Leporillus (Rodentia: Muridae) from Madura Cave, W.A

18 Pages·1999·6.1 MB·

by  E L Lundelius

Leporillus (Rodentia: Muridae)
from Madura Cave, W.A.
'Ernest L. Lundelius, Jr. and 2William D. Turnbull
'DepartmentofGeological Sciences, University ofTexas, Vertebrate Paleontology
Laboratory, Texas Memorial Museum, University ofTexas, Austin Texas 78712, USA;
department ofGeology FieldMuseum ofNatural History, Chicago Illinois, USA
Lundelius, E.L. Jr. andTurnbull, W.D. (1999). Leporillus (Rodentia: Muridae) from Madura
Cave,W.A.ProceedingsoftheLinneanSocietyofNewSouth Wales121, 129-146.
TwospeciesofthegenusLeporillusarerepresentedinthePleistocene-Holocenesedi-
ments ofMadura Cave. Leporillus conditor is abundant and ranges from the surface to the
deepest level (38,000 BP). L. apicalis is less abundant and appears to be restricted to levels
datingfrom7,500to22,400BP.
Mostofthe specimens are dissociated because they are derivedfromowl pellets and
thusspecificidentificationisdifficult.Manyofthedimensionsoftheteethofthetwospecies
overlapandtherearefewdiagnosticfeaturesthatseparatethem.WattsandAslingavecriteria
forthe genus based on modern material. We have attempted to evaluate features that would
separatethespeciesonthebasisofincompletecranialanddentalmaterials.
Wedescribeafewofthebetterspecimens,discusstheirmorphologicfeaturesandhis-
toricdistributions. Fromthisworkweareabletodocumentthetimespanoftheirpresenceon
theRoePlain,thatpartoftheNullarborPlainsouthoftheHamptonScarp.Thespeciesdonot
showanysignificantevolutionarychangesduringtheseintervals.
Manuscriptreceived28July 1999,acceptedforpublication 15December 1999.
KEYWORDS: Australia, dentition, Holocene, Leporillus apicalis, Leporillus conditor,
Muridae,NullarborPlain,Pleistocene,Rodentia.
INTRODUCTION
This report is abstracted from an ongoing study ofthe rodents from Madura Cave,
Part VIII of THE MAMMALIAN FAUNA OF MADURA CAVE. Here we report the
presence of both species of the murid rodent genus Leporillus; L. conditor, the greater
sticknest rat, or Walpilkara, and L. apicalis, the lesser sticknest rat, orTchujalpi, Turulpa,
Tweealpi and show theirchronologic distributions withinthe cave deposits. There are well
over 1,700 specimens of L. conditor ranging from the surface, all units between Unit 1,
dated at 7,500 BP, to the bottom unit ofthe deepest trench, Unit 7, dated at 38,000 BP. L.
apicalis is much less abundant; 59 specimens were recovered, none from the surface,
most(38) fromUnit 1 and21 fromthe upperpartofUnit2. (15,600to22,400BP).
Madura Cave is located on the Roe Plain, the area on the southern edge of the
Nullarbor Plain, six miles south ofMadura, 110 miles west ofEucla. A fullerdescription
of the cave is given in Lundelius and Turnbull (1973). The earlier illustrations of the
cave map and trench sections are repeated here (Figs. 1^1) to give the reader convenient
access to the stratigraphy encountered in each trench.
AGE OFDEPOSITS
Five radiocarbon dates from Trench 4 span a 30,000 year period between 7,470 ±
129 BP (TX 1146) and 37,880 ± 3,500 BP (TX 1143). Two radiocarbon dates from
Trench 3 are 15,600 ± 250 BP (TX 1145) from the top ofthe second unit (red clay) and
Proc.Linn.Soc.n.s.w., 121. 1999
130 LEPORILLUS(RODENTIA:MURIDAE)FROMMADURACAVE,WA
.REAR TRENCH(#S)
010V—APPROX.POSITION TRENCH #2fELL-1956)
ROCK HOLE=a
REFERENCE POINTS—
.
MAGNETIC
Figure 1.MapofMaduraCaveshowingthecentraldoline,thenorthernandsoutherntunnels,andthepositions
oftheexcavations.
(T« VI4B) 18.600t250V«P
limi
r
CXCAVATION
4. WHITE SANOV SU.T
RED CLAY
•j
Section C-C, Entrance Trench, 3.
Figure2. Stratigraphicsectionexposed inTrench#3.
Proc.Linn. Soc.n.s.w., 121. 1999
E.L.LUNDELIUSANDW.D.TURNBULL 131
ROCK HOLE
„l_LI~ j. : l_T_LT_LT.i_,JLT-l.-I-l-,.-I--r
pIpZI LIMESTONE ^XpI_ _
.X.pi.—J—j ,,,; ,-^r--- ( t . [-LT-r^-aT.
^ ^-T-l- -1. I „;„,,,.x,.
--j-LL:..t,Yr}i^p±r±,
l~r"iT'tT"
DARK REDCLAV SILT
{T*11**) 22,200 + S70 YHS»
|.-4$&'..'•''•] SHAV-BPOWN SiLT RED-OKAY SAND AND HRAVCL
Y'l:l.'^l.-M SCO CL*v. GRAVEL AT 'OP j 7I3HT SILT AND CLAV SEAMS
VtUOW-OMANGE GRITTV HAND I HEO-ORAVOE SILTY CLAV
!
(t»'1*3) 37,Hf)Ol 3.SJO VEIP
Section A-A', Middle Trench, 4.
Figure3.StratigraphicsectionexposedinTrench#4.
B
B'
TRENCH GOES ON FOR CA-20'
fflBgggBEBi brownsilt AND WHITE StLTV CLA
REDDISH-BROWN SILT ORANGE-REO SAND AND GRAVEL
REDDISH ORANGE CLAV AND GILT HED0I3H-BROWN 3ILT
Figure4.CrosssectionofnortherntunnelatTrench#5showingthestratigraphicsectionexposedinthistrench.
Proc.Linn.Soc.n.s.w., 121. 1999
132 LEPORILLUS(RODENTIA: MURIDAE)FROMMADURACAVE,WA
22,400 ± 580 BP (TX 1142) from the bottom of that unit. Correlations with the upper
two units in Trenches 3 and 4 and Trench 1 (Lundelius 1963) can be made with reason-
able confidence, but no firm correlations canbe madeforthe lowerunits ofthe trenches.
MATERIALS AND METHODS
Measurements, abbreviations and statistical and dental terminology are either those
in standard use orthey aredefined where used. Specimen numbers beginning with PM are
in the Field Museum of Natural History collection. Specimen numbers beginning with
TMM are in the collection of the Texas Memorial Museum, University of Texas. The
TMM
designation is omitted from the number in the material lists. Measurements of the
dentition were taken with a microscope reticle and with micrometer calipers calibrated to
.01 mm.
Cusp identifications and homology designations of murid upper molars have not
been satisfactorily resolved. Hence it seems best to utilize a simple cusp designation
scheme that makes no pretense at implying cusp homologies. Therefore we avoid using
the Cope-Osborn scheme, or Vandebroek 1966, Hershkovitz 1971, Engesser 1972 or
Jacobs 1977 and instead utilize that of Miller (1912, p. 801) as modified by Misonne
(1969, p. 36) and here, so as to eliminate the remaining Cope-Osborn implied homolo-
gies. In Miller's scheme the upper molarcusps are designated by tl through t9 notations.
This gives an unambiguous designation to each major cusp without any implied homolo-
gy. Further, we follow Michaux's (1971) and Jacobs' (1977) use of the term "chevron"
foreach transverse row ofcusps (Fig. 5A, left side).
Most workers have used the Cope-Osborn terminology for the lower molars. We
do not consider the implied homologies to be certainties but use the terms rather than
introduce new terms which would only add confusion (Fig. 5B and C, center and right).
The cusps labeled Prd, Hyd, End and Hyldprobably are the Cope-Osborn homologues of
protoconid, hypoconid, entoconid and hypoconulid respectively. The homologies of
those labeled Pad (paraconid) and Med (metaconid) however are dubious. For example,
Misonne used Pad, which he states is more distal than the Prd. However that is the more
usual position ofthe Med. Engesser (1972) uses Med for a cusp that is more mesial than
the Prd., i.e. is in the usual Pad position. Our use ofthese terms is simply as cusp identi-
fiers without any implied homologies. For the variable additional elements we use the
designations Misonne employed (following Van de Broek 1966): sm, si, and sv.
The homology ofthe cusps ofthe upperteeth ofmurids with those ofotherrodents
is uncertain. The terminology used here is that ofMiller (1912) as modified by Michaux
(1971).
ORDER RODENTIA BOWDICH, 1821:7, 51
FAMILY MURIDAE ILLIGER, 1811:84
SUBFAMILY MURINAE ILLIGER, 1811:84
LEPORILLUSTHOMAS 1906:83
Watts and Aslin (1981) gave features ofthe skull that distinguish Leporillus from
other genera of Australian rodents. In addition to size Table 1 summarizes the outstand-
ing cranial and dental differences between L. conditorandL. apicalis.
Leporillus conditor(Sturt 1848)
Most of the hundreds of specimens are fragmentary, and are most likely derived
from owl pellets.
Proc.Linn.Soc. n.s.w., 121. 1999
E.L.LUNDELIUSANDW.D.TURNBULL 133
B
med
end
med
end
med
end
Figure 5. Diagrams ofmuriddentitions (modifiedfrom Misonne 1969), showingcuspterminology (modified
from Misonne 1969). Upperteeth are shown in A on left, lower teeth in B and C, center and right. Numbers
1-9 indicatethecusps(ortuberclesofsome authors)oftheuppermolars, a-lab=anterolabialcuspid, a-ling=
anterolingualcuspid,end=entoconid, hyd=hypoconid, med=metaconid,pcd=postcingulid, andprd=pro-
toconid. Forthe lowerteeth we show different age/wear stages. In B, the youngerofthe two, apost-cingulid
cuspidispresent(pcdofml,m2),andinCthosecuspidshavewornawaysothattheir basesarefusedwiththe
posteriorlophids.Forlowerteeth,MisonnefollowedVandebroek(1966)addingtheCope-Osborneequivalents,
afewofwhichwequestion(seetext).
Table 1.
Size,cranialanddentalfeaturesthatdifferentiatethespeciesofLeporillus.
Feature Leporillusapicalis Leporillusconditor
Bodysize small large
Lowermolars,median shallow deep
longitudinalgroove
m1,anteriorlophid nearlyevenlyrounded decidedlyV-shaped,openingforwards,
sometimeswithacentralcuspid
m2,posterior(3rd)lophid locatedinacentralposition central,butmoretiedtolingualendof
(chevron) 2ndlophid
m3,posteriorcuspid narrowbase;doesnotreach basebroad;swingstolingualsideof
tolabialside tooth
PosteriorlophofMl andM2 length&widthapprox.equal widerthanlong
Anteriorpalatalforamen endsatfrontofMl usuallyextendstowidestpartofanterior
lophofMl
PositionofmentalforamenJustatfrontofmasseterictuberclewellanteriortomasseterictubercle
Proc.Linn.Soc.n.s.w., 121. 1999
134 LEPORILLUS(RODENTIA:MURIDAE)FROMMADURACAVE,WA
Material
Surface
2 specimens, a skull in 3 pieces (TMM 41106-28, Fig. 6 A-D); and a left maxilla
withMl-3
Trench 1. Unit 1. top 1 foot
Skull
4partial skulls includingPM 6195 (Fig. 7)
Upperdentition
35 left and 35 right specimens withteeth
5 left and 6 rightedentulous maxillae
Lowerdentition
8 leftand 15 rightrami with i - m3, including PM 6181 (Fig. 6E-G)
32 leftand 22 rightrami with teeth, 1 edentulous rightramus
Trench 1. top 30 inches
Lowerdentition
1 leftramus with i, 1 edentulous leftramus
Trench 1. 30 inches below surface
Upperdentition
3 partial right maxillae with teeth
Lowerdentition
5 leftand4 rightpartial rami withteeth
Trench 2. Unit L Level 1
Upperdentition
1 right maxillawith Ml-3
Lowerdentition
1 left and 2 rightpartial rami with teeth
Trench 2, 2 1/2 feetbelow surface
Upperdentition
3 rightmaxillae withteeth, 1 edentulous rightmaxilla
Lowerdentition
2 leftand 5 rightrami with teeth, 1 edentulous right ramus
Trench 3. Unit unknown
Upperdentition
1 left maxillawith Ml
Trench 3, Unit2. Level unknown
Skull
1 with left andrightMl-3, 1 with rightM2-3
Upperdentition
94 left and 108 right specimens with teeth, 6 isolated molars
Lowerdentition
134 left and 129 right rami with teeth
16 left and 16 right edentulous rami
Trench 3, Unit 2, Level 2
Upper dentition
33 left and 33 right maxillae with teeth, 1 right I
15 left and 12 rightedentulous maxillae
Lowerdentition
6 left and 19 right rami with teeth, 2 left and 7 right edentulous rami
Proc.Linn.Soc.n.s.w., 121. 1999
E.L.LUNDELIUSANDW.D.TURNBULL 135
Trench 3, Unit3
Upperdentition
14 leftand22rightmaxillae with teeth, 35 edentulous maxillae
Lowerdentition
13 left and 10rightrami withteeth, 6 edentulous rami
Trench4 Unit 1. Level 1 (top 1 foot)
Skull
1 edentulous, lackingbackofbraincase
Upperdentition
10leftand9 rightmaxillae withteeth, 5 edentulous maxillary fragments
Lowerdentition
21 leftand 15 rightrami withteeth
14leftand9 rightedentulous rami
Trench4, Unit2, Level 1
Upperdentition
24leftand 38 rightmaxillae withteeth
6leftand 3 rightedentulous maxillae
Lowerdentition
53 leftand63 rightrami withteeth
4leftand 8 rightedentulousrami
Trench4, Unit2, Level 1 (Middle Pit, top 6 inches ofred)
Upperdentition
4leftand2rightmaxillae withteeth, and2 edentulous leftmaxillae
Lowerdentition
8 leftand 8rightramiwithteeth, 3 edentulous rami
Trench4. Unit2. Level 2
Upperdentition
22 leftand25 rightmaxillae withteeth
10leftand 14rightedentulous maxillae
Lowerdentition
79 leftand56rightrami withteeth
12 leftand 13 rightedentulous rami
Trench4. Unit2. Level 3
Upperdentition
1 leftand 1 rightmaxillae withteeth, 2 edentulous maxillary fragments
Lowerdentition
1 leftand 8 rightrami withteeth, 2 leftand4rightedentulous rami
Trench4Unit4-5
Upperdentition
9 leftand 16rightmaxillae withteeth, 24edentulous maxillaryfragments
Lowerdentition
6 leftand 11 rightrami with teeth
12leftand 11 rightedentulousrami
Trench4, Unit7. Level 1
Upperdentition
2 leftand 3 right maxillae with teeth, 1 edentulous maxillary fragment
Lowerdentition
2 leftand 1 rightrami withteeth
Proc.Linn.Soc.n.s.w., 121. 1999
136 LEPORILLUS(RODENTIA: MURIDAE)FROMMADURACAVE,WA
Figure6. Leporillus conditor. A-D,TMM 41106-28, a nearlycomplete skull shown in A, anterior; B, leftlat-
eral; C, dorsal; and D, ventral stereo views; E-G, PM 6181, left mandibular ramus with I, ml-3 shown in E,
leftlateral; F.occlusal;andG, lingual views. Scalebarsare2cm. long. FMNH negativenumbersareG 85962-
85967.
Proc. Linn. Soc. n.s.v... 121. 1999
E.L.LUNDELIUSANDW.D.TURNBULL 137
Figure 7. Leporillusconditor. A-D,PM6195, anearlycompleteskull shown in A,anterior; B,dorsal;C, left
lateral;andD,ventralstereoviews. Scalebarsare2cm.long.FMNHnegativenumbersareG85954-85958.
Proc.Linn.Soc.n.s.w., 121. 1999
138 LEPORILLUS(RODENTIA:MURIDAE)FROMMADURACAVE,WA
Trench4. Unit7. Level 2
Upperdentition
5 leftand 14rightmaxillae with teeth, 6edentulous maxillary fragments
Lowerdentition
11 left and 8 rightrami with teeth, 9 left and 8 rightedentulous rami
Trench4. Unit7
Upperdentition
2 leftand 3 rightmaxillae withteeth, 6 edentulous rightmaxillae
Lowerdentition
6 leftand 3 rightrami withteeth, 9 left and4rightedentulous rami
Trench 5, LowerRedUnit
Upperdentition
5 leftand5 rightmaxillae withteeth
15 leftand 21 rightedentulous maxillae
Lowerdentition
2leftand 3 rightrami withteeth, 9 leftand 10rightedentulous rami
Trench 5, LaminatedUnit
Upperdentition
1 rightmaxillawithMl-3, 1 edentulous leftmaxilla
1 rightMl, and 1 leftM2
Descriptions
Skull
The skulls have the normal murid form. They have the myomorphous enlargement
ofthe infraorbital foramina for the transmission ofa part ofthe M. maxillomandibularis.
It is more oval, less circular than in Rattus norvegicus. There is an enlargement of the
anterior face ofthe zygomatic arch for the origin ofthe anterior part ofthe M. masseter,
pars profunda. The anterioredge ofthe zygomatic plate is straight. Atits ventral endthere
is asmall tuberclethatmarks theoriginoftheM. masseter,pars superficialis andprobably
alsothe M. masseter, pars reflexa. There is no spineonthedorsal end. In anteriorviewthe
zygomatic plate ofL. conditortends tobe relativelybroaderdorsally ratherthan inL. api-
calis. The anteriorpartofthe zygomatic archisnotbroadenedas inNotomys.
In dorsal view the interorbital width is narrow compared with the width of the
braincase which is expanded laterally. This is true forboth species butis moreextreme in
L. conditor. There are no raised supraorbital ridges on the frontal bone, although it turns
ventrally very abruptly to form the medial side ofthe orbit. The dorsal margin ofthe area
oforigin ofthe M. temporalis closely corresponds to the suture between the parietal and
squamosal.
The incisive foramen is large and is located at the front ofthe palate, immediately
posterior to the upper incisors. The anteriorpalatal foramina are long, extending forward
fromjust posteriorto the anteriorend ofthe Ml three fourths ofthe distance to the upper
incisors. They have the shape oflong ovals and are about equally contained by the max-
illary and premaxillary bones. The median parts ofthe maxillaries and the premaxillaries
are expanded to nearly fill the anterior three fourths ofthe foramina. The palate has shal-
low lateral grooves that connect the anterior and posterior palatine foramina. These
grooves are separated from the alveoli by a ridge which is especially well defined in
younger individuals. The posterior palatal foramina are oval in shape and are located
opposite the M2. The postpalatine spine is largerthan that ofRattusnorvegicus.
The cranial foramina are similar in their arrangement to those of Rattus
norvegicus. The foramen ovale is about the same size in L. conditor as in R. norvegicus
Proc.Linn.Soc.n.s.w., 121. 1999