A new species of water mouse, of the genus Chibchanomys (Rodentia, Muridae, Sigmodontinae) from Ecuador

6 Pages·1997·2.6 MB·

by  Paulina D Jenkins

Bull. nat. Hist. Mux. Land. (Zool.)63(2): 123-128 Issued28November 1997
A new species of water mouse, of the genus
Chibchanomys (Rodentia, Muridae,
Sigmodontinae) from Ecuador
PAULINA D. JENKINS^ fifeU ZQ&^Cf
DepartmentofZoology, TheNaturalHistoryMuseum, CromwellRoad, London SW75BD, U.K.
ADRIANA. BARNETT
SchoolofLifeSciences, Roehampton Institute, WestHill, London SW155SN, U.K.
SYNOPSIS. A new speciesofthe rodentgenus Chibchanomys is described from Ecuadoron the basisofexternal andcranial
morphology.Aphylogeneticanalysisisusedtoassesstherelationshipofthenewspeciestootherichthyomyinetaxa.
INTRODUCTION hypothesised primitive state, using the criteria defined by Voss, is
scored as '0'.
TsuhbefaNmeiwlyWSoirglmdodroondteintnsaecu(rsreennstulyCaprllaecteodni&n tMhuesslearrg,e1a9n8d4)coinmcplluedxe 21.. VPeenltargael:pgelloasgseyc(0o)u;ntduelrlsh(a1)d.ed: absent (0); present (1).
amorphologicallyandecologicallydistinctivegroupofsemi-aquatic 3. Tail: unicolored (0); bicolored (1).
SouthAmericangenera(Voss, 1988),forwhichitisconvenienthere 4. Philtrum: present (0); absent(1).
to use the name ichthyomyines. In a monograph ofichthyomyine 5. Pinnae: large, visible abovefur(0); small, concealed in fur(1).
rodents, Voss (1988) included five genera: lchthyomys Thomas, 6. Superciliary vibrissae: present (0); absent (1).
1893(fourspecies),AnotomysThomas, 1906a(monotypic),Rheomys 7. Plantarpadsofmanus: hypothenarpadseparate, notfusedwith
Thomas, 1906b (four species), Neusticomys Anthony, 1921 (four third interdigital pad(0); hypothenarandthirdinterdigital pads
species) and a new genus, Chibchanomys Voss, 1988 for an enig- fused (1); hypothenar and thenar pads fused respectively with
matic species ofuncertain generic affinity. Chibchanomys trichotis adjacent third and first interdigital pads (2).
q(uTehnotmlays,ass1i8g9n7e)dwtaosRohreigoimnyalsly(speleacTaetde,in1l9c3h2t;hyCaobmryesrbau,t1w9a6s1s),ubtshee-n 98.. LFroiwnegrintghihradirmsoolnarp:ese:ntwoecaoknliydd-ehvyeploocpoendid(0c);uswpelplaidrevdeisltoipnectd((01)):.
to Anotomys (see Handley, 1976). Subsequent to the revision by m3peglike,entoconid-hypoconidcusppairabsentorreducedto
V&osSso,rainanaod,di1t9io9n1a,lhiacshtbheyeonmydeisncerispbeecdi.es,NeusticomysmussoiOchoa 10. aNassmaalllbocnoensu:lelo(n1g),.producedanteriorlybeyondpremaxillae(0);
During the course of several zoological surveys of Las Cajas short, truncated behind premaxillae (1).
Plateau,Ecuadorfrom 1981to1987,fivespecimensofanundescribed 11. Supraorbital foramina: on the lateral surface of the frontals,
species ofichthyomyine rodent were captured. Observations were within orbital fossae (0); on the dorsal surface ofthe frontals
made on two ofthese animals, which subsequently escaped, while between theorbital fossae (1).
tAhnroetehesrpescpiemceinmsenwewraesdfoinlamteeddftoor Tthhee1N9a9t2urBalBCHistNoartyioMnaulseGuemo.- 12. Cpaatrtoetrind2a(r1te)r;iaplatstueprpnly3((s2)e.eVoss, 1988page296): pattern 1 (0);
graphic wildlife film 'Avenue ofthe Volcanoes' (Jim and Theresa 13. Orbicularapophysis ofmaleus: present (0); absent(1).
Clare, personal communication). On the basis of external and 14. Metatarsalconfiguration: III>IV>II»V> 1 (0);IV>III>II,
craniodentalcharactersthestudyspecimensagreemostcloselywith V>I(1).
the generic diagnosis of Chibchanomys but are also sufficiently 15. Omohyoid muscle: present (0); absent(1).
similarin some features to Neusticomys to warrant a phylogenetic 16. Gastric glandularepithelium: present (0); restricted(1).
analysis. 17. Gall bladder: present (0); absent (1).
18. Bacular cartilage: tridigitate, medial digit lacking a calcified
centre (0); single digit (1); tridigitate, medial digit grossly
MATERIALSAND METHODS swollen withcalcifiedcore (2).
ThecharacterstatesforthenewspecieswereassessedbyPJbutthe
Thedescriptionofthenewspeciesisbasedonconventionalmorpho- character state assessments for the other taxa were taken directly
logicalcharacteristicsandtheterminologyusedfollowsVoss(1988). fromVoss(1988Table45,page441).Charactersofthevisceraland
Specimens were measured using dial calipers, with all measure- reproductive systems (characters 15-18 above) were unobservable
ments provided in millimetres. The skeletal elements remaining in in the new taxon because ofthe lack ofwhole bodies. In an initial
the skins were observedby means ofX-rays. analysis, all character states were unordered; in a second analysis,
A parsimony analysis (PAUP Version 3.0) was carried out to multistate characters were ordered (as by Voss): —> 1 —> 2 for
determine the position of the new species relative to other characters7, 12butalsoforcharacter 18.Forcharacter 18,theorder
ichthyomyines. Details of the eighteen characters used, listed recommended by Voss (1988) was —» 1; —> 2, a sequence not
below, are given more fully in Voss (1988 pages 440^442); the readilyhandledbytheanalysisandaffectingonlyonegenericgroup
©TheNaturalHistoryMuseum, 1997
124 P.D.JENKINS ANDA. BARNETT
(Rheomys);Voss (personalcommunication)recommendedanalter- Table1 ExternalandcranialmeasurementsofChibchanomystrichotis
nativeorderingofthischaracter(1 —» —>2) soinathirdanalysis, andC. orcesi.Dimensionsgivenasmean,plusorminusstandard
characters7 and 12 wereorderedasaboveandcharacter 18by this deviation,followedbyrange,withsamplesizeinparentheses.
alternative. C. trichotis C. trichotis C. trichotis C. orcesi
Venezuela Colombia Peru Ecuador
Headandbody 113.5±5.50 105±1.63
ABBREVIATIONS USED IN THETEXT length 105-120(4) 125(1) 102(1) 103-107(3)
Taillength 126.8±7.36 113.3±6.18
BMNH-TheNatural History Museum [formerly British Museum 115-133(4) 131(1) 123(1) 108-122(3)
(Natural History)] Hindfootlength 31.8±1.09 22±2.16
Ml, M2, M3 respectivelyfirst, secondandthirduppermolars 30-33 (4) 30,33(2) 31(1) 19-24(3)
ml, m2, m3 respectivelyfirst, second andthird lowermolars Earlength 7.5±1.5 11.5±1.87
6-10(4) 8(1) 6(1) 9.5-14(3)
Weight(ingrams) - - - 37+2.83
ABBREVIATIONS USED FORTAXA IN THE 35^1 (3)
PAUPANALYSIS: Ratiooftail 1.12±0.02 1.08±0.06
lengthtohead 1.10-1.15(4) 1.05(1) 1.21(1) 1.02-1.16(3)
andbodylength
Ale AnotomysleanderThomas, 1906a
Ratiooftail 4.9±0.12
Ctr Chibchanomys trichotis (Thomas, 1897)
lengthtocondylo- 4.7-5.0(4) 5.1(1) 5.2(1) 4.3,4.7(2)
Cor Chibchanomys undescribed species
incisivelength
Ihy Ichthyomyshydrobates (Winge, 1891)
& Ratioofhindfoot 0.28±0.00 0.21 ±0.02
Ipi Ichthyomyspittieri(Handley Mondolfi, 1963) lengthtohead 0.28-0.29(4) 0.26(1) 0.30(1) 0.18-0.23 (3)
Itw Ichthyomys tweediiAnthony, 1921 andbodylength
Nmo NeusticomysmonticolusAnthony, 1921
Condyloincisive 25.7± 1.01
Nve Neusticomys venezuelae (Anthony, 1929)
Rme Rheomysmexicanus Goodwin, 1959 length 24.3-26.9(4) 25.9(1) 23.8(1) 23.0,24.6(2)
DiastemaLength 6.3±0.54 - 5.3±0.29
Rha Rheomys raptorGoldman, 1912
Rtt Rheomys thomasiDickey, 1928 5.7-7.0(3) 5.7(1) 5.0-5.7(3)
Run Rheomys underwoodiThomas, 1906b Lengthofupper 4.4±0.08 4.2±0.05
molars 4.3-L5(3) 4.4(1) 4.2(1) 4.1-4.2(3)
Incisiveforamina 5.0±0.27 4.5±0.09
length 4.6-5.3 (4) 5.1(1) 4.5(1) 4.4-4.6(3)
RESULTS
Breadthof 1.2±0.11 1.4±0.05
incisortips 1.0-1.3(4) cl.2, 1.3(2) 1.0(1) 1.4-1.5(3)
Chibchanomys orcesi, sp. nov. Breadthofincisive 1.9±0.15 2.1 ±0.09
Holotype. BMNH82.816,adultmale,skinandskull;collectors' foramina 1.7-2.1 (4) 2.4(1) 1.9(1) 2.0-2.2(3)
number 148; collected 22 August 1981 by members ofthe Oxford Breadthof 3.1 ±0.29 2.2±0.08
Expedition to Las Cajas from Lake Luspa, Las Cajas, Provincia palatalbridge 2.7-3.4(3) - 2.6(1) 2.1-2.3(3)
Azuay, Ecuador, 02°50'S 79°30'W, altitude3700m. Nasallength 9.0±0.41 9.3±0.29
BMNH 8.5-9.5 (3) 8.1(1) 8.5(1) 8.9-9.6(3)
PnAuRmAbTeYrPE1S46.,otherdetai8l2s.8as15f,oardtuhlethmoalloet,yspkei.nBanMdNsHkul8l;4.c3o4l9le,ctaodrusl't Nasalbreadth 3.0±0.05 3.2±0.05
2.9-3.0(4) 3.0(1) 2.8(1) 3.1-3.2(3)
male,skinandskull;collectors'number78;collected7August 1983 Interorbital breadth 4.7±0.13 4.6±0.08
by members ofthe Combined Universities Expedition to Ecuador 4.5-4.8(4) 4.9(1) 4.3(1) 4.5-4.7(3)
1983,fromLakeLlaviucu,ZorracuchoValley,LasCajas, Provincia Zygomaticbreadth 13.4±0.66
Azuay, Ecuador, 02°5l'S 79°01'W, altitude 3100m. 12.3-14.1 (4) cl3.9(l) 11.7(1) cl2.8(l)
Diagnosis Braincasebreadth 13.4±0.27
An ichthyomyine speciesbelonging tothe genus Chibchanomys in 13.0-13.7(4) 13.8(1) 12.4(1) 1.9, 12.0(2)
the following combination of features. Dorsal pelage dull; small Ratioofinter- 0.35±0.02
pinnaeconcealedinpelageofhead;taillongerthanheadandbody; orbitalbreadthto 0.33-0.37(4) 0.36(1) 0.35(1) 0.38,0.39(2)
manus with five separate plantar pads; hindfoot broad with well braincasebreadth
developedfringinghairs;supraorbitalforaminaopenlaterallywithin Breadthof 1.1 ±0.05 1.1±0
orbits; carotidcirculation pattern 1. zygomaticplate 1.0-1.1 (4) 1.0, 1.2(2) 1.0(1) 1.1(3)
Differing from Chibchanomys trichotis in the following charac- Breadthoffirst 1.6±0.05 1.3±0.05
ters. Rhinarium light brown; philtrum present; nasals medium in uppermolar 1.5-1.6(3) 1.5(1) 1.4(1) 1.3-1.4(3)
length,barelyprojectinganteriortopremaxillae; orbicularapophy- Heightofupper 4.6±0.33 4.3-4.5(3)
sisofmaleuspresent; upperincisorsslightlyinclinedmedially;M3 incisor 4.1-5.0(4) 5.3(1) 3.9(1) 4.4±0.08
ainnddicmat3edroenduacnetderoicnonsiidze;ofamnlte;rmoemteadtairasnalfsleIIxIid>aIbVse>ntIIo»r Vbar>elI.y iDnecpitshorofupper 11..31-±10..41(24) 1.2(1) 1.0(1) 11..32-±10..30(53)
Description Breadthacross 7.4±0.18
Tail subequal toorslightly longerthanheadandbody (seeTable 1 occipitalcondyles 7.2-7.6(4) 7.6(1) 7.8(1) 6.6,6.7(2)
A NEW SPECIES OFCHIBCHANOMYS 125
Fig. 1 LivespecimenofChibchanomysorcesi.
Fig.2 SkullofChibchanomysorcesi(BMNH 1982.816)fromlefttorightindorsal,ventralandlateralview.
126 P.D.JENKINSANDA.BARNETT
for measurements). Pelage soft, dense and woolly, dark brownish configuration differs in the two species: IV >III> II=V > I in C.
grey dorsally, light grey ventrally; tail greyish brown, densely trichotis;III>IV>II»V>IinC. orcesi.Thetwospeciesdifferin
haired,greybrownandbrownhairspredominateproximally,witha thefollowingcranialfeatures:whilethenasalsofbothspeciesareof
proportional increase of buff and cream hairs distally, extending comparablelength,thoseofC.orcesiareslightlybroaderandbarely
beyond tip in a shortpencil. Distal portion ofmuzzle light grey in project anterior to the premaxillae, unlike those of C. trichotis.
young adults, cream in older individuals (age based on degree of whichprojectanteriorlyandconcealtheincisorsandnasalorificein
dental wear); rhinarium light brown in dry specimens; philtrum dorsal view. In lateral view, the globose braincase of C. trichotis
present; conspicuous silvery-grey mystacial vibrissaepresent. Pin- rises abruptly in the frontal region, unlike the narrower and less
naesmall,concealedbypelage;regionofmore-or-lessconspicuous inflatedbraincaseofC. orcesi;thebraincaseisslightlybroaderand
lightgreyhairsventro-lateraltopinnae.Manuswiththreeinterdigital the breadth across occipital condyles is greaterin C. trichotis (see
andtwocarpalpads.Welldevelopedfringeofstiffhairsonmargin Table 1). The orbicular apophysis of the maleus is present in C.
ofmetatarsus and digits ofpes; claw offifth digit extends beyond orcesibutabsentin C. trichotis.TheupperincisorsofC. orcesiare
firstinterphalangealjointoffourthdigit; claw offirstdigitreaches lessdelicateandslightlybroaderthanthoseofC. trichotis(seeTable
midwayalongfirstphalangeofseconddigit. SeeFig. 1 forexternal 1),theanteriorenamelsurfaceofC. trichotisiscreamcolouredand
features visible inaphotographofalive specimen. not medially inclined unlike C. orcesi. The third upper molar is
Skull(seeFig. 2)withmoderatelylongnasals,overlappingnasal smallerrelativetoMl andM2,andm3issmallerrelativetoml and
orifice to conceal incisors in dorsal view but barely projecting m2 in C. orcesi than in C. trichotis. The anteromedian flexid is
m
beyond premaxillae; rostrum shortandnarrow, naso-lacrymal cap- absentorbarelyindicatedontheanteroconidof 1 inC. orcesibut
sules evidentin dorsal view; interorbital region moderately narrow present in C. trichotis, dividing the anteroconid into small but
relative to braincase breadth (0.38, 0.39 (n = 2); frontals slightly distinct lingual and labial conulids. The posteriorconulid ofm3 is
inflated, braincase moderately broad and long; posteriorborder of positioned more basally in C. orcesi than in C. trichotis (when
M
incisiveforaminabetweenanteriorrootsof 1s,palatalforaminalie present).
between posterior roots ofMis; bullae slightly inflated; orbicular AccordingtoVoss(1988)theyoungspecimenthatheidentifiedas
apophysisofmaleuspresent.Carotidcirculationpattern 1,basedon C. trichotis from Peru differs from the northern specimens of C.
osteological features (seeVoss, 1988: 298). trichotisin severalfeatures: thebraincaseismuch less inflated, the
Upper incisors moderately narrow, anterior enamel surface pale occipital condyles are slightly broader, the bullae are somewhat
buff, slightly inclined medially. No anteroloph on Ml; small smallerandanindistinctphiltrumis indicated; featuresthatresem-
posteroloph on M2; M3 small, protocone and paracone evident in ble thoseofthenew species.Voss mentionedthatthese differences
unworndentition, posteriorconule absent.Anteroconidofml sim- might indicate that southern populations of Chibchanomys are
pleorwithslightindicationofanteromedianflexid;noanterolophid phenotypically distinctive from theirnorthern counterparts. Unfor-
on m2; small posterolophids on ml and m2, small mesolophids tunatelyithasnotprovedpossibletoexaminethePeruvianspecimen,
presentorabsent;m3 small,withsmallposteriorbasallypositioned although information on it was kindly provided by Mark Hafner
conulid. (personal communication). It is possible that the Ecuadorian and
Metatarsalproportions:thirdmetatarsalslightlylongerthanfourth, Peruvian specimens are conspecific but additional material and
fourth longer than second; all three far longer than first and fifth; more extensive comparisons are required to elucidate the status of
fifth longerthanfirst. Configuration: III >IV>II »V >I. the latterspecimen.
Comparison with other ichthyominegenera
Etymology
pTihoinseesrpeocfiEescuiasdonraimaendmaimnmhaolnooguyr.oHfePwraosfeosfsogrreaGtushtelapvotoOArBcesw,itha aCnhdibRchheaonmomyyss(isseereaVdoislsy,di1s9t88i)n.guiCshhiedbcfhraonmoAmnyostoamnyds,NeIucshttihcyoommyyss
differfromotherichthyomyinesinshowingcarotidarterialcircula-
fieldworkorganisationinEcuador,andhiskindnessandknowledge
wereasource ofinspiration. tion pattern 1 and in the distribution of the glandular epithelium
around the stomach. Chibchanomys differs from Neusticomys in
Distribution andEcology having small pinnae concealed in the pelage (pinnae obvious in
Known only from Las Cajas Plateau, Ecuador, where specimens Neusticomys); ventral countershading present (absent in
havebeenrecordedfromthreelocalities:LakeLuspa,LakeLlaviucu, Neusticomys);taillongerthanheadandbody(tailshorterthanhead
ZorracuchoValleyandLakeTorreadora.Allspecimensweretrapped andbodyinNeusticomys);thehindfootisbroaderwithlongerdigits
and the fringing hairs are well developed (narrower with shorter
incloseproximitytofast-flowing streamsataltitudesrangingfrom
3100m to 4000m, in high-altitude moorland vegetation (paramo) digits and less developed fringing hairs in Neusticomys). The new
speciesdoeshowevershareseveralfeatureswithNeusticomyswhich
(see Barnett, 1992). Formore precise details ofthe habitat at each
are not exhibited by C. trichotis, such as the similar metatarsal
siteandnotes ondiet seeBarnett(1997).
configuration and presence ofaphiltrum, while the orbicularapo-
Comparisonwith c. trichotis physisofthemalleusisalsopresentinsomespeciesofNeusticomys.
The new species is similar in external appearance to C. trichotis, Results ofthephylogenetic analysis
exceptthatthepelageispalerandslightlyharsher,andtherhinarium Thereisevidenceinsupportoftheichthyomyinesasamonophyletic
islightbrownindryspecimensofC. orcesi,blackinC. trichotis.A group ofthe subfamily Sigmodontinae (sensu Carleton & Musser,
philtrum is present in C. orcesi but absent in C. trichotis. 1984) (see Voss, 1988). In contrast, evidence in support of the
Chibchanomysorcesiissmallerinexternalsizeandaveragessmaller monophyly of the Sigmodontinae is lacking and a tribal level
in cranial size than all known specimens of C. trichotis, with the classificationofthis subfamily, whileconvenient inmanyrespects,
exception of the single specimen from Peru (see below for com- isunsatisfactoryfromaphylogeneticpointofview,makingdifficult
mentsonthestatusofthisspecimen).BothspeciesofChibchanomys thechoice ofsatisfactory outgroups forphylogenetic analyses (see
are similar in external proportions, except that the hindfoot is Voss, 1988: 436-438, 1991: 33-37; Carleton&Musser, 1989: 53-
proportionately shorter in C. orcesi (see Table 1). The metatarsal 55;Voss&Carleton, 1993: 21-22).Thenecessityofmakingsucha
ANEW SPECIES OFCHIBCHANOMYS 127
Table2. Matrixshowingcharacterstatedistributionsamong 12 onlythreetreeswereretained.Thevariationintreatmentofcharac-
ichthyomyinespecies(fordetailsseetextandVoss, 1988).Thecharacter ter 18,wasnotconsideredtobeparticularlyimportantinthisstudy,
sftraotmeaVsossesss(m1e9n8t8sTfaobrleall45t,axpaagoeth4e4r1t)h.aCnhCa.raocrtceersistwaetreseftoarktehnednireewctly since character state 2 is exhibited only by taxa of the genus
specieswereassessedbyPJexceptforthoseofthevisceraland Rheomys. InbothofthelatteranalysesC. orcesiandC. trichotisare
reproductivesystems(characters 15-18)whichwereunobservablein non-monophyleticinallthreetreesandalsointhesemistrictconsen-
thenewtaxon,soscoredas '?'. susofthesetrees(seeFig. 3).Theonlyevidenceofamonophyletic
generic grouping shown in the semistrict consensus tree is for
Characters Ichthyomys, and this tree is similar in most respects to the most
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 parsimonius hypothesis of ichthyomyine relationships shown by
Taxa Voss (1988: Fig.88).
Ale 1 1 1 1 1 1 1 1 1 1 1 1
Ctr 1 1 1 1 1 1 1 1
Cor 1 1 1 1 1 ? 7 ? 7 DISCUSSION
Ihy 1 1 1 1 2 1 1 1
Ipi 1 1 1 1 2 1 1 1
Itw 1 1 1 1 2 1 1 1 There is obvious conflict in that the results of the phylogenetic
Nmo 1 1 analysis do not support the generic classification currently in use.
Nve 1 1 The morphological data is sufficiently persuasive toconclude that,
Rme 1 1 1 1 2 1 1 2 1 1 1 2 ontheavailablematerial,thenewtaxoniscorrectlyattributedtothe
Rha 1 1 1 2 1 1 2 genus Chibchanomysascurrently construed.
Rtt 1 1 1 2 1 1 2
Run 1 1 1 1 2 1 2 1 1 2
Acknowledgements. We are grateful to Jim and Theresa Clare for
cdheotiecremihnaisngbeetnheavloeviedledoifnatfhfeinciutryreonft stthuedy,neswincteaxitonis atoimoetdheart OurnpcuebslfiosrhesdupipnofrotrmaantdioenncoonuCrhaigbecmhenatnodmuyrsinagndfiteoldthweorlka.teWPerofareessionrdGeubtsetdavtoo
ichthyomyines,ratherthanseekingtoaddanynewdimensiontothe tRhoebeurntiVqousense(sAsmeofritchaennMeuwssepuecmieosfNaantdurwalhoHisptroorvyi)dewdhomuincihtiahlellyprfeuclogandivsiecde
phylogenetic status of the ichthyomyines as a group. Instead an whencommentingondraftsofthemanuscript.Particulargratitudeisowedto
hypothetical outgroupwasconstructed in which all characterstates DarrellSiebert(NaturalHistoryMuseum)forguidancewiththephylogenetic
were assessedas primitive, which was used toroot the trees. analysis, and for constructive comments and criticism of the manuscript.
Using branch and bound algorithms, a search was made ofthe Mark Hafner (Museum ofZoology of Louisiana State University) kindly
character data summarised in Table 2. In the analysis in which all providedphotographsandmeasurementsofthespecimenofC.trichotisfrom
characterstates were unordered, the length ofthe shortest tree was Peru. As always the staffofthe Natural History Museum freely provided
equal to 32 character state transformations and six trees were support;inparticularwethankRichardSabin(MammalGroup)andDeryck
retained.Ineachoftheotheranalyses(withthemultistatecharacters Jones (Electronics) forthe X-rays, Phil Hurst (Photographic Unit) for the
7 and 12ordered,andcharacter 18 varyinglyordered) the lengthof photographs,whileCliveMoncrieff(Biometrics)patientlyassistedwiththe
theshortesttreewasequal to33 characterstatetransformationsbut PAUPanalysis.
Ale
Ihy
Itw
Ipi
Rha
Rtt
Rme
Run
Ctr
Cor
Nmo
Nve
Fig.3 SemistrictconsensustreeshowinghypotheticalphylogeneticrelationshipofChibchanomysorcesitoothertaxaofichthyomyinerodents.
ConsistencyIndex0.636,RetentionIndex0.786.
.
128 P.D.JENKINSANDA.BARNETT
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