an Archaic Late Oligocene Dolphin

30 Pages·2009·2.52 MB·English

Waipatiamaerewhenua^NewGenusandNewSpecies(Waipatiidae,New
Family),anArchaicLateOligoceneDolphin(Cetacea: Odontoceti:
Platanistoidea)fromNewZealand
R.EwanFordyce
DepartmentofGeology,UniversityofOtago,P.O.Box56.Dunedin,NewZealand
ABSTRACT.—Waipatiamaerewhenua,fromtheOtekaikeLimestone(lateOligocene).WaitakiValley.NewZealand,isanewgenusand
smpmecileosngi;naronsetwrufmamliolnygWaanidpantairirdoawe;(iOndcoinstoorcsetloin:g,Plpartaonciusmtboeindeta,)annedargrtahceilbea;sechoefetkhetereatdhiahteitoenroofdopnltataannidstpooildys.doIntts:femaatxuirlelsaienctleuldeescsokpueldlabbaocukto6v0e0r
frontalstowardsupraoccipital;parietalnarrowlyexposedonvertex;pterygoidsinusfossarestrictedtobasicranium;andpalatinebroadandnot
invadedbypterygoidsinusfossa.Featuresofthetympano-periotic,perioticfossa,andforamenspinosumindicateplatanistoidrelationships.
WaipatiamaerewhenuaismorecloselyrelatedtotheSqualodelphidaeandPlatanistidaethantotheSqualodontidae.Ofthesimilarsmalldolphins
pSraekvhiaoluisnl)yarideenptoisfsiiebdleaswaSiqpuaatlioiddosn.tMiideareo.cMeiteursocheecttuosriam(beairgliueusst(MliaoteceOnlei.goNceenwe.ZGeaelramnadn!yis)aanpdroSbaacbhlaelisnqoucaeltoudselcphhoildm.icPursos(qeuarallyoodronmimdadrlpeleMsiioc(eeanrel.y
Miocene.NewZealand)istransferredtoNotocetus(Squalodelphidae)asNotocetusmarplesi(newcombination).Sulakocetusdagestanicus(late
Oligocene,Caucasus)isprobablyawaipatiidclosetoW.maerewhenua.ThesetaxarevealanearlyradiationofthePlatanistoideabythelate
Oligocene.
INTRODUCTION biology,NationalMuseumofNaturalHistory,SmithsonianInstitu-
tion.Washington,D.C.
Thisarticledescribesanewfamily,newgenus,andnewspecies
oflateOligocenemarineplatanistoiddolphinfromNewZealand. SYSTEMATICS
HeterodontdolphinsfromOligoceneandMiocenerocksworld-
wbeicdaeuhsaevethpelyayaerdeatkraenysirtoiloenailniinntegrrpraedteatbioentswoefencetaarccehaaincevCoeltuatcieoan OrderCetaceaBrisson,1762
(Archaeoceti) and extant odontocetes. Waipatia maerewhenua SuborderOdontocetiFlower.1867
meetstraditionalconceptsoftheSqualodontidae,afamilyoften
usedforheterodontodontocetes.butismorecloselyrelatedtothe SuperfamilyPlatanistoideaSimpson.1945
adSMPtpmimWonohnlqooairtilauirroyedtpeappTpcraaahlaahphheerniotrnoo,enlinedidlylsestaeaoato"flrngmhiogtmptdoydoreaiyhaf,acmxmdiPeelaotedlbearhhlfaaeneeaoiahotedrwnnaanmggnisddahoyein,ocnl,enstgfdouontuhl(gmoarpsutt2Pieynrmah)ildeP,doeeamelbatnaatmadapaat.htteacblnenualiiaoillsndintnsymyimatg,pshinfisttaatiudeoasriosnact;nticetnhtgotiisethtioimhoetodnhopenhtssnalet:h,nurliceawacpSt(ortdoaaeqtov1itnuerea)itrteadftroaahxlraiinxetoeomd(nsaadpn3eiSgnro)slqftaentcyoubsshtcrrarsaeliilotpnapdnPooadettaleddidlcieaoestoeieot.tnhddnernaietestScnotaidrqliocsdoeausrepsafvaettdteteiolloice".oaeoivtrtfwddhesiIihieeerttvoianlslhonsei.g-epe--rfs ddlmWaoiaawsgiy.cepIDTCusaniyosittcpasnmailegcenmaunldigeduomceebndsuandeetisuelgss.rose.Mewp—nc—e.woehchfrTieeWaefdha.nsaleiu—miFpoaidaafl.zmftWyieiaaM.iai,lmin—,pyiealtr1ntWhyAo9ieeacs7aiwe,6opptnagrfunlt(eoosleyinrbaiwutaaidsetbnan.gheldceOe,lynluSuinodasgieecn,odnhlwcoacyengllnleiueyinnd.,unoesccsC,leatuuWudScaseuia;dlpsaautkstshpioe)easc,c,eeitaebaunesrds-,e
s(hPilpast.aniAstnoiedwea:coSmqbuianlaotdieolnp,hiNdoateo)c.etisususmeadrptlhersoiug(hDoiuctksfoonr.th1e96s4o)- — GenusWaipatia,new
calledProsqualodonmarplesiofNewZealand. Typespecies. Wa—ipatiamaerewhenua,newspecies.
Includedspe—cies. Waipatiamaerewhenua.newspecies,only.
MATERIALANDMETHODS Diagnosis. Asfortheonlyincludedspecies.Waipatiamaere-
whenua,below.—
mtmiooorrnpDeeehdsoioclnnrfoilogpyrytmiiafaotraniessvyeba,marmseweeidtbtraohsynedidpiseferofvsneiordneteanhnlcete.osrbUisgnbehrertetvfawoetreireoelnennfsct.reisdTgihhdsteet,aastnwpedhemiceclniehtmfsetevnameberwonaui-sts tgasyapriedEnetEldyonmcagoasllliiiotsngyhd.ye."cPflrairon,Fba"barlbaoelnm.edPt/dr'heoaersniuMivnnaactoi"irahoiteni.:o"nnwa:amiwe,aiW-wapaait-petarit;.i.wpaitatih,palsahpcarelolnnoeowau.rncRteeh-de
pprreeppaarreedduwnidtehrpanmeiucmraotsiccopcehiwsietlhsaanndultsrcarsaopneircs.deFnitnaelsdceatlaeirlsanwderaen Waipatiamaerewhenua,newspecies
air-abrasiveunit;somesuturescouldnotbetracedfullybecausethe Figs.2-8.9b,lOa-k,11,12,13a-g
cwaenrceeltlaokuesnbwointehias3fr5i-abmlmeaAnsdahinotPepnetramxincearamleirzaed.witPhhoato5g0ra-pmhms Material.—Holotypeonly,OU22095:askullwith23teethin
macrolens. Illustrationsderivedfromphotographsarenotcor- place,bothmandibles. 17looseteeth,lefttympanicbulla,right
rectAecdrfoornypamrsalulsaex.dhereareNMNZMa.marinemammalcatalogin paenrtieortiiocr.olefftaxpiesr,iotaincdlaanctkeirnigoranttheoriroarcipcrovceerstse,braat.lasC,olnlaetucrtaeldcbasytRo.f
OZtOhetMeaalgNaoaCn,tdi;oaDnnuOadnlUe,dOMiuMnfso,sesAiNu,lemccwaoattfaaZNlleooaegglwsainZnidne;aGOleUatonaSldgoN,ogMyW,MeluMlsDuieesnpugeatmuor,mnt,,mDeNuUnnenteiwvdoeiZfrnes,aiPltaNaylneedoow;-f qwEuewasaktTne-ysspF,oeo"urtldhNoywcocaerelsti.tthyA.o.—OftGraNDeogubronnttehrf(-oFffio,agnc.ainnad1gn).dRc.lGi1Drf..fi2dCnkoenramnerfeelnWrloae.rintpcJhaeat:noiufaNCr"rZyTeMeh1keS9,91E.5[arNtkehmw-
InA.BertaandT.A.Demere(eds.)
ContributionsinMarineMammalPaleontologyHonoringFrankC.Whitmore,Jr.
Proc.SanDiegoSoc.Nat.Hist.29:147-176.1994
148 R.EwanFordyce
30tJopi^nroitrisreejn smpaasrssievebrlaicmheisotpoondeswith NZslag
iii poorlyexposed
JW=iif,ieii,rii
20::irifif clifftop
i5S massivelimestonewith
occasionalmacrofossils
i i i
iririi
10 0I: I^gl glauconitgircadmeasssuipvelimestone
beddedgreensandwith
"9 3:9'-39'g':9393.::99':S3a:.i3'39. g°ma!rabescuaesnlindrvsaaeanrntbediomouawticsutrrmhobfuraoledsewssdotirolmsnkueedddcylasls
•^—extensivelybored
massivecalcareousmudstone
basenotseen
"TheEarthquakes"
Waipatiamaerewhenua.NewGenusandNewSpecies,anArchaicLateOligoceneDolphinfromNewZealand 149
nation. Here, the lower Otekaike Limestone represents the anarrowbandofparietalsexposeddorsally.Thesupraoccipitallies
nDausntr(eoaornliieasntSMtiaogcee(nlea)teatoppleaaterst1O3l-i1g4ocemne)a,bowvheilethWeaibtaaskeiaonfftahu-e wellRofsotrrwuarmd.,—noTtheenrcorsotarcuhmeidsureploantibveylyfalcoinagl,ewleimdeentats.itsbaseatthe
limestone. — antorbitalnotches,andattenuatedanteriorly(Figs.2a,3a).Each
medDiiuamgnsoiszies.(conOddyolnotboacsealtelewnigtthhasplpirghotxliymaatseylmyme6t0r0icmaml),skautltlenuo-f oarnltoyrbbiuttalisnosthcahl,lowwhidcohrstorvaennstmrialtltye.dtAheprfaocmiialnennetrvaen,toirsboiptaeln(apnrteeorri--
atedrostrum,heterodontpolydontteeth,andbasicraniumofarchaic bital)processextendsforwardtoboundthenotchlaterally.Anterior
grade. Placed in the Platanistoidea because theperiotic has an totherightnotch,therostralmarginofthemaxillaflaresouttoform
incipientarticularprocess,theanteriorprocessisroughlycylindri- amarkedflangemissingontheleft(Figs2a,4a.5a).Therightnotch
calincrosssectionanddeflectedventrally.andthetympanicbulla isdeeperandmoreU-shapedthantheleft.Asviewedlaterally(Fig.
hasanincipientanteriorspine,anterolateralconvexity,andventral 2c). the premaxilla forms all ofthedorsal profile; the ventral
grooveextendinganteriorlyasaseriesoflongfissures.Alliedwith surfaceoftherostrum,formedbythemaxilla,isroughlyflat,and
theSqualodelphidaeandPlatanistidae,ratherthantheSqualodonti- therostrumthinsonlyalittleapically.Inventralview(Fig.2c),the
dae,becausethelongasymmetricalposteriorapexofthepremaxilla anteriorhalfoftherostrumisgroovedmedially,whileposteriorlyit
extendsposteriortothenasaltowedgebetweentheelevatededge isgentlyconvex. Palatalridgesareindistinct,andthereareno
ofthemaxillaandfrontalonvertex,thecheekteetharesmall,the rostral fossae for pterygoid sinuses. In dorsal view, the open
incisorsarerelativelydelicateandprocumbent,thepremaxillary mesorostralgrooveiswideposteriorlybutnarrowanteriorly.Other
sacfossaisrelativelywideandexpandedmediallytoformasignifi- profilesofther—ostrumareshowninFigs.2and4
cant prenarial constriction, the pterygoid sinus fossa is in the Premaxilla. Anteriorly,thepremaxillaisnarrowestindorsal
alisphenoidand/orbasioccipital dorsolateraltothebasioccipital view at mid-rostrum, where it bounds and slightly roofs the
carfefsetctsantdhepeoxstteerrnoalmepdrioafliletoofthtehefpoerraiomteinc.orveanldee,ritnhgeiltatseirgamloigdraolovien cmaelso5ro5s+trmalmgroofovteh.eFruorstthreurmf.orTwhaerd,dotrhsealprreomsatxrialllasuftuorremswithtehatphie-
dorsalview,thedorsalridgeontheanteriorprocessandbodyofthe maxilla is prominent but not deep. The premaxilla forms an
perioticisassociatedwithadepressionnearthegrooveforthe internarialconstrictionmedially,wherethepremaxillarysacfossa
tensortympani. the profile ofthe anteroexternal sulcus ofthe iswidestbetweenthelevelofthenaresandpremaxillaryforamina.
perioticisrecurvedandconcavedorsally,andthesquamosalcarries Anteriorly,thefossaisnearlyhorizontalintransverseprofile;it
asmoothlyexcavatedperioticfossaassociatedwithanincipient narrowsandiselevatedbehindtheprenarialconstriction. Each
subcircular fossa (enlarged foramen spinosum) dorsal to the premaxillaryforamenissingle;therightislongerthantheleftand
periotic.MorederivedthandescribedSqualodelphidae,Platanisti- liesmoreposteriorly,butbothopenanteriortotheantorbitalpro-
dae,andDalpiazinidaeinthatthemandibleshaveashorterunfused cess.Theanteromedialand,particularly,theposterolateralpremax-
symphysis,thesinusfossainthealisphenoidand/orbasioccipitalis illarysulciareprominent(Fig.4a).buttheposteromedialsulcusis
larger,andtheanteriorprocessoftheperioticisrelativelylargerand shallowandindistinct.Thenasalplugmuscleprobablyoriginated
amborrueptliynfvleantterdal—ltyr.ansversely, with a blunter apex reflected more ogrnotohveenaarnrtoewrosmheedlifaolftthoetphreemparxeimlalxaitlhlaatroyvefrohraanmgesn.theMumecshoroosftrtahle
Etymology. FromtheMaorinameMaerewhenua,nameofa outermarginofthepremaxillalateraltothepremaxillarysulci
rivernearthetypelocality.Probablederivation: maere,perhaps carriesalowthickroundedridge.Indorsalview,thelateraledgeof
from maru. shelter,ormaero.theoriginalinhabitants; whenua. thepremaxillaisgentlyconvexaroundtheregionoftheexternal
countryorland.Regardedasindeclinable.Pronunciation:mae-re- nares.Lateraltoeachnarisandwithinthepremaxillaisalong
whe-nua, witha pronounced as in English "far." e as "ea" in median premaxillary cleft (new term; Figs. 4d, 5b). perhaps a
English"leather."whusuallyas"f"butsometimesas"wh"asin vascularfeature,whichascendsposteriorlytowardthejunctionof
"when,"uasdouble"o"—inEnglish"moon." premaxilla,maxilla,nasal,andfrontalatthevertex.Thecleftlies
Generaldescription. Theskullisnearlycomplete;itlacksthe justinternaltotheprominentmedialfacialcrestformedbythe
apexoftherostrum,thepterygoids,andallbutthebasesofthe maxillaandpremaxillaanddoesnotstrictlymarktheboundary
jtuogtahlso.seTohnerteheisleaftl)itbtuletsnhoeamraj(ostrrduictaugreensetoinctdhiestroirgthitons;idteheliberaainntecraisoer bpreetmwaexeinllat.heOpnosttheerolleaftt,ertahlepplraetmeaxainldlarpyosctleerftomgerdaidaelssfpolrinwtarodfitnhteo
ilsaes.liagnhdtlbyacsreuosfhetdh.eTrohsetrausmymamppeetarrysorfeatl.heTnhaesaslksu,llfrwoantsalfso,upnrdemuapxsiild-e theTpohseterporleamtaexrialllsaulicsuss.plitorbifurcatedposteriorlyintoamore
dpeorwfno;rattheedbriyghmtaxmialnldairbylteeetlha.yTbheenteaorvbeorntehsearnodst1r7upmarwtiitalhoirtswbhoodlye dvoernstarla,lppoosstteerroolmaetderiaallptlhaitnea(ssceennsduiFnogrdpryoccees1s98(1s)p.liTnth)eapnodstaermoloarte-
teethwerelooseinthematrixaroundtheskull.About 1.5nrwas eral plate isdeveloped where a thin portion ofthe premaxilla
excavatedwit—houtrevealingtherestoftheskeleton. externaltotheposterolateralsulcusoverlapsthemaxilla:thisplate
Cranium. Thecranium(thatportionofskullposteriortothe isconspicuousinlateralview(Figs.4c,6b)butisindistinctfrom
antorbitalnotches)isaboutaslongasitiswide.Inlateralview above (Figs. 4d, 5b).The narrow posteromedial splintextends
T(Fhieg.e2xet)e,rntahleonrabrietsisolpiettnleferloevmatseudbvaebrtoivcealthnearbiaaslepoafstshaegersosatbroumu.t bseephairnadtienagchthenansaaslaltofwroemdgtehebmeatxwiellean.tThheemalexfitlalnadarnidghftrosnptlailn,tsthaurse
tlheveelnawsiatlhs,thtehepofsatcoerbiitsalupprotoces3s0e-s35ofmthmefdreonetpa,ls.inAdtictahteinlgevweelllo-f asymMmaextilrliac.a—l(RFoisgtsr.a4ldp,ro5fbi)l.esofthemaxillaareshowninFigs.2a,
developed maxillo-naso-labialis(facial)muscles(Fig. 2). Facial b,eand4a-c.Atleastonemaxillaryforamenopensintheshallow
mnaursrcolweaonridginnost,efxopramneddedbyortdheeepmeanxieldlap,ostaerreolraetleartailvleyl;ytlhoenpgosatned- dtewporeorsstihorneebfeotrwaemeinnathaelsmoaoxiplelnarayrofulnadngeeacahndnoatnctho,rbbiuttalnunmobtcehr,saanrde
rtrdaiholoerrscraorelfelsatttehidevwgeiefltayhcolefaarisgtlehosenhtgaeflmolspstoosrwraa.a;iglThwhtfieotpshomsisaantx(oiFrtlibhlgieast.aafl2noasdb,soabfr)rd.otenAhrteaplbrboorounamnliidynnscepanasatrlelttloyeisfmrpnotooho-tef utcfernorocvsne.etrratTleahdiaennbdybrielgtcahhacteursiammenaatxlotirhlcbeliaatbn.aolbnVeeepnrltsooruccarealfsllasiyc,z.eedftiohsoerndmlameyamdxatiogbleywldia.tthhfCeioonrnlmaatscafrcemitmwosaslmtw,iiltoilhsfimntteohh-ete
obviouslyinflated.Theintertemporalconstrictionisreduced,with surfaceoftherostrum;itextendsbackbetweenthesubhorizontally
[50 R.EwanFordyce
Figure2.Waipatiamaerewhenua,holotype.OU22095.Skull,coatedwithsublimedammoniumchloride.Alltosamescale;scale=200mm.A,dorsal;
B.rightposterolateral;C,ventral;D,posterior;E.leftlateralofskullandleftmandible.
15!
Figure3.Waipatiamaerewhenua,holotype,OU22095.Skull,coatedwithsublimedammoniumchloride.A.ventralview,posteriorofbasicranium,
rightside.Scale=100mm.B-Ealltosamescale;rulerdivisionsareImm.B.ventromedialview,posteriorofbasicranium,rightside.C,ventralview,
posteriorofbasicraniumwithperioticinplace,rightside.D.ventralview,posteriorofbasicraniumwithperioticinplace,leftside.E,ventrolateralview,
posteriorofbasicraniumshowingpterygoidsinusfossaposteromedialtoforamenovale,rightside.
Figure4.Waipatiamaerewhenua,holotype,OU22095.A-D.skull,coatedwithsublimedammoniumchloride.A-Catsamescale;scale=100mm.A.
aCn,tleerfotdaonrtsearlo;laBt,ersaklu;llD.widtehtaairltiocfulvaetretdexm.anSdcialbele=s,50antmemr.iorE-aJn.dhsolliogthtylpye.dolresftaltyvmipeawn(imcanbudlilbal,ecsoaarteeddiwsittohrtsedubsloitmheadtasymmmpohnyisiusmdcohelsorniodte.arStciacluleat=e2p0rompemr.ly)E;.
dorsal;F,ventral;G,obliquedorsolateralofmedialface.H,medial;1,posterior;J.lateral.
Waipaiiamaerewhenua,NewGenusandNewSpecies,anArchaicLateOligoceneDolphinfromNewZealand 153
temporalfossa
anteromedialsulcus
premaxillaryforamen
posleromedialsulcus
premaxillarysacfossa
posterolateralsulcus
supraorbitalprocessofmaxilla_ frontal \_temporalcrest
maxillaryforamina
supraoccipital
naris
nasal
frontal
posteromedialsplintofpremaxilla
crestonmaxilla
posterolateralplateofpremaxilla
.parietal
frontal
.premaxillarycleft
Figure5.ReconstructionsofdorsalviewofskullofWaipaiiamaerewhenua.A,generalprofile.Scale=200mm.B.detailofvertex.Scale=50mm.
directedinfraorbitalforamenandthepalatinebutdoesnotcontrib- concavesurface.Themaxillarisesabruptlyatthevertextoforma
utetotheanteriorwalloftheorbit(Figs.2c.3a,7a). barelyelevatedmaxillarycrestthatcontactsthepremaxilla(anteri-
Thecranialpartofthemaxilla(e.g..Figs.2a,4a,c)formsalong orly)andfrontal(posteriorly)(Figs.4c,5b).justbehindthebifurca-
narrowsupraorbitalprocessthatcoversallofthefrontalbutfora tionofthepr—emaxilla.
thinlateralbandovertheorbitandcurvesingentlybehindthe Palatine. Broadlyexposedpalatinesformtheposteriorpor-
nasals.Althoughthemaxillaisslightlythickenedjustbehindthe tionofthepalatebetweenthechoanae(posteriornares)ataboutthe
antorbitalprocess,thereisnofacialcrest.Eachsupraorbitalprocess levelofthemostposteriorcheektooth(Figs. 2c, 3a,7a).The
hastwocentrallyplacedposteriorlydirectedmaxillaryforamina palatinesarecontinuoustransverselyacrosstheconvexpalate,not
aboutlevelwiththepostorbitalprocessofthefrontal;thesefo- narrowedorsplitbycontactofthepterygoidswiththemaxillae.
raminasuppliedbloodvesselsandnervestothefacialmuscles.The Contactswiththemaxillaandfrontalarelocalizedtowithinafew
maxillacarriesanteriorlydirectedgrooves,notobviouslyvascular, millimeters;thesuturesappeartobesimple.Thepalatinesulcion
anteriortothemaxillaryforamina.Posteriorly,theroundedapexof themaxillaextendbacktowardthepalatines,butthemaxillary-
themaxillaisseparatedfromthesupraoccipitalbyathinbandof palatinesutureispreservedtoopoorlytotellwhetherapalatine
thefrontalandparietal.Thoughthemaxillaissubhorizontalover foramenispresent. Mediallythepalatinescontacteachotherto
theorbit, itbecomes steeperposteromedially, with a markedly formanindistinctflatpalateboundedbyfaintpalatalcrests.Each
154 R.EwanFordyce
nasal
parietal
frontal
posteromedialsplintofpremaxilla
premaxilla
posterolateralplateofpremaxilla
premaxillarycleft
maxillaryforamen
squamosal
Figure6.ReconstructionsoflateralviewofskullofWaipatiamaerewhenua.A,generalprofile.Scale=200mm.B.detailofface.Scale=50mm.
palatineisprominentlyexcavatedposteroventrally,justbelowthe Thefossaapparentlydidnotextendanteriorlyordorsallybeyond
choana,withashallow,crescenticdepressionatthepterygopalatine thepterygoid,andthereisnoevidenceofafossainthepalatine
suture(Fig.3a).Thepalatinelacks—alateral(outer)lamina. (Figs. 2c, 3a). Fartherdorsally, the palatine and/orfrontaljust
Pterygoidandpterygoidsinus. Neitherpterygoidispreserved. belowtheorbital infundibulumlacksanychannelforanorbital
Thelossofthepterygoidsrevealsanoverlyinglargechanneltorthe extensionofthepterygoidsinus;theorbitlacksfossae.Behindthe
maxillarybranchofthetrigeminalnerve(V,).whichranfromnear orbit,theprominentsubtemporalcrest(Fig.7a)furtherindicates
theforamenovaleinternallyoutviatheforamenrotundumtothe thatthepterygoidsinuswasconfinedtotheskullbase.Smooth
orbit(Figs.3a,7a).Thelonglateralmarginofthebasioccipital. bonesurfacesposteriortothemainpterygoidfossaindicateother
basisphenoid.andvomerinfrontofthebasioccipitalcrestindicates lobesofthesinus.Probablefossaeincludethelargedepressionin
ttthhhaeetbbtaahsseiiosicnpcnhieeprniotliaaldmicanrnaedsotvfoitnmhdeeircpatatereresywgcoioidndteawc(aFtisgw.liot3nhag):.thatenhepatinetnrenyregirooirldaf.maicSenitanoconef taphrneodcaealsisss.mpoAhoetnfohoissddaea,pnrpteersresisiouromntaobbtelhtyewfegoerronoatvhleearffgoeorrptahomesetmnearnoodvmiaelbdeuilaaalnrdlnofebarelvceoiff(otVrh3me)
thepterygoidwasprobablynarrow,notexpandedmedially.Thereis pterygoidsinus,liesposteromedialtotheforamenovalearoundthe
noevidenceofawell-developedbonylaterallaminaoftheptery- carotidforamen.Suturesherearefused;thefossaprobablyinvolves
goidassociatedwiththesubtemporalcrest;thesubtemporalcrestis the alisphenoid. basisphenoid, and the dorsal part of the
theabruptventrointernalmarginofthetemporalfossa(heremainly basioccipit—alcrest(Figs.3e.8a).
formedbyalisphenoid)thatextendsfromnearthechoanaetoward Nasal. Nodular, anteroposterior^ short, wide nasals are
thesquamosal,toseparatethebasicraniumfromthetemporalfossa crudelyrectangularindorsalview,withaconvexanteriormargin
andorbit.Thiswell-preservedcrestlacksathinbonyridge,which and abiconcave posterior margin (Figs. 2a, 4a-d). In vertical
wouldbeexpectedifapterygoidlaterallaminahadextendedven- profiletheanterioredgeisrounded.Eachnasalextendsposterolat-
tral tothecrest, and lacksadefinite suture forthe pterygoid. erallybetweenthefrontalandpremaxilla,markedlysoontheleft.
Furthermore,thefalciformprocessofthesquamosal(Figs.3a-e, The interdigitating internarial suture and, particularly, the
8a,bA)rlealcaktsiveelvyidleanrgceehoefmciosnpthaecrticwailthpttehreygpotiedrysgioniuds.fossaispresent; noansloyfrsolingthatllysuotvuer—rehaarnegdtehpereesxsteerdnbaultnnaortesd.eepornarrow.Thenasals
despiteitsname,thisfossaliesmainly inthealisphenoid.The Mesethmoid. Themesethmoidformsmuchofthebordersof
missingpterygoidprobablyformedtheanteriorpartofthefossa. thenanalpassagesbelowthenasals(Figs.4d.5b).Anteromedially.
Waipatiamaerewhenua,NewGenusandNewSpecies,anArchaicLateOligoceneDolphinfromNewZealand 155
post-tympanicprocess
externalauditorymeatus
subtemporalcrest
postorbitalridgeoffrontal
frontal
infraorbitalforamen
jugal
lacrimal
frontalforamina
channelformaxillarynerveV2
pterygoidsinusfossa basioccipitalcrestJ exoccipitalJ
D _cheektooth1 mandibularforamen
canine
Figure7.ReconstructionsofWaipariamaerewhenua.Scale=200mm.A,ventralview,skull;B.dorsalview,mandible.
itformsalowrimonthenarialpassageattheposteriorofthe thechoanae,wherethenarialpassagesturnabruptlydorsallyto-
oomsresspiofrrieoessdpthrieannltoerigndra.oroivFauelr,tswheehpretrupemositatebirosoudptorro1sba0albmllyym,ftwuhisedemed.ewsiTeththehtmdhooeirsvdaolfmoesrrumrsafnaacdne/ owlveaaarsltde,6t5hteomecmxotveeprornsattlheerniaboraressti.osTtphhheeenphoaoilraditziaonnnedt,abalrlopmaaordstltyolfretvoeholefwvtihotemhebtrahseeixcftroearnnadimsueman.t
hereandfurtherventrallyinthemesorostralgrooveisdiffuseand Themarginsofthehorizontalpartaresubparallelposteriorlybut
probablycarriedcartilagethatformedaseptumbetweenthesoft (Tareoutanter—iorlyasthechoanaewiden.
tissuesofthenaresandalsofilledthemesorostralgroove.The Lacrimal. Thelacrimalisexposedtodorsalview(Figs.2a,
mesethmoiddoesnotsignificantly supportthenasals(Fig.4b). 4a-c)attheantorbitalprocess,whereitformsthelateralmarginof
Behindandlaterally,anarrowgroove(fortheolfactorynerve?) theantorbitalnotch.Suturesareilldefinedbecausethinedgeson
ascendsto—adiagonaldepression(fortheolfactoryforamen?). themaxillaarepreservedpoorly.Thelacrimalisthinbothdorso-
Vomer. Thislinesthemesorostralgroove,withathinsliver ventrally andanteroposteriorly. istransverselywide, isdirected
exposedventrallyonthepalate(Figs.2c,7a)betweenthemaxillae. anterolaterally,andhasonlyasmallventralexposure.Ventrally.the
Furtherposteriorly(Fig.3a),thesagittalpartofthevomerseparates transversely wide, anteroposteriorly narrow broken baseofthe
basioccipitalcrest
posteriorlaceratetoramen
condyle
exoccipital
hypoglossalforamen
jugularnotch
squamosal
paroccipitalprocess
foramenspinosum
spinyprocess
posteriormeatalcrest
exoccipital
externalauditorymeatus
tympanosquamosalrecess
posteriorpartoffalciformprocess
anteriorpartoffalciformprocess
pathformandibularnerveV3
pterygoidsinusfossainalisphenoid-basisphenoid
carotidforamen
subtemporalcrest
postglenoid process
tympanosquamosalrecess
sutureforbulla
post-tympanicprocess
posteriorportion,
perioticfossa-i
anteriormeatalcrest
posteriormeatalcrest
supratubercularridge
B anteriorportion,perioticfossa
foramenspinosum
alisphenoid-squamosalsuture
foramen1
foramenovale
foramen2 L- pterygoidsinusfossainalisphenoid-basisphenoid
Figure8.InterpretationsofdetailsofbasicraniumofWaipatiamaerewhenua.Scale=20mm.A.ventrolateral,rightsidewithventraluppermost,
showingpositionoffossaforpterygoidsinusinalisphenoidandbasioccipitalposteromedialtoforamenovale.B,ventralandslightlymedialaspect,right
sideshowingperioticfossa,presumedforamenspinosum,andotherstructuresaroundperiotic.