Myers & Grant_2009_Anomaloglossus Confusus

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P UB LI SH ED B Y T HE A ME RI CA N M US EU M O F N AT UR AL H IS TO RY

C EN TR AL P AR K W ES T A T 7 9 TH S TR EE T, N EW Y OR K, N Y 1 0 02 4

Number 3659, 12 pp., 6 figures, 1 table August 28, 2009

Anomaloglossus confusus, a New Ecuadorian Frog

Formerly Masquerading as Colostethus chocoensis(Dendrobatoidea: Aromobatidae)

CHARLES W. MYERS 1 AND TARAN GRANT2

ABSTRACT

Anomaloglossus confusus, new species, is a small (2126 mm SVL) riparian frog from the Pacificversant of the Andes in northwestern Ecuador. It inhabits rocky forest streams in an elevationalrange of about 6001540 m. It is the only known Anomaloglossus in Ecuador, where it can bedistinguished from all other dendrobatoids by the generic synapomorphy of a median lingualprocess. The only other named trans-Andean species ofAnomaloglossusare the western ColombianA. atopoglossus and A. lacrimosus.

Anomaloglossus confususwas previously confused with Hylixalus or Colostethuschocoensis(currently in Hyloxalus), a rare species described by Boulenger on the basis of a subadult femalefrom Pacific lowland Colombia. The first adult specimen ofHyloxalus chocoensis, an adult male, isdescribed. The generic name Hylixalus is not an incorrect subsequent spelling as recentlyinterpreted, but an emendation with its own authorship and date of publication (Boulenger, 1882);as such, it is a junior objective synonym ofHyloxalus and is an available name.

RESUMEN

Anomaloglossus confusus, especie nueva, es una rana riberena pequena (2126 mm LRC) de lavertiente pacfica de los Andes del noroccidente del Ecuador. Se encuentra en quebradas rocosas enbosques de 6001540 m.s.n.m. Es la unica especie de Anomaloglossus conocida en el Ecuador,donde se distingue de las demas especies de Dendrobatoidea por poseer la sinapomorfa generica

Copyright E American Museum of Natural History 2009 ISSN 0003-0082

1 Curator Emeritus, Division of Vertebrate Zoology (Herpetology), American Museum of Natural History.2

Research Associate, Division of Vertebrate Zoology (Herpetology), American Museum of Natural History. ProfessorAdjunto, Faculdade de Biociencias, Pontifcia Universidade Catolica do Rio Grande do Sul, Porto Alegre, Brazil([email protected]).


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del proceso medial lingual. Las unicas otras especies trans-andinas de Anomaloglossus son A.atopoglossusy A. lacrimosus del occidente colombiano.

Anomaloglossus confusus fue confundido anteriormente con Hylixalus o Colostethuschocoensis (actualmente en Hyloxalus), una especie escasa de las tierras bajas del pacfico

colombiano descrita por Boulenger a partir de una hembra subadulta. Aqu se describe el primerejemplar adulto de la especie, un macho. El nombre generico Hylixalus no es una ortografaincorrecta subsequente, como fue interpretado recientemente, sino una emendacion con su propiaautora y fecha de publicacion (Boulenger, 1882); por consiguiente, es un sinonimo menor deHyloxalusy es un nombre nomenclaturalmente disponible.

INTRODUCTION

Nearly a century ago, G.A. Boulenger(1912) described the frogHyloxalus chocoensisbased on a single subadult female from theRo San Juan drainage in western Colombia.

The species was assigned to several differentgenera over the years; it has been inColostethus for the last several decades, butit recently was returned toHyloxalus(Grant etal., 2006: 168). Despite the taxonomic shuf-fling, little is known about the species.

Myers (1991) redescribed and illustrated thechocoensis holotype and extended the geo-graphic range north into Panama based onone specimen from that country. However,new material obtained in Panama by Roberto

Ibanez and colleagues shows that the isthmianfrog represents still another secretive dendro-batoid (unpublished data).

Myers (1991: 1) also tentatively extendedthe range ofchocoensis south into northwest-ern Ecuador, but pointed out that theEcuadorian population conceivably repre-sents a different species [that] cannot bereliably diagnosed at this time. However,our discovery of the median lingual process(Grant et al., 1997) in New World dendroba-

toid frogs provided a definitive answer for thiscase. The holotype of H. chocoensis lacks alingual process, whereas the Ecuadorian frogspossess one and were temporarily referencedas Colostethus species (C. chocoensis auct.)in Grant et al. (1997: 24, 35). All dendrobatoidfrogs characterized by presence of the medianlingual process are now referred to the genusAnomaloglossusGrant et al. (2006: 158).

We here provide the formal description of theonly known Ecuadorian species of Anoma-

loglossus, followed by notes on the first adultspecimen ofHyloxalus chocoensis. Institutionalabbreviations are AMNH (American Museumof Natural History, New York, USA), BMNH

(Natural History Museum, London), ICN(Instituto de Ciencias Naturales, UniversidadNacional de Colombia, Bogota, Colombia),KU (Natural History Museum and BiodiversityResearch Center, the University of Kansas,Lawrence, USA), and MHNG (MuseumdHistoire Naturelle, Geneva, Switzerland).

Anomaloglossus confusus, new species

Figures 1, 2 (upper), 35

Colostethus chocoensis (Boulenger): Myers, 1991(part: Ecuadorian specimens, including figs. 1A,8AB); Coloma, 1995: 2526, figs. 1 (hand andfoot), 2D (dorsal color pattern), 5A (testes), 10(map).

Colostethus species (C. chocoensis auct.): Grant,Humphrey, and Myers, 1997: 35.

A[nomaloglossus] chocoensis auctorum: Grant etal., 2006: 158.

HOLOTYPE: AMNH A-104819 (field no.CWM 15955), an adult female from about 7air km SSW El Corazon, 800 m elev., Bolvar-Cotopaxi border, northwestern Ecuador, col-lected by Charles W. Myers, John W. Daly,and Eugene W. Schupp on November 13,1979. The type locality is roughly 01u109S,79u099W.3

PARATYPES: AMNH A-104820104824, pa-ratopotypes collected with the holotype. KU166157, 166158 from 3.5 km NE Mindo,1540 m, Pichincha, Ecuador, collected by W.E.Duellman on April 8, 1975. KU 221616 from

3Collection of specimens reported in this paper precededcivilian GPS satellite receivers. Coordinates for the typelocality were estimated on the map Republica del Ecuador1:1,000,000, Instituto Geografico Militar, circa 1981.Thetype locality was 11 km by gravel road SSW El Corazon

on the way to Moraspungo and Quevedo. Confusingly,Moraspungo is plotted about 8 km southeastward of ElCorazon on earlier editions of official maps (MapaGeografico de la Republica del Ecuador 1:500,000,Instituto Geografico Militar, 19561957).

2 AMERICAN MUSEUM NOVITATES NO. 3659


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[San Francisco de] Las Pampas, [1800 m],Cotopaxi, Ecuador, collected by GiovaneOnore. MHNG 2258.572258.63 from Tan-dapi, [1460 m],4 Pichincha, Ecuador, collectedby G. Onora in December 1983.

REFERRED SPECIMENS: Additional speci-mens (not seen by us) identified by LuisColoma asColostethus chocoensis, from prov-

inces of Carachi, Cotopaxi, and Pichincha,Ecuador (see Coloma, 1995: 68).

ETYMOLOGY: The specific nameconfususisthe perfect passive participle of the Latinconfundo (to confound or mix together),referring to the fact that this species was

confused with another one.DIAGNOSIS: The median lingual process

(fig. 2) distinguishes Anomaloglossus confususfrom all other dendrobatoid frogs known fromEcuador. The only other trans-Andean frogswith a median lingual process are A. atopo-

glossus and A. lacrimosus from westernColombia.

Anomaloglossus atopoglossus and A. lacri-mosus are visually distinguished from A.confusus by a white oblique postocular stripe

(absent in confusus) and by at least theanterior belly white in life (pale blue or bluishwhite in confusus; often dark spotted inatopoglossus).A. confususis appreciably larger

Fig. 1. Anomaloglossus confusus, new species.Left- and right-side views of the adult femaleholotype in life (AMNH A-104819, 24 mm SVL).The blackish ground color appeared dark olive-green in sunlight. About 2.33 life size.

Fig. 2. The median lingual process as diagnos-tic character. Upper: Slender median process(arrow) present in Anomaloglossus confusus, newspecies (AMNH A-104820, U paratopotype).Lower: Median lingual process absent in Hyloxaluschocoensis (Boulenger) (BMNH 1947.2.14.27, Uholotype).

4Data in brackets are added from the gazetteer in Lynchand Duellman (1997: appendix 2).

2009 MYERS AND GRANT: ANOMALOGLOSSUS CONFUSUS 3


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than A. lacrimosus and slightly larger thanA. atopoglossus, as shown by comparison ofsnout-vent lengths (SVL):

A. confusus: - 21.7 mm (n 5 1), U 2326 mm(x 5 24.2, n 5 6)

A. lacrimosus: - 15.8 mm (n 5 1), U 17.719.6 mm(x 5 18.7 n 5 9)

A. atopoglossus: - 18.520.7 mm (x 5 19.7 n 5 19),U 21.725.2 mm (x5 23.3, n 5 16)

MEASUREMENTS (IN MM) OFHOLOTYPE: The

specimen is an adult female, as shown bypresence of convoluted oviducts and enlargedova. Length from snout to vent 23.7; tibialength between heel and outer surface of flexedknee 12.1; greatest width of body < 10; headwidth between angles of jaws, and betweenouter edges of upper eyelids, 8.2, 6.9 respec-tively; approximate width of interorbital area2.5; head length (sagittal) from tip of snout toangle of jaw < 7; tip of snout to center of naris(sagittal) 0.9; center of naris to anterior edge

of eye 2.0; distance between centers of nares3.2; eye length from anterior to posterior edge3.2; horizontal diameter of tympanum about1.5; corner of mouth to lower edge of

tympanic ring 0.7; hand length from proximaledge of large medial palmar tubercle to tip oflongest (third) finger 6.8; width of disc of thirdfinger (and width of penultimate phalanxbelow disc) 1.1 (0.7); width of discs (andpenultimate phalanges below discs) of thirdand fourth toes 1.2 (0.8) and 1.2 (0.8),respectively.

DESCRIPTION

The type series comprises 16 specimensfrom four localities in northwestern Ecuador.One adult male and six adult females areincluded, the other specimens being juve-niles. Size and proportions are summarizedin table 1 for all specimens, including juve-niles. Measurements and proportions givenin the following description are for adultsonly.

MORPHOLOGY: Adult male (KU 166158)21.7 mm SVL; testes unpigmented (white),large, right testis 3.8 mm long, slightly longerthan eye (for illustration of large testes ofreferred specimen MHNG 19107 see Coloma,1995: 10, fig. 5). Adult females 23.026.0 mmSVL (n 5 6; x 5 24.2260.45); oviducts ofadults large and convoluted, unpigmented(white); mature ova yellowish brown (incontrast to white or cream immature ova)but lacking dark pigmented animal pole, large,approximately 3 mm in diameter (measured inKU 221616). An elongate, conical, smooth(nonpapillate), unretracted median lingualprocess with pit is present in all specimens(fig. 2, upper).

Dorsal surfaces weakly granular in life

(fig. 1), becoming smooth in preservative;ventral surfaces smooth. A usually well-developed cloacal tubercle at base of eachthigh (see Grant et al., 1997, p. 25, fig. 11); asmall round postrictal tubercle. Head widthbetween angles of jaws 34%39% of SVL.Snout sloping, in profile slightly pointed torounded, in dorsal and ventral view eitherrounded with median point or broadly round-ed (outline drawings in Myers, 1991, figs. 8A,8B). Canthus rostralis gently rounded (e.g.,

AMNH A-104820) to sharply defined (e.g.,KU 221616). Loreal region flat or weaklyconcave, vertical or barely sloping outward tolip. Eye-naris distance 5771% of eye length.

Fig. 3. Right hand and left foot of Anoma-loglossus confusus, new species (AMNH A-104819,holotype). Scale line 5 1 mm.



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Nares visible from in front, barely visible fromabove or below, slightly protuberant, directedposterodorsad. Tympanum well defined, con-cealed posterodorsally by low supratympanicbulge formed by superficial slip of m. depres-

sor mandibulae. A pronounced, usually ven-trally elongate or (in one specimen) roundbulge at the anterior edge of the upper armoverlies the lower part of the m. latissimus

5The m. dorsalis scapulae appears not to contribute tothe bulge, as it is a narrow, relatively small muscle that liesanteriomediad to the large triangular m. latissimus dorsi.

The latter originates as a broad thin sheet of muscle thatthickens and bulges proximolaterad. When round (inAMNH A-104820), the bulge has the appearance of adiffuse preaxillary tubercle. (Dissections based on AMNHA-104820 and KU 221616, both adult females.)

Fig. 4. Anomaloglossus confusus, new species. Dorsal and ventral views of two adult females, showingminor variation in color pattern. AMNH A-104819 (holotype) on left, AMNH A-104820 (paratopotype) onright. Scale 5 10 mm.

dorsi. 5 Teeth present on maxillary arch.



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Hand length 29%31% of SVL, 76%92% of

greatest head width. Finger discs weakly tomoderately expanded. Finger III not swollen.Fringes (sensu Grant et al., 2006: 66; see alsoMyers and Donnelly, 2008: 43) present on pre-and postaxial edges of all fingers of MHNG2558.602558.61 and KU 221616 (three largestspecimens); remaining specimens with weaker(but still well defined) fringes on preaxialedges of fingers II and III and strong dermalthickening (but not fringes) on other edges offingers. Hand webbing absent. Metacarpalfold present. Appressed fingers I and IIsubequal in length (II usually slightly longer);II . I when measured from digit tip to base ofpalmar tubercle (Character 5, State 1 of Grantet al., 2006: 64). Finger II extends to middle ofthe distal subarticular tubercle of finger III;finger IV extends beyond the distal subarticulartubercle of finger III. Relative appressed fingerlengths III . IV . II < I (fig. 3). Subarticulartubercles 1122. All tubercles strongly protu-berant; subarticular and thenar tubercles ellip-tical; palmar tubercle subcircular.

Tibia and foot length 47%53% and 45%52% of SVL, respectively. Relative lengths ofappressed toes IV . III . V . II . I (fig. 3).Toe III extends to distal edge of ultimate

subarticular tubercles of toe IV; toe V extends

approximately midway between penultimateand ultimate subarticular tubercles of toe IV.Extensive webbing present between all toes;webbing formula I 1(1O 2)II 1(22K) III(11K)(1K2K)IV(22K)(11M)V. Wherethe webbing fails to reach the disc, it extendsdistally as a narrow fringe, which turnsdownward on each side of toe IV and on thepreaxial side of toe III. Outer metatarsal foldstrong. Discs moderately expanded. Tuberclesstrongly protuberant. Subarticular tubercles 1-1-2-3-2. Inner metatarsal tubercle elongate.Outer metatarsal tubercle subcircular, diameterroughly one-half the length of inner metatarsaltubercle. Medial metatarsal tubercle absent,but thickening of skin is notable in somespecimens (for discussion of relevance seeMyers et al., 1991: 2324). Tarsal keel welldefined, straight or weakly curved, slightlyenlarged proximally but not forming tubercle-like structure, extending diagonally from innermetatarsal tubercle along distal half of tarsus.

COLOR PATTERN: In life (fig. 1), the holo-type and paratopotypes were very dark olivegreenappearing virtually black in some lightand in the photographswith a few bronzytan dots scattered on sides of body and with

Fig. 5. Anomaloglossus confusus, new species. Dorsal and ventral views of an adult male paratype (KU166158). Scale 5 10 mm.



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vague crossbands on the limbs. A pale markatop the base of the arm appears (based on acolor transparency of holotype) to have been

golden bronze with a small area of pale blue.The throat and venter were pale blue; ventrallimb surfaces were grayish brown, some with aslight suffusion of orange under the hindlimbs. Iris pale green in the holotype, palebronze in the other specimens, with denseblack venation in all.

William E. Duellman (field notes) describedKU 166157166158 as brown with darkbrown markings dorsally and with bluishcream flecks laterally; throat and ventralsurfaces of limbs pale gray; belly bluish whitewith gray reticulations; iris dull bronze.

In preservative (figs. 4, 5), dorsum brown orpale brown, with dark brown markingsvarying from conspicuous, well-defined dark

brown interocular chevron, scapular W,and sacral bands (e.g., MHNG 2558.60) tofaint, diffuse, and irregularly distributed

blotches (e.g., AMNH A-104819). Pale lateralstripes absent, but flank often with small,scattered cream spots. Loreal region (andusually dorsal snout) dark brown, the darkcolor extending posteriorly through eye andabove supratympanic bulge. Postocular regionanterior and ventral to supratympanic bulgepale brown, lacking pale oblique postocularstripe. Upper lip area brownish tan, paler thanadjacent loreal region but not forming adiscrete stripe and lacking any pale spots.

Ventral coloration cream with dark brownreticulation, usually darkerandmore conspicuouson throat than on belly, not sexually dimorphic.

Exposed surfaces of arms brown or brownwith dark brown blotches or crossbands.

TABLE 1Size and Proportions of Anomaloglossus confusus, New Species

Character N Mean 6 1 S.E. S.D. C.V. (%) Range

Snout-vent length (SVL) in mm 1 ad.- 21.70 21.7

6 ad. U 24.22 6 0.45 1.10 4.56 23.026.0

9 juv. 15.63 6 0.57 1.70 10.86 13.018.7

Tibia lengtha/SVL 1 ad.- 0.525 0.53

6 ad. U 0.511 6 0.010 0.024 4.71 0.470.53

9 juv. 0.535 6 0.013 0.038 7.03 0.500.62

Head widthb/SVL 1 ad.- 0.355 0.36

6 ad. U 0.353 6 0.007 0.018 5.17 0.340.39

7 juv. 0.378 6 0.004 0.012 3.14 0.360.39

Center naris to edge eye/eye length 1 ad.- 0.613 0.616 ad. U 0.637 6 0.022 0.053 8.34 0.570.71

6 juv. 0.608 6 0.015 0.036 5.95 0.560.64

Hand lengthc/SVL 1 ad.- 0.300 0.30

6 ad. U 0.301 6 0.004 0.011 3.65 0.290.31

6 juv. 0.287 6 0.007 0.017 5.99 0.270.31

Hand length/head width 1 ad.- 0.844 0.84

6 ad. U 0.853 6 0.023 0.055 6.48 0.760.92

6 juv. 0.761 6 0.019 0.047 6.23 0.720.82

Width 3rd-finger disc/finger width

below discd

1 ad. - 1.667 1.67

6 ad. U 1.518 6 0.039 0.096 6.34 1.381.57

6 juv. 1.317 6 0.048 0.127 9.67 1.171.50

aTibia length is the shank measured from heel to the convex surface of knee (with limb segments flexed at right angles),

roughly approximating length of the tibiofibula.bGreatest head width as measured between jaw articulations.cHand length measured from proximal edge of large medial palmar tubercle to tip of longest (3rd) finger.dDigit width measured near distal end of penultimate phalanx.



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Concealed surfaces of arms pale brown.Palmar surfaces pale brown. Hand dorsallybrown. Fingers I and II dorsally cream or palebrown with brown blotches, fingers III and IVbrown with cream blotches (i.e., inner fingerspaler than outer fingers).

Exposed surfaces of legs brown or palebrown with variably defined dark browntransverse bands on thigh, shank, and footthat align on flexed limb. Anterior surface ofthigh solid brown; posterior surface brown orpale brown with diffuse dark brown mottling.Pale paracloacal marks absent. Groin brown,lacking flash mark. Concealed surfaces ofshank and foot cream or cream with diffusebrown stippling or mottling. Plantar surfacespale brown. Webbing cream, often with brownstippling, stronger adjacent to toes.

DISTRIBUTION AND ECOLOGY

Anomaloglossus confusus occurs on thePacific versant of the Andes in northwesternEcuador, at known elevations of 6001540 m(see distribution map [as Colostethus chocoen-sis] in Coloma, 1995: fig. 10).

Judged from the distribution, and observationat the type locality, the habitat is rocky clear-water streams in lower montane rain forest. Theholotype and paratopotypes were found by day,mainly under rocks along the edge of a fast-flowing stream, but individuals also were seenmoving actively among the rocks. At anotherlocality, W.E. Duellman found two specimens(probably sleeping) perched on leaves of herbs10 cm over water at night (Duellmans fieldnotes for April 8, 1975).

At the type locality, Anomaloglossus confususwas microsympatric withHyloxalus infragutta-tus (Boulenger) and Epipedobates tricolor(Boulenger), although the latter occurred morecommonly on slopes away from the stream. Forother localities, Coloma (1995: 26) recordedsympatry with Hyloxalus awa (Coloma), H.breviquartus (Rivero and Serna), H. toachi(Coloma), and Epipedobates espinosai(Funkhouser).

DISCUSSION

There are only three named trans-Andeanspecies of AnomaloglossusA. confusus, newspecies from lower Andean slopes in north-

western Ecuador, and A. atopoglossus (Grant,Humphrey, and Myers) and A. lacrimosus(Myers) from western Colombia. The remain-ing 18 cis-Andean species comprise a GuayanaShield radiation, with species distributed northof the Amazon River between elevations of50 m (e.g., A. stepheni [Martins]) and 2700 m(A. roraima [La Marca]). Due to lack ofmaterial trans-Andean species have not beenincluded in quantitative phylogenetic analyses,but their placement inAnomaloglossuswith thecis-Andean species is supported by the synapo-morphic presence of the median lingual process(Grant et al., 2006).

As suggested by their extensively webbed feetand collection data, the three trans-Andeanspecies of Anomaloglossus all appear to beriparian, occurring under and among rocksalong clear-water streams in or near forest. Thevocalization of A. atopoglossus is a frequencymodulated series of high-pitched notes (Grant etal., 1997: 2728, fig. 13); calls are unknown forA. confusus andA. lacrimosus. The cis-Andeanspecies of Anomaloglossusmore diverse interms of number of species, morphology, andlife historyinclude robust, extensively webbed,riparian species like the trans-Andean taxa,small, slender species almost free of webbing,and phytotelm breeders with nidicolous andoophagous larvae (Grant et al., 2006).

The holotype and paratopotypes ofAnoma-loglossus confusus exuded a milky secretionfrom the dorsal and lateral body surfacesduring fixation of the specimens in formalin;unfortunately, a skin sample in methanol hadnot been first obtained for analysis. Althoughsecretions from dendrobatoid granular glands

(Neuwirth et al., 1979) may contain defensivealkaloids having noxious or toxic properties,the mucous glands have not been ruled out asa source of some milky and possibly defensivesecretions (e.g., Daly et al., 1987: 10651069).Skin alkaloids have not been documented inAnomaloglossusor in any other member of thefamily Aromobatidae (Grant et al., 2006:157163), but an extraordinary alternativeform of chemical defense occurs in at least onespecies of the type genus. Aromobates noctur-

nus produces both a sticky mucus and avolatile compound that has a vile mercaptan-like odor (Myers et al., 1991: 14, 16). Fieldbiologists need to be alert for new kinds of



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chemical defense among dendrobatoids andother tropical frogs.

A NOTE ONHYLOXALUS CHOCOENSIS(BOULENGER)

Figures 2 (lower), 6

Hyloxalus chocoensis s.s. has long beenknown only from the holotype, a subadultfemale (fig. 6, upper), collected at Noanamaon the lower Ro San Juan, Depto. Choco, inwestern Colombia (Boulenger, 1912). The

specimen described below is the first adultspecimen known to us that appears assignableto H. chocoensis (fig. 6, lower). The descrip-tion below parallels Myers (1991) redescrip-tion of the subadult female holotype (BMNH1947.2.14.27).

The specimen (ICN 47971) is an adult male26.0 mm SVL, with large paired vocal slitsand a shallow subgular vocal sac; the right

testis is white, 1.8 mm long. There is nomedian lingual process.

COLLECTION DATA: ICN 47971 (field no.JMR 892), collected near Campamento

Fig. 6. Hyloxalus chocoensis (Boulenger) in dorsal and ventral view. Upper: Subadult female holotype(BMNH 1947.2.14.27). Lower: Adult male (ICN 47971). Scale 5 10 mm.



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Ingeominas (ca. 6u429N, 76u279W), near theheadwaters of Ro Amparrado, MunicipioDabeiba, Departamento Antioquia, Colombia,805 m elevation, by Juan Manuel Renjifo.

MEASUREMENTS (IN MM): Length from snoutto vent 26.0; tibia length between heel and outersurface of flexed knee 12.8; greatest width ofbody 11.8; head width between angles of jaws,and between outer edges of upper eyelids, 10.3,8.0 respectively; approximate width of interor-bital area 3.0; head length (sagittal) from tip ofsnout to angle of jaw 7.4; tip of snout to center ofnaris (sagittal) 1.0; center of naris to anterioredge of eye 2.3; distance between centers of nares3.5; eye length from anterior to posterior edge4.0; horizontal diameter of tympanum about 1.5(estimated, posteriorly concealed); corner ofmouth to lower edge of tympanic ring 0.5; handlength from proximal edge of large medialpalmar tubercle to tip of longest (third) finger7.5; width of disc of third finger (and width ofpenultimate phalanx below disc) 1.2 (0.7); widthof discs (and penultimate phalanges below discs)of third and fourth toes 1.2 (0.8) and 1.3 (0.8),respectively.

MORPHOLOGY: Skin nearly smooth dorsally(under high magnification, appearing weaklygranular posteriorly where patches of stratumcorneum are lacking); skin smooth ventrally.Greatest head width (between angles of jaws)40% of SVL. Snout sloping, rounded in profile,rounded in dorsal and ventral view. Naresvisible from in front, barely visible from aboveor below; posterior rim of naris raised slightlyand bearing a low, rounded prominence poster-odorsad to naris. Canthus rostralis rounded;loreal region slightly concave, nearly vertical,

sloping slightly outward to lip. Interorbitalregion slightly wider than upper eyelid. Lengthof snout in lateral view shorter (80%) than eyelength; center naris to edge of eye 58% of eyelength. Tympanum evident but concealed pos-terodorsally, seemingly one-third or more of eyelength. Teeth present on maxillary arch.

Hand moderate, its length 29% of SVL, 73%of greatest head width. Relative lengths ofappressed fingers on right hand (left mal-formed) III . IV . II . I; tip of finger I

reaching disc of finger II; finger III not swollen.Discs of all fingers moderately expanded; thirdfinger disc 1.7 times wider than distal end ofadjacent phalanx. Base of palm with a large

rounded median metacarpal tubercle, a smallerelliptical inner metacarpal tubercle on base offirst finger; one or two subarticular tubercles(one each on fingers I, II; two each on fingersIII, IV); all tubercles low, with slightly roundedsurfaces. A weak (narrow), fleshy keel-likefringe along sides of fingers; fringe on medianside of first finger extending faintly to innermetacarpal tubercle; fringe on lateral side offourth finger continuous with a weak outermetacarpal fold extending to large palmar(outer metacarpal) tubercle.

Hind limbs relatively long, with heel ofappressed limb reaching between eye and tip ofsnout; tibia 49% of SVL. Relative lengths ofappressed toes IV . III . V . II . I; first toereaching middle of subarticular tubercle ofsecond. Toe discs noticeably expanded, thoseon third and fourth toes 1.31.6 times widerthan adjacent phalanges. Feet webbed to base ofeach toe disc, although the web is reduced to afringe on medial sides of toes IIIII and on bothsides of toe IV distal to the second subarticulartubercle; the proximal part of the fringe tends tofold downward along each side of toe IV; a well-developed fringe along the outer free edges oftoes I and V. One to three nonprotuberantsubarticular tubercles; a small round outermetatarsal tubercle and a slightly larger ellipticalinner metatarsal tubercle. A strong tarsal keel,on distal half of tarsus, is continuous with fringeon free edge of first toe; no tubercle or elevationat proximal end of tarsal keel.

COLOR PATTERN (FIG. 6 LOWER): Dorsalsurfaces gray owing to detaching stratumcorneum, under which the head and bodyappear to be covered overall in a very fine

brown reticulum. (There is no discernibleinterocular bar or dorsal dark marking.) Afew large irregular pale spots along the lowersides merge into the ventral color. (Obliquelateral and ventrolateral stripes lacking.) Theforelimbs are brown, with vague crossbands;fingers III and tops of finger discs 13 arepartly whitish. A well-defined pale axillary spot(flash mark). The hind limbs are brown withcrossbands on thigh and shank; rear of thighsbrown with vague mottling. Ventral surfaces

whitish, with suffusions of pale brown on thechin and across throat. Palms and soles brown.

A pale ill-defined streak on snout, from nearnostril to lower edge of eye; upper lip below



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streak is brown, becoming pale and pigmentlessalong edge of mouth. An ill-defined pale areaextending from the lower rear edge of the eyeacross the upper edge of the tympanum to theforelimb, forming a narrow, very vague post-ocular stripe.

SUMMARY NOTES ONHYLOXALUS CHOCOENSIS(BOULENGER)

The genus Hyloxalus is currently defined byunambiguous DNA sequence transformationsobtained from 17 of the 57 species currentlyassigned to the genus (Grant et al., 2006: 168169). There are no unambiguous morphologicalsynapomorphies. It should be noted that the twospecimens ofH. chocoensis seen by us lack oneor two of the general characteristics listed forHyloxalus by Grant et al. (2006: 169): (1) a paleoblique lateral stripe is lacking in these speci-mens; (2) there is no indication in eitherspecimen that dorsal skin texture is posteriorlygranular (however, skin granulation often isdiminished in preservative and weak granula-tion may be lost).

The holotype ofHyloxalus chocoensis wasjudged by Myers (1991: 3) to be a subadult orsexually inactive female based on examina-tion of the ovaries and oviducts. Although itwas said to measure 26 mm in the originaldescription, Myers obtained repeated mea-surements of 24.3 mm SVL with dial calipers.Adult female Hyloxalus are expected onaverage to be larger than males. Since theholotype is smaller than the adult male(26.0 mm) described above, we conclude thatit had yet to reach sexual maturity and that it

is indeed a subadult.The specimen ICN 47971 is in general

agreement with Myers (1991) redescription ofthe holotype. The holotype has two broad V-shaped blackish brown markings, one betweenthe eyes and the other between the upperarmsbut these are very ill defined and bestviewed when the specimen is immersed in liquid.The stratum corneum is becoming detached onthe adult male, giving it an overall grayappearance. Initially we saw no indication of

dark dorsal markings when the specimen wasimmersed in liquid and examined under brightlight, but a hint of vague dark markings wascaptured in the photograph (fig. 6, lower). The

dorsal coloration otherwise appears to consistof a very fine brown reticulum.

Differences appear to be minor. Both have apale flash mark in the axilla, which extendsdorsad onto the base of the arm in the holotype.The male has a broad pale brown band acrossthe base of the throat, but it appears to beassociated with the male vocal sac. The handsare similar, with very narrow keel-like fringeson the fingers; the fringe on the median side offinger I extends as a faint fold to the innermetacarpal tubercle; the fringe on the lateralside of finger IV is continuous with a weakouter metacarpal fold extending to the outermetacarpal tubercle (Myers, 1991: fig. 2). The

feet also are similar, with extensive webbing thatreduces to well-developed fringes along themedial sides of toes IIIV;6 however, the malealso has the webbing reduced to a fringe on thelateral side of toe IV, although webbing is welldeveloped on the lateral side of toe IV in theholotype (Myers, 1991: fig. 2).

A NOTE ON THE NAME HYLIXALUSBOULENGER,1882

Boulenger (1912) originally describedHyloxalus chocoensis as Hylixalus chocoen-sis. The earlier-emended generic nameHylixalus Boulenger (1882: 137) was a pre-sumed correction ofHyloxalus Jimenez dela Espada (1870), which had been explicitlyderived from Greek hyle (forest) + ixalos(leaping).7 Nonetheless, Hylixalus Boulenger

6Myers and Donnelly (2008: 43) noted the presence of theusually overlooked character folded flaplike fringes inthe holotype of Hyloxalus chocoensis, in which the

fringes along the distal half of toe IV are abruptly folded,as are the fringes on the medial sides of toes II and III andthe outer fringing along toes I and IV (see also Grant etal., 2006: 66).7The etymology as given by Jimenez de la Espada (1870:

59) was Ulg, sylva; Ijaloz, saltatorius [sic, initialletters of the Greek words lack the aspiration marksusually shown nowadays]. Boulenger merely combined thetransliterated hyle + ixalos by deleting the final letter inhyle and Latinizing ixalos, whereas Jimenez de la Espadahad additionally added the connective -o- (as commonlydone following Greek stems ending in a consonant) andalso deleted the first letter of the second element (probablyfor euphony). With rare exceptions such as Linnaeus, few

emenders ever published rules or principles for changingnames whose constructions they thought objectionable;they relied on a consent of the learned, which (in thematter of botanical and especially zoological Latin andGreek) is not readily articulated in this day and age.



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is an unjustified emendation of Hyloxalusunder modern rules of nomenclature andtherefore it is a junior objective synonym withits own author and date (ICZN, 1999: art.33.2.3); it is an available name.

Hylixaluswas incorrectly considered to be anincorrect subsequent spelling (ICZN, 1999:art. 33.3) by Grant et al. (2006: 11). However,Boulenger (1882: ix, 4, 137, 138) consistentlyreferenced the original spellingHyloxalusin thegeneric and two species synonymiessufficientevidence that his Hylixalus was a demon-strably intentional change in the originalspelling (ICZN, 1999: art. 33.2). Therefore,HylixalusBoulenger, 1882, should be added to

the list of available dendrobatoid genus-groupnames in Grant et al. (2006: 210, appendix 2).

It is to be noted that the spelling Hylexalusappears at one place in the index to BoulengersCatalogue (1882: 485). There is no internalevidence to interpret this as anything other thana simple misspelling (i.e., an incorrect subse-quent spelling) ofHylixalus, which was usedby Boulenger (1882, 1912, 1919) over a longperiod of time.

ACKNOWLEDGMENTS

For lending specimens in their care, we aregrateful to William E. Duellman (KU), JohnD. Lynch (ICN), and Jean Mariaux (MHNG).We thank Janalee P. Caldwell and Roy W.McDiarmid for reading and commenting onthe manuscript. Photographs of preservedspecimens were taken by Peter Goldberg andfigure 3 was executed by Patricia J. Wynne,with this work made possible through funds

provided by Robert G. Goelet.

REFERENCES

Boulenger, George Albert. 1882. Catalogue of theBatrachia Salientia s. Ecaudata in the collectionof the British Museum. 2nd ed. London: BritishMuseum, xvi, 503 pp. + 30 pls.

Boulenger, George Albert. 1912. Descriptions of newbatrachians from the Andes of South America,preserved in the British Museum. Annals andMagazine of Natural History (8) 10: 185191.

Boulenger, George Albert. 1919. Descriptions oftwo new lizards and a new frog from the Andesof Colombia. Proceedings of the ZoologicalSociety of London 1919 (12): 7981.

Coloma, Luis A. 1995. Ecuadorian frogs of the genusColostethus (Anura: Dendrobatidae). University ofKansas Museum of Natural History MiscellaneousPublication 87: [iv], 172 + 3 color pls.

Daly, John W., Charles W. Myers, and NoelWhittaker. 1987. Further classification of skinalkaloids from Neotropical poison frogs(Dendrobatidae), with a general survey of toxic/noxious substances in the Amphibia. Toxicon25(10): 10231095.

Grant, Taran, D.R. Frost, J.P. Caldwell, R. Gagliardo,C.F.B. Haddad, P.J.R. Kok, D.B. Means, B.P.Noonan, W.E. Schargel, and W.C. Wheeler. 2006.Phylogenetic systematics of dart-poison frogs andtheir relatives (Amphibia: Athesphatanura:Dendrobatidae). Bulletin of the AmericanMuseum of Natural History 299: 1262.

Grant, Taran, Elaine C. Humphrey, and CharlesW. Myers. 1997. The median lingual process offrogs: a bizarre character of Old World ranoidsdiscovered in South American dendrobatids.American Museum Novitates 3212: 140.

ICZN. 1999. International code of zoological no-menclature. 4th ed. London: International Trustfor Zoological Nomenclature, xxxix, 306 pp.

Jimenez de la Espada, Marcos 1870 (June). Faunaeneotropicalis species quaedam nondum cognitae.Jornal de Sciencias Mathematicas, Physicas eNaturaes, Academia Real das Sciencias de Lisboa

3(9): 5765. (A rare paper, often misdated 1871based on the final title page for vol. 3, whichapparently was issued in parts in 18701871.)

Lynch, John D., and William E. Duellman. 1997.Frogs of the genusEleutherodactylusin westernEcuador. University of Kansas Museum ofNatural History Special Publication 23: iv,1236 + 8 color pls.

Myers, Charles W. 1991. Distribution of the dendro-batid frogColostethus chocoensisand descriptionof a related species occurring macrosympatrically.American Museum Novitates 3010: 115.

Myers, Charles W., and Maureen A. Donnelly. 2008.The summit herpetofauna of Auyantepui,Venezuela: report from the Robert G. GoeletAmerican MuseumTERRAMARExpedition. Bul-letin of the American Museum of NaturalHistory 308: 1147.

Myers, Charles W., Alfredo Paolillo O., and John W.Daly. 1991. Discovery of a defensively malodor-ous and nocturnal frog in the familyDendrobatidae: phylogenetic significance of anew genus and species from the VenezuelanAndes. American Museum Novitates 3002: 133.

Neuwirth, Maria, John W. Daly, Charles W. Myers,and Lois W. Tice. 1979. Morphology of thegranular secretory glands in skin of poison-dartfrogs (Dendrobatidae). Tissue and Cell 11(4):755771.


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