Ambystoma taylori Brandon, Maruska, and Rumph, 1982. Taylor’s Salamander is a state endemic species known only from Laguna Alchichica, a saline crater lake in eastern Puebla (Frost, 2016). The IUCN SSC Amphibian Specialist Group (2015) noted water extraction and diversion as the most serious threats to this species, and that pollution and the continued transformation of the lake would result in its disappearance. Wilson et al. (2013a) determined the Environmental Vulnerability Score (EVS) of this salamander as 15, placing it in the lower portion of the high vulnerability category, and the IUCN has assessed its conservation status as Critically Endangered. In the following article the authors ' provide details on the distribution and conservation status of the herpetofauna of the state of Puebla, Mexico. © Valeria Mas 779900 Woolrich-Piña et al. The herpetofauna of Puebla www.mesoamericanherpetology.com www.eaglemountainpublishing.com The herpetofauna of Puebla, Mexico: composition, distribution, and conservation status Guillermo A. Woolrich-PiñA1, elí GArcíA-PAdillA2, dominic l. deSAntiS3, Jerry d. JohnSon3, Vicente mAtA-SilVA3, And lArry dAVid WilSon4 1Laboratorio de Zoología. División de Biología, Subdirección de Investigación y Posgrado, Instituto Tecnológico Superior de Zacapoaxtla, Carretera Acuaco Zacapoaxtla Km. 8, Col. Totoltepec, Zacapoaxtla, Puebla, C.P. 73680, Mexico. E-mail: [email protected] 2Oaxaca de Juárez, Oaxaca 68023, Mexico. E-mail: [email protected] 3Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas 79968-0500, United States. E-mail: [email protected], [email protected], and [email protected] 4Centro Zamorano de Biodiversidad, Escuela Agrícola Panamericana Zamorano, Departamento de Francisco Morazán, Honduras; 16010 SW 207th Avenue, Miami, Florida 33187-1056. E-mail: [email protected] AbStrAct: The herpetofauna of the state of Puebla, Mexico, is composed of 267 species, including 64 an- urans, 25 salamanders, 174 squamates, and four turtles. We document the distribution of the herpetofaunal members among the six physiographic regions we recognize. The number of species ranges from 41 in the Sierra Madre del Sur to 185 in the Sierra Madre Oriental. The individual species occupy from one to six – regions (x = 2.4). The largest number of single-region species occurs in the Sierra Madre Oriental (50), fol- lowed by the Upper Balsas Basin (26), the Trans-Mexican Volcanic Belt (20), the Gulf Coastal Lowlands (four), the Valley of Tehuacán (four), and the Sierra Madre del Sur (one). A Coefficient of Biogeographic Resemblance (CBR) matrix demonstrates that the number of shared species ranges from five between the Gulf Coastal Lowlands and the Sierra Madre del Sur to 98 between the Sierra Madre Oriental and the Trans-Mexican Volcanic Belt. A similarity dendrogram based on the Unweighted Pair Group Method with Arithmetic Averages (UPGMA) reveals two well-defined clusters, one associated with three physio- graphic regions on the Pacific versant of Mexico (Sierra Madre del Sur, Valley of Tehuacán, and Upper Balsas Basin), and the other associated with three regions on the Atlantic versant (Trans-Mexican Volcanic Belt, Sierra Madre Occidental, and Gulf Coastal Lowlands). About 79% of the herpetofauna is distributed in one or two of the six regions, indicating the relatively narrow distribution of many species in the state. We allocated the largest number of herpetofaunal species (154 of 259) to the Mexican endemic category, followed by the non-endemic category (98), the Puebla endemic category (four), and the non-native cate- gory (three). The principal environmental threats to the herpetofauna are deforestation, livestock ranching, the construction of infrastructure, extractive industries (hydroelectric dams and mines), the desiccation and contamination of water bodies, diseases, and global warming. We evaluated the conservation status of the native species by using the SEMARNAT (NOM-059), IUCN, and EVS systems, of which the EVS proved to be the most helpful. We also employed the Relative Herpetofaunal Priority (RHP) methodology to determine the rank order importance of the physiographic areas, and found the highest values for the Sierra Madre Oriental, followed by the Trans-Mexican Volcanic Belt, the Sierra Madre del Sur, and the Mesoamerican Herpetology 791 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla Gulf Coastal Lowlands. An analysis of the features for the 14 protected areas in the state reveals their rel- ative capability for providing protection to the members of the herpetofauna. Finally, we develop a set of conclusions and recommendations for the future protection of the Pueblan herpetofauna. Key Words: Anurans, caudates, physiographic regions, protected areas, protection recommendations, squamates, turtles reSumen: La herpetofauna del estado de Puebla, México, está conformada por 267 especies, incluyendo 64 anuros, 25 salamandras, 174 escamosos y cuatro tortugas. Documentamos la distribución de la herpe- tofauna entre seis regiones fisiográficas que aquí reconocemos. El número de especies varía de 41 en la Sierra Madre del Sur a 185 en la Sierra Madre Oriental. Cada una de las especies ocupa desde una hasta seis – regiones (x = 2.4). El mayor número de especies distribuidas en una sola región ocurre en la Sierra Madre Oriental (50), seguido por la Cuenca Alta del Balsas (26), la Faja Volcánica Transmexicana (20), Tierras Costeras del Golfo (cuatro), Valle de Tehuacán (cuatro) y la Sierra Madre del Sur (una). Una matriz con un coeficiente de similitud biogeográfica (CSB) demuestra que el número de especies compartidas varía de cinco entre la Tierras Costeras del Golfo y la Sierra Madre del Sur a 98 entre la Sierra Madre Oriental y la Faja Volcánica Transmexicana. Un dendrograma de similitud basado en el Método por Agrupamiento de Pares no Ponderado con Media Aritmética (MAPMA) revela dos grupos bien definidos, uno asociado con tres regiones fisiográficas en la vertiente del pacífico (Sierra Madre del Sur, Valle de Tehuacán y Cuenca Alta del Balsas) y el otro asociado con tres regiones en la vertiente del atlántico (Faja Volcánica Transmexicana, Sierra Madre Occidental y Tierras Costeras del Golfo). Cerca del 79% de la herpetofauna está distribuida en una o dos de las seis regiones, indicando una relativa distribución restringida de muchas de las especies en el estado. Ubicamos a la mayoría de los miembros de la herpetofauna (154 de 259) en la categoría de endémicas a México, seguido de las especies no endémicas (98); endémicas a Puebla (cua- tro) y la categoría de especies no nativas (tres). Las principales amenazas son la deforestación, ganadería, construcción de infraestructura, industria extractiva (presas hidroeléctricas y minas), desecación y contam- inación de cuerpos de agua, enfermedades, y el calentamiento global. Evaluamos el estatus de conservación de las especies nativas con los sistemas de SEMARNAT (NOM-059), IUCN y EVS, del cual, el EVS fue más útil. También empleamos la metodología para establecer la Prioridad Herpetofaunística Relativa (PHR) para determinar la categoría del orden de importancia de las áreas fisiográficas, encontrando los va- lores más altos para la Sierra Madre Oriental, seguida por la Faja Volcánica Transmexicana, Sierra Madre del Sur y Tierras Costeras del Golfo. Un análisis de las características de las 14 áreas protegidas en el es- tado revela su capacidad relativa para brindar protección a los miembros de la herpetofauna. Finalmente, desarrollamos una serie de conclusiones y recomendaciones para la futura protección de la herpetofauna poblana. Palabras Claves: Anuros, caudados, escamosos, recomendaciones para protección, regiones fisiográficas, tortugas Citation: Woolrich-Piña, G. A., E. García-Padilla, D. L. DeSantis, J. D. Johnson, V. Mata-Silva, and L. D. Wilson. 2017. The herpetofauna of Puebla, Mexico: composition, distribution, and conservation. Mesoamerican Herpetology 4: 791– 884. Copyright: Woolrich-Piña et al., 2017. This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License. Received: 16 November 2017; Accepted: 12 December 2017; Published: 30 December 2017. Mesoamerican Herpetology 792 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla “… If you are lucky enough to live among threatened species…your job, if you want to make a difference, is to protect them. Those species really don’t live anywhere else…and if you don’t keep them alive, no one else can.” —Anthony D. BArnosky (2014) INTRODUCTION The state of Puebla, located in east-central Mexico, encompasses portions of three significant mountain ranges, the Sierra Madre Oriental (SMO), the Trans-Mexican Volcanic Belt (TMV), and the Sierra Madre del Sur (SMS); three other physiographic regions include the Upper Balsas Basin (UBB), small segments of the Gulf Coastal Lowlands (GCL), and the Valley of Tehuacán (VOT) (Fig. 1). Puebla is bounded to the east by Veracruz, to the southeast by Oaxaca, to the south and southwest by Guerrero, to the west by Morelos, México, and Tlaxcala, and to the northwest by Hidalgo. The surface area of Puebla consists of 34,306 km2, which ranks it 21st among the 31 states of Mexico (www. wikipedia.org; accessed 15 May 2017). In 2015 the population of Puebla was estimated as 6,168,883, which ranked 5th in the country, as well as 6th in population density, with 180 people/km² (www.wikipedia.org; accessed 15 May 2017). Fig. 1. Physiographic regions of the state of Puebla, Mexico. Abbreviations are as follows: GCL = Gulf Coastal Lowlands; SMO = Sierra Madre Oriental; TMV = Trans- Mexican Volcanic Belt; SMS = Sierra Madre del Sur; UBB = Upper Balsas Basin; and VOT = Valley of Tehuacán. Puebla contains the three highest mountains in Mexico, the volcanoes Pico de Orizaba (or Citlaltépetl) at an elevation of 5,747 m, Popocatépetl at 5,452 m, and Iztaccíhuatl (or Ixtaccíhuatl) at 5,286 m, which are shared with adjacent states (i.e., Pico de Orizaba with Veracruz, Popocatépetl with the state of México, and Iztaccíhuatl with the state of México); they also lie along the eastern boundary of the TMV, are snow-capped, and contain (or used to con- tain) glaciers, and Popocatépetl is active and the other two are dormant (www.wikipedia.org; accessed 15 May 2017). The TMV is considered the southern edge of the Central Plateau, and Campbell (1999) and Wilson and Johnson (2010) primarily regarded the UBB and VOT as part of the Pacific Lowlands from Sinaloa to Western Chiapas (SC), a region that also includes inland intrusions associated with the Balsas Basin and Central Depression of Chiapas. Given the confluence of three species-rich montane centers of endemism in east-central Mexico, the state of Puebla would be expected to contain a relatively species rich herpetofauna, with many endemic species. Still, her- petological undertakings in Puebla have not rivaled many contemporary investigations conducted in some adjoin- ing states, such as in Hidalgo (Ramírez-Bautista, 2014), Veracruz (Pérez-Higareda and Smith, 1991 [snakes only]), Mesoamerican Herpetology 793 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla Guerrero (Pérez-Ramos et al., 2000), and Oaxaca (Casas-Andreu, et al., 2004; Mata-Silva et al., 2015). Based on some of these papers, the state species richness values range from a high of 442 species in Oaxaca to a low of 136 species in Guerrero. The low figure for Guerrero probably is due to collecting bias, as the surface of that state is relatively large and mountainous and thus potentially contains more endemic species. Hidalgo, with 183 reported species, is somewhat smaller in area than Guerrero, but more herpetological investigations have been conducted in this state because of the efforts of an active group of local university professors and students. The states of Tlaxcala and Morelos are small in area, and to date their herpetofaunal species richness has not been fully determined. Similarly, the species richness of the herpetofauna of Veracruz has not been fully established. Conversely, García-Vázquez et al. (2009) provided the most recent herpetofaunal list for Puebla, which at 246 species included numerous state records derived from previous sources. Subsequently, Canseco-Marquez and Gutiérrez- Mayén (2010) added two more species to the state’s list, in their study of the VOT. In this study, we recompiled the species list for Puebla and updated taxonomic and nomenclatural information, and also provide an analysis of the conservation status of each species. We also compare our information to that of other known herpetofaunas of selected states in Mexico. MATERIALS AND METHODS Our Taxonomic Position Herein we adopt the same taxonomic position as explained in previous papers on other portions of Mesoamerica (Johnson, et al., 2015a, b; Mata-Silva et al., 2015). Johnson (2015b) can be consulted for a statement on this posi- tion, with special reference to the subspecies concept. Updating the Herpetofaunal List We assembled our list for the herpetofauna of Puebla primarily based on the information in the following publica- tions: Vega-López and Álvarez-Solórzano (1992), Canseco–Márquez et al. (2000), Canseco-Márquez et al. (2004), Parra-Olea et al. (2004), Woolrich-Piña et al. (2005), Flores-Villela and Canseco-Márquez (2007), García-Vázquez et al. (2006, 2009), Garza Castro et al. (2006), Canseco-Márquez and Gutiérrez Mayén (2006), Gutiérrez Mayén and Salazar Arenas (2006), Canseco-Márquez and Gutierrez-Mayén (2010), García-Vázquez et al. (2010), Gutiérrez- Mayén et al. (2011), Mendoza-Hernández et al. (2012), Pavón-Vázquez et al. (2013), Solano-Zavaleta et al. (2013), and Rovito et al. (2015). System for Determining Distribution Status We used the same system originated by Alvarado-Díaz et al. (2013) for determining the distribution status of mem- bers of the herpetofauna of Michoacán for that of Puebla. This system also has been used for other areas of Mexico (see Mexican Conservation Series, below). We used the following distributional categories for the state of Puebla: SE = endemic to Puebla; CE = endemic to Mexico; NE = not endemic to Mexico; and NN = non-native in Mexico. Systems for Determining Conservation Status To evaluate the conservation status of the herpetofauna of Puebla, we used the same systems (i.e., SEMARNAT, IUCN, and EVS) employed in papers detailed in the following paragraph. These papers contain detailed descrip- tions of the three systems. THE MEXICAN CONSERVATION SERIES The Mexican Conservation Series (MCS) was initiated in 2013 with a study on the herpetofauna of Michoacán (Alvarado-Díaz et al., 2013), as a part of a set of five papers designated as the Special Mexico Issue in the journal Amphibian & Reptile Conservation. The basic format of the MCS was established in that paper (i.e., to examine the composition, physiographic distribution, and conservation status of the herpetofauna of a given Mexican state or group of states). Two years later, the MCS was resumed with a paper on the herpetofauna of Oaxaca (Mata-Silva et al., 2015), followed by one on the herpetofauna of Chiapas (Johnson et al., 2015a). The following year three more entries were published, on Tamaulipas (Terán-Juárez et al., 2016), Nayarit (Woolrich-Piña et al., 2016), and Nuevo León (Nevárez-de los Reyes et al., 2016), and this year two more, on Jalisco (Cruz-Sáenz et al., 2017) and Mesoamerican Herpetology 794 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla the Mexican Yucatán Peninsula (González-Sánchez et al., 2017). Thus, this paper on the herpetofauna of Puebla is the ninth entry in this series. Carbajal-Márquez and Quintero-Díaz (2016), who were not directly part of the MCS team, used a similar format for their paper on the herpetofauna of Aguascalientes. PHYSIOGRAPHY AND CLIMATE Physiographic Regions We recognize six physiographic regions within the state of Puebla, based on modifications of the schemes in Campbell (1999) and INEGI (2013), which we briefly describe below. Gulf Coastal Lowlands (GCL).—This region is the smallest in the state, occupying an area of ca. 176 km2 (0.54% of Puebla’s land surface; Fig. 1). The GCL (Fig. 2) is bordered to the northwest by the GCL of northern Veracruz, to the west by the SMO, and to the east by the Gulf Coastal Plain of central Veracruz. The geomorphology of the GCL con- tains characteristics of an emerged coastal plain that is interrupted by some isolated mounts, especially near the SMO. Most of the rocks in this region are sandstones, limestones, and shales dating from the Cretaceous and Tertiary. The municipalities located in this region are: Acateno, Ayotoxco de Guerrero, Cuetzalan del Progreso, Francisco Z. Mena, Hueytamalco, Jonotla, Tenampulco, Tuzamapan de Galeana, Venustiano Carranza, and Zoquiapan. The elevations lie between 150 and 550 m, so the uplifted areas between about 200 m and 550 m are those connected to the lower border of the SMO. In this case, we consider a coastal plain as the essentially flat areas associated with the adjacent Gulf of Mexico (Fig. 2). The same system was used by Johnson et al. (2010, 2015a) for the Pacific Coastal Plain in Chiapas and by Cruz-Sáenz et al. (2017) for Jalisco, where the coastal plain attained a maximum elevation of around 200 m. Fig. 2. Gulf Coastal Lowlands. Rancho Las Margaritas, Km 9 marker on the Hueytamalco–Tenampulco road, at an elevation of 400 m. The ' vegetation consists of patches of tropical forest that still exist in this region. © J. Guillermo Ortega-Vázquez The main vegetation of the GCL is evergreen forest with secondary formations. Rainforest also is repre- sented, and occurs in transitional areas with evergreen forest. Plant species distributed in this region include Alnus jorullensis, Liquidambar styraciflua, Trema micrantha, Conostegia xalapensis, Clethra sp., Cyathea sp., Bocconia frutescens, and Pteridium aquilinum (www.wikipedia.org; accessed 27 May 2017). Sierra Madre Oriental (SMO).—The SMO (Fig. 1) is characterized by a series of mountain ranges dating from the Lower Jurassic to the Late Cretaceous-Tertiary, as well as by volcanic intrusive rocks. The SMO (Fig. 3) is located Mesoamerican Herpetology 795 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla in the northern and eastern portions of the state and is positioned between sections of the GCL and TMV, forming what also is called the Sierra Nororiental of Puebla, which comprises the Sierras of Zacapoaxtla, Huauchinango, Teziutlán, Tetela de Ocampo, Chignahuapan, and Zacatlán. The highest peaks in this area are Apulco, Chichat, Chignahuapan, Soltepec and Tlatlauquitepec, whose elevations lie between 1,500 m (at La Cumbre, Apulco) and 2,200 m (at Cerro Cabezón, Tlatlauquitepec). The southern Sierra Nororiental of Puebla is a geologic transitional zone between the SMO and TMV. This region occupies an area of ca. 4,489 km2 (13% of the state’s surface), and the elevations are between 600 and 1,900 m. The vegetation of the SMO is composed of pine forest, pine-oak forest, rainforest, and sub-deciduous lowland forest. Species distributed in this region include Ceiba parviflora, Bursera simaruba, Cedrela odorata, Swietenia macrophylla, Spondias mombin, Brosimum alicastrum, Coccoloba barbadens, Pithecellobium arboreum, Lysiloma divaricata, Phoeba tampicensis, Bursera simaruba, Acacia coul- teri, and Ficus spp. (Luna et al., 2004). Fig. 3. Sierra Madre Oriental. Pine-oak forest at Xochititán, 25 km W of Tetela de Ocampo, in the municipality of Tetela de Ocampo, at an ' elevation of 1,800 m. © Guillermo A. Woolrich-Piña Trans-Mexican Volcanic Belt (TMV).—The TMV (Fig. 1) is characterized as a mass of volcanic rock resulting from successive volcanic episodes dating from the late Miocene and Pliocene (≈7–3.5 million years ago). In Puebla, this physiographic region is the largest, covering an area of ca. 15,454 km2 (45% of the entire state). This region is composed of the Sierra Nevada and Serranías de los Frailes, Temixco, Amozoc, Tepeaca, and Soltepec. The highest elevations are the volcanoes Pico de Orizaba (Citlaltépetl; 5,747 m), Popocatépetl (5,452 m), Iztaccíhuatl (5,286 m), and Malinche (Malintzin; 4,461 m), the highest mountains in Mexico. The elevations in Puebla generally range between 2,200 and 3,500 m. In this region there is a transition zone with the SMO, called Axalapazcos, in which the crater lakes Tecuila, Quechulac, Alchichica (Fig. 4), Atexcac, Aljojuca, and La Preciosa are located; these lakes contain brackish water due to underground erosion caused by the groundwater on the limestone rocks of the subsoil. The vegetation in this region is composed of pine, pine-oak, and oak forests, as well as grassland (Abies religiosa, Pinus pseudostrobus, P. hartwegii, P.attenuata, P. ayacahuite, P. leiophylla, P. patula, P. teocote, Quercus spp., Q. rugosa, Alnus spp., Arbutus spp., Cupressus spp., Juniperus spp., and Festuca tolucensis; Luna et al., 2009). Sierra Madre del Sur (SMS).—The Sierra Madre del Sur (Fig. 1) is the result of complex geological processes. The basement is formed of metamorphic rocks (shale, gneiss, quartzite and marble) that date from the Paleozoic; above these rocks are sandstones, limestones, and shales from the Jurassic and Cretaceous, and finally conglomerate, vol- canic rocks and alluvium from the Tertiary and Quaternary. In Puebla, this physiographic region (Fig. 5) contains Mesoamerican Herpetology 796 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla only a small section sandwiched between the UBB and VOT in the southeastern part of the state, which is an ex- tension of the Mixteca region of Oaxaca, covering an area of ca. 1,300 km2. The elevations of the SMS in Puebla are between 1,400 and 2,500 m. The vegetation in this region is composed of thorny xeric scrub forest and trop- ical dry forest, including cacti (Neobouxbamia tetetzo, Cephalocereus spp.), mesquite trees (Prosopis laevigata), “pata de elefante” trees (Beucarnea gracilis), and other plants (Myrtillocactus geometrizans, Echinocactus viznaga, Fouquieria formosa, and Holocantha stewartii), among others (Valiente-Banuet et al., 2009). Fig. 4. Trans-Mexican Volcanic Belt. View of the saline Lago de Alchichica, in the municipality of Alchichica, at an elevation of 2,300 m. The ' lake lies in a volcanic crater, and is the only known locality for the Pueblan endemic salamander Ambystoma taylori. © Enrique Barquet Fig. 5. Sierra Madre del Sur. Thorn scrub forest near Ixcaquixtla, in the municipality of Ixcaquixtla, 18 km S of Tepexi de Rodríguez, at an ' elevation of 2,000 m. © Guillermo A. Woolrich-Piña Mesoamerican Herpetology 797 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla Incilius cristatus (Wiegmann, 1833). The Large-crested Toad occurs in “central-western Veracruz and adjacent Puebla, Mexico” (Frost, 2016). This individual was found near the Barranca of Xocoyolo, in the municipality of Cuetzalan del Progreso, Puebla. Wilson et al. (2013a) determined its EVS as 14, placing it at the lower portion of the high vulnerability category, the IUCN has assessed it as Critically Endangered, ' and SEMARNAT lists this toad under the category of special concern (Pr). © José Alfredo Hernández-Díaz Dryophytes plicatus (Brocchi, 1877). The Ridged Treefrog is distributed in the Sierra Madre Oriental and the Cordillera Volcanica along the southern edge of the Mexican Plateau (in Michoacán, Morelos, México, D.F., Tlaxcala, Puebla, Veracruz, and Hidalgo) (Frost, 2016). This individual was found in San Andrés Cholula, in the municipality of San Andrés Cholula, Puebla. Wilson et al. (2013a) calculated its EVS as 11, placing it in the lower portion of the medium vulnerability category, the IUCN has assessed it as Least Concern, and SEMARNAT lists this treefrog as threatened (A). ' © Elí García-Padilla Upper Balsas Basin (UBB).—The UBB (Fig. 1) is directed transversely from east to west and is located immedi- ately south of the TMV region, covering an area of ca. 9,000 km2 and extending in an arc by the highlands that lie to the west of the VOT, and end by joining north of Ixcaquitla and southeast of the city of Puebla, at the edge of the Mesa de Anáhuac (Fernández-Nava et al., 1998). The southern border of the UBB is formed by the higher areas of the SMS in Guerrero, and the northern border by sections of the TMV, VOT, and the Mixteca area of the SMS. The southeastern boundary of the UBB also is aligned with the SMS. The elevational gradient of the UBB in Puebla Mesoamerican Herpetology 798 December 2017 | Volume 4 | Number 4 Woolrich-Piña et al. The herpetofauna of Puebla mostly lies between 1,500 and about 2,000 m, but also contains a few peaks with elevations above 2,000 m, such as Cerro Tecorral at 2,060 m, in which the Río Atoyac formed a canyon. Geologically, the UBB is structured by heterogeneous Cenozoic rocks consisting mainly of clastics, including gypsum and limestone, and by volcanic rock overlapping the Mesozoic rocks. Several lithologic formations are recognized (Pie de Vaca Formation, Cuayuca Formation, Oapan Formation, and Jolalpan gypsum), which have been assigned to a late Eocene-Early Oligocene age (Carranza-Sierra, 2001). Tropical deciduous forest is distributed in the higher portions of the UBB of Puebla, which consists of Bursera aptera, B. fagaroides, B. lancifolia, B. morelensis, B. schlechtendalii, Actinocheita filicina, Euphorbia fulva, Acacia bilimekii, A. coulteri, A. pennatula, Conzattia multiflora, Croton rzedowskii, Pithecellobium acatlense, Tecoma stans, and Wimmeria pubescens. Floristic elements such as Hauya elegans, Euphorbia fulva, Cedrela salvadorensis, Bursera grandifolia, B. vejar-vazquezi, Sideroxylon capari, Lasiacis divaricata, Dorstenia drakeana, Euphorbia antisiphyllitica, Cyrtocarpa procera, Thevetia thevetioides, and Ceiba parviflora are found in the lower parts and along rivers and streams (Guízar, 1991). Xerophilous scrub vegetation also occurs within the UBB of Puebla, pri- marily in the municipalities of Acatlán and Petlalcingo. In this region, the slopes are covered with dense xerophilous scrub composed of Castela tortuosa, Schaefferia stenophylla, Gochnatia obtusa, and Fouquieria formosa, as well as the shrub Cercidium praecox; associations of Escontria chiotilla and large aggregates of the thorn scrubs Celtis pallida, Randia armata, and Schaefferia pilosa also are common (Fernández-Nava et al., 1998). Valley of Tehuacán (VOT).—The VOT (Fig. 1) encompasses an area of ca. 3,900 km2, at elevations ranging from 1,400 to about 3,000 m (Miguel-Talonia et al., 2014); the Sierra de Zapotitlán is representative of this region, and the highest peaks in the valley are Cerro Pajarito at an elevation of 2,700 m, and Cerro Chacatecas at 2,500 m (Woolrich-Piña et al., 2010). The arid conditions of the VOT (Fig. 6) are the result of a rain shadow effect caused by the Sierra de Zongolica. Geologically, the VOT originated from an event caused by the progressive deformation of the Earth’s crust during the Cenozoic, after the Laramide orogeny, which involved four phases. In the northern portions of the valley the predominant vegetation consists of tropical deciduous forest and xerophytic scrub, but the southern portions contain pine-oak forest and small patches of cloud forest (Villaseñor et al., 1990). Valiente-Banuet et al. (2000) recognized 29 plant associations, of which nine are physiognomically dominated by such columnar cacti as Cephalocereus columna-trajani, Escontria chiotilla, Neobuxbaumia macro- cephala, N. mezcalaensis, N. tetetzo, Pachycereus fulviceps, P. weberi, Polaskia chichipe, Stenocereus stellatus, and S. dumortieri. According to Arias et al. (2012), 86 species of cacti are found in the VOT. Fig. 6. Valley of Tehuacán. Xeric vegetation in the Jardín Botánico Helia Bravo Hollis in Zapotitlán de las Salinas, municipality of Zapotitlán ' de las Salinas, at an elevation of 1,700 m. © Elí García-Padilla Mesoamerican Herpetology 799 December 2017 | Volume 4 | Number 4