Biogeography of the genus Neptunea (Gastropoda: Buccinidae) from the Pliocene and the lower Pleistocene of the Japan Sea borderland

11 Pages·1997·4.5 MB·English

by  Kazutaka Amano

© byontthoelogPiaolaaleoRnetsoeloagriccha,lvSolo.ci1,etnyo.o4f,Jpapp.a2n74-284, 4Figs., 30 December, 1997
Biogeography of the genus Neptunea (Gastropoda
:
Buccinidae) from the Pliocene and the lower
Pleistocene of the Japan Sea borderland
KAZUTAKA AMANO
Department of Geoscience, Joetsu University of Education, Joetsu, Niigata Prefecture, 943 Japan
Received 2 April 1997 Revised manuscript accepted 8 November 1997
;
Abstract. Fourteen speciesofNeptunea are listedfrom the Pliocene and lowerPleistoceneoftheJapan
Sea borderland. Amongthem,Neptunea(Neptunea)eos(Kuroda),N.(N.)hataiiNoda,andN.(Golikovia)
nikkoensis Nomura are extinct. These species and a part of the N. polycostata stock in the Japan Sea
suffered extinction before the end of the early Pleistocene. However, the N.polycostata stock survived
in the Okhotsk and Bering Seas. On the other hand, N. intersculpta (Sowerby) and N. (Barbitonia)
arthritica (Bernardi) are still living in the Japan Sea. This contrast isduetothe Plio Pleistocene records
on the Pacific side and eurythermal ecology of N.intersculpta and N.arthritica.
Key words Biogeography, Japan Sea, Neptunea, Pleistocene, Pliocene
:
Introduction Iwai, N. eos (Kuroda), N. (Sulcosipho) hataii Noda, N. inter-
sculpta (Sowerby), N. i. pribiloffensis (Dall), N. i. urataensis
The buccinid genus Neptunea is a group of cold-water Noda, N. aff. intersculpta (Sowerby), N. iwaii Hatai, Masuda
species now living in the Northwest Pacific, Arctic and North and Suzuki, N. lyrata (Gmelin), N. modesta (Kuroda), N. nik-
Atlantic oceans. The genusoriginated in the upperEocene koensis Nomura, N. rugosa Golikov, N. sakurai (Ozaki), N.
of North Kyushu and invaded the Arctic and north Atlantic soluta (Hermann), N. uwasoensis Otuka, N. vinosa (Dall) and
basins afterthe opening ofthe Bering Strait during Pliocene N. vinosa (Dall) var. (Hatai and Nisiyama, 1952; Masuda and
time (MacNeil, 1965; Strauch, 1972). Noda, 1976; Ogasawara, 1977; Masuda et al., 1981 ; Noda
Recently, Amano et al. (1996)found that some Ancistrole- et al., 1983; Ogasawaraand Naito, 1983; Nodaetal., 1984;
pidinae (Buccinidae) which occurred in the Japan Sea Ogasawara et al., 1984; Matsui, 1985; Matsuura, 1985;
borderland duringthe PliocenetoearlyPleistocenenolonger Noda and Amano, 1985; Ogasawaraetal., 1986; Amanoet
live in the Japan Sea. Instead, they survive in the Okhotsk al., 1989; Akamatsu and Suzuki, 1990,1992; Nakata and
and Bering Seas. Amano et al. (1996) attributed this dis- Amano, 1991 ; Amano and Sato, 1995). However, some
tributional pattern tothe extinction oftheJapan Sea popula- taxonomic problems exist among the above-recorded
tion by glaciation after the early Pleistocene. The reason speciesbecausethefossil speciesweredescribed on oneor
why the species of Ancistrolepidinae could not reinvade the a few ill-preserved type specimens and insufficiently
Japan Sea istheir non-planktotrophic larval life, the shallow compared with one another.
sill depth, and the higher water temperature. In this paper, firstly, I revise the taxonomy of Neptunea by
Neptunea (Neptuneinae) is phylogenetically close to the comparing the described specimens with allied species in
Ancistrolepidinae (Goryachev, 1987). However, Neptunea detail. Secondly, I will discuss the historical biogeography
includes many more species than the Ancistrolepidinae. of the group.
Moreover, the neptuneid species have various depth ranges
in contrast with the deep-water ancistrolepidines. There- Subdivision of Neptunea
fore, the genus is suited for confirming the cause of extinc-
tion observed in the Ancistrolepidinae and forexamining the The genus Neptunea is subdivided into three subgenera:
relationship between the depth range and the extinction Neptunea (s.S.), Barbitonia and Golikovia (Habe and Sato,
event. 1972 ; Tiba and Kosuge, 1988). The subgenus Golikovia is
Up to this time, the following species and subspecies of characterized by a smooth later stage, sculpture being
Neptunea have been recorded from the Pliocene and lower confined to the early whorls, and it differs from Neptunea
Pleistocene strata of theJapan Sea borderland : N. arthritica (s.S.) in having two marginal teeth on its radula. The outer
(Bernardi),N. a. asamusiNomuraand Hâtai,N. a hirosakiensis lipwith crenulations on its innerside distinguishesBarbitonia
Biogeography of Pliocene and Pleistocene Neptunea 275
Table1. TaxonomicsubdivisionofNeptunea byGoryachev Material and methods
(1987).
Neptunea intersculpta stock Some new specimens were collected by hand from the
(1) N. intersculpta group following localities (Figure1).
N. intersculpta (Sowerby) Loc.1. Roadside cliffabout850m eastofthe pass between
(2) N. contstricta group Kitaubushi and Kitakawaguchi, Teshio Town, north-
N. constricta (Dali), N. varicifera (Dali), N lamellosa western Hokkaido; siltstone bearing many calcareous
Golikov concretions; Pliocene Yuchi Formation.
Neptunea lyrata stock Loc.2. River bank about 2.5km upstream of the Soibetsu
River, Kuromatsunai Town, southwestern Hokkaido
(1) N. lyrata group ;
fine- to medium-grained sandstone lower Pleistocene
N. lyrata (Gmelin), N. stielesi Smith ;
Setana Formation.
(2) N. beringiana group Loc. 3. Outcrop about 1.5 km upstream of the
N. beringiana (Middendorff), N. ventricosa (Gmelin)
Hosokomata-zawa, Kami-iso Town, southwestern Hok-
(3) N. communis group
N. communis (Middendorff), N. denselirata Broegger kaido; granule-bearing fine- to medium-grained sand-
stone lower Pleistocene Tomikawa Formation.
N(4.)deNs.pedcetsape(cLtianngareouusp) Loc.4. Ri;ver-side cliff about 800m upstream of the Chi-
(5) N. antiqua group kagawa River, Mutsu City,Aomori Prefecture; medium-
N. antiqua (Linnaeus), N. contraria (Linnaeus) grained sandstone including pumice' lowerPleistocene
Hamada Formation.
Neptunea polycostata stock Loc.5. River bank along the Yodo River, 200m east of
(1) N. polycostata group Ichinowatari, Kyowa Town, Akita Prefecture sandy
N. polycostata Scarlato,N. laticostata Golikov,N. vinosa ;
siltstone Pliocene Tentokuji Formation.
(Dali), N. amianta (Dali) (syn. N. insularis (Dali), N. Loc.6. Road;side cliff near the Shohei Bridge of Kami-
p(2r)ibilNo.ffbeunlsibsac(eDaalgI))roup skutsoantesu,PliYoacweanteaKanTnoownnj,i FYoarmmaatgiaotn.a Prefecture ; silt-
N. bulbacea (Bernardi), N. rugosa Golikov Loc.7. Ri;ver bank along the Shinano River, 250m north-
(3) Golikovia group east of Unoki, Ojiya City, Niigata Prefecture conglo-
N. smirnia (Dali), N. fukueae Kuroda merate including mudstone pebbles P;liocene
(4) N. arthritica group Kawaguchi Formation. ;
N. arthritica (Bernardi), N. cumingi (Crosse) Loc.8. Riverside cliff upstream of the lida River, Maki
Village, Niigata Prefecture siltstone Pliocene Higa-
; ;
shigawa Formation.
Loc.9. Roadside cliff near Narao, Togakushi Village,
from the type species of Neptunea. Nagano Prefecture muddy fine-grained sandstone
; ;
Based on Golikov's (1963) study of shape of the penis, Pliocene Ogikubo Formation.
radula, and egg capsule, Goryachev (1987) classified the Loc.10. Riverside cliffabout400m upstream ofthe Urano-
genus Neptunea into the following three stocks N. inter- sawa, Nakajo Village, Nagano Prefecture fine-grained
: ;
sculpta, N. lyrata, and N. polycostata. Moreover, he sub- sandstone Pliocene Joshita Formation.
;
divided each stock into many groups (Table1). From the Loc.11. Roadside cliff near Shimo-yukawa, Nanao City,
viewpoint of hard parts, the first stock has spiral cords Ishikawa Prefecture siltstone Pliocene Sakiyama
; ;
intercalating with secondary cords. The second one is Formation.
characterized by nearly equal strong ribs while the last has Loc.12. River bank ofthe Sai River, 1.1 km upstream ofthe
smooth or sculptured whorls with an angulated shoulder. Okuwa Bridge, Kanazawa City, Ishikawa Prefecture;
Goryachev(1987)includedBarbitonia and Golikovia inthelast fine-grained sandstone lower Pleistocene Omma For-
;
stock. mation.
On the other hand, Nelson (1978) considered Barbitonia as Above specimens are housed in the Joetsu University of
an independent genus of Buccinulidae, mainly based on a Education (JUE). Besides these specimens, types stored at
unique microstructure shown by Togo (1974) and the sculp- the following institutes and museums were taxonomically
ture of the early whorls. Moreover, Sulcosipho Dall, which reexamined : Tohoku University (IGPS), Saito Ho-on Kai
was included in the family Melongenidae by Goryachev Museum of Natural History (SHM), University of Tsukuba
(1987), was treated as a subgenus of Neptunea by Nelson (IGUT), UniversityMuseum ofthe UniversityofTokyo(UMUT),
(1978). His classification is based largely on the pattern of and Kyoto University(KUGM). Moreover, private collections
spiral ribs, however, thischaracter isvariable in a population. by Dr. Nobuomi Matsuura of Shiramine-mura Dinosaur
As noted earlier, all species of Barbitonia have similar penis Museum and Mr. Masayuki Shimizu of Toyama Prefectural
morphology and radula with other neptuneids. General Education Center were also examined.
In addition to my collections and the above reexamina-
tions, assessed the question of geographical distribution by
I
a critical surveyofthe literature(Kanehara, 1937; Iwai, 1959,
276 Kazutaka Amano
1965; Sawada, 1962 ; Ogasawara et al., 1986; Akamatsu, between N. uwasoensis and N. eos,theformer isasynomym
1984 Akamatsu and Suzuki, 1990,1992). of the latter.
;
In this paper, I use Goryachev's subdivision of the stocks Nelson (1978) classified N. uwasoensis (=A/. eos) as a
in Neptunea (s.s.) as well as Tiba and Kosuge's concept of species ofthe subgenus Sulcosipho. However, the present
the subgenera. The Recent specimens showa wide range species lacks the diagnostic features ofSulcosipho such as
ofvariation, especially in heightofspireand numberofspiral a tabulated shoulder bounded by a raised, scaly spiral cord.
ribs on a body whorl. I considered a shell shape and the As an angulated shoulder is sometimes observed in species
number of ribs on the penultimate whorl to be important. of the N. polycostata stock, I tentativelyassign N. eos to this
stock.
Systematic notes on extinct species
Measurements (in mm).—
Family Buccinidae Rafinesque, 1815 Specimens Diameter BR» PA1R2»3IAR3)SSR4>
Subfamily Neptuneinae Troschel, 1869 KUGM JC no.610043 holotype 42.5 3 13 +
Genus Neptunea Roeding, 1798 UMUT CM no.12434 33.2 4 +
Subgenus Neptunea s.S.
"Numberof ribs below the shoulder of penultimatewhorl. 2,Numberof
Diagnosis.—Shell large, fusiform, consisting of six to eight primary ribs above the shoulder of penultimate whorl. 3>Number of
whorls body whorl large, occupying half to four-fifths of secondary ribs above the shoulder of penultimate whorl. 4,Subsuturai
; ridge.
shell height. Surface sculptured by one or some spiral ribs
and occasionally by axial rounded ribs or axial thin varices. Neptunea (Neptunea) hataii Noda, 1962
Inner side of outer lip smooth and without any crenulations
observed in Barbitonia. Marginal teeth on radula number Figures 2-10a, b; 3-10
three to five. Neptunea (Sulcosipho) hataii Noda, 1962, p.230, pi.16, fig.16.
Neptunea (Neptunea) eos (Kuroda, 1931) Type specimen.—Holotype, IGPS no.79055 (Figure2-10a,
Figures 2-4,5,7—9,11a,b,12 b).
Type locality.—Riverside outcrop along the Higashigawa
Chrysodomus eos Kuroda, 1931, p.80, pi.10, fig.80. River near Nakao, Matsunoyama Town, Niigata Prefecture.
NNCeehpprttyfuusinngo.eed7aao5mucu;fw.saAusmuwoawaeansnsoosoeieensntssi(aiOslst.,u(kO1Oatt9)uu8,kk9a,aO),t,pu.1kM91aa13,25s-au11,19d33ap,5.bep5,i1t.0p,2a.l0.f,8,i6g1f.9i9g-38.g81.2,760.p,i.p5i,.f5i4g,. owfitRhoenmaearkdkeesefl.o—raTmnehddeasppreseuscreifnmatecnse.pesccIiutelhsptaiussredadensbcarynigbnueuldamteoerndotushsheowubleadsaeikrs
Nept1u5ne;aOg(aNespatwuanreaa)aunwdasNoaeitnos,is19(8O3t,ukpa.)5,2N-5o3d,apeif.8a,/.,fi1g.98131., p.7, spiNraoldtahr(e1a9d6s2.) classified this species in the subgenus Sul-
pi.3, figs.9a-b. cosipho. However, the species lacks a tabulated narrow
Neptunea eos (Kuroda), Amano and Sato, 1995, fig.5-8. shoulder and the raised spiral cord on itwhich are important
2-1T1ya,peb).specimen.—Holotype, KUGM JC no.610043 (Figure tcehhxaactreaptchttisefrossrpehocafiveiSsunlgbceonsluiompnehgors.otuosIttshrpeiersNae.lmpbroillbesy.scosNTt.haretruaegfsootsroaec,kG.oIlitkhoivn,k
Type locality.—Sakae, NakajoVillage, Nagano Prefecture
;
Joshita Formation. Subgenus Golikovia Habe and Sato, 1972
Remarks.—The present species is characterized by a
rather small shell (diameter of holotype=42.5mm), an an- Diagnosis.—Shell small to medium in size, slender, fusi-
gulated shoulder, a blunt ridge just below the suture, one form. Shell surface sculptured by low, wide spiral ribs on
primary rib intercalating with three or four interstitial ribs on earlywhorls, becoming obsolete on laterwhorls bodywhorl
wtihtehfolantearinetaersatibtoiavleritbhbeeslhoowultdheer,shtohurledeeroroffotuhre ppreinmualrtyimraitbes sMamrogoitnhalatnedethpoolnisrhaeddu.laInnunmerbersitdweo.of outer ;lip smooth.
whorl.
uwaTshoeesnesischOartaucktaer(i1s9t3i5cas)(adrieamesthearroefd"hwoiltohtypCe"hr=y3s3o.d2ommmu)s Neptunea (Golikovia) nikkoensis Nomura, 1937
from the Pliocene Sakiyama Formation in Ishikawa Prefec- Figures 2-1, 2a, b, 6
etuorse.byOltauckkiang(1a9n35aan)gudliastteidngsuhiosuhledderN.. uHwoawseoveenrs,isthefrpoemnulN.- Neptunea nikkoensis Nomura,1937, p.176-177, pi.24,figs.13ab;
tainmgautleatwehdorslhooufldtehre(hFoilguorteyp3e-11abn).d sAosmethetroepoitsynpoesdihfafevreenacne 85N2oa,dbap,,i.p1i8.9,64f29i,,gsfp.ii.g7s,1.61,138faai,,g.bb12;; ;ONgaOkagasatasawaawaranardaeAtamnaaldn.,oN,1a9it18o96,9,11,p9ip.8i3.2,97,,p.ffii5gg1ss-..
Figure1. Collecting localities of Neptunea (using the topographical maps of "Onoppunai", "Utasutsu", "Hakodate",
"Chikagawa", "Osawa", "Koguchiseto", scale1 :50,000; "Ugo-Sakai", "Ojiya", "Yanagishima", "Togakushi", "Shinano-Naka-
jo" and "Kanazawa", scale 1 :25,000 published by Geographical Survey Institute of Japan).
Biogeography of Pliocene and Pleistocene Neptunea 277
Kami-kusatsuf^
;
m^
Hokkaido
Mà$M
IPPII
ilpllff
UMmmtâ teô#!§
m?È*rm$i
27S Kazutaka Amano
8a b. Thesecond groupofspecies(Btype) now live in theTatar
INeptunea arthritica hirosakiensis Iwai, 1959, p.50, pi.1, figs.17a, Straitand offPrimorieofJapanSeaaswellasintheOkhotsk
Tybpe; Iswapie,c1i9m65e,n.p.—5H5o,lopit.y2p0e,,fSigHs.M13nao.b.12635 (Figures2-2a, lSyeraata,(NGolbiukolvb,ace1a9,63a;ndTiNb.arugaonsda.KoTshuegey,liv1e98in8)t:heNeupptpeurnetao
lower sublittoral to bathyal zone (Golikov, 1963).
b). The third type (Ctype) of species are now dwellers of the
Type locality.—Masuda, YawataTown, Yamagata Prefec- N
Japan Sea Neptunea intersculpta, constricta, and N.
turRe.emarks.—The presentspecies hasarathersmall,slender arthritica. Th: eyalso surviveon the Pacificside of Northeast
Honshu and Hokkaido (Golikov, 1963 Tiba and Kosuge,
polishedshellwithashortand straightsiphonal canalandan 1988). Fossils of N. intersculpta and N.;arthritica have been
irregular suture. Early whorls are sometimes sculptured by reported from the Pacific side of Northeast Honshu (see
4th-e7vperreyswenetakspriebcs.iesJucdagningbefroimnctlhuedaedbovien cthhaeracsteurbigsetincuss, FigTuhree5reocfenAtmaspneociemteanl.,o1f99N6).sakurai has been once illus-
GolIiwkaoiv(i1a95a9s,1s9u6g5g)epsrtoepdosbyedNaelnseonws(1u9b7s8)p.eciesofN. arthritica trated from off Monbetsu, Northeast Hokkaido as N vinosa
hirosakiensis from the Pliocene Higashimeya Formation in by Okutani et al. (1988). However, as there is only one
Aomori Prefecture, based on one imperfect specimen. His record, it is hard to determinewhichtypethisspeciesshould
figures show a slender shell and smooth surface lacking belong to.
weak spiral ribs. I tentatively synonymize this subspecies finTeh-rgereaienxetdinscetdsipmeecniteosf(tEhteyJpea)paonccSuerraedbofrrdoemrltahnedPlNi.oceeosn,e
with N. nikkoensis. N :
Comparison.—The present species is closely allied to N. N. hataii and nikkoensis. These species might have lived
(G.) fukueae Kira, 1959 which is now living in the Southwest mainly in the lower sublittoral zone.
Pacific-side of Japan. However, the latter differs from the
former by its long and recurved siphonal canal. Shaping of modem Japan Sea neptuneids
N. (G.) ennae Sakurai and Tiba, 1969 is easily separated
from the presentonebyhavingamoreconvexshell andvery In the Pliocene, the extinct species N. eos and N. nikko-
ensis dominated the neptuneids of the Japan Sea border-
long siphonal canal.
land. In association with both species, some boreal popula-
N
tionsoftheN. polycostata stockand of arthriticawereable
Geographical distribution to invade the Japan Sea because of cold climate and deep
sill depth (Ogasawara, 1994; Tada, 1994).
The Pliocene and early Pleistocene species of Neptunea Both Aand Etypespeciessufferedextinction untiltheend
in the Japan Sea borderland are summarized in Table2. ofthe early Pleistocene. On the other hand, Ctype species
Among these species, N. iwaii was established by Hatai, such as N. arthritica and N intersculpta have been recorded
Masuda and Suzuki (1961), based on one specimen from the from the middle Pleistocene Shibikawa and Anden forma-
lower Pleistocene Hamada Formation in Aomori Prefecture. tions in Akita Prefecture (Ogasawara er al., 1986).
However, it is difficult to separate this species from N. Ecologically, the C type speciestolerates highertempera-
constricta (Dall) by having low spiral ribs and five even fine ture of water than the stenothermal Atype species (Golikov,
spiral ribs just below the suture. 1963). From the stand point of sedimentology, Tada (1994)
The distributional pattern of extant species in thetabulat- pointed out that bottom conditions started oscillating
ed listcan besubdivided intothreetypes(A-Ctypes Figure between oxic and anoxic along with glacioeustatic sea level
;
4). The first species group (Atype) does not live in the change at 2.5 Ma. Possible causes of extinction of the A
Japan Sea, but does so in the lower sublittoral to the upper type species are warming during interglacial highstands as
bathyal zone of the Okhotsk and Bering seas, as do the well as the brackish surface and euxinic bottom waters
Ancistrolepidinae (Golikov, 1963 Tiba and Kosuge, 1988 during glacial lowstands. The warm Tsushima current
; ;
Table3): Neptunea lamellosa, N. insularis, N. vinosa and N. flowed into the Japan Sea during interglacials while the
satura. ItisnoteworthythatmanyspeciesoftheN. polycos- JapanSeawasenclosed during glacial periods. Inthecase
tata stock show this distributional pattern or suffered total ofthe Atype species, the population of Okhotsk and Bering
extinction at the end of the early Pleistocene. Seas survived during the deteriorated environments as did
byOgFaigsuarwea2r.aa1,nd2,N6ai:tNoe(p19t8u3n).ea2(Gaolbik;ovXi1a.)5,niSkHkoMennsoi.s1N2o6m35u,raK.ann1on;jix1F,orImGaPtSionno,.H9o7l3o8t9yp-e2., K6an;noxn1j,iJFUoErmnaot.io1n5,612c,olLloecc.te5d,
Tenntokuji Formation. 3a,b: Neptunea(Neptunea)satura(Martyn); x1,JUEno.15613,Loc.7, Kawaguchi Formation. 4,5,
7LUo-Mc9.U,1T111,,C1S2Mak:inNoye.ap1mt2au4n3Fe4o,armJ(aoNtseihpoitntu.aneFa7o);rmeaoXt1si.o2(n,K,uJr"oUhdEoal)o.ntoy.p41e"5;26oxf61,,NeKJpuUtwEuanneeoa.F1ou5rw6ma1as4t,oieoLnno,sci.si1l0lO,utstJurokasath.eidtab9y;FoArxmmlaa,tniJooUn.Eefna5ol..;1(5\16191,869,)J.ULoEc8.an1,o,.b1Y;5u6cx1h51i,,
Formation. 11a,b; x1, KUGM JC no.610043, Joshita Formation, Holotype. 12; x1, UMUT CM no.12650, Sakiyama
bFoyrmNaotdiaon.(196120)a,asbN:.Ne(Sputlucnoesiaph(oN)ephtatuaniei.a) hataii Noda; x0.8, IGPS no. 79055, Higashigawa Formation, Holotype described
Biogeography of Pliocene and Pleistocene Neptunea 279
Kazutaka Amano
280
Biogeography of Pliocene and Pleistocene Neptunea 281
Table2. Summarized list of Neptunea from the Pliocene F. (Figure3-3; Loc.12). Ctype.
and the lower Pleistocene of the Japan Sea borderland. Subgenus Golikovia Habe and Sato, 1972
Genus Neptunea Roeding, 1798 N. nikkoensis Nomura. Pliocene: Kannonji F. (Figures
Subgenus Neptunea s.S. 2-1, 2a, b) ; Tentokuji F. (Figure2-6 ; Loc. 5) ;
Neptunea intersculpta stock Kawaguchi F. (Loc.7); Kurokura F.; Tomikura F.;
N. intersculpta (Sowerby)* Poliocene: Tentokuji F. ; Ogikubo F. (Loc.9); ? Higashimeya F. Etype.
Kannonji F.; Nagasawa F. (Figure3-12); Yabuta F. *extant species "distributional type
Ctype**.
N. constricta (Dall)* Early Pleistocene: Hamada F., Table3. Bathymétrie distribution of the extant ne-
Setana F. Syn. N. iwaii Hâtai, Masuda and Suzuki, ptuneids occurred from the Pliocene and lower Pleis-
1961 ("holotype", Figure3-7). C type. tocene ofthe Japan Sea borderland.
N. lamellosa Golikov* Pliocene: HigashigawaF.(Loc. Species Bathymétrie range
8). Early Pleistocene: Hamada F. (Figure3-9a, b). A type
Atype. N. lamellosa 57-550m", 300-500m2)
Neptunea lyrata stock N. satura 13-245m"
N. lyrata (Gmelin)* Pliocene: Yuchi F. (Figure3-13). N. insularis 230-1,000m1', 100-400m2)
Btype. N. vinosa 29-400m1», 30-100m2)
N. sakurai (Ozaki)* Early Pleistocene: Hamada F. Btype
(Figures3-4,5). N. lyrata 16-1,724m11
Neptunea polycostata stock N. bulbacea 0.5-585-m1»
N. bulbacea (Bernardi)* Pliocene: Yuchi F. Early N rugosa 9-76m"
Pleistocene: Setana F. (Figure3-11 ; Loc.2). B Ctype
type. N. intersculpta 36-895m», 150-750m2)
N. rugosa Golikov* Pliocene: Seguchi F.(Figure3-8). N. constricta 20-468m1', 200-600m2>
Btype. N. arthritica 0-150m", 0-20m2'
N insularis (Dali)* Pliocene: Mita F. (Figure3-2a, b). « Golikov (1963) 2) Tiba and Kosuge (1988)
Early Pleistocene: Tomikawa F. (Figure3-1 ; Loc.
3). ?Syn. N. intersculpta urataensis Noda, 1962. A
type. the Ancistrolepidinae (Amano et al., 1996). Because the
N. vinosa (Dali)* Early Pleistocene: Shimonopporo distribution of Etype species is confined to only the Japan
F. ; Tomikawa F.; Hamada F. (Figure3-6; Loc.4). Sea borderland, they became extinct.
Atype. There aretwo explanationsforthe distributional pattern of
N. satura (Martyn)* Pliocene: Kawaguchi F. (Figures the Btype species. First, the populations of Btype species
2-3a, b; Loc.7). Atype. suffered extinction before the end of early Pleistocene.
N. eos(Kuroda) Pliocene: JoshitaF.(Figures2-4,11a, Later, perhaps in the Holocene, they reinvaded the cold
bF.;; LKouc.wa10e);FY.uc(hFiiguFr.e(2F-i7gu)r;eM2i-t9a; LF.oc;.S1a)k;iKyaanmnaonjFi. wwaatteerripnatshseagTeast.arSTthraeitsaencdonofdfePxrpilmaorniaetitohnroiusgahrtehsetrnioctritohneronf
((FOitguukrae,s129-355,)8a(,"hbo,lo1t2yp;eL"o,c.U1M1)U.TSCynM. Nn.o.u1w2a4s3o4e).nsisE braentgweeeanfttehretAheanmdidBdlteypePlsepiesctoiceesneis.theThdeeptmhaiantwdhiifcfhertehnecye
type. live. The Btype species extend up to the upper sublittoral
N.1h0aat,aibi) NoKadnanonPjliioFc.e(nFeig:urHeig3-a1s1)h.igaEwatypFe..(Figures2- fziorsntehyopfotthheesOikshiostasckceSpetaed(,Goiltikisove,as19y63t)o.exTphlearienfworhey, tifhethAe
;
Subgenus Barbitonia Dall, 1916 type species was not able to reinvade the northern part of
N.sF.aar;wthaSreiFtt.iac;naaMi(FtB.aer;nFT.arodmiEi)a*krlaywPaPllieFo.ics;etnDoecaei:nsYehua:ckhZaiaiF.mF.;o;kOuNmzamagwaaa- tsBhpeeeccaiuJesasepiasntdheeeSpeseharaltlthohawrneostuthgahtdeoptfththeheosBchcatulyrlproeewsnpceencoiroetfsh,etrthnheefsAtortraiymtpeser.
Figure3. 1,2: Neptunea (Neptunea) insularis (Dall). 1 ; x1, JUE no.15617, Loc.3, Tomikawa Formation. 2a,b; x1,
Mita Formation, collected by Mr. M.Shimizu. 3: Neptunea (Barbitonia) arthritica (Bernardi); x1, JUE no.15618, Loc.12,
Omma Formation. 4,5: Neptunea (Neptunea) sakurai (Ozaki); 4, X1.5, IGPS no.102710-2; 5, x1, IGPS no.102710-1,
Hamada Formation, illustrated by Hâtai et al. (1961). 6: Neptunea (Neptunea) vinosa (Dall); x1, JUE no.15619, Loc.4,
Hamada Formation. 7: Neptunea (Neptunea) constricta (Dall); x1, IGPS no.93224, Hamada Formation, "holotype" of N.
iwaii Hatai, Masuda and Suzuki, 1961. 8: Neptunea (Neptunea) rugosa Golikov; x1, JUE no.15355, Seguchi Formation,
illustrated by Nakata and Amano (1991). 9a,b: Neptunea (Neptunea) lamellosa Golikov; x1, IGPS no.102711-2, Hamada
Formation, identified as N vinosa Dall var. by Hatai efa/. (1961). 10: Neptunea (Neptunea)hataii Noda; x1, JUE no.15620,
Loc.6, Kannonji Formation. ÎI: Neptunea (Neptunea) bulbacea (Bernardi); x1, JUE no.15621, Loc.2, Setana Formation.
12: Neptunea (Neptunea) intersculpta (Sowerby); x0.8, JUE no.15363, Nagasawa Formation, illustrated by Nakata and
Amano(1991)as"N. intersculptapribiloffensis (Dall)". 13: Neptunea (Neptunea)lyrata (Gmelin); x0.8, IGUTno.10992,Yuchi
Formation, illustrated by Noda and Amano (1985).
Kazutaka Amano
cannot invade the RecentJapan Sea. Ifthe second expla- can fauna from the Pliocene Joshita Formation in the
nation isaccepted, it isdifficulttoexplain howthesespecies northern part of Nagano Prefecture—. Fossils, no.59,
could survive in the brackish surface water. N. rugosa, in p.1-13. (in Japanese with English abstract)
particular, is now living at depths of 9-76m (Golikov, 1963). Amano, K., Ukita, M. and Sato, S. 1996. Taxonomy and
The modern neptuneid fauna around the Japan Sea distribution of the subfamily Ancistrolepidinae (Gas-
tropoda: Buccinidae) from the Plio-Pleistocene of
borderland consists of the N. intersculpta stock and Bar- Japan. Transactions and Proceedings of the
bitonia (Tiba and Kosuge, 1988) in contrastwith the Pliocene Palaeontological Society of Japan, New Series, no.182,
and early Pleistocene faunawhich wasdominated bytheN. p.467-477.
polycostata stock and Golikovia. Dali, W.H., 1916: Prodrome of a revision of the chrysodo-
The distribution of a part of the Neptunea polycostata moid whelks of the boreal and Arctic regions. Pro-
stock and of the subgenus Golikovia is similarto that ofthe ceedings of the Biological Society of Washington, vol.
Ancistrolepidinae. However, the distributional patterns of 29, p.7-8
the B and Ctypes have never been recognized in the Golikov, A.N., 1963: Gastropod genus Neptunea Bolten.
Ancistrolepidinae. The Band Ctypespeciesdifferfrom the Fauna of the USSR, Mollusca, vol.5, Sect.1, p.1-217,
latter in having shallower habitats or a eurythermal ecology. pis.1-28. (in Russian)
Amano etal. (1996)emphasized thataQuaternaryextinction Goryachev, V.N., 1987: To the history of the formation of
event, thermal tolerance and the bathymétrie distribution of Neptunea (Gastropoda, Buccinidae) fauna of the North
each species are important determinants of distribution of Pacific. In, Kafanov, A. ed., Fauna and distribution of
speciesin the Japan Sea. Therefore, the results of this molluscs: North Pacific and Polar Basin, p.57-64, Far
East Science Center, Vladivostok, (in Russian)
study support those of the previous study. Habe, T. and Sato, J., 1972: A classification of the family
Buccinidaefrom the North Pacific. Proceedings ofthe
Acknowledgments Japan Society of Systematic Zoology, no.8, p.1-8, pis.
1-2. (in Japanese with English abstract)
I am grateful to GeeratJ.Vermeij (Univ. CaliforniaatDavis) Hatai, K., Masuda, K. and Suzuki, Y., 1961 : A note on the
for his critical reading of the manuscript. I thank Hiroshi Pliocene megafossil fauna from the Shimokita Penin-
Noda (Univ. Tsukuba), Kiyotaka Chinzei (Osaka-gakuin sula, Aomori Prefecture, Northeast Honshu, Japan.
Univ.), Akira Tsukagoshi (Univ. Mus., Univ. Tokyo), Masanori Saito Ho-on Kai Museum, Research Bulletin, no.30, p.
Shimamoto (Tohoku Univ.), SadakoTakeuti (Saito Ho-on Kai 18-38, pis.1-4.
Mus., Nat. Hist), Nobuomi Matsuura (Shiramine-mura Dino- Hatai, K. and Nisiyama, S. 1952. Check list of Japanese
saur Mus.), Masayuki Shimizu (Toyama Prefectural General Tertiary marine Mollusca. Science Reports of the
Education Center), and Tsuguya Mizuno (Towada Elemen- Tohoku University, 2ndSeries, Special Volume, no.3, p.
1-464.
tmaernys.School) for their help in examining some fossil speci- Iwai, T, 1959: The Pliocene deposits and molluscanfossils
fromtheareasouthwestofHirosakiCity,Aomori Prefec-
ture, Japan. Bulletin ofEducational FacultyofHirosaki
References cited University, no.5, p.39-61, pis.1-2.
Iwai,T.1965. Thegeological and paleontological studies in
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:
the Ishikari Hills, Hokkaido. Annual Report of the ture, Japan. Bulletin ofEducational FacultyofHirosaki
Historical Museum of Hokkaido, no.12, p.1-33. {in University, no.15, p.1-68, pis.12-20.
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Akamatsu, M. and Suzuki, A., 1992: Stratigraphy and Kuroda, T., 1931 : Mollusca. In, Homma, F. ed., Shinano
paleoenvironment of the lower Pleistocene on the hills Chubu Chishitsu-shi(GeologyofCentralShinano), pt.4,
aroundthe Ishikari Lowland, Hokkaido. AnnualReport p.1-90, pis.1-13, Kokin-shoin, Tokyo, (in Japanese)
of the Historical Museum of Hokkaido, no.20, p.1-30. MacNeil, S.S., 1965: Evolution and distribution ofthe genus
(in Japanese with English abstract) Mya andTertiary migration of Mollusca. UnitedStates
Amano, K. and Kaetsu Group of Society for Earth Science Geological Survey, Professional Paper, vol.483-G, p.1-
EducationofNiigataPrefecture,1989: Pliocenemollus- 51, pis.1-11.
can fauna from Asahi-mura, Iwafune-gun, Niigata Pre- Masuda, F., Amano, K., Katsura, Y. and Ito, M., 1981 : Shal-
fecture. Bulletin of the Mizunami Fossil Museum, no. low marine faciès of Neogene and Quaternary strata at
16, p.109-115. (in Japanese with English abstract) the northwest and southeast parts of Teshio Town in
Amano, K. and Sato, H., 1995: Relationship between em- Hokkaido. Human Culture and Environmental Studies
baymental associations and relict species. —Mollus- in Northern Hokkaido, vol.2, p.1-41, pis.1-6. (in
Figure4. Distributional pattern of Neptunea. (Recent geographical distribution and fossil records in Kamchatka are
mainly after Golikov, 1963).
Biogeography of Pliocene and Pleistocene Neptunea 283
A type B type
QJOOkm
C ty*pre no E tYP6 no,
Fossil
•Neptunea (Ncptunca) eos (Kuroda)
ON. (N.) hataii Noda
AW. {Golikovia) nikkoenale Nomura
40"N-