The Ungulinidae (Bivalvia, Lucinoidea) of the Red Sea

2006·3.8 MB·English

by  Van Aartsen, J J

BASTERIA, 70: 41-52,2006
The Ungulinidae (Bivalvia, Lucinoidea)oftheRed Sea
J.J.vanAartsen&]J. Goud
National MuseumofNaturalHistory Naturalis,P.O.Box9517,NL2300 RALeiden, TheNetherlands;
[email protected] &[email protected]
The Ungulinidae ofthe Red Sea are revised. Allthe species are considered to belong to
Diplodonta,butonly oneofthesecanbeclassified withDiplodontas.s.Fivespecies, includingD.
moolenbeeki spec. nov., are provisionally placed inDiplodontas.l. and onein the subgenus
Timothynus.The latter species, recorded onthe basis of asingle valve from Eilat,mightnot
belongtothe autochthonous Red Seamolluscan fauna.
Key words:Bivalvia,Lucinoidea,Ungulinidae,Diplodonta,taxonomy,newspecies,RedSea.
INTRODUCTION
During the past twenty years the study of marine mollusks of the northwestern
IndianOceanwas intensified.Newly collectedmaterialfromthis, oftennot easily acces-
sibleregion, helped muchin theprogressof ourknowledge onthesystematics and dis-
tributionof mollusksfrom theRedSea,southernArabia(Yemen and Oman), theGulfof
OmanandtheArabianSea.
The result of this renewed interest in the malacology of the seas surrounding the
ArabianPeninsulacanbefoundin astillgrowing numberofpublications onthearea,of
whichthebooks byBosch (1982),Sharabati(1984),Oliver(1992)andDance (ed.; 1995)are
well known.
Reviews of thelocalUngulinidae H.Adams & A. Adams, 1857, are givenby Oliver
(1992)[Red Sea],Kilburn(1996) [South Africa and Mozambique], Oliverin Dance(1995)
[EasternArabia], VanAartsen(2001) [Europe], Habe (1977) [Japan], Powell(1979) [New
Zealand], Noonan (1991a, 1991b, 1992a, 1992b), as well as Lamprell & Healy (1998)
[Australia],Dall(1899,1901)[United States] andCoanetal.(2000)[NW.America].Forthe
Ungulinidae fromtheRedSea,thecontributionsby Oliver(1992), Oliverin Dance(1995),
and Kilburn(1996) are of mainimportance. Older works e.g. by Lamy (1916, 1921)are
helpful too.
Only one genus, viz. Diplodonta Bronn, 1831,is usually recognized in theRed Sea.
Although Chavan (1962, 1969) pretends to solve the supraspecific units of the
Ungulinidae, thesepapersare not veryuseful in practice. We agreewithKilburn (1996:
267)that"Unfortunately, inpractice, differencesbetweenthehigher taxa are not always
clear-cut
Moreover,theoutlineoftheshells, which wastakenas the maindiscriminating fac-
tor by authors in the past seems to be variable. For instance, for Diplodonta rotundata
(Montagu, 1803)thetype species of thegenus,theoutlinevariesbetweenperfectly ellip-
ticalandconspicuously quadrangular. Alsothe depthof thevalvesis somewhatvariable.
Inour view, thespecies withaclearly recognizable nymph (and ligament) shouldbe
consideredtobelong to Diplodonta s.s. However,mostspecies fromtheRed Seahaveno
nymph atall.
Thesespecies arecongeneric withUngulina scleractinicaKilburn, 1996.FromKilburn's
42 BASTERIA, Vol. 70, No. 1-3,2006
figureofthehinge plate (Kilburn, 1996:269,fig.l)we concludethatthisspecies doesnot
belong totheWestAfricangenus Ungulina deRoissy, 1805, however.Thestructure of the
hinge plate is analog to thatofDiplodonta sericata A.Adams & Reeve,1850,as figured by
Lamy (1921: 339,figure intext).Lamy (1921:339) consideredthis typeof hinge and liga-
menttoberepresented byMysia ustaGould,1861,typespecies ofFelaniellaDall, 1899.We
havenot beenable to confirmthis and, therefore, use thegeneric nameDiplodonta in a
broad sense ('s.l.'), realizing that severalof the species dealtwithmay in fact belong to
another genus.
Inthecaseof theSouthAfricanspecies Diplodontapinnaculum Kilburn, 1996,ofwhich
we saw only one valvefromtheoldportofEilat, weagreewithKilburntouse Timothynus
Harris&Palmer, 1946,as asubgenus.
Abbreviationsforcollections:BMNH, TheNaturalHistoryMuseum,London,United
Kingdom; HD, H.Dekker,Winkel, TheNetherlands;HUJ, HebrewUniversity, Jerusalem,
Israel; MNHN, Museum National de Histoire Naturel, Paris, France; MRSN Museo
Regionale di Scienze Naturali, Torino, Italy; NHMW, Naturhistorisches MuseumWien,
Austria;NMW,NationalMuseum ofWales,Cardiff, UnitedKingdom; RMNH,Nationaal
NatuurhistorischMuseumNaturalis,Leiden,TheNetherlands;TAU,TelAvivUniversity,
TelAviv, Israel; UMC, University MuseumCambridge, UnitedKingdom; ZMA, Zoolo-
gisch Museum,Universiteitvan Amsterdam,Amsterdam,TheNetherlands.
Additionalabbreviations:juv, juvenile; p,paired valves; v, valve(s).
Key fortheUngulinidae species oftheRedSea.
l.a.Aclearlydefinednymph fortheexternal ligament ispresent
Diplodonta (D.) subrotunda
l.b. Nonymph apparent 2
2.a.Shellsvery tumid/globose 3
2.b.Shellslenticular, not very tumid/globose 5
3.a.The posterior cardinalin theright valveis fully split-up into two divergent separate
teeth.Only one valveknown fromtheRedSea D.(Timothynus) pinnaculum
3.b. The posterior cardinalin the right valveis clearly bifidbutnot separated into two
independent teeth 4
4. a.Hinge-plate nearly straight,outlineregularly elliptical[<35mm] D. globosa
4.b.Hinge-plate nearly straight, outlinemore roundish and posterior side more or less
straight [<25mm] D. moolenbeeki
4.c. Hinge-platecurved, shellssmaller[< 15mm] D. genethlia
5.a. Hinge-plate nearly straight, shellsratherlarge [<25 mm] D. moolenbeeki
5.b.Hinge-plate curved, shellssmaller[< 15mm] 6
6.a. Outer surfacewith many punctures, outlinesomewhatquadrangular. Only known
fromdeep water D. raveyensis
6.b.Outersurfacesmooth withonly slightgrowthlines D. bogii
Van Aartsen& Goud: The Ungulinidae oftheRedSea 43
Diplodonta Bronn,1831
Type species: Venus lupinus Brocchi, 1814 [= Tellinarotundata Montagu, 1803], by subse-
quentdesignationby Herrmannsen, 1846:392.
Other species belonging to this genus: D. rotundata(Montagu, 1803) [S.and W.Europe];
D. lateralisE.A. Smith, 1876[S. and E. Africa]; D. planissima Kilburn, 1976 [S.Africa]; D.
zelandica(Gray, 1835)[NewZealand],
Figs1,2.Diplodontasubrotunda Issel, 1869,Egypt,GreatBitterLake,RMNH (ex coll.Beets,St.01),actual
length16mm; 1,leftvalve;2,rightvalve.
Diplodonta subrotundaIssel, 1869(figs 1,2)
Diplodontasubrotunda Issel, 1869:253-254,pi. 3 fig.2.
Diplodontarotundata (Montagu,1803)[inpart];Lamy, 1916: 187-188.
?Diplodontalateralis Smith;Lamy, 1938:32.
Diplodontarotundata Montaguetvar.subrotunda Issel[inpart];Moazzo,1939:93,pi.8fig.4right[nonfig.
4left].
Diplodontasubrotundata [sic] Issel; Oliver, 1992:102[inpart,not: 96textfig.24,pi.21 fig.2];Oliver, 1995:
237nr. 1039;Hoenselaar &Dekker, 1998:205[inpart]; Zuschin&Oliver, 2003: 109,figs26.6-10.
Anodontia edentula (L.,1758);Coulombel,1994:125,figs[nonL.].
Diplodontasubrotunda Issel; Dekker &Orlin,2000:11
Material studied. —Holotype:Red Sea,subfossil,MRSN lv[= Issel, 1869,pi. 3 fig.2]
Egypt:SafagaBay,NMW 1997.021.000604v, 1997.021.00071lp, 1997.021.00091lp&5v,GreatBitter
Lake,RMNH(exColl. Beets: St.l:4p&6v,St.4:lp&4v,St.6:lv, St.7:6v,St.21:manyv,St.26:lv,St.31: 6v,
St.40:lv and St.42:many v), HUJ 7900 2p & lv, 7904 2p & 3v, Little Bitter Lake,HUJ 3584 lv,Ras
Muhamed,HUJ 8112 lv,TAU NS12068 lp, Suez, MNHN2p & 2v; Israel: Dahab, Gulf ofElat, TAU
NS12058 lp;Sudan:Souakim,MNHN2p;Ethiopia:Assab,HUJ2946lp,Dahlak Archipel,MuseriTAU
exM030012 lv, Massaouah: MNHN4p& lv;SaudiArabia: Musselamiwah Bay, NMW1992.001.00011
2v;Yemen:Red Sea coast: alHudaydah,Ra's alKatib,westcoast, HD lp& 13v; south coast:al-Marah,
Khaysayt, 15° 36'06" N 52°11' 02"E, HD 2v, Aden, NMW 1955.158.11310 lp, 1968.130.00034 4v,
44 BASTERIA,Vol. 70,No. 1-3,2006
Figs3,4.Diplodontaglobosa(Forsskål inNiebuhr,1775),Egypt,Suez,MNHN[=Oliver,1992:pl. 21fig. 1a,
b];3,leftvalve,actuallength30.5mm,4,right valve,actuallength31.5 mm.
1992.023.001802p, MNHN lp &4v, Khor Rowri, NMW 1995.008.00064lv; Oman: 1991-102,HD 15v,
Arabian Sea, NMW 1993.061.01737 3v, Fehel Island, ZMA lp, Masirah, NMW 1993.061.00488 5v,
1993.061.00507 3v, 1993.061.01736 lp;Muscat;Fujayrah, NMW 1993.061.01691 6v, Ras al Hadd, NMW
1993.061.0049222v, 1993.061.1581 lp[=OHver, 1995fig. 1039],1995.008.000632v; UnitedArab Emirates:
Abu Dhabi,NMW 1993.061.01738 lv,Khor Umm,NMW 1993.061.00479 lOv; Pakistan: Karachi, NMW
1955.158.11317 lp&3v.
Diagnosis. —Shellofmediumsize, 20-25mm.Hinge withclearnymph. Outlineusu-
ally roundish,not very angular. Shape nottumidbutratherlenticular.
Notes. —Thisspecies is theonly onein theRedSeashowing a clear nymphfor the
external ligament. All otherspecies of Diplodonta show an"internal"external ligament
whichis fastenedin a grooveontheoutsideofaresilium. Thiswas already discussedby
van Aartsen(2004: 74,75 figs 1-4).
Diplodonta subrotunda was describedatthetimeoftheconstructionoftheSuez-canal,
fromafossil valveoriginating fromtheRedSeacoastofEgypt. Thereforewe considerit
mostunlikely thatD. subrotundashouldberegarded asavarietyoftheEuropean D.rotun-
data(Montagu, 1803)as suggested by Issel ( 1869:253),Lamy ( 1916: 187)and Moazzo(
1939:93), although both species haveseveral charactersin common.Study of thetypeof
Diplodonta lateralisSmith, 1876, convincedus thatthisis adifferentspecies, also showing
aclearnymph as canbe seenfrom thefiguresby Kilburn(1996:273, figs 9-12).
D. subrotundaIssel, 1869is notrestrictedtotheRedSea,but livesalso intheArabian
Sea, theGulfofOmanup toKarachi, as canbe concludedfromthematerialstudied.
Diplodonta s.l.
Diplodonta globosa(Forsskål, in Niebuhr, 1775)(figs 3, 4)
Venus globosaForsskal, 1775:122,nr.53;Yaronetal., 1986: 175,figs9-10,
Van Aartsen &Goud: The Ungulinidae oftheRedSea 45
DieKugelvenus;Chemnitz,1784: 36,pi. 40figs 430-431.
;Savigny, 1817:pi. 8 figs7.1-7.5.
DiplodontasavignyiVaillant, 1865:117, 124-125;Issel, 1869:81, 358;Bouchet &Danrigal, 1982:15,fig. 9.
DiplodontabullataDunker, 1865:76,pi.26 figs1-3.
DiplodontaglobosaForskal;Lynge,1909:175;Lamy, 1916:188-189;Moazzo,1939:92-93,pi. 8 fig.3.
Diplodontaglobosa(Forskal) Chemnitz;Pallary, 1926: 102,pi. 12fig. 7.1-7.7.
Diplodontaglobosa(F.);Oliver, 1992: 101,96fig.23,pi.21 fig. 1.
Diplodontaglobosa(ForsskalinNiebuhr);Dekker& Orlin,2000:11.
Diplodontaglobosa;Zuschin&Oliver, 2003: 110,0gs 26.1-2.
Material studied. —Egypt: Suez,MNHN 2v [= Oliver, 1992: pi. 21 fig. 1] &lp juv& llv, NMW
1955.158.11454 lv (exLamy);GreatBitterLake,RMNH (exColl BeetsSt.27lvjuv); Jordan:Aqaba,HUJ
2951 lv;Erythrea:Massaua HUJ 2938 lv;Yemen:Aden,MNHN lpjuv& 2v.
Diagnosis. — Shelllarge, 30-35 mm.Hinge withoutnymph butwithlongandnarrow
resilifer. Outlineelliptical: length somewhatgreaterthanheight. Shape very tumidand
globose.
Notes. — Thefirstspecies ofDiplodonta tobe describedfrom theRedSea.Although
rather rare itis atthe sametime thelargest species and forthis reasonnoted by authors
in theearly daysofmalacology. Specimens of D.globosa can reachupto35mm in dimen-
sionand theiroutlineis aperfect ellipse. Young specimens have theposterior sidesome-
whatquadrangular and as such caneasily be confoundedwithD. moolenbeekispec. nov.
However,theinternalligament (resilium) inD.globosais muchlongerandnarrower com-
pared withthatofD. moolenbeeki.
We couldstudy only a fewspecimens and valves, all of whichoriginating fromthe
Red Sea.
No specimens fromthePersianGulf,as reported by Melvill(1928: 114),were avail-
able.
Diplodonta moolenbeeki spec.nov.(figs 5,6)
Diplodontarotundata (Montagu,1803)[inpart];Lamy, 1916:187-188.
Diplodontarotundata Montaguetvar.subrotunda Issel [inpart]; Moazzo, 1939:93,pi. 8 fig. 4-left[nonfig.
4-right],
Diplodonta subrotundata [sic] Issel [inpart]; Oliver, 1992: 102, 96 textfig. 24,pi. 21 fig. 2;Hoenselaar &
Dekker, 1998:205.
Diplodontacf.globosa(F.);Oliver, 1995: 237nr. 1038
Diplodontaglobosa(F.);Hoenselaar &Dekker, 1998:205
Diplodontasp.;Dekker&Orlin,2000:11
TypeMaterial. — Holotype:Egypt: Suez,MNHN[=01iver, 1992pl.21fig.2];Paratypes:Egypt:Suez,
NMW 1955.158.11355 lp, 1992.001.00013 2v, HUJ 8109 lv, MNHN 4p & many v; SafagaBay, NMW
1997.021.00038 many valves;Sharmel-Naga, HD lp, HD2v; Great BitterLake,RMNH (ex coll. Beets,
St.18: lv,St.32:lv,St.46: lv); 7km S ofHurghada(ElSamaka Village),RMNH 102213(ex coll.J. Goud,
6p); RasMuhamed,HUJ8111 lp, TAUNS1422 2v; Shora-el MarquataHUJ 8110 12v; Sudan:Souakim:
MNHN 2p; Ethiopia: Dahlak Archipel, TAU MO 30011, 30012 3p; Saudi Arabia: Dahran, NMW
1993.061.01742lv; Yemen,Red Sea coast:Midi,OrestePoint 16°22'N42°46'E,HD8v;Ras Hasik,NMW
1993.061.00497 lv;Aden,NMHN lp&llv; Oman: Mussadam,NMW 1995.008.000535v;Quriyat, ZMA
46 BASTERIA,Vol. 70, No. 1-3,2006
Figs5,6.Diplodontamoolenbeeki spec. nov.,holotype,Egypt, Suez, MNHN[=Oliver,1992:pl. 21 fig.2a,b],
actual length18mm;5,left valve,6,right valve.
many p& v, NMW1993.061.017263p &33v; stat. 1991-91,HD lv; stat. 1991-102, HD 2v;Ras Suwadi,
RMNH 102306 (leg. E. Bostock), 2v; Muscat: Masirah, NMW 1993.061.00484 3v, 1993.061.00496 lv,
1993.061.005012v, 1993.061.00503lv, 1993.061.00505 lp & 12 v, 1993.061.00506 8v, 1993.061.01682 2v,
1995.008.00052lp, ZMA lv; Fujayrah, NMW 1993.061.00485lv, 1993.061.016663v, 1993.061.01667 2v,
1993.061.01728 many valves;RasalHadd,NMW 1993.061.004986v, 1993.061.005022v, 1993.061.01508lp
[Oliver, 1995: 237,fig. 1038), 1993.061.01727 4v, 1995.008.00063lv; Bahrain: OuterTubli Bay, NMW
1993.061.00508 many v;UnitedArab Emirates:Khor Umm,NMW 1993.061.017392p;AbuDhabi,NMW
1993.061.01741 lp& lv,1993.061.01743 3v.
Diagnosis. — Shellof mediumsize, 20-25 mm. Hinge without nymph butwithcon-
spicuous resilifer. Outlinemoreorless angular posteriorly. Shape varying fromtumidto
less swolenandlenticular.
Description. — Shell more or less angular posteriorly and moderately tumid.The
outer surfacesmooth, only showing slight growth-lines. Thehinge consists of twocardi-
nals, the anterior in the left valveand the posterior in the right valve aresplit intotwo
equal parts. Therearenolaterals. Thehinge-plate nearly straight andrathernarrow. The
resilium for the internalligament rathershort and pear-shaped. There seems tobe no
external ligament.
The largest specimen is 22 x 25 mm.Theholotype measures 16x 18mm
Differentiation. — Thisnew species has been confused with Diplodonta subrotunda
Issel, 1869, as well as withDiplodonta globosa (Forsskal in Niebuhr,1775).Diplodonta sub-
rotunda differsbecause it has a clearly recognizable external ligament and nymph as
shownby vanAartsen(2004:75,figs 1-2).
Full-grown Diplodonta globosa hasaregularly elliptical outlinewhichis notangulated
as in D. moolenbeekispec. nov. Only youngspecimens ofbothspecies are easily confused.
However, theresilium inD. globosa is muchlonger and narrower thanthatin D. moolen-
beeki.
Ethymology. — This species is namedafterRobertMoolenbeek(ZMA), well known
forhis work ontheMolluscaof theGulfofOman andfriendoftheauthors.
Van Aartsen &Goud: TheUngulinidae oftheRedSea 47
Figs7, 8.Diplodontagenethlia(Melvill,1898);7,leftvalve,Oman,NMW1993.061.01733,actuallength12.5
mm,8,rightvalve,Yemen,Aden,NMW1955.158.02251 (exLamy)[=Oliver, 1992:102,pl.21figs3a,bs.n.
Diplodontaravayensis],actual length8.1mm.
Diplodonta genethlia (Melvill, 1898)(figs 7, 8)
DiplodontagenethliaMelvill,1898: 32-33,pi.2 fig. 11
Diplodontaravayensis[sic] Sturany;Oliver, 1992:102,pi.21 fig.3,3a,
Diplodonta genethila[sic]Melvill;Oliver, 1995:237,fig. 1036.
Material studied. — Egypt:SafagaBay, NMW 1997.021.0038 lv; Suez,MNHN 4v; Israel: offElat,
TAU MO30013 lv, NS26762 4v;Yemen:Aden,NMW1955.158.02251lv (exLamy)[Oliver, 1992: 102,
pl.21 figs 3a,b], MNHN 9v,Djibouti, MNHN 7v; Iran:Gais (=Kais) Island,BMNH 98.7.5.120-121,lp&
2v.(syntypes);Muscat: NMW 1955.158.00685 lp& lv (syntypes)[excoll Townsend],1955.158.11328 lp,
1955.158.11449 2p, 1955.158.11490 2p, Fujayrah, NMW 1991.102.00025 3v [Oliver, 1995 fig. 1036],
1993.061.00481 2v, 1993.061.01729 12v, 1993.061.01730 31v, 1993.061.01731 85v, 1993.061.01732 many
valves, 1993.061.01733 3p & 33v, Ras al Hadd, NMW 1993.061.00478 lv, 1993.061.00480 2v; Bahrein:
Juffair,GrandMosqueBeach,NMW1993.061.04943v;Oman:Arabian Sea, NMW 1003.061.01737lv.
Diagnosis. — Shellsmall, 10-15 mm. Hinge withoutnymph. Shape tumid,triangular
in outline.
Notes. — D.genethlia hasneverbeenmentionedfromtheRedSea.FromtheMNHN-
materialwefoundthatitwas confoundedbyLamy withD. bogii underthenameD. tumi-
da(H.Adams, 1871).
AnotherDiplodonta valve was published by Oliver (1992: 102, pi. 21 fig.3) underthe
nameofD.ravayensis[sic] Sturany, 1899.ThisvalveoriginatesfromtheMelvill-Tomlincol-
lection.
A labelstating “Diplodonta tumidaH.Ad probably written by Lamy, confirms the
,
factthat Lamy consideredDiplodonta tumida(H. Adams, 1871)in a verybroad sense.
Fromtheample materialofD. genethliaoriginatingfromOman,the Arabian Sea and
48 BASTERIA,Vol. 70,No. 1-3,2006
Figs 9,10.DiplodontaraveyensisSturany, 1899,GulfofOman,-150ftms. [excoll.Townsend];9,rightvalve,
actuallength8.5mm, 10,rightvalve, actuallength11.5mm.
otherlocalities, itis clear thatD. genethlia is not asynonymofD. raveyensis Sturany, 1899
too. Theoriginal descriptionandfigures by Sturany (1899: 285,pi. 21 fig.3a,b) are com-
pletely differentfrom the relative thick, tumidand more or less triangular D. genethlia
witha smoothexteriorsurface.
D. genethlia doesnot only occur atthe southern entrance of the Red Sea (Djibouti,
Aden)but isalsopresent at SuezandSafaga bay in thenorthernRedSea.The species is
thickershelled, moretriangular inshape andlarger thanD. bogii.
Notethatthe"threetofourplates" [=folds] attheanteriorside,mentionedintheorig-
inaldescriptionby Melvill(1898: 32) occuronlyin less thanhalfthespecimens as canbe
concludedfrom the abundantmaterialin NMW, and which was mentioned alreadyby
Oliverin Dance (1995:237,fig. 1036).
Diplodonta raveyensis Sturany, 1899(figs9, 10)
DiplodontaraveyensisSturany, 1899:285-286,pi. 6 figs8-11
Diplodonta tumida H.Adams [inpart?];Lamy, 1916: 189-190[non H.Adams, 1871][raveyensisinsyn-
onymy]
Material studied. —Gulf ofOman, 150ftms:NMWZ.1955.158.11452[excoll. Townsend)2v.
Diagnosis. — Shell small, 10-15 mm. Hinge without nymph. Outline quadrangular.
Shape relativelyflat, lenticular.Outersurfacewithmanypunctures.
Notes. —The shells areratherthin: thecharacteristicpuncturesof theoutsidecanbe
seenfromtheinside!
Only seenfromonesample inNMW,originating fromtheGulfofOman.Atthesame
time thisis theonlysample availablefromdeeper water (~ 250 m).
Van Aartsen &Goud: The Ungulinidae oftheRed Sea 49
Figs 11,12.DiplodontabogiivanAartsen,2004,Egypt,GreatBitter Lake,RMNH (ex coll.Beets, St.10),
actual length7.5mm;11,left valve,12,right valve.
Diplodonta bogii van Aartsen,2004(figs 11, 12)
DiplodontabogiivanAartsen;vanAartsen,2004:73-76,figs3,4,
DiplodontatumidaH.Adams;Lamy, 1916[inpart?]: 189-190;Moazzo, 1939: 93-94.
Diplodontasp.;Oliver,1992: 102,96 textfig.26,pi. 21fig. 4;Hoenselaar &Dekker, 1998:205.
Diplodontasubrotunda Issel; Bogi&Galil,1999:29-30,figs1-2.
Diplodontatumida(H.Adams);Dekker & Orlin,2000:11
Diplodontasubrotunda sensuBogi&Galil;vanAartsen,2001:51,49 figs10,11
Diplodontaravayensis [sic]Sturany; Zuschin &Oliver,2003:110,figs26.3-5.
Diplodontacf.subrotunda Issel; Zenetosetal., 2004:260-261,fig.
Diagnosis. — Shellsmall, 7-10 mm.Hinge withoutnymph. Outlineroundish. Shape
lenticular.
Notes.—Recently describedbyoneoftheauthorsithasbeenregarded asMysiatumi-
daH.Adams,1871. Manyof thesamplesin theMNHNshow, thatLamy consideredthis
as wellas Diplodonta genethlia Melvill, 1898tobeAdams's species. VanAartsen (2004:75,
76) showed that Diplodonta tumida can not be recognized at present and so the name
shouldnot beused. The species discussedby Zuschin & Oliver(2003: 110,figs 26.3-5)
under the nameDiplodonta ravayensis;[sic] Sturany, 1899is in fact Diplodonta bogii van
Aartsen,2004.
Diplodonta (Timothynus) Harris&Palmer, 1946
Type species: Sphaerella bullaConrad, 1865;by original designation (Harris &Palmer,
1946:86.)
A synonym is Sphaerella Conrad, 1838 (non Sommerfelt, 1834), with type species
Sphaerellasubconvexa Conrad, 1838;by original designation.
50 BASTERIA, Vol. 70, No. 1-3,2006
Fig. 13.Diplodonta(Timothynus)pinnaculum
Kilburn,1996,Israel,Elat(oldport,-121m),
TAU,right valve,actuallength7.5mm.
Otherspecies belonging inthis subgenus: D. (T).pseudoglobosa Kilburn, 1996,and D.
(T.) pinnaculum Kilburn, 1996)[SouthAfrica],D. verrilliDall, 1899 [United States]
Diplodonta (Timothynus) pinnaculum Kilburn, 1996 (fig. 13)
Diplodonta(Timothynus)pinnaculum Kilburn, 1996:279-281,figs8,19-21
Timothynuspinnaculum(Kilburn);Dekker&Orlin,2000:11.
Material studied.— Israel:GulfofAqaba,Elat (oldport, 121 m)TAUlv.
Diagnosis. — Shellsmall, 10-15mm. Hinge withoutnymph, butwiththreecardinal
teethinsteadofthe usualtwo(oneof whichisbifid).Shape verytumidorratherglobose.
Thininmaterial.
Notes. — This very characteristic species was present in only onevalve. As it was
foundin aninternationalharbourwe doubtitspresence intheRedSeain general.
Thespecies caneasilyberecognized byits verytumidgloboseformandinparticular
by the diplodontid bifidtoothbeing split completely, so as to resultin thehinge consist-
ing of threeindependent teeth.
ACKNOWLEDGEMENTS
ThehelpofDr G.Pavia (MRSN), MrsV.Herosand Dr Ph.Bouchet(MNHN), MrsA.
H.Wood andDr P. G. Oliver(NMW) as well asDr R. Preece (UMC), MrH.Mienis (HUJ
and TAU)by makingavailablematerialin theircareis gratefullyacknowledged. Weben-
efitedfromdiscussionswithMr H.Dekker (Winkel).