline, with weak, ir- When compared with L, megameris, B. obtusi- regular radial striae. Posteri oarddn ¢tor scar an- piicatus sp. noy is smaller and more infiate aqnd gularl yelliptical. Palli allin ebroad and radially has many obsolete radial ribbing son the shell striated. surface, in contrast to the smooth surface of the Etymology The species narne refers to the Jamaican species. obtuse ribbin gon the shell surface. Lucinid bivalve hsave attracted much attention Remarks. Bulacanites obtusiplicatus sp. since many species investigat heodst endosymbi- nov is quit edistin cantd carmot be confused with otic, sulphur-oxidizing bacteri aa,nd sometimes any other modern lucinid sin the tropica lIndo- constitute members in modern and fossi lcold- Western Pacific .Among the livin gforms ,only seep communities (e.g ,Ta,ylor and Glover ,1997, Cbdokia tigerin a(Linna e1u75s8,) and degan- 2000; Sara & Wbodside, 2002; Kitazaki & Maji- odontia acetabulum Bouchet and von Cosel, ma, 2003; Majima et aL, 2003, 2005) .A unique 2004 attain a shell size the same as or larger shell featur aessociated with cold-seep commimi- than B, obtusipgicatus sp. noy, but other distinctties is the acquisition of larg esize (e. gS,au,l et shell feature sseparate them from our new aL, 1996; Bouchet & ven Cosel ,2004; Majima et specles. al., 2005), and fossi lexamples show aggregated When compared with other fossi slpecies from occurrences of such species in calcareous con- the Indo-Wester nPacifi cL,ucina mexima Martin, cretions (e, gM.a,jima et al., 2005). Bulacanites 1883 is comparably 1arge rthan B. obtusiplieatus obtusiplicatus sp. n(rvi is unusually large in shell sp. nom The holotyp eand single specimen de- size arnong lucinid fsrom the tropical Indo-Wdst- scribed by Martin (1883 w)as collected from the ern Pacific .However, judgi fnrgom the sedimen- upper Miocene at Junghulmi glocalit yO (south-tary facies and other associated mollusks and western part of the Bandong high ,Rongga dis- corals, it is evidently an interti daorl subtidal trict G,unung Sera or Cilanan gGap in the Nang- shallow marine dwelle crhiring Pliocene time. gulan area, Java ;see Hoek Ostende et aL, 2002), It is an intern amlold of the right valve that does Acknuwledgements not show any shell characteristics except for the circular and strongly inflat esdhell ouSline. We would lik eto thank M, A, Zepeda, E, Martin (1919 i)llustra taend additional better- Mula, R. Ancog, E. Azurin ,W Mago (MGB) and preserve dspecimen of this species from Solo R. Wani (NSM) for their assistance in our field (=Surakar ctenatr)al, Java, but the shell seems to work and N. Mateer for 1inguisti ccorrection, We be thin according to his illustrat iTohne. authors aeknowledge the time, help ,and access to Mart- were unable to examine the holotyp eand the inl sIndonesia nCenozoic molluscan collections NII-Electronic Library Service NNaatitoinaolnScaieln ceSMcusieuemnce Museum 182 Tomoki Kase and Yblanda M. Aguilar kindly given to us by E P Wesselingh ofNational outer-shelf cold-seep assemblage in forearc basin fill, Museum of Natura lHistor yNaturali sL,eiden, Pliocene [al[anab eForrnation ,Kyushu Island ,Japan. lhleontologicalResearch,7:297-3l1, This study was financial sluypported by the Na- tiona lScienc eMuseum, Tokyo, and by a Grant- M afjbismsai , lRch.em, oZsy ntNheotbicuhar a &as sTem bKliagteasza ki in2 ,0J0ap5a. nR. elvhileawe oef- In-AidfbrScientifiRcesearchfrom the Japan geogmplijl RTIaeolimatolqgy ,lhlaeoecology, 227i 86- Societ yfor the Promotion of Scienc e(JSPS ()no. l23,Martin, 15253008) and by a grant for scientific exehange K., 1883. Nachtrage zu den "Tbrtidrschichten auf from JSPS and the Netherland sOrganizati ofnor Javaj 'Erster Nachtrag: Mollusken. Skimmulungen des ScientifiRcesearch. Geolagischen Reichs-Adeiseum sin Leiden, 1st series, 1: I94265, 9-13. pls Martin, K., 1919. Unsere Palaeozoologische Kenntni svon References Java rnit einleitenden Bemerkungen Uber die GeoLogie der Insel .SZimmulungen des Geoiqgischen Reichs- Bouchet ,R & R. von Cosel ,2004. The world's 1arge sltu- Mitseums in Leiden ,Beilag eBand: 1-158 ,pls 1-4. cinid is an undescribed species from [[biwa (nMolluscaM:atsumoto, E. ,1971 .0Iigocen emollusks from the Seto- Bivalvia) .Zbolagicat Studie s4,3 : 7047 1 1 . gawa Group in central Japan .Bulleti nof the IV2itional Bretsk yS;. S. ,1976. Evolutio nand classification of the SZ]ien cMet{seum, 7blye, 14: 661-669 ,pls 1-3. Lucinidae (Mollus cBai:valvia )f.ulaeonteguphica Melendres, M. M. & R. Versoza ,l960 (unpublis Rhee-d). Americana ,8: 219-337. connaissance geology ancl oil possibilit yof the south- Chavan ,A., 1959 .Superfatni Lluycinace aFleming, 1828. eastern Luzon Central ValleM Philippines S,an Jose Oil, bi:R.C.Moore (ed)7i"eatiseIin,ertebrPakteeleon- Manila. on teIQgy, N, 2. Pp. N491-5l8. The Geological Societ yof Saito ,T,, 1999, Revisien of Cenozoic magnetostratigra- America and the University of Kansas. Boulder, Col- phy and the calibration of planktoni cand microfossil orado. biostratigraph yof Japar iand against this new time Cox, L. R., 1941 .Lamellibranc hfsrom the White Lime- scale. Jbunnal of the JZrpanese Asseeiation fo rfetrole- stone ofJamaica. Proceeding osfth eMblacologtc aSlo- um fechnolqg r6?4,: 2-15. (I nJapanes ewith English ciety ofLondo 2n4,: 135-144, pls 8-10, abstract) Dall, W H., 190la. A gigant ifcbss iLlucina, IV4utilu s1,5: Sara, C. & J. Wbodside, 2002. Lucinorna hazani n. sp. 40-42. (Mollus Bciav:alvia )ev:idence of a livin bgenthi ccom- Dall, W H., 1901b. Synopsis of Lucinacea and of the munity associated with a cold seep in Easterm Mediter- American species. Proceeding sof the Uitite Sdtates ranean Sea. Deep-Slea Researeh, part 1, 49: 99 1-1O05. IVintionMatlLseum,23:779-833, 39-42. Saul,L,R.,R.L,Squires& J,L.Goedert,1996.A pls new Dharma, B, ,2005. Recent and Fossi lIndonesi aShells, genus of cryptic lucini d?bivalv efrom Eocene cold 424 pp. Conch Books, Hackenheim. seeps and turbidite-influenced mudstone, western Gonzales ,B. A,, V R Ocampo & E, A. Espirim ,1971. Washington J.burnal of1]laleon 7t0o: t78o8g-7y9,4. Geology of southeastern Nueva Eclj aand eastern Bula- [Ibylo Jr .,D. & E. A. Gluver ,1997 ,The lucini bdivalve can provinces ,Luzon Central Vhlley .Jbumial ofth eGe- genus Cardiolucina (Mollus cBai,valvi aL,ucinidae): ollrgicai Sbciet oyfth Pehilmpines, 25 (2 )2:4I. systematies, anatomy and relationship. BuUetin ofthe Hoek Ostencl eL,, W van den, J ,Leloux ,E P 1)Liesseling h?VZiin mHlisto, JM,iiseum ,London (Zbolqg 6y3): ,93- & C. E Winlder Prins ,2002. Cenozoic molluscan types 122.[[ajJiog from Java (Indones iina )the Martin Collection (Divi- J ,D. & E. A. Glover, 2000. 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A slope to outer-shelf Survey of Japan, Agency of lndustria lScience and cold-seep assemblage in the Plio-Pleistoc eKnaezusa Ilechnolo ganyd, Ministr oyfInternationa1 Trade and In- Group, Pacifi cside of central Japan. fuleontological dustry (eds R)E.zport ofResea rancd h Develqpment Co- Research, 7: 279-296. operation avT Pizu'ect IsVb .88I3. Pp. 72-89. Ministry Majima, R,, K. Ikeda, H. Wada & K. Kato, 2003. An ofInternational Trade and inctustr y[,Ibkyo. NII-Electronic Library Service NNaatitoinaolnal　 sSocieineoence　 MMuusesuemum A　new 　Pliocene　lucini　gdenus　and 　species 　from　Philippines 183 Woodring，　W 　P．，1982．　Geo］ogy　and　paleontology　Qf States　Gθ010g ∫cαJ　Survey　J）rofession αl　Paper．，（306−F）： 　CanaユZone　and　a（ljoini　npagrts　of　Panama ．　United 541−759，pls　83−124． ・ フ ィ リピン ル ソン 島中部の鮮新世タル タロ 層産ツ キガイ科大型二枚貝の 　　　　　　　新属新種B”lacanit　eobstusiplicatus 　gen．　et　sp．　nov ． ・ ・ ー ・ ー 加瀬友喜 ヨ ラン ダ マ ク アギラ ・ 　フ ィ リピン ルソン島中部のブラカン地方に分布する前期鮮新世後期の タル タロ層から得られた ツキガイ科二枚貝の新属新種Bulacanite　sobtusiplicatus 　gen．　et　sp ．　n。v．を記載した．　Bulacanitesは大型 でこ う歯を欠く点ではAnodontia属とMeganodontia 属に似るが，殻が厚く，殻頂部が より前方に傾 き，さらに殻表面に特徴的な分岐をする放射肋をもつ 点で容易に区別される．産出 した地層の堆積 相と随伴する他の貝化石の解析か ら，この二枚貝は熱帯の潮間帯あるい は潮下帯に生息 して いた と 考えられる． 一 NNI工I工-EElleoetcrotniroonic　 LLiibrbarryary 　Service