Dixon Etal 1993 Chironius Part1

 

Revision f the Neotropical

SnakeGenus

Chironiwsitzinger Chironiws itzinger (Serpentes, olubridae) JamesR. Dixon+,John A. IfiestJr.* andJos M. Cei**

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iJ:g;;1gg1"t 3i:;91;5;*

Fnheriesciences. exas &Muli,enbr, corese tation, -. *turares. n veBidad NaciomreRio uano,5800) 5800)io uarto.

 

TABLE OF CONTENTS Intfoduction Crtorira Adve

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isem nr nfo.mation Mrreridh rnd Methods Sinopsis lrhe cenus Ci ianius Fitzjn}e\ 1g26 I{istorical eriew Family status Chafacter ummarv Identfr catian af Chin hin nius Key to the Species Systematic ccounas (-hitnaid, biarinat , t\t\iedl Chito ius cai aits (Linnaeus) Chircnius einatus cainat .' (LinnaeusJ Chitonius t.tinatusf aprlrr(Wemerl Chttontu\ ortnart)sD,y tHltove]l Chtrunttt. 'ul?t \ tl ionacusl Chircniusl.trolineaus Jan) Chi,04td\ fu, " | | Innreu(r Chtt n , a ,1yu ,1yu , , rr* " fLrnnaeu.r Chtoniu, u..ut cutontt tr. neq .ub.pecres Chi cn usg an and d squamis (p eterc) Chirc tus taetico b (Wied) Chitotiius laurenti, new species Chitoni s ma ticotaRoze I l.t,untu, uhNettth, chmidl n d Wailef . Chironius nultil,enttis cochrcnae ':rogeand Romano Ch; on d \ n Ltl ven t. tnvpa d, Baite,

Chitu ius multit,ent s multterfir Schmidrand Walker Chilouiusmulti,entis sepl  rrrbnar, new subspecies Ch;Iont qua(tti.annaru\Boiet

9 t0 12 t7 I7 l8 24 56 57 59 68 73 17 84 92 105 113 114 t27 135 l,l1 146 14 6 155 160 t64 168 t73 178

 

Chitonius quadicatinatus nkelatr.nttis, new spectes i'" n u' 4,tad, a i40 l, quala.r n a, , I Boie th ' rLu u u (Wasten tnt.mnt I ntrnniut tncenti Boutenger) Interspecifi relationships Formationof phJ,logenetic Tree aenu/ot(H,.tof) o r ( entrut n o South Zoogeographic onsiderations Erol|lIion of Chirc lus

pag. ) 'i 'i

181 184 188 195

r , , ,

200 213 21 3 211 221

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233

r

237

Lite.aturecited Lite.ature cited

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Appendi\ I, specimens no.$n,not examined

2 31

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219 21 9

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250

Intergenedcelationships Summaryol taxonomic hanges

Appendix l, specimens xaoined

 

INTRODUCTION

It has ecently ecomo uiteapparentthat ompfehensiveoogeogmphic studies fNeotroplcal feptiles feptilescannot cannotbe be lerformed efiectively ntil nti l many hi s fevilhorough,basic, lhorough, basic, a-xonomicnvestigations nvestigationsave avebeen been completed. his sionconcerns sion concernshe he genus genusCrl,"orirq Crl,"orirqa a group groupoi oi snak es hich havebeen havebeen radi tionally, a-{onomica a-{onomically llybused. bused. fallNeotropicalsnakesnly fallNeotropicalsnakesnly Crr'r'orirrhave Crr'r'orirrhave relativeabundance 10or 10 or 12scale 12 scale ows at m idbody. idbody.Their Their uniqueness nd relativeabundance make his genusan interesting nd expedient ubject or study. Ourinteresl n Ci,Torr rrdevelo rrdevelo edwh,3n e becameinvolvedn tryinglo idenrify a number of Peruvian Peruviansnakes. snakes. onfusion n tle interpretation f folms n the genusCr;/oflirr had been beendiscussed discussed y Bailey 1955) nd Wiest (1978). fter using he keysofDonoso-Barros 1969) nd Peters nd Orejaswasnotadequatefof notadequatefof Miranda(1970)./e Miranda(1970). /esoon soon ealizedhat ealizedhat existingiteralure existingiteralurewas allocationof identifying hesesnakes. hesesnakes.Much M uch perplexity lso lsoexisted existed n the allocationof sseen ythe wide wideuse useof of Chiro iuscainatus'dn(l iuscainatus'dn(l namesn names n museum oldings sseen Chinnius uscus,bolh Linnean species ames, ames,with with comparatjvely c omparatjvely ittle mention ofthe othorspecies. ulprisingly, omemajor end ng nstitutions f the world worldperyeiuated peryeiuatedhe use ofsynonyms uch asasIeryetodnraschiro Ieryetodnras chiro ius) ius)ol ol usednames ha hatt do he notuseofsynonyms apply o Crirorirr uchas such efilinatus Oydglet,1824), whichbelongs which belongsn n the genusPr  rrrer Bailey,1955; oge, oge,1960a). 1960a).t wasobvindwell well defined, ousearly ous early n thisstudy this study hatwhllo hatwhllo ho genus tselfwasunique nd the speciesimits speciesimits were quite vagueand misunderstood. fact that fuithei emphasizesthisoint s hat 49.34kI 49.34kI all Chinnius pecimens pecimensxamined xaminedn n the cou6e ofthe studywere studywereeither eithermisidentifiod misidentifiodo o speciesr species r unidentified y the lending nstitutions, specimensoane.l as Chironius nstitutions,but but only 0.40/0f the specimensoane.l actuallybelonged actually belonged o other genera. elalionships sl Therehave There havebeen beenno no major presentationsn lhe generic elalionship Althoughsome some nterspecif nterspecific icelationships elationshipsave avebeen beendiscussed discussedy y Crilorlrr. Although

 

10 BaileJ 1955) nd Donoso-Barros1969), Donoso-Barros1969),hereare areviftually viftually no major majorworks works keating he systematicsfthe entiregenus. urther, he general ange file genuss known,but the distribulions fthe specieshaveeenpoorlyundcrstood and noi well deiined.Most ofour loowledgeol stecies, jstriburions comesi-o comes i-om regional tud es,which whichare areoccasionallyncomplete r unfeliable asto speciesdoniifications. hese nclude he worksofDa Cunhaand menro(1978, menro (1978, 983, 984) 984)or or eastemAmazonia;Moonen and van DeuNen Nasci(1979)bf Surinam:Chilpaux (1986)or Frenchcuiana; porez-sanros and an d Moreno 1988)forColombia; C olombia;Via V ia a era1_ 1988) era1_ or CentGlAmerica;Carrillo de Estinosa 1989)or Peru.The ackolecologicai, ehavioral, iochemical, and orher specializedtudies asalso alsohelped helped o impede axonomic tability rvithin he genus.Species S pecies f Criforlrr have havebeen beenmentioned n a numberoi numberoi diverse natomical olated tudies, nd or agroup ofsnakes o be so widely used,i.is mponantthat heir systemalicse realed o removeexisting on fusion n the allocarion f names. C1l//IONIUS ADVERTISEMENT INFORMATION Thegenus The genus Crilorirr canbedefined canbe defined samediumto amediumto1arye 1aryeized, ized,e[estdal_ e[estdal_ arboreal, gl]lhous colubrid. The hemipenis as a single sulcusand sulcus and obe, nakedpocket roximally, pinous ontrally, alyculate isralry, nd s withoui capitation r apicaldisks. d isks.The T he upil is round.There s a ull comllenent of colubridheadscales. here hereare areaboui aboui123 123 o 196 enirals nd96 96b b 2b8 ubcau_ dals.The midbody domalscales re n 12of 12 of l0 rows, rows,with with lhe presence r absence f keeling nd apical its on dorsal cales, epending pon he spe_ Crilorirr is diagnosed s he only Neotropical nake enuswith l0 or 12 scaleows scale owsatmidbody.This Thischaracteraloneseparates characteraloneseparates ,itori6from ellother Centraland Central and South SouthAmerican Americansnakegenera. (h,ro,ttu,hd. d \eor-npical i.rib. ,ion. ,ion.e\tending e\tending iom lhe - o thcrn coasl l HondJ-ri n urugui) drd nolhed.t AJgenltna, u.t spe.ie..re lbund east o the Andes n ot around the Amazon Basin.Chirotli s has reachedhe reached he Island Islandofcorgona ofcorgona along he Pacific oast fColombia, fColombia,several several islands long he Atlantic coast f Brazil, nd ndTrinjdad Trinjdadand andSt. St.Vincentlsland in the CadbbeanSea. Habitatprefercnceadesextensively ithin he genus nd ndwithincertain withincertain species. o\rland tropical ainforest s preferrcdby Crtr,orrrr,bur humid montaneforests nd ndsavan savan alopen ormations ationsarc arcalso also nhabited. heelevation nnge ol the genus s rom sea evel o 2800m. The range nd habitatoI exch axon are expldned n greater etail n the species ccounts. A general escription fthe total sum olvariation n the genus s: Total lengthvaries rom 274mm to 2718mm and he ail s 26.9-43.t ercent fthe

 

ll

total cngth.The cngth.The ventrals ary rom 12l-196 12l-196n n malesand malesand 131-190 n females. The subcaudals fe paircd and vary fiom 96-208 l males.and 9 9-205 n femalcs. he umbilicalscaf umbilicalscaf s normally hree hreeventmls ventmls ong. The anal plate maybe may be dividedof entirc.The entirc.The amountol amountol keeling squiievadablc, nd preseni in all speciesxsept species xseptC,rrrr?/ri, C ,rrrr?/ri, Malesgenerallyave Malesgenerallyavemofe mofepronounccdkeel, ingandir ing andir somo peciesVith peciesVithnofe nofe scxle orvs eeledhan emales. picalpits areabsenl n C ,?ortrold, areabsenl ,?ortrold,present present r ab ent n C 4uotiicainatus,arTd,presenl in all o ther species. The n ofmal comple cnr ofcolubrid do$al headscales headscales re:supralabials nofmally8 or 9;supralabialsntefing 9;supralabialsntefingorbit usually,l+5+6, +5.or +5.or 5+6; nfralabidsnormally labids normally10 10of of 1l rvopain of genials;nfralab nfralabals alscontacting contacting cniels n one side sideusually usually6 6 or 7; usualh preocular; rcoculat su.lly nol in co tact wilh iiontal; usually , somelimes postoculars; ppefpostocular sually n contactwith w ith parietals;empofals adable, sually +1or +1or1+2. 1+2. ometimcs+l +l+ + I or 1+l+2; usually loreal;usually loreal;usually410 410 postcephalics.here hereare are24-51 24-51 glyphousnaxillary ccth, ccth,and and26-46 26-46 entafy eeth. eeth.There Thereafe 2 or l0 scalerowsat nidbody, withscdle ow feductionquitevadable, sually 2-12-10,l2-12-8,10 10-10,ff l0l0-8. 10-10, Hemipenes f ell species fesingle fe single obcd.cylinddcal. n d dillefeniiared. The retfacledength retfacled engthofthehemipenis ofthehemipenis cachesto ubcaudals ubcaudals-13;,41. -13;,41./r?./r/ /r?./r/ ,ragrr.i originates etwccnsubcaudals etwccn subcaudals 5-32. he sulcus /errs Dermaticus simple not divided) nd usually usuallyerninates erninates ubapically. basal ated pocker is presentolposite the sulcus. sulcus.The The basal ofiion of lobe may be with ol without minute spinules. he cntire centralpoflion p oflion oflobe contains pines $hich number4 12 er longltu inal ow.The ow.The cntirc cntircdistal distalportionoflobe ha has s calyces hich number8-26pcr ongitudinal ow-The ow-The cdlyces ave roximal spinous ringes har change o papiUateringcs distally. Inlraspecifially, Inlraspecifi ally, oloraiion nd ndcoior coiorpatlernsmay mayor or meynot meynotbe bevariable, variable, Fofest orms iend to be dafk, usuallygrcen.olive, olive,or or blackdorsally; blackdorsally;open open ibrmalion brms are areuniform uniform yellow brown, olive brown, of havc a stdped paite . Species f Cir"rtrr are oviparcuq errestfial-afb ofeal, ild to vety aggrcssive n disposirion, ndgenefally lcep lcepaboveground aboveground t nighl n trees f bushes. hese nakes reactive reactive oregers ur uring ingdaylight daylight ndpfey ndpfeyalmo$ almo$ ex exc c lusively n fiogs. fiogs.Crn'orlrr, Crn'orlrr,h he ein, s comprised f 13 pecies nd nda a totalof total of 20 tAxa. Chironius Chironiusbia:trhatus bia:trhatus(Wied); C. cainatus utiratrr (Linnaeus); C ../1d, rolrrds (Wemet; C C r"/it(Hal1owe11); r"/it(Hal1owe11);C C a?1 t s (Linnteus); C. a\iali neatus (Jan); C. fuscus uscus Linnae]ls), C. f. leuu)nelaprr, new subs subspecies; pecies;C gtafidisqudmisPeIefi);CC-Laericallis LaericallisNied); spccies;Cno no,, N ied); C.laurcfta ew spccies;C ticolaRoze;C. ticolaRoze; C.nultiwntris nultiwntris rir.irdndr Hogea]1d Hogea]1dRomano; Romano;CC-n.Jovedtus n.Jovedtussaisaileya - m. mull entis Schmidl Schmidland andWalker; Walker;C m-sQlert"loralir, m- sQlert"loralir,now subspecies; C. quddti inalus nda?/r,r,crt ]J, new subspecies;C. C. q. qtradticannaue (tsoio)iC r.?r"/rr (WaSlef);and rir(  rt(Boulengor). rt(Boulengor).Sincc SinccC C /drf srli, C

 

t2 multivnttis, anrl C. vincenti share many uniquely derived chatactef states, these pecies replaced the r,r/rn,entnr lec escomplex, convenientway oI showing he close elationship mong hcse species ut which has no nomenclatural tatus, In 15of the 20 CriloTrtrrlrxamales lrxamalesattain attaina a largefsize han emales. he smallest pecimen xamined as asajuvenile ajuvenile naleC manticola2j4mminLotal jn lengrh.The lengrh. The largest wasa was a male C grdrdtr uamis 718 mm total length. Smallest nd pecimen afgest pecimens pecimensxaminedfoteach xaminedfoteach presented axonarc axon arc in the slecie slecies saccoln|s. MATERIALS AND METHODS Ofrhe 2978 Decimens Decimensll Crilo'irr used n theseanalyses,ess e ss han 400 \yerenotpersonally \yere notpersonally x,rmined y us,Most specimens ereprocured n oans fron museumsand educationalnstituiions n the United States, urope, SouthAmerica,and Cenl|al America, nd hese ollcctions fe isted istedal al the end ofthis section.A list of lnown bur unavailab unavailable le rjlorirr specimenss providedn Appcndi\I and andslecimens slecimens xamined rc isted _by pccies,locality, andmuseum umbor) nAlpendixll. We examined r acquirednforma acquirednforma tion on 19ofthe28 19ofthe28 ),pespecimenslell speciesnd speciesndsubspeciesnamesthatare subspeciesnamesthatare associatedith associated ith Cir)oaiff. The feDaining ine ypes ould ouldeither eithernot not be oca ed after aftere{ensive e{ensive searchiig searchiigof of weropositively eiermined o be ost or desscalecounts,aspects f anatomy,measurements, scalecounts, m easurements,alios,and a lios,and color pa ternsofpresefled terns ofpresefledspecimens ereutilized n analyzing analyzingnterspecificrelarionnterspecificrelarionships nd n nimspecific imspecific ariation. uelo time acto|S ssociated ssociatedith ith his hisstudy study of to thc poor conditionofcerlain snakes, omplete ata atawere werenol obtaincd fiom all specimens. Ventralswe werr  counted ollowing he meihod ofDovling (1951a). ingle half-ventrals efe gnoredsince hey ndicaled ndicaledvertebral vertebral beraiions ting, 1959),ut 1959), ut two hat scales fa divided enrfalwefe w efecounted so sone.Subcaudals pated are and refecounted n he eft sicle rarling ith the irsr irsrscalebehind scalebehind rhe anal platc hat contacted scaleon scale on the ide.Fused Fusedsubcaudal subcaudal were ncluded n all counts, aswas as was heoppositc unfaired,ide. lairsanalplatc elrninalscale. elrninal scale. Conditionofthe Condition ofthe dorsal ead caless calessconsistenifo consisteniforall rall peciesnd ndwas wasno nott rccordedbf rccorded bf most mostspecimens. specimens.he lumberofsupralabials, lumber ofsupralabials,upralabialsnterlng the orbit, nffal nffalabials abials last nfralabial etemined eteminedas as he ast astscale scale t east half covered coveredby by the last supralabial) supralabial),,nfralabials ontacting he genials, genials, feoculars,rcoculars ontacting ontactingheliontal,postocula$,postoculan heliontal,postocula$,postoculan contactinghe parietals,enporals e nporals (scales ehind ostocularsand berween the paietalsand supralabial supralabials), s), oreals, nd ostcephalicsscalesouching he postedormargln oftemporalspa elals) elals)were werenoted. noted.

 

A slashmark slashmark is is used o separate haracter haractercounts counts taken on opposite oppositesides sides ofthe headwith headwith he eft side ndilrated ndilratedirst(e. irst(e.g.,supralabials/8 signifies ine supralabialson the lell sideand eight on the right). A hyphen hdicates range in a charactere.9., enlrals 35-155 eans 35 o 155 entrals). egmenis fa chalacterananged chalacter ananged n a ser series iesarc arc separated y a plus sign (e,9., emporals 1+2 denotesone denotes one primary and two se secondary condary empomis). empomis).Teeth Teeth on the the left maxilla methodof ofmany specimens ereexamined nd counted , rirr using he methodof Myers (1974).The The number of dentary teeth (left side) were noted for a lew specimens f most species. ondition ofthe analplate singie, ivided, ivided,or or incompletely ivided), ositionofapicalpits, nddegree nddegree fkeelingwere fkeelingwerealso also recorded, Wlen no everted emipeniswaspresent,he sexofeach sexofeach spesimen as pai$ determined by maling a post-analslit between the anteiior subcaudalpai$ andchecking and checkingor or the presence frr rr, hemipenes. emipenialmorphology, m orphology, including ength by numberof subcaudalsnvolved), n volved), hape, onditionof sulcusspennaticus, cus spennaticus,nd nd omamentations omamentations described ccordingo ccordingo the erminologyolDowlhg logy olDowlhg and Savage1960).1,,t/ hemipenes fat least hree hreespecimspecimensandseveral ensand several verted emipenes ereused ereused n the descriplionbr descriplionbr each pecies.Eggs cies. Eggspresent n oviductswere oviductswere countcdby countcdby palpation r by incising he midlineoftheposterior midline oftheposterior entrals nd ndvisually visuallynspecting nspectinghem. hem.Witl Witl this atler method, he greatestength and width of the eggswere eggswere measured. nakes with obviously nlarged odies n the stomachcgionhad stomachcgionhad heirstomach ontents emoved nd examined. oti ceable ctocto-and and endoparasitesere endoparasiteserecolcollected and identified. For consistency bbreviated cale orv formulaswefe formulaswefe stardardized y counting the nnmber of dorsal scale ows over the tenth ventral behind the head.over he middleventral. nd overthe enth enthventral ventralanlerior anlerior o the anal p1ate. omplete cale ow formulas ndicating he exact ositionofscale ow reductions ard additions were constructed for most specimensusing specimensusing the melhod (with slight modiflcationt suggested y Dowling (1951b), nd these 1 976). formulaswerc ummarizedollowingthe ummarizedollowingthemodelpresentedbyThomas modelpresentedbyThomas1976). Ali measuements (ir millimetres) were taken on the left side where applicable. noutvent and tail lengths lengthswere were aken rom specimenstraighspecimens traightened againsta againsta meter stick. Other measurementsaken with a vemief calipers weresnoutlength were snoutlength straightine disiancerom disiancerom tip ofsnoutto posterior nd ndof of interprefrontal suture), suture), rontal scaleength, he head ad ength (shaight ine distance headwidth width betweenhe between he ateml from tip of snout o posteriormarginofjaw), m arginofjaw), head marginofthe supraoculars,ead eadwidth width between he e),1emalnares,ostral scale eiglt andwidth, andwidth,and andhorizontal horizontal yediameter. yediameter. pecimensn the 300-500 mm snout-vent size sizeclass classof of most species f Crilo,'?lrsgenerallyshowontogenetic changes n color patterns and degree of keeling. Therefore, the tterm erm juvenile is ruther arbitrarily defined herein asspecimens eiow 400 400mm mm snoutvent lensth.

 

\l"-1..hne .,: rot,.i.r, (.e...c..r,t.r