A Taxonomic Revision of the Leptodactylid Frog Genus Syrrhophus Cope

Part 1

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UNIVERSITY OF KANSAS MUSEUM OF NATURAL HISTORY

Vol. 20, No. 1, pp. 1-45, 22 figs.

February 20, 1970

A Taxonomic Revision of the Leptodactylid Frog Genus Syrrhophus Cope

JOHN D. LYNCH

UNIVERSITY OF KANSAS LAWRENCE 1970

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors of this number: Frank B. Cross, Philip S. Humphrey, William E. Duellman

Volume 20, No. 1, pp. 1-45, 22 figs. Published February 20, 1970

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY THE UNIVERSITY OF KANSAS PRINTING SERVICE LAWRENCE, KANSAS 1970

A Taxonomic Revision of the Leptodactylid Frog Genus Syrrhophus Cope

JOHN D. LYNCH

INTRODUCTION

Cope (1878) proposed the genus Syrrhophus for a medium-sized leptodactylid frog from central Texas; in the ensuing 75 years the genus was expanded to include a heterogeneous group of frogs ranging from Texas to Peru. Taylor (1952) and Firschein (1954) limited the genus to several species of frogs occurring in Guatemala, Mexico, and Texas. Lynch (1968) provided a definition of the previously loosely-defined genus.

With the exception of Taylor (1952), who treated the Costa Rican species, none of these authors dealt with the present status of the nineteen species erroneously assigned to Syrrhophus. These species are listed in Tables 1 and 2 with the name currently applied. Some of them are new combinations and their justifications will be published elsewhere. Gorham (1966) is the most recent author to include South American species in the genus Syrrhophus.

Smith and Taylor (1948) recognized two species groups of the genus in Mexico, an eastern and a western group (here termed complexes for purposes of discussion), separated on the basis of the number of palmar (metacarpal) tubercles (three palmar tubercles in the members of the eastern complex and two in those of the western complex). Duellman (1958) reviewed the species of the genus occurring in western Mexico and concluded that there were five species (two polytypic). Dixon and Webb (1966) described an additional species from Jalisco, Mexico. The distributions of some species have been extended, but otherwise the western complex of species remains unchanged since Duellman's review.

Smith and Taylor (1948) recognized seven species of the genus in eastern Mexico. Firschein revised the eastern complex (as then understood), and in so doing added one new species and treated Syrrhophus verruculatus as a nomen dubium. Dixon (1957) redefined the related genus Tomodactylus and transferred T. macrotympanum Taylor to the genus Syrrhophus. Neill (1965) described a new subspecies of S. leprus from British Honduras. Two species (S. gaigeae and S. marnockii) were recognized in Texas until Milstead, Mecham, and McClintock (1950) synonymized S. gaigeae with S. marnockii. Thus, at present, nine species (one polytypic) are recognized on the eastern slopes and lowlands from central Texas to British Honduras. These are currently placed on one species group equivalent to the western complex reviewed by Duellman (1958).

TABLE 1--Species Described as Members of the Genus Syrrhophus but Now Placed in Other Genera.

======================================================================= Trivial name and author Current combination ----------------------------------------------------------------------- areolatus Boulenger, 1898 Eleutherodactylus areolatus calcaratus Andersson, 1945 Eleutherodactylus anderssoni caryophyllaceus Barbour, 1928 Eleutherodactylus caryophyllaceus coeruleus Andersson, 1945 Eleutherodactylus coeruleus ineptus Barbour, 1928 Eleutherodactylus diastema juninensis Shreve, 1938 Eupsophus juninensis lutosus Barbour and Dunn, 1921 Eleutherodactylus lutosus molinoi Barbour, 1928 Eleutherodactylus molinoi montium Shreve, 1938 Niceforonia montia mystaceus Barbour, 1922 Eleutherodactylus rhodopis obesus Barbour, 1928 Eleutherodactylus punctariolus omiltemanus Gunther, 1900 Eleutherodactylus omiltemanus pardalis Barbour, 1928 Eleutherodactylus pardalis =======================================================================

New combination.

TABLE 2--Species Incorrectly Regarded as Members of the Genus Syrrhophus but Described as Members of Other Genera.

========================================================================== Trivial name, original generic assignment, and author Current combination -------------------------------------------------------------------------- chalceus (Phyllobates) Peters, 1873 Eleutherodactylus chalceus festae (Paludicola) Peracca, 1904 Niceforonia festae hylaeformis (Phyllobates) Cope, 1875 Eleutherodactylus hylaeformis palmatus (Phyllobates) Werner, 1899 Colostethus palmatus ridens (Phyllobates) Cope, 1866 Eleutherodactylus ridens simonsii (Paludicola) Boulenger, 1900 Niceforonia simonsii ==========================================================================

TABLE 3--Nominal Species of Syrrhophus (sensu strictu) and the Name Used Herein.

======================================================================= Original combination Current combination ----------------------------------------------------------------------- campi, Syrrhophus cystignathoides campi cholorum, Syrrhophus leprus leprus cystigathoides, Phyllobates cystignathoides cystignathoides dennisi, Syrrhophus dennisi new species gaigeae, Syrrhophus guttilatus guttilatus, Malachylodes guttilatus interorbitalis, Syrrhophus interorbitalis latodactylus, Syrrhophus longipes leprus, Syrrhophus leprus longipes, Batrachyla longipes macrotympanum, Tomodactylus verrucipes marnockii, Syrrhophus marnockii modestus, Syrrhophus modestus nebulosus, Syrrhophus pipilans nebulosus nivocolimae, Syrrhophus nivocolimae pallidus, Syrrhophus modestus pallidus petrophilus, Syrrhophus guttilatus pipilans, Syrrhophus pipilans pipilans rubrimaculatus, Syrrhophus rubrimaculatus smithi, Syrrhophus guttilatus teretistes, Syrrhophus teretistes verrucipes, Syrrhophus verrucipes verruculatus, Phyllobates Nomen dubium =======================================================================

In the course of preparing an account of the species of Eleutherodactylus occurring in Mexico and northern Central America, it became necessary to reexamine the status of the genus Syrrhophus and its nominal species. It soon became evident that there were more names than species, that some previously regarded species were geographic variants, and that the eastern and western groups (complexes here) were artificial divisions of the genus. I conclude that there are seven species (one polytypic) of Syrrhophus in eastern Mexico, Texas, and El Peten of Guatemala, and seven species (one polytypic) in western Mexico. The current status of each of the 23 names correctly assigned to the genus is presented in Table 3.

The fourteen species recognized by me are placed in five species groups. Two of these groups are presently placed in the western complex (modestus and pipilans groups) and three in the eastern complex (leprus, longipes and marnockii groups). The two complexes do not correspond exactly with the eastern and western groups of Smith and Taylor (1948), Firschein (1954), and Duellman (1958) since S. rubrimaculatus is now associated with the eastern leprus group.

Part 2

The definitions and contents of the five species groups are as follows:

leprus group: digital pads not or only slightly expanded, rounded in outline; first finger longer or shorter than second; snout acuminate or subacuminate, not rounded; outer metatarsal tubercle conical; digits lacking distinct lateral fringes.

content: cystignathoides, leprus and rubrimaculatus.

longipes group: digital pads widely expanded, triangular in outline; first finger shorter than second; snout acuminate; outer metatarsal tubercle not conical; digits bearing lateral fringes.

content: dennisi and longipes.

marnockii group: digital pads expanded, rounded to truncate in outline; first finger equal in length to second or slightly shorter; snout rounded; outer metatarsal tubercle not conical; digits lacking lateral fringes; generally stout-bodied frogs.

content: guttilatus, marnockii, and verrucipes.

modestus group: digital pads expanded, truncate in outline; first and second fingers subequal in length, first usually slightly shorter than second; snout subacuminate; inner metatarsal tubercle twice as large (or larger) as outer metatarsal tubercle; digits bearing poorly-defined lateral fringes.

content: interorbitalis, modestus, nivocolimae, pallidus, and teretistes.

pipilans group: digital pads not or only slightly expanded, truncate in outline; first finger equal in length to second; snout subacuminate; metatarsal tubercles subequal in size; digits lacking lateral fringes.

content: pipilans.

Acknowledgments.--For loan of specimens, I am indebted to Richard J. Baldauf, Texas A & M University (TCWC); W. Frank Blair, University of Texas (TNHC); Charles M. Bogert and Richard G. Zweifel, American Museum of Natural History (AMNH); James E. Boehlke and Edmond V. Malnate, Academy of Natural Sciences of Philadelphia (ANSP); Robert F. Inger and Hymen Marx, Field Museum of Natural History (FMNH); Ernest A. Liner (EAL); Michael Ovchynnyk, Michigan State University collection (MSU); James A. Peters, United States National Museum (USNM); Douglas A. Rossman, Louisiana State University Museum of Zoology (LSUMZ); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); Charles F. Walker, University of Michigan Museum of Zoology (UMMZ); and John W. Wright, Los Angeles County Museum (LACM). Specimens in the collection at the University of Kansas Museum of Natural History are identified as KU. The abbreviations EHT-HMS refer to the Edward H. Taylor-Hobart M. Smith collection and FAS to the Frederick A. Shannon collection. The type-specimens from these collections are now in the Field Museum of Natural History and the University of Illinois Museum of Natural History.

I have profited from discussions concerning this problem with several persons, most notably William E. Duellman, Hobart M. Smith, Edward H. Taylor and Charles F. Walker. Nevertheless, the ideas and conclusions presented here should not be construed as necessarily reflecting their opinions.

David M. Dennis executed all of the figures, and my wife, Marsha, typed the manuscript.

Materials and Methods.--In the course of this study, 1003 specimens of the genus were examined. The holotypes of 21 of the 23 nominal species are extant; I have examined 19 of these. Nine measurements were taken, and five ratios computed for each of 338 specimens. Females are available for all species but one; thus, measurements were taken on individuals of both sexes.

ANALYSIS OF CHARACTERS

Size and proportions.--Frogs of this genus range in size from 16 to 40 mm. in snout-vent length. Five species are relatively small: S. cystignathoides, modestus, nivocolimae, pallidus and rubrimaculatus; one, S. longipes, is relatively large, and the remaining eight species are intermediate in size (22-30 mm.).

Males are generally smaller than females and have proportionately longer heads and usually larger tympani. No significant differences were found among proportions, except that S. longipes has a larger tympanum/eye ratio than any other species. Frogs in the Syrrhophus marnockii group tend to have shorter shanks and feet, thereby giving those species a more stocky appearance. However, the differences are not significant.

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