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Thermal and microhabitat resources are two fundamental requirements that affect the life history of any ectotherm. Furthering our understanding of how reptilian species meet these ecological requirements is crucial for assessing the impact of environmental and anthropogenic changes on populations. Here, we explored some fundamental aspects of the thermal and microhabitat ecology of Conopsis biserialis, a small, burrowing, and endemic earthsnake of central Mexico. The study was conducted during the rainy season in a montane site disturbed by rural activities. The mean field body temperature (Tb) of C. biserialis was 26 ± 0.6 ºC. Field Tb did not differ significantly between sex and development stages. However, we found that Tb was positively correlated with substrate, air, and under-rock temperatures (Ts, Ta, and Tr) in the rural microhabitat. Regression analysis showed that substrate and under-rock temperatures (Ts and Tr) were the parameters that best explained Tb variability in the individuals. The temperature and relative humidity under shelter did not differ significantly among shelter types and/or rock sizes. In addition to these thermal traits, earthsnakes selected and utilized six common biotic and physical elements of the rural microhabitat. Most individuals used high proportions of large and medium rocks for sheltering, and these rocks were selected around crop fences and cleared grasslands where the soil can be either covered with low vegetation or bare. Our results suggest that, during the rainy season, individuals of C. biserialis use and select some biotic and structural resources of the rural microhabitats, and were capable of actively regulating their temperature by using shelters with high values of microclimatic homogeneity. [ABSTRACT FROM AUTHOR]

Urosaurus nigricaudus is a phrynosomatid lizard endemic to the Baja California Peninsula in Mexico. This work presents a chromosome-level genome assembly and annotation from a male individual. We used PacBio long reads and HiRise scaffolding to generate a high-quality genomic assembly of 1.87 Gb distributed in 327 scaffolds, with an N50 of 279 Mb and an L50 of 3. Approximately 98.4% of the genome is contained in 14 scaffolds, with 6 large scaffolds (334–127 Mb) representing macrochromosomes and 8 small scaffolds (63–22 Mb) representing microchromosomes. Using standard gene modeling and transcriptomic data, we predicted 17,902 protein-coding genes on the genome. The repeat content is characterized by a large proportion of long interspersed nuclear elements that are relatively old. Synteny analysis revealed some microchromosomes with high repeat content are more prone to rearrangements but that both macro- and microchromosomes are well conserved across reptiles. We identified scaffold 14 as the X chromosome. This microchromosome presents perfect dosage compensation where the single X of males has the same expression levels as two X chromosomes in females. Finally, we estimated the effective population size for U. nigricaudus was extremely low, which may reflect a reduction in polymorphism related to it becoming a peninsular endemic. [ABSTRACT FROM AUTHOR]

Two new species of Disteniidae are described from Oaxaca, Mexico: Distenia (Distenia) toledoisp. n. and Elytrimitatrix (Grossifemora) chimalapensissp. n. Distinguishing characters from closely related species are given and discussed. New state records are provided for Distenia (Basisvallis) rugiscapis Bates, 1885; Disteniazteca fimbriata (Lacordaire, 1869); and Elytrimitatrix (Grossifemora) sauria Santos-Silva & Hovore, 2008. A complete checklist of species recorded in Mexico is provided. [ABSTRACT FROM AUTHOR]

Not enough research has been conducted on the distribution and population density of the Neotropical otter (Lontra longicaudis annectens) in the state of Tamaulipas. Today, the inhabitants of villages near the Champayán Lagoon System have empirical knowledge of the biodiversity in adjacent areas from experiences in their daily activities. A study was conducted through 35 interviews about the knowledge and perception of the Neotropical otter applied in seven fishermen villages in the Champayán Lagoon System, Altamira, Tamaulipas. Interviews revealed that all of the interviewed fishermen reported knowing the Neotropical otter and having observed it at different spots across the lagoon system. It is reported that the otter is a social species that has been observed in pairs and with offspring. Fishermen mention that otters feed mainly on native and exotic fish and others preys as well as crustaceans, reptiles, and poultry. There is an interaction between fishermen and otters, where the latter steals fish from fishing nets; however, this does not represent an economic loss for fishermen. The 91.4% of fishermen interviewed reported having directly interacted with an otter, and 97.1% mentioned that they had never threatened or disturbed an otter, since they consider it a charismatic species. Only 5.7% mention the otter as a species of great importance for the lagoon system. This work highlighted the need to continue this research applying ethnobiology methodologies to work with local communities, as a first strategy to promote the conservation of the Neotropical otter and to carry out to long-term studies on the interaction of fishermen with otters when their populations may be threatened. [ABSTRACT FROM AUTHOR]

Advances in technology have equipped paleobiologists with new analytical tools to assess the fossil record. The functional traits of vertebrates have been used to infer paleoenvironmental conditions. In Quaternary deposits, birds are the second-most-studied group after mammals. They are considered a poor paleoambiental proxy because their high vagility and phenotypic plasticity allow them to respond more effectively to climate change. Investigating multiple groups is important, but it is not often attempted. Biogeographical and climatic niche information concerning small mammals, reptiles, and birds have been used to infer the paleoclimatic conditions present during the Late Pleistocene at San Josecito Cave (~28,000 14C years BP), Mexico. Warmer and dryer conditions are inferred with respect to the present. The use of all of the groups of small vertebrates is recommended because they represent an assemblage of species that have gone through a series of environmental filters in the past. Individually, different vertebrate groups provide different paleoclimatic information. Birds are a good proxy for inferring paleoprecipitation but not paleotemperature. Together, reptiles and small mammals are a good proxy for inferring paleoprecipitation and paleotemperature, but reptiles alone are a bad proxy, and mammals alone are a good proxy for inferring paleotemperature and precipitation. The current paleoclimatic results coupled with those of a previous vegetation structure analysis indicate the presence of non-analog paleoenvironmental conditions during the Late Pleistocene in the San Josecito Cave area. This situation would explain the presence of a disharmonious fauna and the extinction of several taxa when these conditions later disappeared and do not reappear again. [ABSTRACT FROM AUTHOR]

The growth in our knowledge of the diversity of the herpetofauna of Mexico has occurred over the period of approximately 445 years from the work of Francisco Hernández to that of a broad multinational array of present-day herpetologists. The work of this huge group of people has established Mexico as one of the most significant centers of herpetofaunal biodiversity in the world. This status is the result of a complex orography, in addition to diverse habitats and environments and the biogeographic history of Mexico. The current herpetofauna consists of 1,421 native and introduced species, allocated to 220 genera, and 61 families. This figure is comprised of 1,405 native species and 16 non-native species (as of April 2023). The non-native species include two anurans, 13 squamates, and one turtle. The level of endemism is very high, presently lying at 63%, with this level expected to increase with time. Species richness varies among the 32 federal entities in the country, from a low of 50 in Tlaxcala to a high of 492 in Oaxaca. Amphibian species richness by state-level can be envisioned as comprising three levels of low, medium, and high, with the lowest levels occurring in the Peninsula of Baja California, a group of seven states in north-central and central Mexico, and a group of three states in the Yucatan Peninsula, with the highest levels occupying the southern states of Guerrero, Puebla, Veracruz, Oaxaca, and Chiapas, and the medium level in the remaining states of the country. Reptile species richness also can be allocated to three categories, with the lowest level occupying Baja California Sur, a group of central states, and the states of the Yucatan Peninsula, and the highest level found in a cluster of the states of Veracruz, Guerrero, Oaxaca, and Chiapas. Knowledge of the Mexican herpetofauna will continue to grow with additional studies on systematics, conservation, and the construction of checklists at various levels. [ABSTRACT FROM AUTHOR]

Mexico is a megadiverse country with high endemicity in its herpetofauna. We examine how species richness, proportion of state and country endemic species, and proportion of species in a category of conservation concern using listings in the International Union for Conservation of Nature (IUCN) Red List and the Secretaría del Medio Ambiente y Recursos Naturales (SEMARNAT) in 27 of 32 Mexican states are related to environmental and human demographic and socioeconomic variables. Amphibian and reptile species richness were positively related to latitude range and number of physiographic regions and negatively related to latitude. The proportion of state endemic amphibian species in a state was negatively related to latitude whereas no variables influenced the proportion in reptiles. The proportion of country endemics in a state was positively related to human population density and the number of physiographic regions and negatively related to per capita gross domestic product (GDP) and latitude range for amphibians; it was positively related to human population density and elevation range and negatively related to latitude range for reptiles. The proportion of amphibian species in an IUCN category of concern in a state was positively related to human population density and negatively related to latitude; for reptiles, it was negatively related to human population density. The proportion of SEMARNAT-listed species in a state was positively related to human population density for both amphibians and reptiles and negatively related to latitude range for amphibians. Our analyses found that larger macroecological patterns (e.g., latitudinal species gradient, heterogeneity-richness relationships) and human population density play important roles in determining the richness and conservation status of Mexican amphibians and reptiles. [ABSTRACT FROM AUTHOR]

Knowledge about the biodiversity of Baja California has been obtained mainly from natural protected areas (NPAs), while some unprotected natural areas have been poorly studied. The Sierra Cucapá in the northeast of the peninsula is one example. The objectives of this study are 1) to integrate existing knowledge of bird, mammal, and reptile diversity in Cucapá from public databases, citizen science platforms, and information generated from fieldwork, 2) to identify the spatial distribution of records in the study area, 3) to compare the composition of vertebrate species of Cucapá with that of NPAs of northern part of the peninsula, and 4) to assess the biological conservation value of Cucapá. We obtained records of 150 species of native vertebrates (102 birds, 34 mammals, and 14 reptiles) of which 10 species of birds, four mammals, and seven reptiles are included in a risk extinction category. The different sources of information contributed in a complementary way to the species inventories. Large areas in western and northern Cucapá lack records. The total difference in species composition between Cucapá and nearby NPAs ranged between 58 and 69% for birds, 61 and 79% for mammals, and 69 and 87% for reptiles. The species richness of Cucapá, its particular species composition, the presence of species in risk extinction categories, and the number and size of unexplored areas indicate that this area represents an opportunity for biological conservation in the northern part of the Peninsula. This work provides compelling data for the protection of Cucapá. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biogeographic and taxonomic assessment of South American representatives of the most speciose and most widely distributed genus of turtles, Kinosternon , using mtDNA sequences and 17 nuclear loci and fossil-calibrated molecular clock. • Two main radiations in Kinosternon , one Nearctic and one mainly Neotropical. • Recognition of three subgenera, Kinosternon , Cryptochelys and Thyrosternum. • Redefinition of former Kinosternon scorpioides group as subgenus Kinosternon , containing 19 distinct species-level lineages, 14 of which are currently named. • Kinosternon colonized South America at least three times, once in the Miocene, and then twice in the Plio-Pleistocene. • Phylogenetic discordance between mitochondrial and nuclear phylogenies suggests repeated mitochondrial introgressions and capture, with the possibility of mitochondrial capture from an extinct basal kinosternine lineage in one clade. Kinosternon is the most speciose genus of extant turtles, with 22 currently recognized species, distributed across large parts of the Americas. Most species have small distributions, but K. leucostomum and K. scorpioides range from Mexico to South America. Previous studies have found discordance between mitochondrial and nuclear phylogenies in some kinosternid groups, with the current taxonomy following the nuclear-based results. Herein, based on extended molecular, geographic, and taxonomic sampling, we explore the phylogeographic structure and taxonomic limits for K. leucostomum and the K. scorpioides group and present a fossil-calibrated nuclear time tree for Kinosternon. Our results reveal contrasting differentiation patterns for the K. scorpioides group and K. leucostomum , despite overlapping distributions. Kinosternon leucostomum shows only shallow geographic divergence, whereas the K. scorpioides group is polyphyletic with up to 10 distinct taxa, some of them undescribed. We support the elevation of K. s. albogulare and K. s. cruentatum to species level. Given the deep divergence within the genus Kinosternon , we propose the recognition of three subgenera, Kinosternon , Cryptochelys and Thyrosternum, and the abandonment of the group-based classification, at least for the K. leucostomum and K. scorpioides groups. Our results show an initial split in Kinosternon that gave rise to two main radiations, one Nearctic and one mainly Neotropical. Most speciation events in Kinosternon occurred during the Quaternary and we hypothesize that they were mediated by both climatic and geological events. Additionally, our data imply that at least three South American colonizations occurred, two in the K. leucostomum group, and one in the K. scorpioides group. Additionally, we hypothesize that discordance between mitochondrial and nuclear phylogenetic signal is due to mitochondrial capture from an extinct kinosternine lineage. [ABSTRACT FROM AUTHOR]

Leaf‐toed geckos (Phyllodactylus) exhibit much cryptic diversity, at least in North America. However, the origins of Central American taxa and their relationships with North American congeners remain unknown. The P. tuberculosus species complex is ideal for evolutionary and biogeographic studies because its geographic distribution extends from northern Mexico to Costa Rica. We analyse ~2,500 nuclear loci obtained by the GBS genomic technique to test hypotheses of genetic isolation among taxa and estimate times of divergence using a relaxed molecular clock model, which constitutes the first hypothesis for the diversification of North and Central American phyllodactylids. Phylogenetic analysis recovers three main clades within polyphyletic P. tuberculosus: tuberculosus, magnus and saxatilis. ABBA‐BABA tests show moderate to low levels of gene flow within the latter two clades and yet genetic isolation in Central American lineages. The relaxed molecular clock model dates the age of the MRCA between the Central American and North American lineages to the beginning of the Paleocene (65 mya), suggesting an ancestral distribution in the proto‐Mexican region and the Chortis Block. [ABSTRACT FROM AUTHOR]

The Selva Zoque region is characterized by a great variety of ecosystems for which there is little information about reptile species diversity and their conservation status. This study is the first assessment of the species richness, composition, and conservation status of reptiles of this region. Additionally, this information is compared with that of seven other tropical regions in northern Mesoamerica. In total, 141 native reptile species belonging to 81 genera and 29 families are recorded for the Selva Zoque region. Sixty species (42% of the total) recorded in Selva Zoque are in high-risk categories according to the Mexican Ministry of the Environment, the highest number for the Mexican regions of Mesoamerica. According to the IUCN, six species are in high-risk categories, seven species are in Data Deficient, and 23 (16%) have not been evaluated yet. According to the Environmental Vulnerability Scores approach, 28 species (20%) are in the high vulnerability category. The Selva Zoque species composition is most similar to Los Tuxtlas and Lacandona regions, and most dissimilar to Sian Ka'an Biosphere Reserve. The reptilian fauna of Selva Zoque has a distinctive composition, with the highest number (11 species) of endemic reptiles in the northern Mesoamerican, and species from two biogeographic provinces: the Gulf of Mexico and the Mexican Pacific Coast. These results indicate that the Selva Zoque is the most diverse region in native reptile species in northern Mesoamerica, highlighting it as extremely important for the conservation of the reptile fauna at local (southern Mexico) and regional levels (northern Mesoamerica). [ABSTRACT FROM AUTHOR]

Sceloporus licki, an endemic lizard of the Cape Region from Baja California Sur, Mexico, shows evident sexual dimorphism in coloration and in snout‐vent length between males and females. The gonadal analysis showed that both sexes have a synchronous spring–summer reproductive cycle. The males show maximum gonadal activity from March to July; in August, they show a rapid regression, and in September, quiescence is evident only in some males while in others recrudescence has already begun. Finally, in October and November, the process of recrudescence is obvious. The females showed some asynchrony, but for most, vitellogenesis occurred from April to June and eggs in the oviduct were evident in May, June and August. Oviposition occurs in July and August and by September or October there is no more gonadal activity in the ovaries. The clutch size was 5 ± 0.2 eggs, and hatchlings appeared in May–June and September suggesting that possibly two clutches are produced per breeding season. Reproductive activity in both sexes was like that of other lizards from temperate environments. However, the long period of gonadal recrudescence in both sexes (6 months) and rapid regression and quiescence in males of the studied population suggest plasticity in gonadal activity. [ABSTRACT FROM AUTHOR]

Recently, the first record of Borrelia associated with reptiles in Mexico was published; however, no studies have been done to assess the role of Mexican ticks as potential vectors of this Borrelia group. Amblyomma dissimile is a hard tick mainly associated with amphibians and reptiles in this country. The aim of this study was to evaluate the presence of Borrelia in A. dissimile from Mexico. We collected 60 A. dissimile individuals attached to 16 Rhinella horribilis. DNA was extracted and all specimens were screened individually for Borrelia by amplification of a fragment of the 16S rDNA and an additional fragment of the flagellin gene. Five ticks were positive for Borrelia, DNA sequences corresponded to Borrelia sp. and group with sequences of the reptile‐associated Borrelia group. This is the first report of Borrelia in A. dissimile and the second report of the reptile‐associated Borrelia group in Mexico. This study also highlights the importance of this tick species as potential vector of this group. [ABSTRACT FROM AUTHOR]

The montane cloud forests of the Sierra Madre de Oaxaca (SMO) host a remarkable herpetofauna diversity and represent one of the most important areas of endemism for Mexico and Mesoamerica. Although the area has been previously studied, most of the extant records for this group are biased to locations accessed by paved roads. In addition, an important proportion of this territory is conserved by Indigenous and Community Conservation Areas (ICCA), but little information of the species occurring within these areas exists. Therefore, information on the distribution of many endemic taxa in this region to date is either underestimated or incomplete. With the aim of increasing the ecological and distributional knowledge of this group in remote areas, we carried out field surveys in Santa Cruz Tepetotutla Oaxaca, a locality 25 km in a straight line to the closest paved road that conserves 9,670 ha of land through the ICCAs modality. Surveys were made during 2018 and 2019, including both dry and wet seasons. A total of 40 species of amphibians and reptiles were recorded: 32.5% of these records represent distributional range extensions, while 20% represent altitudinal range extensions. A total of 17.5% are records of species under a high risk category, highlighting both the relevance of studying remote areas to increase species population knowledge and the role of community conservation actions for species persistence. Finally, our records include the rediscovery of Rhadinella schistosa, a species undetected for more than 50 years. [ABSTRACT FROM AUTHOR]

Human alteration toward environment modifies the spatial distribution of available resources that influences habitat selection in animals. Thus, it is necessary to identify the resources that determine species occurrence in modified landscapes to provide the basis for future conservation efforts. We evaluated the habitat use and microhabitat selection of two lizard species with different niche requirements in a resource availability gradient caused by disturbance. Surveys were conducted in El Cielo Biosphere Reserve, Mexico, during 2016 and 2017. The gradient was grouped in four environmental types in the function of climatic (temperature and humidity) and structural variables (included different measures of soil, substrate, and vegetation coverage). For each lizard, 11 variables related to the microhabitat structure were recorded. Microhabitat selection for each environment type along the gradient was determined and compared via discriminant analysis. The results showed that Sceloporus variabilis, a species that uses a wide range of resources, can select different microhabitats along the gradient; while Lepidophyma sylvaticum, a species with a restricted use of resources, select microhabitats with similar specific characteristics and avoided disturbed areas with scarce canopy cover. This differential response was related to the degree of specificity in resources selection and physiological restrictions of each species. [ABSTRACT FROM AUTHOR]

Among the principal causes producing detrimental effects on global biodiversity are introductions of alien species. Very few attempts to control introduced amphibians and reptiles in Middle America (Mexico and Central America) can be identified, so listings are provided for 24 exotic species, 16 translocated species, and 11 species that were removed from the introduced species listing because of lack of substantiating evidence that they are from established populations. Biosecurity methods are also identified that can be applied for preventing, controlling, and managing introduced and especially invasive species. [ABSTRACT FROM AUTHOR]

Records of Pleistocene reptiles are relatively well known in different countries. However, reptile fossil records of Pleistocene from Latin America are scarce and limited to presence data associated with records of megafauna remains. Taphonomic studies in Pleistocene reptiles are focused on finding out the origin of the paleontological remains; that is, if the remains found at a particular place correspond to organisms that lived and died there or if they were carried out and deposited there by water currents or predators. Pleistocene reptiles have been used as a proxy for qualitative paleoclimatic reconstructions of localities. In this study, we describe the fossil record of squamate reptiles from the Pleistocene of San José Buenavista (Puebla, Mexico), and the taphonomic relationship between them and the associated megafauna, as well as reconstruct the paleoclimate of the paleontological site in Central Mexico where the remains were found. We present the first Mexican Pleistocene record of Anolis and Storeria , the third fossil record of the alligator lizard Barisia sp. in Mexico, and the first North American Pleistocene record for the rattlesnake Crotalus triseriatus. The rattlesnake (C. triseriatus) was found inside the mandible of the American mastodon (Mammut americanum). This finding suggests that the mastodon remains were used as burrow by the rattlesnake during the Pleistocene. Paleoclimate was reconstructed using the Mutual Ecogeographic Range method, which uses the distribution and climate niche of the nearest extant representatives of the identified fossil taxa. A mean annual temperature of 13.91 ± 1.54 °C and an annual precipitation of 964.04 ± 316.82 mm were inferred for the locality. This suggests that the assemblage of fossil species found inhabited the locality during a glacial period. [ABSTRACT FROM AUTHOR]

The paleontological diversity of Mesozoic marine reptiles in northeastern Mexico shows an extensive fossil record, composed of different orders, including Ichthyosauria, a group with reports in Jurassic formations of the region. This paper presents two specimens collected in Galeana, Nuevo León, comprised by postcranial elements, from the La Caja Formation, of the Upper Jurassic. The mentioned specimens increase the fossil record of the area and contribute to the greater understanding of the fauna and paleoecological diversity of the Paleo-Gulf of Mexico during the Upper Jurassic. [ABSTRACT FROM AUTHOR]

Mexico is home to a large number of reptile species and has one of the greatest diversities of venomous snakes, among which the rattlesnakes pertaining to the Crotalus genus stand out. Out of more than 40 species in the country, nine are found in Zacatecas: C. aquilus, C. atrox, C. basiliscus, C. lepidus, C. molossus, C. polystictus, C. pricei, C. scutulatus and C. willardi. Although these reptiles are important, due to their relevance in terms of ecology, cultural use and public health, their conservation is impacted by multiple factors, such as habitat fragmentation and indiscriminate killing. Thus, most species within this genus are found in some type of risk category at both the national and international level. The purpose of this study was to determine the potential distribution and diversity of rattlesnakes at the municipal level in the understudied state of Zacatecas. To do this, we analyzed and described the global distribution of nine rattlesnake species by building species distribution models, which determined their potential distribution based on a set of ecological variables and presence records. The resulting models were used to assess the diversity of rattlesnake species potentially present in each municipality within the state. Thirty-nine (67.24%) out of fifty-eight municipalities registered at least one rattlesnake species. Fresnillo, Sombrerete and Valparaíso were some of the municipalities showing greatest diversity. Moreover, C. atrox, C. lepidus, C. molossus and C. scutulatus were the most widely found species in the state. On the other hand, C. basiliscus, C. polystictus, C. pricei and C. willardi were rarely spotted and so, information on their distribution patterns within Zacatecas is limited. Finally, the areas having the largest potential for the distribution of these species were defined. These findings should make field work much more time- and cost-effective, facilitating the collection of in situ data that are useful for management and conservation plans of these species in Zacatecas. [ABSTRACT FROM AUTHOR]

The article presents new records of amphibians and reptiles from Sierra de Zongolica, Veracruz and Puebla, Mexico. Topics include the limited scope of the species richness and distribution patterns of the herpetofauna within the Sierra de Zongolica, facilities where all voucher specimens were deposited, and new species recorded including Hyalinobatrachium fleischmanni (Fleischman's glass frog), Smilisca cyanosticta (blue-spotted Mexican treefrog), and Ophisaurus ceroni (Ceron's glass lizard).

The article offers information on records of amphibians and reptiles from the Wixarica Region in the State of Jalisco, Mexico. Topics discussed include information on red-spotted toad, found under a rock in oak forests; information on geographic location of Canyon Treefrog, Northwest Mexico Leopard Frog, and Montezuma Leopard Frog; and information on Mexican Bullsnake, which was found under a fallen trunk in pine-oak forest.

Cases of pigmentary abnormalities have been documented in several amphibians and reptiles. These abnormalities have been classified as leucism, albinism, melanism and axanthism, among others. We report here the first case of axanthism in the frog Smilisca baudinii, as well as in the entire corresponding genus. To our knowledge, it is also the first report of axanthism in wild amphibians from Mexico. [ABSTRACT FROM AUTHOR]

Sinaloa possesses a rich biota with unique characteristics due to its proximity to the northern deserts, the tropical lowlands of the south, and the temperate environments of the western slopes of the Sierra Madre Occidental in Mexico. However, threats to its environment makes understanding the biological diversity of Sinaloa crucial. A checklist of the amphibians and reptiles has been generated, and the conservation status of Sinaloa's herpetofauna summarized with the aim of understanding the potential conservation or management needs. Sinaloa has 159 species of amphibians and reptiles, including 39 species of amphibians and 120 species of reptiles. The herpetofauna of Sinaloa has relatively few species of conservation concern at a global and national scale (IUCN and SEMARNAT lists), but Environmental Vulnerability Scores suggest that there might be greater conservation concerns for the Sinaloa herpetofauna. Families of particular conservation concern include Craugastoridae, Eleutherodactylidae, Ambystomatidae, Crocodylidae, Dactyloidae, Eublepharidae, Helodermatidae, Iguanidae, Phrynosomatidae, Phyllodactylidae, Colubridae, Natricidae, Viperidae, Cheloniidae, and Dermochelyidae. [ABSTRACT FROM AUTHOR]

The high loss rate of forest ecosystem by deforestation in the Trans-Mexican Volcanic Belt is one of the principal ecological problems of central Mexico, even in natural protected areas. We compiled a checklist and determined β-diversity indexes of amphibians and reptiles of the highly disturbed protected area, La Malinche National Park (LMNP) in Mexico, to determine the principal habitats for herpetofaunal conservation. After our extensive eight-year field sampling, we documented 28 species (nine amphibians and 19 reptiles), representing 11 families and 18 genera; four of these species are new records for LMNP. Of the species, 89% are endemic to Mexico. The IUCN Red List considers 22 species as Least Concern, one as Near Threatened, and four as Vulnerable. Meanwhile, the Environmental Viability Scores categorize three species as low vulnerability, 15 as medium, and 10 as high. According to the Mexican list of protected species, eight species are under Special Protection and nine are considered Vulnerable. The dissimilarity index between habitat types (βsør) in both groups is high, principally due to the environmental gradient generated by the altitudinal range. Abies and Pine forest are high diversity areas for amphibians and rep-tiles, respectively, and must be considered for special protection. LMNP hosts more than 60% of the herpetofauna of Tlaxcala and is the principal "conservation island" for this state. Therefore, based on the percentage of state species represented, endemism and the current social and ecological problems, additional efforts that involve the local communities to protect the biodiversity of this National Park are necessary. [ABSTRACT FROM AUTHOR]

Sonora has a rich natural diversity, including reptiles and amphibians. Sonora's location on the United States-Mexico border creates some unique conservation challenges for its wildlife. We compiled a list of the amphibian and reptile species currently known for Sonora, summarized the conservation status of these species, and compared our list of species with known species lists for adjacent states. The herpetofauna of Sonora comprises 200 species of amphibians and reptiles (38 amphibians and 162 reptiles). Overall, Sonora shares the most species with Chihuahua, Sinaloa, and Arizona. Approximately 11% of the amphibian and reptile species are IUCN listed, but 35.5% are placed in a protected category by SEMARNAT, and 32.6% are categorized as high risk by the Environmental Vulnerability Score. [ABSTRACT FROM AUTHOR]

Abstract. We report the northernmost Atlantic Coast record of the Cloudy Snail Sucker (Sibon nebulatus) from the state of Hidalgo, at a straight-line distance of about 185-km from the nearest historical locality in Sierra Norte de Puebla, Mexico. We assess the potential distribution of this species and compare morphological characteristics of specimens from Mexico and Central America. No significant morphometric or meristic differences were found. A species distribution model suggests that S. nebulatus is widely distributed on both coasts of Mexico, with a high probability of occurrence at a wider range of latitudes than current records indicate. [ABSTRACT FROM AUTHOR]

The beetle Omorgus suberosus (F.) is a facultative predator of eggs of the olive ridley turtle Lepidochelys olivacea (Eschscholtz). Laboratory and field investigations were conducted in order to characterize volatile attractants of O. suberosus and to explore the potential for application of these volatiles in a selective mass trapping method. Headspace sorptive extraction (HSSE) coupled to thermo-desorption gas chromatography–mass spectrometry (TD-GC-MS) analysis of the volatile constituents from beetles or turtle nests revealed 24 potential compounds. However, electroantennographic (EAG) measurements revealed antennal sensitivity only to indole, linoleic acid, trimethylamine, dimethyl sulphide, dimethyl disulphide and ammonia. Behavioural tests showed that these compounds are highly attractive to O. suberosus. Field trapping experiments revealed that indole and ammonia were more attractive than the other volatile compounds and showed similar attractiveness to that produced by conventional baits (chicken feathers). The use of a combined bait of indole and NH3 would therefore be the most effective trap design. The data presented are the first to demonstrate effective massive capture of O. suberosus using an attractant-based trapping method. These findings have potential for the development of an efficient mass trapping method for control of this beetle as part of efforts towards conservation of L. olivacea at La Escobilla in Oaxaca, Mexico. [ABSTRACT FROM AUTHOR]

The goal of this study is to describe patterns of reproductive activity and associated characteristics in a lizard community from an arid environment in the southern Chihuahuan Desert region of Mexico. Results of this study showed variation in snout–vent length (SVL) in adults female and male among 18 species. A similar pattern occurred in body mass of males and females, which varied mainly among species and not substantially between sexes. Mean clutch/litter size and egg/embryo mass and volume varied among species, and egg/embryo mass and volume were positively correlated with female SVL. Oviparous species were larger in SVL than viviparous species; however, SVL in females, clutch/litter size and egg/embryo volume were similar between oviparous and viviparous species, but the oviductal mass of oviparous species was larger than in viviparous species. Clutch/litter size and oviductal mass were correlated with female SVL in both oviparous and viviparous species. This relationship was similar for egg/embryo volume in oviparous species, but not in viviparous species. Seven species showed a prolonged reproductive period, and five had short reproductive periods. The results of this study provide evidence of high diversity in reproductive strategies that have evolved among organisms that live in this environment. • Lizard communities exhibit different forms of reproduction. • Arid environments have extreme conditions for various species of lizards. • We describe the reproductive strategies in a community of lizards. • Various reproductive strategies are recorded. • Environment and phylogeny determine these variations. [ABSTRACT FROM AUTHOR]

Data on reproductive ecology of turtles in New Mexico are limited, and some species living there are among the least studied in the United States. We trapped 4 native species of turtles ( Apalone spinifera, Chrysemys picta, Pseudemys gorzugi, and Trachemys gaigeae gaigeae) in the Rio Grande and Black River (Pecos River drainage) of New Mexico in June 2012 and 2013 to collect data on female reproductive ecology, including clutch size, egg size, timing of egg production, and percentage of gravid females. During our sampling, we found shelled eggs via X-radiography in only 3 native species: C. picta, P. gorzugi, and T. g. gaigeae. Clutch and egg sizes were within the range of previously reported values, although clutch size for P. gorzugi (10 eggs) is only the second published record for that data-deficient species. Clutch size increased with body size in T. g. gaigeae. We observed few differences between reproductive parameters for turtles in New Mexico and their conspecifics and congeners elsewhere in the United States, other than the observation that female C. picta may mature at smaller body sizes in New Mexico relative to other western populations elsewhere in its vast, primarily eastern North American range. [ABSTRACT FROM AUTHOR]

Pine-oak clear-cutting in Ixtlán de Juarez, Oaxaca, have been applied for more than 50 years; such forest management modify continuously the structure, arboreal composition, and associated biota. On the other hand, biota survey effort has been insufficient in communal forest areas in Sierra de Juarez, Ixtlán, Oaxaca. Particularly, it is not clear how this forest management affect the occurrence, presence and distribution patterns in reptiles. Our main goal was identifying composition of amphibian and reptiles, comparing distribution, rich- ness and abundance in three areas with different degree of perturbation (agriculture plots, natural forest, and forest management plots). We found that reptile community is composed by 37 species, grouped in 25 genera and 11 families. According to our estimates, we recorded 76% of the extant species in the region and 8. 37% of the extant species in Oaxaca. Within management forest (BMF), constituted by undisturbed (FC) and clear-cutting areas (FA), we identified 15 species: 13 reptiles and two amphibians. We recorded nine species in FC and eight species in FC. In AM we recorded 31 species grouped in 22 genus and 10 families. Biodiversity richness was higher in disturbed areas (AM and FA) than in FC. Although FC and FA are neighboring areas, similarity was higher between AM, with more than 50 years disturbance; and FA, recently disturbed. We also observed interconnectivity among AM, FC and FA areas which can help to maintain the natural amphibian and reptile ensemble. Our results pointed out that distribution and abundance patters are modified during forest clear-cutting process. Further reptile and amphibian inventory in disturbed and natural areas are needed in order to prevent or diminish herptile biota diversity due to continuous forest management. [ABSTRACT FROM AUTHOR]

This study was conducted from July 2004 to July 2005 in the Sierra de Juarez, in northern Chihuahua. This mountainous area is located west of Ciudad Juarez, is geographically isolated, by both natural features and anthropogenic influence. The objectives were to determine the richness and diversity of amphibians and reptiles along an altitudinal gradient and thus contribute to a better understanding of their spatial distribution and abundance. Five hundred and eleven individuals of 16 species were recorded in 52 samplings. Ecological and environmental conditions that reveal the current status of this fauna and their potential use as indicators of disturbance are described. Knowledge of our study community is urgent, given the dynamic that is beginning to show by invasions and changes being made in the Sierra. [ABSTRACT FROM AUTHOR]

We present a new record of rattlesnake Crotalus scutulatus collected in the county of La Paz, Mexico, that confirms the presence of the species for the Mexican state of Mexico. There is a dubious prior record of a specimen collected on 1967. Either way this species has not been collected again until now. [ABSTRACT FROM AUTHOR]

The present study evaluated the influence of age, sex and habitat on the frequency of tail loss in three species of endemic lizards to Mexico. The treated taxa are Sceloporus bicanthalis, S. subpictus and mesaspis gadovii and are sympatric in the mountains of the Central Valley of Oaxaca. The differences in the frequency of tail loss were evaluated by sex, age, habitat and species by Chi square test on a sample size of 259 organisms collected between April 2010 and March 2011. The results indicate that habitat structure, sex or age of individuals (except in Mgadovii) did not influence significantly in the frequency of mutilation of the tail in the three species analyzed. However, significant differences between species occur, these differences may be the result of agonistic behavior of each species, and of a pressure of predation different for each taxon. [ABSTRACT FROM AUTHOR]

A list of amphibians and reptiles in the Parque Nacional Lagunas de Chacahua (PNLCh) and La Tuza de Monroy was accomplished; diversity and relative abundance were analyzed quantitatively. The work was carried out monthly and alternated for four locations between February 2009 and February 2010 comprising both drought and wet seasons. Species accumulation curves were constructed based on the Chao2 model and the behavior of single and double species. Fifty two species were registered, distributed in 47 genera and 26 families. The greatest diversity of amphibians (H' = 0.98) was obtained in the rainy season; while in the case of reptiles (H' = 1.14) was during the drought season. The Hutcheson test revealed that the diversity of amphibians among seasons was statistically different (t = 1.22, g. l. = 406, P < 0.05) while there were no significant differences between seasons for reptiles (t = 3.07, g. l. = 489, P > 0.05). Rank-abundance curves show a marked dominance by species common in disturbed sites and by invasive species (Rhinella marina and Hemidactylus frenatus). This work represents a contribution to the knowledge of the Oaxacan herpetofauna from the coastal plains and the PNLCh, and groundwork for future studies on natural history and ecology of this important group of organisms. [ABSTRACT FROM AUTHOR]

An isolated supraoccipital from the late Miocene of Chiapas, southern Mexico, can be referred to Caimaninae, a group including the living caimans and their closest extinct relatives. The specimen shares a polygonal shape, indicating lateral contact with the squamosals, with extant Caiman and Melanosuchus, but some extinct caimanine lineages had a similar morphology. This is the northernmost known caimanine occurrence during the Neogene, suggesting that members of this salt-intolerant lineage were present in North America possibly before the Isthmus of Panama was complete. It might also indicate that extant lineages within Caiman, including those found in Mesoamerica today, were distinct earlier than generally believed. [ABSTRACT FROM AUTHOR]

We examined the diet of New Mexico Ridge-nosed Rattlesnakes ( Crotalus willardi obscurus) from the Sierra San Luis and the Sierra Pan Duro in the northern Sierra Madre Occidental, México. All snakes included in this study were encountered during August, September, and October in 2003 and 2004. Including recaptures of previously captured individuals, 107 of 199 snakes contained at least one prey item. We examined 103 prey items from 92 of these snakes; some snakes contained multiple prey items. Approximately two-thirds of prey items were ectotherms (54.4% lizards and 13.6% scolopendromorph centipedes); birds (21.4%) and mammals (10.7%) were also taken. The diet of juvenile snakes ( n = 32) consisted primarily of lizards (62.5%) and centipedes (25.8%), although large juveniles also consumed mammals (6.3%) and passerine birds (6.3%). Adult snakes ( n = 71) fed primarily on lizards (50.7%) and passerine birds (28.2%) but also consumed mammals (12.7%) and centipedes (8.4%). Crotalus willardi in the Sierra San Luis and Sierra Pan Duro consumed more birds than has been reported from C. willardi in nearby populations and continued to consume centipedes as adults. Examinamos la dieta de la New Mexico Ridge-nosed Rattlesnake ( Crotalus willardi obscurus) en la Sierra San Luis y la Sierra Pan Duro en el norte de la Sierra Madre Occidental, México, de serpientes colectadas en los meses de agosto, septiembre y octubre en 2003 y 2004. Capturamos 199 serpientes contando capturas y recapturas. Y de ellas 107 contenían restos de por lo menos una presa. Examinamos 103 restos de presas provenientes de 92 serpientes; algunas serpientes presentaban restos de múltiples presas. Aproximadamente dos tercios de las presas fueron ectotermos (54.4% lagartijas y 13.6% ciempiés); también fueron consumidas aves (21.4%) y mamíferos (10.7%). La dieta de las serpientes juveniles ( n = 32) consistió principalmente de lagartijas (62.5%) y ciempiés (25.8%), aunque los juveniles grandes también consumieron mamíferos (6.3%) y aves paseriformes (6.3%). Las serpientes adultas ( n = 71) se alimentan principalmente de lagartijas (50.7%) y aves paseriformes (28.2%), aunque también consumieron mamíferos (12.7%) y ciempiés (8.4%). Las serpientes en la Sierra San Luis y la Sierra Pan Duro consumieron más aves de lo que ha sido reportado para las poblaciones cercanas y los adultos continúan alimentándose de ciempiés. [ABSTRACT FROM AUTHOR]

Two new records of reptiles for Zacatecas are given, Sceloporus parvus and Lampropeltis alterna, also a distribution extension for Salvadora grahamiae lineata. These records confirm the presence of S. parvus and S. grahamiae lineata in the Mexican high plateau, whereas for L. alterna the known distribution extends to the southern limit for the known distribution limit. This records increase to 67 the number of species recorded in the state. [ABSTRACT FROM AUTHOR]

We registered incidentally Crotalus polysticus in suburban National Park El Cimatario, in Queretaro, Mexico; although this viperid was previously registered several times in Queretaro, it was not considered in recent publications for this state. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: Mexico has great biodiversity of fauna. The use of fauna with medicinal properties is a common practice since pre-Hispanic times. In the last decade, there has been an interest in ethnozoological studies in Mexico. Therefore, more studies are needed in order to gather information regarding the use of fauna with medicinal properties in México. Ethnozoological studies are necessary in order to discover new medications for human health. This review presents current information in terms of ethnozoological, conservation status, trade, toxicological and pharmacological effects of fauna used for medicinal purposes in Mexican traditional medicine (MTM), based on scientific literature. Future prospects for research with medicinal fauna are discussed. Materials and methods: Bibliographic investigation was carried out by analyzing recognized books and peer-reviewed papers, consulting worldwide accepted scientific databases from the last five decades. Reports included in this review complied with the three criteria cited as follows: (i) used in Mexican traditional medicine for medicinal and/or magical-religious purposes, (ii) with experimental studies regarding the toxicological or medicinal effects and/or with studies exploring mechanisms of medicinal effects, and (iii) with information obtained from a clear source. Results: A total of 163 animal species, belonging to 79 families and 4 taxonomic categories, used for medicinal purposes are reported in this review. Medicinal fauna used in MTM come from birds (48), fishes (3), insects (22), mammals (49) and reptiles (41). The most versatile species which had the greatest number of medicinal properties were Mephitis macroura (21 uses), Crotalus atrox (17 uses), Dasypus novemcinctus (13 uses) and Didelphis virginiana (13 uses). However, 14 of the 161 species listed in this review are classified as endangered. Animal species are mainly used for the treatment of inflammatory, respiratory and gastrointestinal diseases. Furthermore, insects and reptiles are the animal groups with more pharmacological studies. Approximately, 11% and 5% of medicinal fauna have been tested in terms of their pharmacological and toxicological effects, respectively. Conclusion: Despite the use of medicinal fauna in MTM, during centuries, there are a very limited number of scientific studies published on this topic. This review highlights the need to perform pharmacological, toxicological and chemical studies with medicinal fauna used in MTM. [Copyright &y& Elsevier]

The article offers information about the nomenclature concern associated with the Aspidoscelis tigris punctilinealis for Sonoran Tiger Whiptail of the Southwestern U.S. and Northern Mexico. It mentions that observations on arboreal behavior in Arizona populations, along with discusses the complicated history of the application of the appropriate name to the insular and mainland populations.

The taxonomy, osteology, phylogenetic position, and historical biogeography of the lambeosaurine hadrosaurid Magnapaulia laticaudus (new combination) are revised. The diagnosis of this species is amended on the basis on two autapomorphies (i.e., longest haemal arches of proximal caudal vertebrae being at least four times longer than the height of their respective centra; base of prezygapophyses in caudal vertebrae merging to form a bowl-shaped surface) and a unique combination of characters (i.e., downturned cranioventral process of the maxilla; tear-shaped external naris with length/ width ratio between 1.85 and 2.85; neural spines of dorsal, sacral, and proximal caudal vertebrae being at least four times the height of their respective centra). A maximum parsimony analysis supports a sister taxon relationship between M. laticaudus and Velafrons coahuilensis. Both taxa constitute a clade of southern North American lambeosaurines, which forms a sister relationship with the diverse clade of helmet-crested lambeosaurines from northern North America that includes well-known genera like Corythosaurus, Lambeosaurus, and Hypacrosaurus. According to the results of a Dispersal-Vicariance analysis, southern North American lambeosaurines split from the northern forms via vicariance from a common ancestor that lived in both the northern and southern regions of the continent. [ABSTRACT FROM AUTHOR]

Mexico possesses high levels of endemic biodiversity, especially for squamate reptiles. However, the evolutionary relationships among many reptiles in this region are not well known. The closely related genera of Sonora Baird and Girard 1853 and Procinura Cope 1879 are coralsnake mimics found from the central and western United States to southwestern Mexico and Baja California. Although species delimitation in this group has historically relied upon colour pattern and other morphological characters, many populations of these species display colour pattern polymorphism, which may confound taxonomy. We used molecular phylogenetics to assess the evolutionary relationships and delimit species within Sonora, focusing on the phylogenetic position of Procinura and the validity of S. mutabilis and aequalis. We sequenced two mitochondrial (ND4 and cytb) and two nuclear (c-mos and RAG-1) genes for the single species of Procinura and each of the four species of Sonora. We analysed these sequences using maximum parsimony, maximum likelihood and Bayesian phylogenetic analyses on separately concatenated mitochondrial and nuclear datasets. Additionally, we used Bayesian coalescent methods to build a species tree (Bayesian species tree analysis) and delimit species boundaries (Bayesian species delimitation). All methods indicated that Procinura is deeply nested within Sonora, and most individual species are well supported. However, we found that one taxon (S. aequalis) is paraphyletic with regard to another (S. mutabilis). We recommend that the genus Procinura be synonymised with Sonora and that S. aequalis be synonymised with S. mutabilis. Additionally, the phylogenetic patterns that we document are broadly congruent with a Miocene or Pliocene divergence between S. michoacanensis and S. mutabilis along the Trans-Mexican Volcanic Belt. Finally, our data are consistent with the early evolution of coralsnake mimicry and colour pattern polymorphism within the genus Sonora. [ABSTRACT FROM AUTHOR]

This study was performed in Cerro Guiengola in the Mexican state of Oaxaca, located in the Isthmus of Tehuantepec, with the objective of contributing to the knowledge on herpetofauna located in that area; 103 collections and 602 visual records of amphibians and reptiles were made during 60 days of field work, and 40 species belonging to 32 genera and 18 families are listed in this study. Based on the data collected, the herpetofauna distribution in Cerro Guiengola was classified according to altitude, vegetation and microhabitat. Vegetation and microhabitat similarity dendograms were made using Jaccard's method. Some species were reported in altitudes and vegetation types different from those cited in the literature. Simpson and Shannon-Wiener's indices of diversity show that the study area varies according to the obtained data; 13 species out of the 40 species recorded are endemic to Mexico and 3 to Oaxaca; 42.5% of the reported herpetofauna are listed in the NOM-059-ECOL-2001 and 47.5% by the International Union for the Conservation of Nature (IUCN). A new species of the Dahlibruchus genus is described and information is given about its bionomics and host plants, also are mentioned general aspects about the archeological site where the insect was found. [ABSTRACT FROM AUTHOR]

This herpetofaunistic study was conducted in Cerro El Potosi in the municipality of Galeana, Mexico, between November 2006 and November 2007. This is the first extensive formal work done in the area, thus increasing the knowledge of the herpetofauna of the Sierra Madre Oriental and in particular of this mountain, a State Protected Natural Area, and providing information that will enhance management and conservation strategies for this vertebrate group. Cerro El Potosí has an altitude gradient between 2000 and 3750 m, where distinct plant communities are found. The objectives of this re search were to identify species that occur in the altitudinal gradient, as well as their substrate preferences and distribution in different plant communities. Sampling was performed using transects, following the sampling and inventory method of Campbell and Christman (1982). A total of 188 individuals of seven species were collected, one species of frog, one species of salamander, four species of lizards and one species of snake. [ABSTRACT FROM AUTHOR]

To delimit the distribution of matrilines of the black iguana ( Ctenosaura pectinata), detect potential contact zones between them, and test the hypothesis of geographic concordance in the structuring of matrilines with respect to genetic structuring across the nuclear genome. Pacific coast of Mexico in the states of Nayarit, Jalisco, Colima, Michoacán in the lowlands adjacent to the western end of the Mexican Volcanic Belt. Tissue samples were obtained every 10-20 km along a transect across the range of three previously described mitochondrial DNA (mtDNA) clades of C. pectinata. Iguanas were genotyped with 11 nuclear microsatellites and maternal lineages were inferred based on mtDNA sequences. Geographic structure and geographic concordance between biparentally and maternally inherited markers were analysed with clustering methods, F and N indexes as well as haplotype networks. Geographic structure was evident for both markers and the existence of contact zones confirmed. Nevertheless, the distribution of nuclear and mtDNA genetic variation is not geographically concordant. Four matrilines exist in the area, whereas only two nuclear clusters occur. A contact zone between nuclear clusters extends along a distance of c. 60 km, and introgression is evident in individuals from several localities. High levels of genetic diversity were detected on the western coast of Mexico. Historical and contemporaneous processes seem to shape the distribution of genetic variation in C. pectinata. There are no evident geographic, environmental or ecological barriers that coincide with genetic subdivisions, and the observed mtDNA structure is likely to be the result of past climatic changes. The less structured distribution of nuclear genetic variation is consistent with the homogenizing effect of male-biased dispersal. Our findings have implications for the taxonomy and conservation strategies for this threatened species, and highlight the fact that geographic analyses of both cytoplasmic and nuclear genetic variation are important for the meaningful inference of evolutionary and demographic histories. [ABSTRACT FROM AUTHOR]

To assess the genealogical relationships of widespread montane rattlesnakes in the Crotalus triseriatus species group and to clarify the role of Late Neogene mountain building and Pleistocene pine-oak forest fragmentation in driving the diversification of Mexican highland taxa. Highlands of mainland Mexico and the south-western United States (Texas, New Mexico, and Arizona). A synthesis of inferences was used to address several associated questions about the biogeography of the Mexican highlands and the evolutionary drivers of phylogeographical diversity in co-distributed taxa. We combined extensive range-wide sampling (130 individuals representing five putative species) and mixed-model phylogenetic analyses of 2408 base pairs of mitochondrial DNA to estimate genealogical relationships and divergence times within the C. triseriatus species group. We then assessed the tempo of diversification using a maximum likelihood framework based on the birth-death process. Estimated times of divergences provided a probabilistic temporal component and questioned whether diversification rates have remained constant or varied over time. Finally, we looked for phylogeographical patterns in other co-distributed taxa. We identified eight major lineages within the C. triseriatus group, and inferred strong correspondence between maternal and geographic history within most lineages. At least one cryptic species was detected. Relationships among lineages were generally congruent with previous molecular studies, with differences largely attributable to our expanded taxonomic and geographic sampling. Estimated divergences between most major lineages occurred in the Late Miocene and Pliocene. Phylogeographical structure within each lineage appeared to have been generated primarily during the Pleistocene. Although the scale of genetic diversity recognized affected estimated rates of diversification, rates appeared to have been constant through time. The biogeographical history of the C. triseriatus group implies a dynamic history for the highlands of Mexico. The Neogene formation of the Transvolcanic Belt appears responsible for structuring geographic diversity among major lineages. Pleistocene glacial-interglacial climatic cycles and resultant expansions and contractions of the Mexican pine-oak forest appear to have driven widespread divergences within lineages. Climatic change, paired with the complex topography of Mexico, probably produced a myriad of species-specific responses in co-distributed Mexican highland taxa. The high degree of genetic differentiation recovered in our study and others suggests that the Mexican highlands may contain considerably more diversity than currently recognized. [ABSTRACT FROM AUTHOR]

The role of human activities in species biogeography can be difficult to identify, but in some cases molecular techniques can be used to test hypotheses of human-mediated dispersal. A currently accepted hypothesis states that humans mediated the divergence of two species of spiny-tailed iguanas in the Ctenosaura hemilopha species complex, namely C. conspicuosa and C. nolascensis, which occupy islands in the Sea of Cortés between the peninsula of Baja California and mainland Mexico. We test an alternative hypothesis that follows the traditional knowledge of the Seri Indians and states that the divergence of these species was not mediated by humans. Mexico, including Baja California, Sonoran and Sinaloan coastal regions, and Isla San Esteban and Isla San Pedro Nolasco in the Sea of Cortés. We analysed mitochondrial (cytochrome b and cytochrome c oxidase subunit III) DNA sequences from four species in the C. hemilopha species complex. Maximum parsimony and Bayesian inference were used to infer matriarchal genealogical relationships between the species and several outgroup taxa. Bayesian methods were used to estimate divergence times for the major nodes on the trees based on previously published, fossil-calibrated priors. Our analysis indicated that lineages within the C. hemilopha species complex diverged long before human colonization of the Americas. The divergence of C. nolascensis and C. conspicuosa could not be attributed to Seri translocations. The matriarchal genealogy of the species complex currently defies a simple biogeographical interpretation. We conclude that humans did not mediate the divergence of C. nolascensis and C. conspicuosa. This conclusion is consistent with the traditional knowledge of the Seri people. These results demonstrate the utility of molecular techniques in investigating potential cases of human-mediated dispersal of plants and animals, and reinforce the importance of considering traditional knowledge in the formation of scientific hypotheses and the interpretation of results. [ABSTRACT FROM AUTHOR]