On reconstructing Giraffa sivalensis, an extinct giraffid from the Siwalik Hills, India

29 Pages·2015·28.33 MB·English

ff
On reconstructing Gira a sivalensis, an
ffi
extinct gira d from the Siwalik Hills,
India
SybrandJ.vanSittert1 andGrahamMitchell1,2
1CentreforVeterinaryWildlifeStudies,DepartmentofProductionAnimalStudies,Facultyof
VeterinaryScience,UniversityofPretoria,SouthAfrica
2DepartmentofZoologyandPhysiology,UniversityofWyoming,LaramieWyoming,USA
ABSTRACT
GiraffasivalensisoccurredduringthePlio-Pleistoceneperiodandprobablyrepre-
sentstheterminalspeciesofthegenusinSouthernAsia.Theholotypeisanalmost
perfectlypreservedcervicalvertebraofdisputedanatomicallocation.Although
thereisalsouncertaintyregardingthisanimal’ssize,otherspecimensthathavebeen
assignedtothisspeciesincludefragmentsoftwohumeri,aradius,metacarpiand
teeth.Hereweestimatenecklength,leglengthandbodymassusinginterspecific
and,unusually,ontogeneticallometryofextantgiraffeskeletalparameters.The
appropriatenessofeachequationtoestimatebodymasswasevaluatedbycalculating
thepredictionerrorincurredinbothextantgiraffes(G.camelopardalis)andokapis
(Okapiajohnstoni).Itfollowedthattheequationswiththelowestpredictionerror
inbothspecieswereconsideredrobustenoughtouseinG.sivalensis.Thesizeof
G.sivalensis,basedontheholotype,isproposedas400kg(range228kg–575kg),
withanecklengthofapproximately147cmandaheightof390cm.Themolar
lengthsoftoothspecimensconsideredagreewiththissizeestimate.Thehumeruswas
themostappropriatelongbonetoestablishbodymass,whichestimatesaheavier
animalofca790kg.Thediscrepancywiththevertebralbodyweightestimatemight
indicatesexualdimorphism.RadialandmetacarpalspecimensestimateG.sivalensis
tobeasheavyasextantgiraffes.Thismayindicatethattheradiusandmetacarpusare
Submitted 13March2015 unsuitableforbodymasspredictionsinGiraffaspp.Alternatively,certainlongbones
Accepted 7July2015 mayhavebelongedtoanotherlongleggedgiraffidthatoccurredduringthesame
Published 4August2015
periodandlocalityasG.sivalensis.Wehaveconcludedthatifsexualdimorphism
Correspondingauthor
waspresentthenmaleswouldhavebeenabouttwicethesizeoffemales.Ifsexual
SybrandJ.vanSittert,
[email protected] dimorphismwasnotpresentandallboneswerecorrectlyattributedtothisspecies,
thenG.sivalensishadaslenderneckwitharelativelystockybody.
Academiceditor
JohnHutchinson
AdditionalInformationand
Subjects EvolutionaryStudies,Paleontology,Zoology
Declarationscanbefoundon
Keywords Giraffa,Allometry,Necklength,Giraffidae,Plio-Pleistocene,Scaling,Bodymass,
page25
Siwalik,Okapia
DOI10.7717/peerj.1135
Copyright
INTRODUCTION
2015 vanSittertandMitchell
Giraffasivalensis(Falconer&Cautley,1843)wasthefirstextinctGiraffaspeciestobe
Distributedunder
CreativeCommonsCC-BY4.0 discovered,yetneitheracompleteskullnorspecimensrelatedtotheholotypevertebra
have been found. Notwithstanding this limitation, many fossil specimens have been
OPENACCESS
HowtocitethisarticlevanSittertandMitchell(2015),OnreconstructingGiraffasivalensis,anextinctgiraffidfromtheSiwalikHills,
India.PeerJ3:e1135;DOI10.7717/peerj.1135
assignedasbelongingtothisspecies,withoutadequateconsiderationofitssizeorwithout
explicitlycitingthestratigraphichorizonofdiscovery(TableS1).Inaddition,manyofthe
discoveredspecimenshaveonlybeendescribedintheFaunaAntiquaSivalensis,whichisa
collectionofFalconer’spublicationsandunpublishednotes(Murchison,1868b).Although
alltheplates(notablyplateE)withintheFaunaAntiquaSivalensisarewelldescribed
(Murchison,1868a),manyofthemhaveneverbeenpublished.
History of G. sivalensis discovery
Cautley(1838)brieflydescribedthediscoveryofaremarkablevertebraintheSiwalikHills
inIndia.Hebelievedthespecimentobeverysimilartothatofextantgiraffes—asignificant
statement,becauseupuntilthattimenootherfossilGiraffaspecieswereknown.Falconer
&Cautley(1843)subsequentlynamedthespeciesCamelopardalissivalensisandassigned
thefossil,whichwastobecometheholotype(Badam,1979),asathirdcervicalvertebra.
However,Lydekker(1885)disputedthisandproposedthattheholotypewasinactual
factafifthcervicalvertebraofa‘verysmallindividual’.SinceCautley’sdiscovery,other
Giraffa-likefossilshavealsobeenfoundinAsia,EuropeandAfrica,subsequentlyleading
toproposalsforspeciessuchasG.priscilla,G.jumae,G.stillei,G.gracilis,G.pygmaeaand
G.punjabiensis.Thereferencestothesefossilspecimensareextensive,incompleteand
confusingascanbeseenbythereferencestoG.sivalensisaloneinTableS1.
Geographic and stratigraphic distribution of fossils
Matthew(1929)placedtheupperSiwalikdeposits,whereG.sivalensisfossilsandnearly
allSiwalikfaunadiscoveredbyearlywriterssuchaFalconerhavebeenfound(Lydekker,
1876),aspartofthePinjorzone(Gaur,Vasishat&Chopra,1985;Akhtaretal.,1991;Nanda,
2002;Nanda,2008;Bhatti,2004).ThePinjorzonedatestoroughly2.58–0.6millionyears
ago,placingthefaunadiscoveredinthissiteasoriginatingduringthelatePliocene/early
Pleistocene (Nanda, 2008). The site of discovery of the holotype for G.sivalensis was
presentedbyFalconer&Cautley(1843)onlyas‘theSewalikrangetothewestoftheriver
Jumna’(currentlytheYamunariver).AlthoughSpamer,Daeschler&Vostreys-Shapiro
(1995)describedthelocalityas‘SiwalikHills,nearHardwar,UttarPradesh’,thisisunlikely
asHardwariseastoftheYamuna.Wethereforebelievethelocalitywasprobablyinthe
vicinityofthecurrentShivalikfossilpark,Saketi,HimachalPradesh,India(Fig.1).
Size estimates and controversy
SizeestimatesofG.sivalensishavebeeninadequateorcontradictory.Forexample,ithas
beenproposedthatG.sivalensiswasabout‘onethirdshorter’withaneckabout‘one
tenthmoreslender’thanextantgiraffes(Falconer&Cautley,1843),andthattheholotype
belongedtoaverysmallindividual(Lydekker,1885),thatithadthesamesizedcranium
asextantgiraffesbutwithashorterneck(Lydekker,1876),thatitwasalargespeciesbut
smallerthanextantgiraffes(Bhatti,2004,p.155),thatitwasofcomparablesizetomodern
giraffes(Bhatti,2004,p.255),thatitwaslargerthanextantgiraffes(Mitchell&Skinner,
2003)andthatcertainproportionsofthespecies’neckwerelargerthanextantgiraffes
(Lydekker,1876,p.105).Additionalfossilspecimensoriginallythoughttobelongtoa
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 2/29
Figure1 AmapindicatingtheprobablevicinityofG.sivalensisfossildiscoveries.Themarkerindicates
thelocationoftheShivalikFossilParkintheSiwalikHills,asubHimalayanmountainrange.Thisismost
probablythearea‘westtotheriverJumna’(currentlyYamunaRiver)towhichFalconer&Cautley(1843)
referred.Mapdata:AutoNavi,Google.
separatespecies,G.affinis(Falconer&Cautley,1843),weresubsequentlyshowntobelong
toG.sivalensisandarecurrentlybelievedtoindicatealargerindividualofthespecies
(Lydekker,1876,p.105;Bhatti,2004,p.140).Table1summarisesprevioussizeestimatesfor
G.sivalensis.
InthispaperweoutlineandclarifytherelevantinformationaboutG.sivalensisandits
remains.Inaddition,wehavemadenewestimatesofitssizeandshape.
MATERIALS AND METHODS
Studied material and dimensions measured
AllpostcranialspecimensassignedtoG.sivalensisthatwereavailableattheNaturalHistory
MuseuminLondonwerestudied.Fromthesespecimens,bodyandnecksizeestimates
werecalculatedusinggiraffeontogeneticoravailableinterspecificallometricequations.
Theonlyvertebrameasuredwastheholotype(OR39747,Fig.2),acervicalwhichhadbeen
extensivelydescribedbyFalconer&Cautley(1843).Acaudalfragmentofa‘fourth’cervical
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 3/29
Table1 PrevioussizeestimatesofG.sivalensis.
Sizeestimate Author Relevantspecimens/comments
‘Onethirdshorter’withaneck‘onetenthmore Falconer&Cautley,1843; Holotypevertebra,OR39747.
slender’asextantgiraffes. Lydekker,1876,p.105
Largespeciesbutsmallerthanextantgiraffes. Bhatti,2004,p.155 Nospecimenreferredto.
Ofcomparablesizetomoderngiraffes. Bhatti,2004,p.225 Nospecimenreferredto.
Similarheadsizetoextantgiraffes Lydekker,1876,p.105 OR39747.Lydekkernotedthattheareasofthezygoapohyses
butwithashorterneck. are‘considerablylarger’thaninthoseofextantgiraffes,
makingtheneck‘atleastequallystrong’asthatofextant
giraffes.Thelargercranialandcaudalarticularsurfaceswere
alsonotedbyFalconer&Cautley(1843).
Similarinsizetoextantgiraffes. Lydekker,1883 CervicalvertebrasimilarinsizeasthatofG.camelopardalis.
Referringtoanimperfect‘first’cervicalvertebra,later
cataloguedasa‘third’cervical,BM39746(Lydekker,1885).
Slightlylargerthanextantgiraffes. Murchison,1868b,p.207 Righthumerus.MuseumoftheAsiaticSocietyofBengalno
43,NaturalHistoryMuseumno39749.Exactformtothat
ofextantgiraffes,butalittlelarger(Falconer,1868).Lydekker
(1885)howevermentionedthatthisfossilboneoriginated
froma‘smallindividual’.
Similarinsizetoextantgiraffes. Murchison,1868b,p.206 Leftradius.AsiaticMuseumofBengalno690.Nearlyequalin
dimensionstoexistinggiraffes.
Similarinsizetoextantgiraffes. Murchison,1868b,p.207 Leftmetacarpus.AsiaticMuseumofBengalno52.Ofthesize
ofexistinggiraffe.
Similarinsizetoextantgiraffes. Lydekker,1885 Phalangeals,no17131a.Almostindistinguishablefromthe
correspondingbonesofextantgiraffes.
Similarinsizetoextantfemalegiraffes. Falconer&Cautley,1843 Fragmentsfromupperandlowerjaws.Falconeroriginally
ascribedthesespecimenstoG.affinis.Lydekker(1876)
howeverrefutedthisspeciesandproposedthatitinactual
factG.sivalensis.
Largerthanextantgiraffeswith Mitchell&Skinner,2003 Reviewofliterature.
smallerteeththanextantgiraffes.
(OR39748;Lydekker,1885),alsodescribedasasecondcervicalbyFalconer(1845),aswellas
acaudalpartofa‘third’cervical(OR39746;Lydekker,1885)weremissingfromtheSiwalik
collectionattheNaturalHistoryMuseum.Dimensionsweremeasuredwithavernier
calliperandincluded:vertebralbodylength,cranialvertebralbodyheight,cranialvertebral
bodywidth,caudalvertebralbodyheight,caudalvertebralbodywidthandspinousprocess
length(Fig.2).
AdditionalpostcranialspecimensassignedtoG.sivalensisheldattheNaturalHistory
Museum include fragments of two humeri (OR39749 and OR17136; Figs. 3 and 4
respectively),afragmentofaradius/ulna(OR17130)andvariousfragmentsofmetacarpi
andphalanges.AllmetacarpalspecimensexceptOR39750wereavoidedduetotheunclear
numbering of specimens and deformation of the fossils. Measurements of the long
bonesincludedlength,midshaftcircumferenceandmidshaftdiameterincraniocaudal
andtransverseplanes.Thelengthandcircumferencemeasurementsweredonewitha
measuringtape,whilethecrosssectionaldiametersweredonewithaverniercalliper.
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 4/29
Figure2 Giraffasivalensisholotype,specimenOR39747.Presented,fromlefttoright,inleftlateral(A),
rightlateral(B),cranial(C)andcaudal(D)views.Onleftlateralviewthelineindicatesthelandmarks
forthevertebralbodylength(L)measurement.Oncranialandcaudalviewstheverticallinesindicatethe
height(dorsoventral,DV)whilethehorizontallinesindicatethewidth(transverse,T)measurements.
BecausethereisnocompleteG.sivalensisskeletonitsshapeneedstobeinferredas
analogoustotheonlyotherextantGiraffa:G.camelopardalis.Oneofthemethodsof
inferringbodysizefromamodelanimaloranimalsrequiresthatregressionequationsin
theformy=mxb(Huxley,1932)beconstructed.Theseregressionequationscanbebased
ondatafromdifferentspecies(interspecificallometry),withinthegrowthphaseofasingle
animal(ontogeneticallometry)oramongstadultanimalsofdifferentsizebutwithinthe
samespecies(staticallometry).Weappliedontogeneticaswellasinterspecificallometric
equationstopredictbodymassinthiscase.
Ontogeneticdatawereobtainedfrompreviousstudiesbytheauthors(Mitchell,Van
Sittert&Skinner,2009;VanSittert,Skinner&Mitchell,2010;VanSittert,Skinner&Mitchell,
2015).Thesedatawereusedtoconstructallometricequationstodescribebodymassor
bodydimensions.Thedimensionsusedfromontogeneticvertebraldataaresummarised
inTable2.Interspecificregressionequationsweresourcedfrompreviouslypublishedwork
(Anderson,Hall-Martin&Russell,1985;Roth,1990;Scott,1990;Campione&Evans,2012).
ThedimensionsmeasuredforthelongboneontogeneticdataaresummarisedinTable3.
Thereareinherentproblemsassociatedwithusingdentalmeasurementsasbodysize
predictors,especiallywhenonlyasingletoothisused(Damuth,1990;Fortelius,1990;Janis,
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 5/29
Figure3 SpecimenOR39749.Thisimagerepresentsdifferentviewsofarighthumerusthathasbeen
assigned to G. sivalensis. The different views are not to scale; where only distal parts of the bone are
shown,thesehavebeenenlargedrelativetoimagesofthespecimenintoto.Thescalebarindicates50
mmandpertainstothelateralviewonly.
1990).Nevertheless,wehaveestimatedsizefromteethoriginallymeasuredbyFalconer&
Cautley(1843),eventhoughtheseteethwereinitiallyassignedtoanewspeciesG.affinis,a
speciesthatwaseventuallyabandoned(Lydekker,1883).Uncertaintyregardingtheseteeth
specimenspersisteduntilrecenttimes(Spamer,Daeschler&Vostreys-Shapiro,1995).Teeth
specimensdescribedbyauthorsotherthanFalconerandCautleywhicharenotedinTable
S1werenotevaluatedfurtherastherewaseitheruncertaintyregardingtheauthors’species
association(Lydekker,1876),ortheteethspecimenswerenotnecessarilycollectedinthe
vicinityorstratigraphicallayeroffossilsdescribedbyFalconerandCautley(Lydekker,
1878),orbecausecertainspecimensweredeciduous.Table4presentsdentalspecimensas
wellasdimensionsasmeasuredbyFalconer&Cautley(1843).Bodymasseswereestimated
fromregressionequationsestablishedbyDamuth(1990).
Statistical analyses
Allometricequationsweregeneratedfrombivariatedatathroughordinaryleastsquaresre-
gression.Tofacilitatethis,measurementswerelogarithmicallytransformedtobaseeprior
toanalyses.AccordingtoWartonetal.(2006),ordinaryleastsquaresregressionisappropri-
atewhenonewishestopredictyfromx,evenwhenxcontainsmeasurementerror,aslong
astheresultsareinterpretedinthecontextof‘predictingyfromxmeasuredwitherror’.Itis
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 6/29
Figure4 SpecimenOR17136.Thisrepresentsdifferentviewsoftheproximalpartofalefthumerusthat
hasbeenassignedtoG.sivalensis.Thescalebarindicates50mmandpertainstothelateralviewonlyas
thedifferentviewsarenotdrawntoscale.
worthnotingthatthereiscontroversyregardingthepracticeoflogarithmicallytransform-
ingdatainscalingstudies(Packard,Boardman&Birchard,2009;Packard,Boardman&
Birchard,2010;Cawley&Janacek,2010;Packard,2013).Themainargumentiswhetherer-
rorbecomeslargerasbodymassincreases(multiplicativeerror),inwhichcaselogarithmic
transformationisappropriate,orwhetherthereisnocorrelationbetweenerrorandbody
mass,inwhichcaselogarithmictransformationisnotappropriate(Glazier,2013).Thede-
bateisongoingandwillnotbereviewedhere.Inthisstudyweselectedthemethodoflog-
transformationofdataasitenablesmoreconvenientcomparisonamongsimilardatasets.
Because body dimensions (especially body masses) can be predicted by different
equations and by different fossil specimens, the predictions need to be validated. If
regression equations had reasonable power in estimating body mass in both extant
giraffids(G.camelopardalisandO.johnstoni),thentheywereregardedasrobustenough
toextrapolatetoG.sivalensisaswell.Therefore,dimensionsof10okapiskeletonswere
recordedinadditiontodataobtainedfromG.camelopardalis.Theokapiskeletonswere
housedinvariousmuseumsandwererecordedastheopportunitiespresentedthemselves
(Table5).Adultokapispecimenswereassumedtohaveweighed250kg,witharange
of200kg–300kg(Lindsey&Bennett,1999;Stuart&Stuart,2006).Thematureokapi
specimenswereidentifiedthroughadditionaldataassociatedwitheachmuseumspecimen
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 7/29
Table2 DimensionsfortheG. sivalensisholotype;awellpreservedthirdcervicalvertebra(OR39747). Falconer & Cautley’s (1843) findings
arealsopresented.Allvaluesinmm.NomenclatureisbasedontheNominaAnatomicaVeterinaria(InternationalCommitteeonVeterinaryGross
AnatomicalNomenclature,2012).
Dimensionanddescription Falconer&Cautley(1843)’s Presentstudy’s Falconer&
terminology measurement Cautley(1843)
(±95%confidence measurement
intervalforthree (mm)
measurements)
(mm)
Vertebralbodylength: Lengthofthebodyofthevertebrae 200.2±0.7 198.1
Longitudinalaxisofthevertebralbody(Corpus betweenarticulatingheads.
vertebrae),fromthemostcranialcurvatureof
thecranialextremity(Extremitascranialis(Caput
vertebrae))tothemostcaudalpartofthecaudal
extremity(Extremitascaudalis(Fossavertebrae))
Cranialvertebralbodyheight: Verticalheightarticulatinghead? 25.4
42.9±1.4
Greatestdorsoventralheightofcranialextremity. Antero-posteriordiameterarticulating 48.3
head?
Cranialvertebralbodywidth: Greatestdiameteratarticulatinghead 36.2±2.8 35.6
Greatesttransversewidthofcranialextremity.
CaudalVertebralbodyheight: Verticaldiameter,articularcup,posterior 53.1±0.3 50.8
Greatestdorsoventralheightofcaudalextremity. end
Caudalvertebralbodywidth: Transversediameter,articularcup, 53.4±0.3 50.8
Greatesttransversewidthofcaudalextremity. posteriorend
Spinousprocesslength: 21.8±2.6
Fromroofofthevertebralforamentothe
highestpointofthespinousprocess,perpendicular
tothelongaxisofthevertebralbody.
Table3 DimensionsforlongbonespecimensmarkedasbelongingtoG.sivalensis.Allvaluesinmm.OR39749ismarkedasajuvenile.
Specimenno HL HCirc HCr HTr RL RCirc RCr RTr McL MCirc McCr McTr
OR39750a 389 186 53 60
OR17130b 220 217 53 71
OR39749c 453 212 66 66
OR17136a 279 216 76 57
Notes.
Abbreviations:H,Humerus;R,Radius;Mc,Metacarpus;L,Length;Circ,Midshaftcircumference;Cr,midshaftcraniocaudaldiameter;Tr,midshafttransversediameter.
aDistalproportionlacking.
bOnlydiaphysis.
cProximalmetaphysismissing.
aswellasbythedegreeoffusionoftheepiphyses.Therobustnessofgiraffeontogeneticas
wellasinterspecificequationstopredictbodymassinbothadultgiraffesandadultokapis
correctlywereassessedthroughthepercentpredictionerror,calculatedaccordingtoSmith
(1984)andVanValkenburgh(1990):
((Observedvalue−Predictedvalue)/Predictedvalue)×100.
vanSittertandMitchell(2015),PeerJ,DOI10.7717/peerj.1135 8/29
v
a
n
S
itte Table4 SummaryoffossilteethassignedtoG.affinisbyFalconer&Cautley(1843),andsubsequentlyassignedtoG.sivalensis.Allregressionequationswereobtained
r
t fromDamuth(1990).
a
n
d
M Fossilspecimens Museumno Referencestospecimen Dimensions Relevantregression Bodymass
itc equation(reference) prediction
h
e
ll Jointlengthoftwobackmolars,
(2 maxilla=2.5in=63.5mm
0
15 Greatestwidthoflastmolar=1.4 38.02×TUMW∧2.77 752kg
), in=35.56mm (allungulates)
P
ee 32.36×TUMW∧2.87 945kg
r
J (allselenodonts)
,
DO Fragmentofleftmaxillaincluding 17.78×TUMW∧2.97 718kg
I tworearmolars.The‘backpartof FiguredinPlate2Figs.3Aand3B (selenodontbrowsers)
1 39756a(Lydekker,1885)
0.7 themaxillary,beyondtheteeth,is ofFalconer&Cautley(1843). Greatestwidthofpenultimate 32.36×SUMW∧2.78 731kg
7 attached’. molar=1.45in=36.83mm (allungulates)
1
7/p 22.91×SUMW∧2.96 991kg
ee (allselenodonts)
rj.1 12.02×SUMW∧3.08 801kg
1
3 (selondontbrowsers)
5
Averageofwidthmeasurements 823(117)kg
(SD)
Length=1.2in=30.48mm 19.50×TUML∧2.81 288kg
*itisnotsurewhetherthisisthe (allungulates)
greatestdimensionsorocclusal
surface.
8.71×TUML∧3.12 372kg
(allselenodonts)
6.31×TUML∧3.29 481kg
(selenodontbrowsers)
Averageoflengthmeasurements 380(97)kg
(SD)
Rearmolarofrightmaxilla 39756(Lydekker,1885) FiguredinPlate2Fig.4of Width=1.4in=35.56mm 38.02×TUMW∧2.77 752kg
Falconer&Cautley(1843). *itisnotsurewhetherthisisthe (allungulates)
greatestdimensionsorocclusal
surface.
32.36×TUMW∧2.87 915kg
(allselenodonts)
17.78×TUMW∧2.97 718kg
(selenodontbrowsers)
Averageofwidthmeasurements 795(105)kg
(SD)
(continuedonnextpage)
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v
a
n
S
itte
r
t
a
n
d
Table4(continued)
M
itc Fossilspecimens Museumno Referencestospecimen Dimensions Relevantregression Bodymass
h equation(reference) prediction
e
ll(2 Length=1.7in=43.18mm 6.31×TLML∧2.99 489kg
01 (allungulates)
5), 3.24×TLML∧3.19 533kg
P
e (allselenodonts)
erJ 2.24×TLML∧3.35 673kg
,D (selenodontbrowsers)
O
I Averageoflengthmeasurements 565(96)kg
10.77 Fcorangtaminenintgotfhleeftthmiradnmdiobllaer 39755(Lydekker,1885) F5BiguorfeFdalicnopnelart&e2CFaiugstl.e5yA(1a8n4d3). (GSrDea)testwidth=1.0in=25.4mm 109.64×TLMW∧2.73 750kg
1
7 (allungulates)
/pe 77.62×TLMW∧2.93 1,014kg
e
rj.11 (6a4l.l5s6el×enToLdMonWts)∧2.88 718kg
3
5 (selenodontbrowsers)
Averageofwidthmeasurements 827(162)kg
(SD)
Length=1.0in=25.4mm 79.43×TLPL∧2.76 599kg
(allungulates)
61.66×TLPL∧2.92 780kg
(allselenodonts)
20.42×TLPL∧3.19 618kg
(selenodontbrowsers)
Averageoflengthmeasurements 666(99)kg
Thirdpremolaroftheleft FiguredinPlate2Fig.6of (SD)
39757(Lydekker,1885)
mandible,detached. Falconer&Cautley(1843). Width=0.9in=22.86mm 524.81×TLPW∧2.45 1,121kg
(allungulates)
524.81×TLPW∧2.53 1,440kg
(allselenodonts)
398.11×TLPW∧2.49 964kg
(selenodontbrowsers)
Averageofwidthmeasurements 1,175(243)kg
(SD)
(continuedonnextpage)
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