Jonathan Campbell
University of Texas at Arlington, Biology, Department Member
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The genus Salvadora has not been subjected to a modern phylogenetic analysis. Described in 1853, its taxonomic history is complex and confusing. In this study, we evaluate the monophyly of the genus and present the first phylogenetic... more
The genus Salvadora has not been subjected to a modern phylogenetic analysis. Described in 1853, its taxonomic history is complex and confusing. In this study, we evaluate the monophyly of the genus and present the first phylogenetic hypothesis based on an analysis of 66 qualitative and quantitative morphological characters of over 1000 specimens representing all described taxa across their entire distribution. Morphological characters were processed in Fast Morphology for subsequent phylogenetic analysis in PAUP under the maximum parsimony criterion. We obtained a single tree in which Salvadora appears as a monophyletic group with two clearly defined geographic species groups: a southern mexicana group and a northern grahamiae group. Based on our phylogenetic hypothesis, we evaluate the taxonomic status of all described taxa. Additionally, we include a diagnosis for all species, distribution maps, and an illustrated dichotomous taxonomic key of the genus.
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We describe Sceloporus huichol sp. nov., a new species of spiny lizard of the genus Sceloporus, that is found in the mountainous regions of Jalisco and Nayarit in western Mexico. The new species belongs to the torquatus species group and... more
We describe Sceloporus huichol sp. nov., a new species of spiny lizard of the genus Sceloporus, that is found in the mountainous regions of Jalisco and Nayarit in western Mexico. The new species belongs to the torquatus species group and has previously been confused with Sceloporus melanogaster, from which it differs by its smaller size, head color and nuchal collar. Additionally, Sceloporus huichol sp. nov. is different from the rest of its congeners by relevant genetic and morphologicall data. Despite having a complete nuchal collar, characteristic of Sceloporus torquatus, S. huichol sp. nov. is more closely related phylogenetically to S. melanogaster. Recognition of this new species brings the number of species in the torquatus group to nine.
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Senticolis triaspis is a widespread polytypic colubrid snake that ranges from the southwestern United States southward along the Pacific Coast and part of the Atlantic Coast of Mexico to Costa Rica. Three subspecies have been described... more
Senticolis triaspis is a widespread polytypic colubrid snake that ranges from the southwestern United States southward along the Pacific Coast and part of the Atlantic Coast of Mexico to Costa Rica. Three subspecies have been described based on differences in color pattern and scutellation: S. t. intermedia, S. t. mutabilis, and S. t. triaspis. The last taxonomic revision was completed in 1960. Here, we present an integrative taxonomic analysis of geographic variation using multiple sources of evidence: mitochondrial DNA (817 bp ND4 from 62 samples), traditional morphology (meristic and mensural characters), geometric morphometrics of head shape, and bioclimatic estimates of environmental niche similarity. Molecular data revealed two deeply divergent mitochondrial lineages corresponding to northern and southern clades and eight well-supported clades within these two main groups. Head shape and niche models also showed north–south differences, while traditional morphological analyses did not discriminate among mtDNA lineages. Thus, our study suggests there are at least two candidate species within Senticolis triaspis based on the mtDNA divergence, differences in head shape, and non-overlapping ecological niches. However, we refrain from making taxonomic recommendations pending the addition of nuclear DNA sequence data, finer sampling at contact zones, and additional morphological data; these data are warranted to provide a more robust, stable species delimitation.
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A new species of snake of the genus Salvadora from Oaxaca, Mexico, is described. This taxon was confused with S. intermedia in previous taxonomic descriptions. It is characterized by lacking a pale vertebral stripe and by having... more
A new species of snake of the genus Salvadora from Oaxaca, Mexico, is described. This taxon was confused with S. intermedia in previous taxonomic descriptions. It is characterized by lacking a pale vertebral stripe and by having incomplete dorsolateral stripes that do not reach the posterior part of the body, which is typical of congeners; by having both dorsolateral stripes separated each other by five to six scale rows on anterior part of body; and other scalation characters as well as the number maxillary teeth. The importance of this snake and its conservation is discussed.
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A new species of hylid frog is described from the southwestern edge of the Mexican Plateau from the states of Morelos and Mexico through Michoacán and Jalisco, reaching the Sierra Madre Occidental in Sinaloa and western Durango. The new... more
A new species of hylid frog is described from the southwestern edge of the Mexican Plateau from the states of Morelos and Mexico through Michoacán and Jalisco, reaching the Sierra Madre Occidental in Sinaloa and western Durango. The new species is part of the widespread Mexican hylid Sarcohyla bistincta (sensu amplo) complex, comprised of S. bistincta, S. pentheter, S. calthula, and S. ephemera. One subspecies of S. bistincta (labeculata) was proposed for an isolated population in Oaxaca. We restrict the group's nominal species, S. bistincta (sensu stricto), to the Sierra Madre Oriental of Mexico and southward into the Sierra Madre del Sur of Guerrero and Oaxaca. Examination of type material places S. calthula and S. ephemera in the synonymy of S. labeculata (new combination). The species allied to S. bistincta, namely, S. bistincta, S. labeculata, S. pentheter, and the new species described herein, are diagnosed and described following recent suggested taxonomic changes and new...
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ABSTRACT A new minute salamander of the genus Thorius is described from the western highlands of the Mexican state of Guerrero. Previously , three congeners were known from the central portion of the state. The fourth species we herein... more
ABSTRACT A new minute salamander of the genus Thorius is described from the western highlands of the Mexican state of Guerrero. Previously , three congeners were known from the central portion of the state. The fourth species we herein describe occurs in the western portion of the Sierra Madre del Sur of Guerrero and is allopatric from nearest congeners by about 80 km. The new species is distinguished from Guerreran congeners by a combination of body size, external morphology, and dentition. Resumen. Se describe una nueva especie de salamandra diminuta del género Thorius de las tierras altas del oeste del Estado de Guerrero, México. Anteriormente se conocían solamente tres congéneres en el centro del estado. La cuarta especie que describimos aquí habita la región oeste de la Sierra Madre del Sur de Guerrero y es alopátrica por aproximadamente 80 km con respecto a las otras especies cercanas del mismo género. La nueva especie se distingue de sus congéneres en Guerrero por su tamaño corporal, morfología externa, y su dentición.
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Research Interests: Herpetology, Polymorphism, Molecular Systematics, Taxonomy, Biology, and 15 moreEcology, Systematics, Coalescent Theory, Biological Sciences, Maximum Likelihood, Paraphyly, Squamata, Colubridae, Genus, Morphological Characters, Molecular phylogenetics, western United States, Monophyly, Phylogenetic Tree, and Maximum Parsimony
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Abstract The Chiricahua Leopard Frog (Lithobates chiricahuensis) occurs in parts of the southwestern United States and northwestern Mexico. In the United States, it is listed as a federally threatened species. Although extensive research... more
Abstract The Chiricahua Leopard Frog (Lithobates chiricahuensis) occurs in parts of the southwestern United States and northwestern Mexico. In the United States, it is listed as a federally threatened species. Although extensive research has been conducted on populations in the United States, the status of most Mexican populations is unknown. We used mitochondrial and nuclear DNA to identify a population of L. chiricahuensis from the Mexican state of Durango. To better characterize this poorly known population, we examined morphological variation in 30 individuals that included adult males, adult females, and subadult females. Multivariate analyses of 21 size-adjusted body measurements revealed putative shifts in body dimensions associated with gender and ontogeny. Additionally, we observed notable amounts of color pattern variation in female specimens. Our field observations from 2008 suggest that this population is large and thriving. In light of this, a more comprehensive examination may yield valuable conservation insights and have implications for the management of declining L. chiricahuensis populations in the United States. Resumen La rana leopardo de los Chiricahua (Lithobates chiricahuensis), ocurre en partes del suroeste de los Estados Unidos y del noroeste de México. Esta especie está en la lista federal de especies en peligro de los Estados Unidos, como una especie amenazada. Mientras que en los Estados Unidos se ha hecho mucha investigación sobre su estado de conservación, de la mayoría de las poblaciones mexicanas, éste es desconocido. En la presente investigación, utilizamos ADN mitocondrial y nuclear para identificar una población de L. chiricahuensis del estado de Durango. Para caracterizar mejor esta población pobremente conocida, examinamos la variación morfológica en una muestra de 30 individuos que incluyeron machos adultos, hembras adultas, y hembras subadultas. Se hizo un análisis multivariado de 21 medidas corporales ajustadas a la talla, mismas que revelaron cambios putativos de las dimensiones corporales asociados a la ontogenia y al sexo. Además, se observó una gran variación en el patrón del coloración que presentan las hembras. Nuestras observaciones de campo a partir del 2008 sugieren que esta población es grande y próspera. A la luz de este trabajo, el examen más detallado de esta población pudiera rendir datos valiosos sobre la conservación de esta especie los cuales pudieran tener implicaciones para el manejo de las poblaciones del L. chiricahuensis que están declinando en los Estados Unidos.
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Research Interests: Zoology, Biology, Ecology, Information, Viperidae, and 4 moreLong Tail, Ophidia, Crotalus, and Ecological Applications
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The Mohave Rattlesnake (Crotalus scutulatus) is a highly venomous pitviper inhabiting the arid interior deserts, grasslands, and savannas of western North America. Currently two subspecies are recognized: the Northern Mohave Rattlesnake... more
The Mohave Rattlesnake (Crotalus scutulatus) is a highly venomous pitviper inhabiting the arid interior deserts, grasslands, and savannas of western North America. Currently two subspecies are recognized: the Northern Mohave Rattlesnake (C. s. scutulatus) ranging from southern California to the southern Central Mexican Plateau, and the Huamantla Rattlesnake (C. s. salvini) from the region of Tlaxcala, Veracruz, and Puebla in south-central Mexico. Although recent studies have demonstrated extensive geographic variation in venom composition and cryptic genetic diversity in this species, no modern studies have focused on geographic variation in morphology. Here we analyzed a series of qualitative, meristic, and morphometric traits from 347 specimens of C. scutulatus and show that this species is phenotypically cohesive without discrete subgroups, and that morphology follows a continuous cline in primarily color pattern and meristic traits across the major axis of its expansive distribu...
Research Interests: Evolutionary Biology, Zoology, Phylogeography, Biology, Ecology, and 3 moreMedicine, Viperidae, and Subspecies
Hyla ephemera, new species, is described from the cloud forests of Cerro Las Flores in south-central Oaxaca, Mexico. We tentatively place this species in the phenetic H. bistincta group. It is most similar to H. calthula in color pattern... more
Hyla ephemera, new species, is described from the cloud forests of Cerro Las Flores in south-central Oaxaca, Mexico. We tentatively place this species in the phenetic H. bistincta group. It is most similar to H. calthula in color pattern but differs in having a greater snout–vent length, a relatively shorter snout and tibia, a relatively wider head, and a larger tympanum. We also report an additional locality record for H. calthula, previously known only from the type locality.
Research Interests: Evolutionary Biology, Zoology, Biology, Hylidae, Cloud Forest, and 3 moreType Locality, Hyla, and Snout
A new species of Tantilla is described from a single specimen obtained from Volcán Ceboruco, southern Nayarit, Mexico. The new species closely resembles other species of the Tantilla calamarina group. With the addition of the taxon... more
A new species of Tantilla is described from a single specimen obtained from Volcán Ceboruco, southern Nayarit, Mexico. The new species closely resembles other species of the Tantilla calamarina group. With the addition of the taxon described herein, the calamarina ...
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ABSTRACT The Craugastor rhodopis Species Group includes two leaf-litter frog species (C. loki and C. rhodopis). These direct-developing frogs inhabit tropical regions of Mexico and northern Central America. Characterizing diversity within... more
ABSTRACT The Craugastor rhodopis Species Group includes two leaf-litter frog species (C. loki and C. rhodopis). These direct-developing frogs inhabit tropical regions of Mexico and northern Central America. Characterizing diversity within the group has been difficult due to high levels of phenotypic polymorphism within and between species. Because of these polymorphisms, each taxon has junior synonyms. Using a fragment of mitochondrial DNA (mtDNA), we investigated genetic diversity in the C. rhodopis Species Group. We then examined type specimens (including types of junior synonyms) to match nomenclature to geographically circumscribed genetic clusters. Our molecular analyses revealed four major lineages within the C. rhodopis Species Group: (1) a widely distributed clade in western Mexico, (2) a highland clade in eastern Mexico, (3) a widely distributed lowland clade occurring in eastern Mexico, Guatemala and El Salvador, and (4) a haplotype from Volc an San Mart ın in Veracruz, Mexico. We identified the first clade as C. occidentalis, a taxon currently placed in the ecologically similar but phylogenetically distant C. mexicanus Species Series. In light of this we place C. occidentalis in the C. rhodopis Species Group and designate a lectotype and paralectotype for the species. The second and third clades inhabiting eastern Mexico and northern Central America correspond to C. rhodopis and C. loki, respectively. Additionally, we examined the taxonomic distribution of certain colour pattern traits and compensatory mutations in Domain III of the mtDNA 12S ribosomal RNA gene. Our recovery of the divergent Veracruz haplotype and extensive mtDNA structure within species indicates that additional taxonomic revision will be necessary.
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The Mohave Rattlesnake (Crotalus scutulatus) is a highly venomous pitviper inhabiting the arid interior deserts, grasslands, and savannas of western North America. Currently two subspecies are recognized: the Northern Mohave Rattlesnake... more
The Mohave Rattlesnake (Crotalus scutulatus) is a highly venomous pitviper inhabiting the arid interior deserts, grasslands, and savannas of western North America. Currently two subspecies are recognized: the Northern Mohave Rattlesnake (C. s. scutulatus) ranging from southern California to the southern Central Mexican Plateau, and the Huamantla Rattlesnake (C. s. salvini) from the region of Tlaxcala, Veracruz, and Puebla in south-central Mexico. Although recent studies have demonstrated extensive geographic variation in venom composition and cryptic genetic diversity in this species, no modern studies have focused on geographic variation in morphology. Here we analyzed a series of qualitative, meristic, and morphometric traits from 347 specimens of C. scutulatus and show that this species is phenotypically cohesive without discrete subgroups, and that morphology follows a continuous cline in primarily color pattern and meristic traits across the major axis of its expansive distribu...
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ABSTRACT The Craugastor rhodopis Species Group includes two leaf-litter frog species (C. loki and C. rhodopis). These direct-developing frogs inhabit tropical regions of Mexico and northern Central America. Characterizing diversity within... more
ABSTRACT The Craugastor rhodopis Species Group includes two leaf-litter frog species (C. loki and C. rhodopis). These direct-developing frogs inhabit tropical regions of Mexico and northern Central America. Characterizing diversity within the group has been difficult due to high levels of phenotypic polymorphism within and between species. Because of these polymorphisms, each taxon has junior synonyms. Using a fragment of mitochondrial DNA (mtDNA), we investigated genetic diversity in the C. rhodopis Species Group. We then examined type specimens (including types of junior synonyms) to match nomenclature to geographically circumscribed genetic clusters. Our molecular analyses revealed four major lineages within the C. rhodopis Species Group: (1) a widely distributed clade in western Mexico, (2) a highland clade in eastern Mexico, (3) a widely distributed lowland clade occurring in eastern Mexico, Guatemala and El Salvador, and (4) a haplotype from Volc an San Mart ın in Veracruz, Mexico. We identified the first clade as C. occidentalis, a taxon currently placed in the ecologically similar but phylogenetically distant C. mexicanus Species Series. In light of this we place C. occidentalis in the C. rhodopis Species Group and designate a lectotype and paralectotype for the species. The second and third clades inhabiting eastern Mexico and northern Central America correspond to C. rhodopis and C. loki, respectively. Additionally, we examined the taxonomic distribution of certain colour pattern traits and compensatory mutations in Domain III of the mtDNA 12S ribosomal RNA gene. Our recovery of the divergent Veracruz haplotype and extensive mtDNA structure within species indicates that additional taxonomic revision will be necessary.
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... with appropriate verbs would make the text more readable and could save the serious reader much time. ... onic development of the maxillary and pre-frontal bones in relation to fang rotation and the pit. ... The $75.00 price tag and... more
... with appropriate verbs would make the text more readable and could save the serious reader much time. ... onic development of the maxillary and pre-frontal bones in relation to fang rotation and the pit. ... The $75.00 price tag and the tech-nical nature of most of the book may turn ...