 2001 by the American Society of Ichthyologists and Herpetologists Copeia, 2001(1), pp. 52–64 Reevaluation of the Status of Taxa of Central American Caecilians (Amphibia: Gymnophiona), with Comments on Their Origin and Evolution J AY M. SAVAGE AND MARVALEE H. WAKE New specimens and a new analysis provide the basis for systematic revision of Central American caecilians. We recognize seven species in the genus Dermophis ( oaxacae, mexicanus, gracilior, costaricense, glandulosus, parviceps, and occidentalis). Two species of Gymnopis ( syntrema and multiplicata), three of Oscaecilia ( osae, elongata, and ochrocephala), and four of Caecilia ( nigricans, volcani, isthmica, and leucocephala) occur in Central America. New information about the geology of the region permits reevaluation of the biogeographic history of the group. Data for specimens, distri- bution maps, and a key are provided. M ORE than 25 years ago, we (Savage and Wake, 1972) reviewed the systematic sta- tus and distribution pattern of Mesoamerican caecilians. This effort provided a conservative analysis of then-available material that led to recognition of only eight species: three Dermo- phis, one Gymnopis, four Caecilia and one Oscae- cilia in the region. Taylor (1973) correctly pre- dicted that our paper would not be the final word on the matter, because since that time ad- ditional specimens from critical localities, espe- cially in lower Central America, have encour- aged us to undertake a reassessment of the sys- tematics and biogeography of Mesoamerican gymnophionan taxa. The current situation is presented by the Sav- age and Wake (1972) revision, which dealt pri- marilywith geographic variation and the validity of species of the genera Dermophis and Gymnopis, which had been allocated to three genera and 13 species (one with a subspecies) by Taylor (1968) in his monograph of the world’s caeci- lians. We followed Taylor (1968, 1969) in rec- ognizing Oscaecilia ochrocephala, Caecilia elongata, C. nigricans, C. tentaculata and C. volcani as valid taxa. The latter are all Panamanian forms, three of which ( O. ochrocephala, C. nigricans, and C. tentaculata) were thought to range for varying distances into South America. Our treatment of Dermophis involved the syn- onymization of manytaxa recognized as valid by Taylor (1968). The nominal species Dermophis balboai Taylor, 1968, D. glandulosus Taylor, 1955, and D. occidentalis Taylor, 1955, were regarded as conspecific with Dermophis parviceps (Dunn, 1924). Dermophis costaricense Taylor, 1955, D. ebu r- atus Taylor, 1968, D. septentrionalis Taylor, 1968, and D. mexicanus clarki (Barbour, 1926) were al- located to the synonymy of Dermophis mexicanus (Dumerı ´l and Bibron, 1841). Within the genus Gymnopis, we regarded Gym- nopis oligozona (Cope, 1877) as conspecific with Gymnopis multiplicata Peters, 1874, and showed that Gymnopis proxima (Cope, 1875) intergraded with G. multiplicata, with which it was synony- mized. In addition, we demonstrated that all caecilians assigned by Taylor to the putative ge- nus Cryptosophis Boulenger, 1883, based on Si- phonops simus Cope, 1877, are representatives of G. multiplicata. In the interim since our work, Taylor (1973) restated the case for recognizing Dermophis gra- cilior as a valid form and reduced Dermophis ebur- atus to subspecific status within D. mexicanus. Wake and Campbell (1983) described a newge- nus and species, Minasaecilia sartoria from Gua- temala. Nussbaum (1988) indicated that M. sar- toria was conspecific with Siphonops syntremus Cope, 1866, the generic type of Taylor’s (1968) putative genus Copeotyphlinus and Gymnopis oli- gozon a (Cope, 1877) and concluded that the tax- on should be recognized as Gymnopis syntremus. MHW disagrees with Nussbaum’s concept of the genus Gymnopis as it relates to G. syntremus; she will treat that issue elsewhere. Wake (1985) and Nussbaum and Wilkinson (1989) preferred to assign Caecilia elongata to the genus Oscaecilia, an option later followed by Lahanas and Savage (1992). As presently understood, the known Middle American caecilian fauna differs from that rec- ognized in our 1972 paper by the desynonymi- zation of Dermophis gracilior and D. eburatus (but only as a subspecies), the resurrection of Gym- nopis syntremus from obscurity, the shift of C. elongata to Oscaecilia, and the addition of Caecilia volcani and Oscaecilia osae . Our review of newly collected or discovered specimens from Guatemala, Nicaragua, Costa Rica, and Panama (Appendix 1) provides more