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Color nemann' Medical Books, London. polymorphism in Pacific treefrogs. Science 142: ZIMMERMAN, H., AND E. ZIMMERMAN. 1987. Min- 1081-1083. destanforderungen fur eine artgerechte Haltung SAVAGE, J. M., AND S. B. EMERSON. 1970. Central einiger tropischer Anurenarten. Zeit. Kolner Zoo American frogs allied to Eleutherodactylusbrans- 30:61-71. fordii (Cope): A problem of polymorphism. Copeia 1970:623-644. Accepted: 12 March 1988 Associate Editor: John Iverson SCHIOTZ, A. 1971. The superspecies Hyperoliusvir- idiflavus (Anura). Vidensk. Medd. Dansk Natur- hist. Foren. 134:21-76. Herpetologica,45(1), 1989, 23-36 ? 1989 by The Herpetologists'League, Inc. ON THE STATUS OF NECTOCAECILIA FASCIATA TAYLOR, WITH A DISCUSSION OF THE PHYLOGENY OF THE TYPHLONECTIDAE (AMPHIBIA: GYMNOPHIONA) MARK WILKINSON Museum of Zoology and Department of Biology, University of Michigan, Ann Arbor, MI 48109, USA ABSTRACT: Nectocaecilia fasciata Taylor is a junior synonym of Chthonerpetonindistinctum Reinhardt and Liitken. The range of Nectocaecilia is restricted to northern South America. A hypothesis of phylogenetic relationships among the four genera of the Typhlonectidae is proposed, and alternative hypotheses are evaluated. The recently established genus Pseudotyphlonectes and other higher taxonomic categories proposed by Lescure et al. (1986) for the Typhlonectidae are invalid. Pseudotyphlonectes is a junior synonym of Typhlonectes Peters. It is suggested that phy- logenetic studies of the Gymnophiona should proceed independently of taxonomic considerations until a compelling hypothesis is accepted. Key words: Nectocaecilia; Chthonerpeton; Potomotyphlus; Typhlonectes; Pseudotyphlo- nectes; Phylogeny; Taxonomy; Typhlonectidae; Gymnophiona RECENTLY, within a single year, three sults are essentially in agreement with his, separate taxonomic treatments and hy- resulting in a single taxonomic change. potheses of phylogeny of the Gymno- Laurent (1986) and Lescure et al. (1986) phiona were published. These three works both produced hypotheses of intra-generic differed in scope, methodology, and re- relationships within the Gymnophiona. sults. Duellman and Trueb (1986) used cla- Laurent's methodology was not made clear, distic techniques to analyze relationships but that of Lescure et al. was claimed to among families and subfamilies. They re- be cladistic. The latter authors' phyloge- lied heavily on characters that Nussbaum netic hypothesis was coupled with a pro- (1977, 1979) had reported, and their re- posal for major taxonomic rearrangements 24 HERPETOLOGICA [Vol. 45, No. 1 within the Gymnophiona. The phyloge- positioned perpendicular to the body sur- nies and taxonomic treatments of these au- face at the level of the third nuchal groove thors are markedly different from each or were inserted into the body at this level. other and from that of Duellman and Counts made in these ways did not differ Trueb (1986). Nussbaum and Wilkinson from counts made from radiographsof the (in press) critically evaluated the three same specimens without markersusing the phylogenetic hypotheses and concluded visible constriction corresponding to the that the proposed phylogenies of Laurent third nuchal groove to delimit the nuchal (1986) and Lescure et al. (1986) are not region. These counts are frequently not supported by the evidence and that too whole numbers, presumably because the little is presently known about variation in external muscular sheath, to which the caecilian characteristics to justify taxo- dermis attaches, is itself not strongly at- nomic rearrangements at or above the fa- tached to deeper vertebral structures milial level. (Gaymer, 1971; Naylor and Nussbaum, The taxonomy of the Gymnophiona is 1980), and relative movement between the also unstable at the generic and specific vertebral column and external annular or levels. Research is constantly revealing taxa nuchal grooves is possible. Most frequent- that are invalid and errors in established ly, fractional numbers of nuchal vertebrae taxonomic treatments (Nussbaum, 1985, are encountered in preserved specimens 1986a, in press; Nussbaum and Gans, 1981; that have the nuchal region bent or oth- Savage and Wake, 1972; Wilkinson, 1988). erwise contorted. At present, genera are poorly defined, and Postcloacal vertebral counts were made for many there can be little guarantee that from radiographs using pins inserted into they are natural. Whilst such problems the cloacal aperture perpendicular to the persist, hypotheses of intra-generic rela- body surface. The numbers of postcloacal tionships are flawed by their reliance on vertebrae may be subject to artifactual possibly artificial units. Thus, it is impor- variation, increasing with dehydration as tant to redefine natural units that may then the soft body parts shrink around the ver- serve as a basis for meaningful comparison. tebral column (Nussbaum, in press). The In this paper, I point out one such prob- range of postcloacal vertebrae in Chtho- lem in the genus Nectocaecilia. By re- nerpeton is increased by such variation, stricting the concept of Nectocaecilia, I but for the purposes of this paper, it was evaluate its position within the Typhlo- not necessary to discriminate between nectidae and present evidence for an al- counts derived from well preserved or de- ternative phylogenetic hypothesis for the hydrated specimens. typhlonectid genera. I argue that this hy- Measurementswere made to the nearest pothesis should be preferred over those 0.1 mm with dial calipers, except total proposed by Laurent (1986) and by Les- lengths, measured to the nearest 1 mm by cure et al. (1986). I cannot evaluate the stretching specimens along a meter rule. work of Duellman and Trueb (1986) with In order to evaluate the results and the evidence presented here, because they methodology of Lescure et al. (1986), their did not address the interrelationships of data for the Typhlonectidae were reana- the typhlonectid genera. lyzed with a computerized parsimony al- gorithm (PAUP, version 2.4: Swofford, 1985). All charactersthat varied acrossthe METHODS typhlonectid taxa considered by Lescure Counts of vertebrae in the nuchal region et al. were included in the reanalysis.These were made from radiographs. Specimens characters were recoded in binary form in which the nuchal region was well de- using the morphoclines of Lescure et al., fined and clearly delimited by the third except for their annulation character for nuchal groove (= first primary groove) which polarization of the character states were used. For some specimens, pins were was not possible. For this character, the used as radio-opaque markers and were states reported by Lescure et al. in the March 1989] HERPETOLOGICA 25 "remarques sur segments succesion an- only the number of primary annuli and tero-posterieure" section of their data ma- tooth counts reportedby Taylor are similar trix were assigned symbols and run unor- to my data for IMZT An-786 (Table 1). dered. It would seem that Taylor's type de- The topology of the cladogram of Les- scription was based on a different speci- cure et al. (1986) was specified and PAUP men, and if this was the case, Nectocaecilia was used to distribute the character states fasciata would be a nomen dubium until upon this cladogram so as to minimize ho- either the unknown "holotype" or new moplasy. The ALLTREES routine of specimens corresponding to Taylor's de- PAUP was used to generate all possible scription are discovered. Taylor's data for cladogram topologies and to identify the the "holotype" of N. fasciata includes a ones that best fit the data. PAUP provided 1.0 mm projection of the snout. This is consistency indices for each of these trees anomalous because the Typhlonectidae is and for the cladogram of Lescure et al. a family typified by strongly recessed which facilitated comparison. mouths, and a typhlonectid as large as the holotype (390 mm total length) should have STATUSOF NECTOCAECILIAFASCIATA a snout projection greater than 3.0 mm. If Taylor (1968) established the genus Taylor actually examined a specimen that Nectocaecilia to receive Chthonerpeton corresponds to his description of N. fas- petersii Boulenger, a species then known ciata, then it is surprising that this speci- only from the holotype and for which the men was referred by Taylor to the Typh- only available locality was the Upper Am- lonectidae, and that the minimally recessed azon; C. haydee Roze, from Venezuela; mouth, which would be its most distinctive and two new forms, N. ladigesi, from Rio feature, was neither commented upon nor Moju, Brazil, and N. fasciata from Buenos