UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 18, No. 1, pp. 1-10 September 24, 1968 The Genera of Phyllomedusine Frogs (Anura: Hylidae) BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1968 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors of this number: Frank B. Cross, Philip S. Humphrey, J. Knox Jones, Jr. Volume 18, No. 1, pp. 1-10 Published September 24, 1968 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY ROBERT R. (BOB) SANDERS, STATE PRINTER TOPEKA, KANSAS 1968 32-3687 The Genera of Phyllomedusine Frogs (Anura: Hylidae) BY WILLIAM E. DUELLMAN One of the most distinctive phyletic lines among the diverse Neotropical hylid frogs is composed of a group of 40 species placed in the genus _Phyllomedusa_ (Funkhouser, 1957) or in two or three different genera (Goin, 1961; Lutz, 1966). These species differ from all other Neotropical hylids by possessing a vertical, instead of horizontal, pupil. The only other hylids having a vertical pupil belong to the Papuan genus _Nyctimystes_. Goin (1961) erroneously stated that _Nyctimantis_ and _Triprion_ have vertical pupils. Although limited information is available on the cytotaxonomy of hylids, the data show that phyllomedusine species have _n_=13 (2_n_=26) chromosomes. _Acris_ has _n_=11 (2_n_=22) (Cole, 1966). Members of the _Hyla leucophyllata_, _microcephala_, and _parviceps_ groups have _n_=15 (2_n_=30), _Gastrotheca ceratophrys_ has a haploid number of 14, the Papuan hylid genus _Nyctimystes_ and all but one of the Australo-Papuan _Hyla_ for which the numbers are known have a haploid number of 13, and all other New World hylids studied have _n_=12 (2_n_=24) (Duellman and Cole, 1965; Duellman, 1967). Cei (1963) and Cei and Erspamer (1966) noted that phyllomedusine frogs differ notably from other Neotropical hylids on the basis of the amines and polypeptides in the skin. All species of phyllomedusines deposit their eggs in a gelatinous mass on leaves or branches above water. Although this type of egg deposition is characteristic of some rhacophorines and apparently all centrolenids, it is known among hylids only in the phyllomedusines and in two species of _Hyla_. The distinctive combination of morphological, physiological, chromosomal, and behavioral characteristics is strongly suggestive that these frogs represent an early phyletic divergence within the Hylidae. Günther (1859) proposed the familial name Phyllomedusidae for _Phyllomedusa bicolor_ (Boddaert). I suggest the recognition of the group as a subfamily. The following classification of the phyllomedusines is based on my own knowledge of the Middle American and some South American species and on evidence from the literature on those South American species with which I am not personally familiar. Subfamily Phyllomedusinae Günther, 1859 Phyllomedusidae Günther 1859 [Type genus, _Phyllomedusa_ Wagler, 1830]. _Definition._--Moderately small to large hylids having vertical pupils, _n_=13 (2_n_=26) chromosomes, skin containing large amounts of powerful bradykinin-like and physalaemin-like polypeptides, eggs suspended from vegetation above water, and tadpoles have a ventral spiracle sinistral to midline. _Range._--Low and moderate elevations in South and Middle America, including Trinidad, from northern Argentina and northwestern Ecuador to Veracruz and southern Sonora, México. _Content._--Three genera, one of which probably is composite. Genus =Agalychnis= Cope, 1864. _Agalychnis_ Cope, 1864 [Type species, _Hyla moreletii_ Duméril, 1853, by subsequent designation]. _Definition._--Fingers and toes at least half webbed; terminal discs large; first toe shorter than second and not opposable to others; skin smooth, lacking osteoderms; parotoid glands, if present, poorly developed and diffuse; palpebral membrane reticulate (except in _A. calcarifer_); iris red or yellow; skull shallow, depth less than 40 per cent of length; nasals large; frontoparietal fontanelle large; quadratojugals reduced; prevomerine teeth present. _Range._--Central Veracruz and northern Oaxaca, México, southeastward through Central America to northwestern Ecuador; one species disjunct in Amazonian Ecuador. _Content._--Eight species [synonyms in brackets]: _annae_ (Duellman, 1963); _calcarifer_ Boulenger, 1902; _callidryas_ (Cope, 1862) [_helenae_ Cope, 1885; _callidryas taylori_ (Funkhouser, 1957)]; _craspedopus_ (Funkhouser, 1957); _litodryas_ (Duellman and Trueb, 1967); _moreleti_ (Duméril, 1853) [_holochroa_ (Salvin, 1861)]; _saltator_ Taylor, 1955; _spurrelli_ Boulenger, 1913. _Remarks._--Savage and Heyer (1967) provided evidence that _A. callidryas taylori_ (Funkhouser) and _A. helenae_ Cope were junior synonyms of _A. callidryas_ (Cope). Genus =Pachymedusa=, new genus Type species, _Agalychnis dacnicolor_ Cope, 1864. _Definition._--Fingers and toes having basal webs and lateral fringes; terminal discs large; first toe shorter than second and not opposable to others; skin smooth or shagreened, lacking osteoderms; paratoid glands present, diffuse; palpebral membrane reticulate; iris golden yellow with black reticulations; skull deep, depth more than 50 per cent of length; nasals large; frontoparietal fontanelle moderately large; quadratojugal robust; prevomerine teeth present. _Range._--Pacific slopes and lowlands from southern Sonora to the Isthmus of Tehuantepec, México. _Content._--Monotypic: _dacnicolor_ Cope, 1864 [_alcorni_ Taylor, 1952]. _Remarks._--The generic name is derived from the Greek _pachy_ meaning thick and the Greek _Medousa_ (Latin, _Medusa_) in reference to _Phyllomedusa_; the sense implied is the heavy body of _Pachymedusa dacnicolor_. Genus =Phyllomedusa= Wagler, 1830 _Phyllomedusa_ Wagler, 1830 [Type species, _Rana bicolor_ Boddaert, 1772]. _Pithecopus_ Cope, 1866 [Type species, _Phyllomedusa azurea_ Cope, 1862 (=_Phyllomedusa hypochondrialis_ Daudin, 1803), by original designation]. _Hylomantis_ Peters, 1872 [Type species _Hylomantis aspera_ Peters, 1872, by monotypy]. _Phrynomedusa_ Miranda-Ribeiro, 1923 [Type species, _Phrynomedusa fimbriata_ Miranda-Ribeiro, 1923, by subsequent designation]. _Bradymedusa_ Miranda-Ribeiro, 1926 [Type species, _Bradymedusa moschada_ Miranda-Ribeiro, 1926 (=_Phyllomedusa rohdei_ Mertens, 1926) by subsequent designation]. _Definition._--Fingers and toes having greatly reduced webbing or lacking webs; terminal discs small; first toe shorter than, equal to, or longer than second, opposable or not; skin smooth or rugose having osteoderms or not; parotoid glands present, in most species, usually distinct and elevated; palpebral membrane not reticulate; iris uniformly silvery white to orange-bronze with black reticulations; skull moderate to deep, depth more than 38 per cent of length; nasals moderately small; frontoparietal fontanelle present, variable in size; quadratojugal reduced in some species; prevomerine teeth present or absent. _Range._--Low and moderate elevations in South America east of the Andes from the Caribbean (including Trinidad) to northern Argentina; Costa Rica and Panamá in Central America. _Content._--Thirty-one species [synonyms in brackets]: _aspera_ (Peters, 1872); _ayeaye_ (B. Lutz, 1966); _bahiana_ A. Lutz, 1925; _bicolor_ (Boddaert, 1772) [_scleroderma_ Cope, 1868]; _blombergi_ Funkhouser, 1957; _boliviana_ Boulenger, 1902; _buckleyi_ Boulenger, 1882; _burmeisteri burmeisteri_ Boulenger, 1882; _burmeisteri distincta_ B. Lutz, 1950; _centralis_ Bokermann, 1965; _cochranae_ Bokermann, 1966; _coelestis_ (Cope, 1874); _edentula_ Andersson, 1945; _feltoni_ Shreve, 1935; _fimbriata_ (Miranda-Ribeiro, 1923) [_appendiculata_ A. Lutz, 1925]; _guttata_ A. Lutz, 1925; _hypochondrialis_ (Daudin, 1803) [_azurea_ Cope, 1862; _megacephala_ (Miranda-Ribeiro, 1926)]; _iheringi_ Boulenger, 1885; _lemur_ Boulenger, 1882; _loris_ Boulenger, 1912; _medinae_ Funkhouser, 1962; _nicefori_ Barbour, 1926; _orcesi_ Funkhouser, 1957; _pailona_ Shreve, 1959; _perlata_ Boulenger, 1882; _rohdei_ Mertens, 1926 [_moschada_ (Miranda-Ribeiro, 1926)]; _sauvagei_ Boulenger, 1882 [_rickettsii_ Günther, 1897]; _tarsius_ (Cope, 1868); _tomopterna_ (Cope, 1868) [_palliata_ Peters, 1872]; _trinitatis_ Mertens, 1926, _vaillanti_ Boulenger, 1882, _venusta_ Duellmann and Trueb, 1967. _Remarks._--_Phyllomedusa_ includes 1) a series of large species (_bicolor-burmeisteri_) showing progressive specialization of the feet; 2) a series of small species having grasping feet (_ayeaye_, _centralis_, _cochranae_, _guttata_, _hypochondrialis_, and _rohdei_); 3) a series of small, relatively unspecialized species (_lemur_, _loris_, and _medinae_); and 4) several other species of questionable affinities. Lutz (1966) resurrected Cope's (1866) _Pithecopus_ for 12 species (_ayeaye_, _boliviana_, _burmeisteri_, _coelestis_, _hypochondrialis_, _nicefori_, _rohdei_, _sauvagei_, _tarsius_, _tomopterna_, _trinitatis_, and _vaillanti_). Adequate material is not available for detailed study of all South American species; consequently, a firm classification cannot be established at this time. Nevertheless, it is obvious that Lutz's arrangement is unnatural. If subsequent investigations show, as seems likely, that the small specialized phyllomedusines are a natural phyletic unit, the generic name _Pithecopus_ is available. However, species such as _boliviana_, _burmeisteri_, _nicefori_, and _trinitatis_ do not belong in _Pithecopus_. As noted by Funkhouser (1962), the small, relatively unspecialized species (_lemur_, _loris_, and _medinae_) form a natural group; possibly this group should be accorded generic recognition. Until more evidence on the interspecific relationships is acquired, the maintenance of the current classification is desirable. DISCUSSION Noble (1931) considered the species of _Phyllomedusa_ having opposable digits, reduced terminal discs, and no webbing to be advanced and such species as _Agalychnis moreleti_, _calcarifer_, and _spurrelli_ to be primitive. Funkhouser (1957) followed Noble's suggestion and attempted to explain the evolution of the species of _Phyllomedusa_ (_sensu lato_) by assuming that they evolved from an advanced _Hyla_-like ancestor. Therefore, she placed those species having large, fully webbed hands and feet near the base of her phylogenetic scheme and hypothesized that evolutionary sequences involved stages of reduction and eventual loss of webbing, followed by the development of grasping toes. Such an evolutionary history is highly unlikely. The _Agalychnis_ phyletic line has one kind of specialization for an arboreal existence. It is contrary to evolutionary theory that a specialized group would evolve into a generalized form and then evolve new kinds of specializations to meet the needs imposed by the same environmental conditions affecting the earlier specialized group. A more reasonable hypothesis is that the evolution of opposable digits took place in a phyletic line that had as its ancestral stock a frog with generalized hands and feet. If this assumption is correct, _Phyllomedusa_ and _Agalychnis_ represent different phyletic lines; each exhibits divergent modes of adaptation for arboreal habits, whereas _Pachymedusa_ probably remains relatively little changed from the basic phyllomedusine stock. On the basis of modern distribution and areas of diversification alone (no fossils are known), it is evident that _Phyllomedusa_ underwent its adaptive radiation in South America, _Agalychnis_ evolved in Central America, and _Pachymedusa_ ended up in western México. If we follow the Matthewsian concepts of the American herpetofauna outlined by Dunn (1931) and modified by Schmidt (1943) and Stuart (1950), _Pachymedusa_ represents a "hanging-relict" of a group that moved southward. According to Savage's (1966) interpretation of the origins and history of the American herpetofauna, _Agalychnis_ and _Pachymedusa_ are members of the Mesoamerican fauna, and _Phyllomedusa_ is part of the Neotropical fauna. Perhaps the phyllomedusines arose in South America; from there a primitive stock spread northward and survived as _Pachymedusa_ in México, whereas the stock in Central America and South America evolved into _Agalychnis_ and _Phyllomedusa_, respectively. Evidently the primitive phyllomedusines evolved the habit of arboreal egg deposition and a walking gait; the latter is best developed in the small, highly specialized species of _Phyllomedusa_ (Lutz, 1966). Probably the other divergent arboreal adaptations resulted from environmental stresses and competition. The generalized _Pachymedusa_ inhabits relatively dry areas characterized by low forest. Throughout its range it coexists with no more than five other arboreal hylids. The species of _Agalychnis_ live in rain forests and humid montane forests. In any given area one species of _Agalychnis_ occurs sympatrically with no more than a dozen other arboreal hylids. With few exceptions the species of _Agalychnis_ are more arboreal in their habits than are other hylids. The species of _Phyllomedusa_ live in the same kinds of habitats as do those of _Agalychnis_, but throughout the ranges of most of the species of _Phyllomedusa_ the diversity of arboreal hylids is much greater than in Central America. In the upper Amazon Basin as many as 35 hylids occur sympatrically. Many groups of _Hyla_ in this area (for example, the _Hyla boans_ and _Hyla marmorata_ groups) are equally as arboreal in their habits as are the species of _Agalychnis_ in Central America. Conceivably, competition within this array of tree frogs resulted in selection for modification of the extremities, thereby bringing about a different mode of climbing in _Phyllomedusa_. The walking gait already present in phyllomedusines provided a source for further modification, which resulted in the development of opposable digits and the associated lemuroid manner of climbing. The known life histories of most species of _Phyllomedusa_, all species of _Agalychnis_, and that of _Pachymedusa_ are similar. Characteristically the tadpoles are generalized pelagic types that develop in ponds, but at least some of the small specialized _Phyllomedusa_ in southeastern Brazil have stream-adapted tadpoles with funnel-shaped mouths (Cochran, 1955; Bokermann, 1966). Knowledge of the life histories of the other species of _Phyllomedusa_ should aid in the interpretation of the phylogenetic relationships of the several groups of frogs now assigned to that genus. ACKNOWLEDGMENTS I am grateful to Linda Trueb who provided the osteological data included, and who helped me in formulating some of the ideas expressed in the discussion. This paper is a result of investigations on hylid frogs supported by the National Science Foundation (NSF-GB-5818). LITERATURE CITED BOKERMANN, W. C. A 1966. A new _Phyllomedusa_ from southeastern Brazil. Herpetologica, 22:293-297. CEI, J. M 1963. Some precipitin tests and preliminary remarks on the systematic relationships of four South American families of frogs. Bull. Serological Mus., 30:4-6. CEI, J. M. and V. ERSPAMER 1966. Biochemical taxonomy of South American amphibians by means of skin amines and polypeptides. Copeia, no. 1:74-8. COCHRAN, D. M 1955. Frogs of southeastern Brazil. Bull. U. S. Natl. Mus., 206; xvi + 423 pp. COLE, C. J 1966. The chromosomes of _Acris crepitans blanchardi_ Harper (Anura: Hylidae). Copeia, no. 3:578-580. COPE, E. D 1864. Contributions to the herpetology of tropical America. Proc. Acad. Nat. Sci. Philadelphia, 16:166-181. 1866. On the structures and distribution of the genera of arciferous Anura. Jour. Acad. Nat. Sci. Philadelphia, ser. 2, 6:67-112. DUELLMAN, W. E 1967. Additional studies on chromosomes of anuran amphibians. Syst. Zool., 16:38-43. DUELLMAN, W. E. and C. J. COLE 1965. Studies of chromosomes of some anuran amphibians (Hylidae and Centrolenidae). Syst. Zool., 14:139-143. DUMÉRIL, A. H 1853. Memoire sur les batraciens anoures de la famille des hylaeformes ou rainettes comprenant la description d'un genre nouveau et de onze espèces nouvelles. Ann. Sci. Nat., ser. 3, 19:135-179. DUNN, E. R 1931. The herpetological fauna of the Americas. Copeia, no. 3:106-119. FUNKHOUSER, A 1957. A review of the Neotropical tree-frogs of the genus _Phyllomedusa_. Occas. Papers Nat. Hist. Mus., Stanford Univ., 5:1-90. 1962. A new _Phyllomedusa_ from Venezuela. Copeia, no. 3:588-590. GOIN, C. J 1961. Synopsis of the genera of hylid frogs. Ann. Carnegie Mus., 36:5-18. GÜNTHER, A. C. L. G. "1858" [1859], Catalogue of die Batrachia Salientia in the collection of the British Museum. Taylor and Francis, London, xvi + 160 pp., 12 pls. LUTZ, B 1966. _Pithecopus ayeaye_, a new Brazilian hylid with vertical pupils and grasping feet. Copeia, no. 2:236-240. MIRANDA-RIBEIRO, A. DE 1923. As Phyllomedusas do Museu Paulista. Bol. Mus. Nac, Rio de Janeiro, 1:3-6. 1926. Notas para servirem ao estudo dos gymnobatrachios (Anura) brasileiros. Arch Mus. Nac., Rio de Janeiro, 27:1-227, pls. 1-22. NOBLE, G. K 1931. The biology of the Amphibia. McGraw-Hill, New York, 577 pp. PETERS, W. C. H 1872. Über eine, zwei neue Gattungen enthaltende, Sammlung von Batrachiern des Hrn. Dr. O. Wucherer aus Bahia, so wie übereinige neue oder weniger bekannte Saurier. Monatsb. Akad. Wiss. Berlin, 1872:768-776. SAVAGE, J. M 1966. The origins and history of the Central American herpetofauna. Copeia, no. 4:719-766. SAVAGE, J. M. and W. R. HEYER 1967. Variation and distribution in the tree-frog genus _Phyllomedusa_ in Costa Rica, Central America. Beitr. Neotrop. Fauna, 5:111-131. SCHMIDT, K. P 1943. Corollary and commentary for "Climate and Evolution." Amer. Midl. Nat., 30:241-253. STUART, L. C 1950. A geographic study of the herpetofauna of Alta Verapaz, Guatemala. Contr. Lab. Vert. Biol., Univ. Michigan, 45:1-77, pls. 1-9. WAGLER, J. G 1830. Näturliches System der Amphibien, mit vorangehender Classification der Saügethiere und Vögel. München, vi + 354 pp., 9 pls. _Transmitted April 18, 1968._ --- Provided by LoyalBooks.com ---