Abstract
We perform a review of the Erythrolamprus reginae species group and putative related taxa (E. dorsocorallinus, E. zweifeli, and E. oligolepis), based on external morphology and hemipenial characters. We infer species boundaries among taxa traditionally associated with this group, recognizing two nominal subspecies (Erythrolamprus reginae reginae and E. r. macrosomus) in the species level. We propose the synonymy of E. r. semilineatus with E. reginae and recognize the validity of the related taxa, such as: E. dorsocorallinus, E. zweifeli, and E. oligolepis. In addition, two specimens occurring in the state Amapá, Brazil, are herein described as a new species. Therefore, we provide an identification key for the species of the group and discuss some of the combination of morphological features useful to delimitate the species of this group, in comparison with other representatives of the genus Erythrolamprus.
References
Aleixo, A. (2007) Conceitos de espécie e o eterno conflito entre continuidade e operacionalidade: uma proposta de normatização de critérios para o reconhecimento de espécies pelo Comitê Brasileiro de Registros Ornitológicos. Revista Brasileira de Ornitologia, 15, 297–310.
Amaral, A. (1935) Collecta herpetologica no centro do Brazil. Memórias do Instituto Butantan, 9, 235–346.
Andersson, L.G. (1899) Catalogue of the Linnaean type-specimens of snakes in the Royal Museum in Stockholm. Bihang till Konglika Svenska Vetenskaps-Akademiens Handlingar, 24, 1–34.
Arzamendia, V. (2016) New southern record of Erythrolamprus reginae (Linnaeus, 1758) (Serpentes: Dipsadidae), a vulnerable species in Argentina. Checklist, 12 (5), 1–4.
https://doi.org/10.15560/12.5.1976
Auguie, B. & Antonov, A. (2017) Miscellaneous Functions for “Grid” Graphics. Available from: https://CRAN.R-project.org/package=gridExtra (accessed 23 November 2017)
Ávila-Pires, T.C.S., Hoogmoed, M.S. & Rocha, W.A. (2010) Notes on the vertebrates of northern Pará, Brazil: a forgotten part of Guianan region, I. Herpetofauna. Boletim do Museu Paraense Emílio Goeldi, Ciencias Naturais, 5 (1), 13–112.
Ávila-Pires, T.C.S., Lima, J.D., Hoogmoed, M.S., Lima, J.R.F.L. & Rocha, W.A (2013) Variation in Amapasaurus tetradactylus (Reptilia: Squamata: Gymnophthalmidae), a rare Guiana lizard. Boletim do Museu Paraense Emílio Goeldi, Ciencias Naturais, 8 (3), 419–429.
Bernard, E. (2008) Inventários biológicos rápidos no parque nacional Montanhas do Tumucumaque, Amapá, Brasil. RAP Bulletin of Biological Assessment, 48, 1–149.
Boulenger, G.A. (1905) Descriptions of new species in collection of the British Museum. Annals and Magazine of Natural History, Series 7, 15 (89), 453–456.
https://doi.org/10.1080/03745480509442832
Boulenger, G.A. (1908) Descriptions of new South-American reptiles. Annals and Magazine of Natural History, Series 8, 1 (1), 111–115.
https://doi.org/10.1080/00222930808692365
Boulenger, G.A. (1894) Catalogue of the Snakes in the British Museum (Natural History). Vol. II. Containing the Conclusion of the Colubridæ Aglyphæ. British Mus. (Nat. Hist.), London, xi + 382 pp.
https://doi.org/10.5962/bhl.title.8316
Cohen, J., Cohen, P., West, S.G. & Aiken, L.S. (2003) Applied Multiple Regression/Correlation Analysis for the Behavioural Sciences. 3rd Edition. Erlbaum, Mahwah, 736 pp.
Cope, E.D. (1860) Catalogue of the Colubridae in the Museum of the Academy of Natural Sciences of Philadelphia, with notes and descriptions of new species. Part II. Proceedings of the Academy of Natural Sciences of Philadelphia, 12, 241–266.
Cope, E.D. (1868) An examination of the Reptilia and Batrachia obtained by the Orton Expedition to Equador and the Upper Amazon, with notes on other species. Proceedings of the Academy of Natural Sciences of Philadelphia, 20, 96–140.
Cope, E.D. (1899) Contributions to the herpetology of New Granada and Argentina, with descriptions of new forms. The Philadelphia Museum Bulletin, 1, 1–19.
https://doi.org/10.5962/bhl.title.54674
Cunha, O.R. & Nascimento, F.P. (1993) Ofídios da Amazônia. As cobras da região leste do Pará. Boletim do Museu Paraense Emílio Goeldi, Nova Série Zoologia, 9, 1–191.
Curcio, F.F. (2008) Revisão Taxonômica e Variação Geográfica do Gênero Erythrolamprus Boie (Serpentes, Xenodontinae). Unpublished PhD Thesis, Universidade de São Paulo, São Paulo, 305 pp.
Curcio, F.F., Piacentini, V.Q. & Fernandes, D.S. (2009a) On the status of the snake genera Erythrolamprus Boie, Liophis Wagler and Lygophis Fitzinger (Serpentes, Xenodontinae). Zootaxa, 2173, 66–68.
Curcio, F.F., Sanchez-Pacheco, S.J., Mueses-Cisneros, J.J. & Rodrigues, M.T. (2009b) Notes on distribution, variation and characterization of Erythrolamprus pseudocorallus Roze, 1959 (Serpentes: Colubridae) with the first records from Colombia. Zootaxa, 2045, 33–42.
Curcio, F.F., Scali, S. & Rodrigues, M.T. (2015) Taxonomic status of Erythrolamprus bizona Jan (1863) (Serpentes, Xenodontinae): assembling a puzzle with many missing pieces. Herpetological Monographs, 29 (1), 40–64.
https://doi.org/10.1655/HERPMONOGRAPHS-D-15-00002
De Queiroz, K. (1998) The general lineage concept of species, species criteria, and the process of speciation: a conceptual unification and terminological recommendations. In: Howard, D.J. & Berlocher, S.H. (Eds.), Endless forms: Species and Speciation. Oxford University Press, Oxford, pp. 57–75
De Queiroz, K. (2005a) Ernst Mayr and the modern concept of species. Proceedings of the National Academy of Sciences, 102, 6600–6607.
https://doi.org/10.1073/pnas.0502030102
De Queiroz, K. (2005b) A unified concept of species and its consequences for the future of taxonomy. Proceedings California Academy of Sciences, 56, 196–215.
De Queiroz, K. (2007) Species concepts and species delimitation. Systematic Biology, 56, 879–886.
https://doi.org/10.1080/10635150701701083
Dixon, J.R. (1980) The Neotropical snake genus Liophis, the generic concept. Contributions in Biology and Geology of the Milwaukee Public Museum, 31, 1–40.
Dixon, J.R. (1983a) Systematic of Liophis reginae and L. williamsi (Serpentes, Colubridae), with a description of a new species. Annals of the Carnegie Museum, 52, 113–138.
Dixon, J.R. (1983b) Systematics of the Latin American snake, Liophis epinephelus (Serpentes: Colubridae). In: Rhodin, A.G. & Miyata, K. (Ed.), Advances in Herpetology and Evolutionary Biology. Museum of Comparative Zoology, University of Harvard, Cambridge, Massachusetts, pp. 132–149.
Dixon, J.R. (1983c) The Liophis cobella group of the neotropical colubrid snake genus Liophis. Journal of Herpetology, 17, 149–165.
https://doi.org/10.2307/1563456
Dixon, J.R. (1987) Taxonomy and geographic variation of Liophis typhlus and related “green” species of South America (Serpentes: Colubridae). Annals of the Carnegie Museum, 56, 173–191.
Dixon, J.R. (1989) A key and checklist to the Neotropical snakes genus Liophis with country list and maps. Smithsonian Herpetological information Service, 79, 1–28.
https://doi.org/10.5479/si.23317515.79.1
Dixon, J.R. (1991) Geographic variation and taxonomy of Liophis almadensis (Wagler) (Serpentes: Colubridae), and description of a new species of Liophis from Argentina and Bolivia. Texas Journal of Science, 43, 225–236.
Dixon, J.R. (2000) Ecuadorian, Peruvian, and Bolivian snakes of the Liophis taeniurus complex with descriptions of two new species. Copeia, 2000, 482–490.
https://doi.org/10.1643/0045-8511(2000)000[0482:EPABSO]2.0.CO;2
Dixon, J.R. & Soini, P. (1986) The reptiles of the upper Amazon basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
Dixon, J.R. & Markezich, A.L. (1992) Taxonomy and geographic variation of Liophis poecilogyrus (Wied) from South America (Serpentes: Colubridae). Texas Journal of Science, 44, 131–166.
Donnelly, M.A. & Myers, C.W. (1991) Herpetological results of the 1990 Venezuelan expedition to the Summit of Cerro Guaiquinima, with new Tepui reptiles. American Museum Novitates, 3017, 1–57.
Dowling, H.G. (1951) A proposed standard system of counting ventrals in snakes. British Journal of Herpetology, 1, 97–99.
Dowling, H.G. & Savage, J.A. (1960) A guide to snake hemipenis: survey of basic structure and systematic characteristics. Zoologica, 45, 17–28.
Duméril, A.M.C, Bibron, G. & Duméril, A.H.C. (1854) Erpétologie Générale ou Histoire naturelle Complète des Teptiles. Vol. 7. Librairie Encyclopédique de Roret, Paris, 1536 pp.
https://doi.org/10.5962/bhl.title.112278
Dunn, E.R. (1937) New or Unnamed Snakes from Costa Rica. Copeia, 1937 (4), 213–215.
Dunn, E.R. (1944) A revision of the Colombian snakes of the genera Leimadophis, Liophis, Lygophis, Rhadinaea, and Pliocercus, with a note on Colombian Coniophanes. Caldasia, 11 (10), 489–495.
Esqueda, L.F., Natera, M., La Marca, E. & Ilija-Fistar, M. (2007) Nueva especie de serpiente (Reptilia: Colubridae: Liophis) de un bosque tropical relictual en el estado Barinas, Venezuela. Herpetotropicos, 2 (2), 95–103.
Fernandes, D.S., Germano, V.J., Fernandes, R. & Franco, F.L. (2002) Taxonomic status and geographic distribution of the lowland species of the Liophis cobella group, with comments on the species from the Venezuelan tepuis (Serpentes: Colubridae). Boletim do Museu Nacional, Nova serie, Zoologia, 481, 1–14.
Giraudo, A.R. (2001) Serpientes de la Selva Paranaense y del Chaco Húmedo. LOLA, Buenos Aires, 328 pp.
Gomes, J.F. (1918) Contribuição para o conhecimento dos ophidios do Brazil. III. Ophidios do Museu Paraense. Memórias do Instituto Butantan, São Paulo, 1 (1), 57–77.
Google Earth (2018) Search of geographic coordinates. Version 7.3.2. Available from: http://www.google.com/earth/index.html (accessed 4 December 2018)
Grazziotin, F.G., Zaher, H., Murphy, R.W., Scrocchi, G., Benavides, M.A., Zhang, Ya-Ping & Bonatto, S.L. (2012) Molecular phylogeny of the New World Dipsadidae (Serpentes: Colubroidea): a reappraisal. Cladistics, 1, 1–23.
https://doi.org/10.1111/j.1096-0031.2012.00393.x
Greene, H.W. (1997) Snakes. The Evolution of Mystery in Nature. University of California Press, Berkeley, 365 pp.
Günther, A. (1858) Catalogue of Colubrine snakes of the British Museum. Printed by order of the Trustees, London, 281 pp.
Henle, K. & Ehrl, A. (1991) Zur Reptilien fauna Perus nebst Beschreibung eines neuen Anolis (Iguanidae) und zweier neuer Schlangen (Colubridae). Bonner Zoogische Beiträge, 42, 143–180.
Hoge, A.R. (1952) Notas erpetológicas. Uma nova subspécie de Leimadophis reginae. Memórias do Instituto Butantan, 24 (2), 241–244.
Hoge, A.R. (1958) Notes sur la position systematique de Opisthoplus degener Peters 1882 et Leimadophis regina macrosoma Amaral 1935 (Serpentes). Memórias do Instituto Butantan, 28, 67–71.
Jan, G. (1863) Enumerazione sistematica degli ofidi apparteneti al gruppo Coronellidae. Archivio per la Zoologia l’Anatomia e la Fisiologia, 2 (2), 213–320.
Kaliontzopoulou, A., Adams, D.C., Van der Meijden, A., Perera, A. & Carretero, M.A. (2012) Relationships between head morphology, bite performance and ecology in two species of Podarcis wall lizards. Evolutionary Ecology, 26 (4), 825–845.
https://doi.org/10.1007/s10682-011-9538-y
Kawashita-Ribeiro, R.A., Carvalho, V.T., Lima, A.C., Ávila, R.W. & Fraga, R. (2011) Morphology and geographical distribution of the poorly known snake Umbrivaga pygmaea (Serpentes: Dipsadidae) in Brazil. Phyllomedusa, 10, 177–182.
https://doi.org/10.11606/issn.2316-9079.v10i2p177-182
Krysko, K.L. & Judd, W.S. (2006) Morphological systematics of kingsnakes, Lampropeltis getula complex (Serpentes: Colubridae), in the eastern United States. Zootaxa, 1193, 1–39.
Kuhn, M. (2008) Building predictive models in R using the caret package. Journal of Statistical Software, 28 (5), 1–26.
https://doi.org/10.18637/jss.v028.i05
Lacepède, B.G.E.L. (1789) Historie naturelle des Quadrupedes Ovipares et des Serpens. Tome second, Imprimerie du Roi, Paris, 527 pp.
Linnaeus, C. (1758) Systema Naturæ per Regna tria Naturæ, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis. Tomus I. Editio decima, reformata. 10th Edition. Laurentii Salvii, Holmiæ, 824 pp.
Manly, B.F.J. (2004) Multivariate Statistical Methods: A Primer. CRC Press, New York, 269 pp.
https://doi.org/10.1201/b16974
Markezich, A.L. & Dixon, J.R. (1979) A new South American species of snake and comments on the genus Umbrivaga. Copeia, 1979, 698–701.
https://doi.org/10.2307/1443879
Merrem, B. (1820) Versuch eines Systems der Amphibien I Tentamen Systematis Amphibiorum. Johann Christian Kriegeri, Marburg, 191 pp.
Natera, M, Esqueda, L.F. & Castelaín, M. (2015) Atlas de las Serpientes de Venezuela: Una Visión Actual de su Diversidad. Dimacofi Negocios Avanzados S.A., Santigo de Chile, 456 pp.
Nóbrega, R.P., Montingelli, G.G., Trevine, V., Franco, F.L., Vieira, G.H., Costa, G.C. & Mesquita, D.O. (2016) Morphological variation within Thamnodynastes pallidus (Linnaeus, 1758)(Serpentes: Dipsadidae: Xenodontinae: Tachymenini). Herpetological Journal, 26 (2), 165–174.
Nunes, P.M.S., Fouquet, A., Curcio., F.F., Kok, P.J.R. & Rodrigues, M.T. (2012) Cryptic species in Iphisa elegans Gray, 1851 (Squamata: Gymnophthalmidae) revealed by hemipenial morphology and molecular data. Zoological Journal of the Linnean Society, 166, 361–376.
https://doi.org/10.1111/j.1096-3642.2012.00846.x
Olave, M., Avila, L.J., Sites, J.W. & Morando, M. (2017) Hidden diversity within the lizard genus Liolaemus: genetic vs morphological divergence in the L. rothi complex (Squamata: Liolaeminae). Molecular phylogenetics and evolution, 107, 56–63.
https://doi.org/10.1016/j.ympev.2016.09.009
Passos, P. & Prudente, A.L.C. (2012). Morphological variation, polymorphism and taxonomy of the Atractus torquatus complex (Serpentes: Dipsadidae). Zootaxa, 3407 (1), 2–21.
Passos, P., Prudente, A.L.C., Ramos, L.O., Caicedo-Portilla, J.R. & Lynch, J.D. (2018) Species delimitations in the Atractus collaris complex (Serpentes: Dipsadidae). Zootaxa, 4392 (3), 491–520.
http://doi.org/10.11646/zootaxa.4392.3.4
Paynter, R.A. (1982) Ornithological Gazetteer of Venezuela. Museum of Comparative Zoology, Harvard University, Cambridge, 244 pp.
http://doi.org/10.5962/bhl.title.14633
Paynter, R.A. (1988) Ornithological Gazetteer of Chile. Museum of Comparative Zoology, Harvard University, Cambridge, 329 pp.
http://doi.org/10.5962/bhl.title.14589
Paynter, R.A. (1989) Ornithological Gazetteer of Paraguay. 2nd Edition. Museum of Comparative Zoology, Harvard University, Cambridge, 59 pp.
https://doi.org/10.5962/bhl.title.14584
Paynter, R.A. (1992) Ornithological Gazetteer of Bolivia. 2nd Edition. Museum of Comparative Zoology, Harvard University, Cambridge, 185 pp.
https://doi.org/10.5962/bhl.title.14591
Paynter, R.A. (1993) Ornithological Gazetteer of Ecuador. 2nd Edition. Museum of Comparative Zoology, Harvard University, Cambridge, 247 pp.
https://doi.org/10.5962/bhl.title.14626
Paynter, R.A. (1995) Ornithological Gazetteer of Argentina. 2nd Edition. Museum of Comparative Zoology, Harvard University, Cambridge, 1045 pp.
https://doi.org/10.5962/bhl.title.14627
Paynter, R.A. (1997) Ornithological Gazetteer of Colombia. 2nd Edition. Museum of Comparative Zoology, Harvard University, Cambridge, 537 pp.
https://doi.org/10.5962/bhl.title.14638
Paynter, R.A. & Traylor, M.A. (1991) Ornithological Gazetteer of Brazil. 2 Vols. Museum of Comparative Zoology, Harvard University, Cambridge, 788 pp.
http://doi.org/10.5962/bhl.title.14635
Peracca, M.G. (1914) Reptiles et Batraciens de Colombie. In: Fuhrmann, O. and E. Mayor (Ed.), Voyage d'Exploration Scientifique en Colombie. Memoires de la Societe Neuchateloise des Sciences naturelles, 5, 1–1090.
http://doi.org/10.5169/seals-100120
Pesantes, O.S. (1994) A method for preparing the hemipenis of preserved snakes. Journal of Herpetology, 28, 93–95.
https://doi.org/10.2307/1564686
Peters, J.A. & Orejas-Miranda, B. (1970) Catalogue of the neotropical Squamata: part I. Snakes. United States National Museum Bulletin, 297, 1–347.
https://doi.org/10.5479/si.03629236.297.1
Prudente, A.L.C. & Passos, P. (2010) New Cryptic Species of Atractus (Serpentes: Dipsadidae) from Brazilian Amazonia. Copeia, 2010 (3) 397–404.
https://doi.org/10.1643/CH-08-193
QGIS Development Team (2017) QGIS: Quantum GIS Geographic Information System. Open Source Geospatial Foundation Project. Version 2.18.15. Available from: https://www.qgis.org/ (accessed 6 December 2017)
Ramírez-Reyes, T., Piñero, D., Flores-Villela, O. & Vázquez-Domínguez, E. (2017) Molecular systematics, species delimitation and diversification patterns of the Phyllodactylus lanei complex (Gekkota: Phyllodactylidae) in Mexico. Molecular Phylogenetics and Evolution, 115, 82–94.
https://doi.org/10.1016/j.ympev.2017.07.008
Rivas, G.A., Molina, C.R., Ugueto, G.N., Barros, T.R., Barrio-Amoros, C.L. & Kok, P.J. (2012) Reptiles of Venezuela: an updated and commented checklist. Zootaxa, 3211, 1–64.
Roze, J.A. (1959) Taxonomic notes on a collection of Venezuelan reptiles in the American Museum of Natural History. American Museum Novitates, 1934, 1–14.
Roze, J.A. (1964) The snakes of the Leimadophis-Urotheca-Liophis complex from the Parque Nacional Henri Pifier (Rancho Grande), Venezuela, with a description of a new genus and species (Reptilia, Colubridae). Senckebergiana Biologica, 45, 533–542.
Ruane, S., Burbrink, F.T., Randriamahatantsoa, B. & Raxworthy, C.J. (2016) The cat-eyed snakes of Madagascar: phylogeny and description of a new species of Madagascarophis (Serpentes: Lamprophiidae) from the Tsingy of Ankarana. Copeia, 104 (3), 712–721.
https://doi.org/10.1643/CH-15-346
Sabaj, P.M.H.E. (2016) Standard symbolic codes for institutional resource collections in herpetology and ichthyology: an online reference. Version 6.5. Available from: http://www.asih.org/resources (accessed 12 December 2017)
Schlegel, H. (1837) Essai sur la Physionomie des serpents. Kipps & Van Stockum, La Haye, 606 pp.
Shaw, G. (1802) General Zoology or Systematic Natural History III. Thomas Davidson, London, 303 pp. [pp. 313–615]
Shine, R. (1977) Reproduction in Australian elapid snakes I. Testicular cycles and mating seasons. Australian Journal of Zoology, 25, 655–666.
https://doi.org/10.1071/ZO9770655
Shine, R. (1982) Ecology of the Australian elapid snake Echiopsis curta. Journal of Herpetology, 16, 388–393.
https://doi.org/10.2307/1563569
Shine, R. (1993) Sexual dimorphism in snakes. In: Seigel, R.A. & Collins, J.T. (Ed.), Snakes; Ecology and Behavior. McGraw-Hill, NewYork, 49–86 pp.
Shine, R. & Harlow, P.S. (1998) Ecological divergence among sympatric colour morphs in blood pythons, Python brongersmai. Oecologia, 116 (1–2), 113–119.
https://doi.org/10.1007/s004420050569
Sokal, R.R. & Rohlf, F.J. (2012) Biometry: The Principles and Practice of Statistics in Biological Research. 4th Edition. Freeman, New York, 915 pp.
Souto, N.M., Pinna, P.H., Machado, A.S. & Lopes, R.T. (2017) New Records, Morphological Variation, and description of the skull of Liophis dorsocorallinus Esqueda, Natera, La Marca and Ilija-Fistar, 2005 (Serpentes: Dipsadidae). Herpetological Review, 48 (3), 532–537.
Stephens, L. & Traylor, M.A. (1985) Ornithological gazetteer of the Guianas. Museum of Comparative Zoology, Harvard University, Cambridge, 121 pp.
http://doi.org/10.5962/bhl.title.14590
Strauss, R.E. (1985) Evolutionary allometry and variation in body form in the South American catfish genus Corydoras (Callichthyidae). Systematic Zoology, 34 (4), 381–396.
https://doi.org/10.2307/2413203
Tschudi, J.J. (1845) Reptilium conspectum quae in republica Peruana reperiuntur er pleraque observata vel collecta sunt in itenere. Archiv für Naturgeschichte, 11 (1), 150–170.
https://doi.org/10.5962/bhl.part.7963
Uzzell, T. (1973) A revision of lizards of the genus Prionodactylus, with a new genus for P. leucostictus and notes on the genus Euspondylus (Sauria, Teiidae). Postilla, 159, 1–67.
https://doi.org/10.5962/bhl.part.11535
Venables, W.N. & Ripley, B.D. (2002) Modern Applied Statistics with R. 4th Edition. Springer-Verlag, New York, 495 pp.
https://doi.org/10.1007/978-0-387-21706-2
Vidal, N., Dewynter, M. & Gower, D.J. (2010) Dissecting the major American snake radiation: a molecular phylogeny of the Dipsadidae Bonaparte (Serpentes, Caenophidia). Comptes Rendus de l’Academie des Sciences, 333, 48–55.
https://doi.org/10.1016/j.crvi.2009.11.003
Wagler, J. (1824) Serpentum Braziliensium species novae, ou histoire naturelle des espèces nouvelles de serpens. In: Spix, J. (Ed.), Animalia Nova Sive Species Novae. Typis Francisci Seraph, Hübschmanni, 75 pp.
Wagler, J. (1830) Natürliches System der Amphibien, mit vorangehender Classification der Säugethiere und Vögel. J.G. Cotta, München-Stuttgart-Tübingen, 354 pp.
Wallach, V., Williams, K.L. & Boundy, J. (2014) Snakes of the world: A Catalogue of Living and Extinct Species. Taylor and Francis, CRC Press, 1237 pp.
https://doi.org/10.1201/b16901
Wickham, H. (2009) ggplot2—Elegant Graphics for Data Analysis. 2nd Edition. Springer-Verlag New York, 211 pp.
Wickham, H. (2017) Graphical scales map data to aesthetics, and provide methods for automatically determining breaks and labels for axes and legends. Available from: https://CRAN.R-project.org/package=scales (accessed 23 November 2017)
Wied‐Neuwied, Maximilian Prinz zu (1825) Beiträge zur Naturgeschichte von Brasilien. Weimar, 612 pp.
Zaher, H. (1999) Hemipenial morphology of the South American xenodontinae snakes, with a proposal for a monophyletic Xenodontinae and a reppraisal of colubroid hemipenes. Bulletin of the American Museum of Natural History, 240, 1–168.
Zaher, H., Grazziotin, F.G., Cadle, J.E., Murphy, R.W., Moura-Leite, J.C. & Bonatto, S. L. (2009) Molecular phylogeny of advanced snakes (Serpentes, Caenophidia), with an emphasis on South America xenodontines: a revised classification and descriptions of new taxa. Papéis Avulsos de Zoologia, 49, 115–153.
https://doi.org/10.1590/S0031-10492009001100001
Zaher, H. & Prudente, A.L.C. (2003) Hemipenis of Siphlophis (Serpentes, Xenodontinae) and techniques of hemipenial preparation in snakes: a response to Dowling. Herpetological Review, 34, 302–307.
Zar, J.H. (1999) Biostatistical Analysis. 4th Edition. Prentice-Hall, New Jersey, 620 pp.