Remarks on the Geographical Distribution and Phylectic Trends of South American Toads

Contents: Introduction -- Discussion - Conclusions and Summary -- BibliographyTexas Memorial Museu

Los caracteres biocenóticos de las lagunas basálticas del oeste de Neuquén

Fil: Roig, Virgilio G.. Universidad Nacional de Cuyo. Instituto de BiologíaFil: Cei, José M.. Universidad Nacional de Cuyo. Instituto de Biologí

A Review of the Leptodactylid Frog Genus, Odontophrynus

The frogs of the neotropical genus Odontophrynus form a distinctive and phyletically compact group of warty toadlike bur- rowers, readily distinguished from other members of the family Leptodactylidae. One wide-ranging species, Odontophrynus ameri- canus, is among the commonest amphibians in the drier subtropical regions of Argentina and adjacent portions of Bolivia, Brazil, Paraguay, and Uruguay. A second well-differentiated species, Odontophrynus cultripes, of southeastern Brazil and Argentina, is characterized by enormous dorsal poison glands. A third nominal form, Odontophrynus occidentalis, originally described from Territorio de Neuquén, Argentina, has been of questionable status. The present study was initiated by the rediscovery of Odontophrynus occidentalis from a number of localities along the eastern foothills of the Argentina Andes. Subsequently, in the course of investigations to establish the systematic position of the three known members of the genus, an undescribed species from northeast Brazil was discovered. The principal aims of this report are to review briefly the systematics and distribution of the four valid species of Odontophrynus, provide diagnoses for identification, describe the larvae of three of the forms, and describe the new Brazilian species. Detailed analysis of geographic variation and the ecology of O. americanus and O. occidentalis is reserved for a future paper by Cei. Barrio (1964) has recently discussed breeding calls and ecological characters in these two species.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Some models of ecogeographic speciation explaining the herpetological diversity of the Andean-Patagonian region

Se analizan cuatro modelos de especiación geográfica en el área andino-patagónica. Un primer y simple modelo involucra las mesetas basálticas aisladas a través del territorio extra-andino, las que han soportado desde el Terciario Tardío prolongados períodos de diastrofismo climático y geológico. Su biota exhibe altas tasas de formas endémicas pertenecientes a hábitats muy restringidos, significativos para cada meseta. Dichos ecosistemas aislados llegan a constituir verdaderos refugios o "centros de neo-dispersión", con peculiares biocenosis caracterizadas por especies de iguánidos (Liolaemus, Phymaturus) y anuros (Atelognathus). Un particular patrón de distribución propio de Liolaemus darwinii, con una extendida población central a la cual periféricamente se oponen poblaciones de varias especies filéticamente relacionadas, podría adecuarse al modelo conocido como "especiación centrífuga". Este sugiere un probable proceso inicial de especiación a través de una progresión "centrífuga" que involucra fases de contracción opuestas a fases de expansión de las poblaciones: lo que estaría de acuerdo con una previsible acumulación de diferencias genéticas entre algunas poblaciones periféricas aisladas y el amplio centro poblacional radiante de distribución ancestral. El modelo del "médano invasor" puede aplicarse a los rangos de distribución de varias especies de lagartijas arenícolas pertenecientes al grupo Liolaemus wiegmannii. A partir de una antigua área de origen post-glacial, una barrera ecológica natural de dunas y médanos voladores podría haber favorecido cambios morfológicos y hasta una evolución independiente con un aislamiento geográfico de poblaciones de estas especies arenícolas relacionadas filéticamente. El modelo de "refugio en desaparición" como mecanismo para la especiación eco-geográfica puede asimismo explicar la actual distribución de las especies de lagartos del género Pristidactylus. Desde un primitivo ancestro común habitando extensos bosques, que han estado continuamente en deterioro a través del tiempo, algunas poblaciones disyuntas quedaron en refugios aislados. Subsecuentemente, ellas pudieron adquirir varias pre-adaptaciones a ambientes más abiertos, rocosos, secos y con formaciones arbustivas, evolucionando hacia los presentes taxa, diferenciados para distintos habitats.Four populational models of geographic speciation are discussed. A first tentative model points out several basaltic tablelands along the extra-Andean territory, standing lengthy periods of geological and climatic diastrophisms from the late Tertiary. A very high rate of endemic forms can be emphasised for such biota, inhabiting very restrictive ecosystems along each plateau. These isolated formations constitute reliable refuges or neo-dispersal centres, of peculiar biocenoses such in the case of lizards (Liolaemus, Phymaturus) and anurans (Atelognathus). On the other hand, the distribution pattern showed by the widespread central populations of Liolaemus darwinii and the several peripherally opposite but phyletically related species could be supported by the so-called "centrifugal speciation" model. It suggests a probable speciation process following a centrifugal progression, which involves opposite phases of contraction and expansion of the populations. That could be in agreement with an expected accumulation of genetic differences between some isolated peripheral remnants and the wide radiating centre of ancestral populations. The "invading dune" model can be applied to the distribution ranges of several sand-dwelling species of lizards belonging to "Liolaemus wiegmannii group". From ancient postglacial precursors, an interposed ecological barrier of aeolean dunes and sandbanks could have favoured morphological changes that independently characterised the population evolution and the geographic isolation of these phyletically related sand-lizard species. The "vanishing refuge" model as a mechanism for ecogeographic speciation may explain the actual distribution of lizards of the Pristidactylus genus. From a primitive common ancestor inhabiting large forest, continuously deteriorated, over time some disjoined populations remained in isolated refuges. Subsequently they could have acquired several preadaptations to environments of more open, dry, rocky and shrubby formations, evolving towards the differentiated taxa actually recognised.Fil: Scolaro, Jose Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Videla, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Cei, José M.. Universidad Nacional de Río Cuarto; Argentin

A Review of the Leptodactylid Frog Genus, Odontophrynus

The frogs of the neotropical genus Odontophrynus form a distinctive and phyletically compact group of warty toadlike bur- rowers, readily distinguished from other members of the family Leptodactylidae. One wide-ranging species, Odontophrynus ameri- canus, is among the commonest amphibians in the drier subtropical regions of Argentina and adjacent portions of Bolivia, Brazil, Paraguay, and Uruguay. A second well-differentiated species, Odontophrynus cultripes, of southeastern Brazil and Argentina, is characterized by enormous dorsal poison glands. A third nominal form, Odontophrynus occidentalis, originally described from Territorio de Neuquén, Argentina, has been of questionable status. The present study was initiated by the rediscovery of Odontophrynus occidentalis from a number of localities along the eastern foothills of the Argentina Andes. Subsequently, in the course of investigations to establish the systematic position of the three known members of the genus, an undescribed species from northeast Brazil was discovered. The principal aims of this report are to review briefly the systematics and distribution of the four valid species of Odontophrynus, provide diagnoses for identification, describe the larvae of three of the forms, and describe the new Brazilian species. Detailed analysis of geographic variation and the ecology of O. americanus and O. occidentalis is reserved for a future paper by Cei. Barrio (1964) has recently discussed breeding calls and ecological characters in these two species.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Specific supraocular scutellation patterns as significant diagnostic characters: a taxonomic inter and intrageneric "finger-print" in lacertilia

The specificity of the supraocular patterns in lacertilian is recognized and analysed. Inter and intrageneric specific differences in lizards belonging to families of Iguania as Leiosauridae, Tropiduridae, Liolaemidae are pointed out. A significant comparison with the very different supraocular scutellations of teiid genera Dicrodon and Kentropyx is carried out. The suitable diagnostic use of this morphological trend of systematic value is put in evidence. Its peculiar structure and unquestionable specificity give to it a physiognomy of some unusual kind of herpetological “finger-print”

Deep canyon desert reserch area, en el Colorado desert, California

Fil: Cei, José M.. Universidad Nacional de Cuyo. Instituto de Biologí

Taxonomic and Evolutionary Significance of Biogenic Amines and Polypeptides in Amphibian Skin. II. Toads of the Genera Bufo and Melanophryniscus

The value of the study of biogenic amines and active polypeptides of the amphibian skin in providing taxonomic evidence has been pointed in an earlier paper (Cei, Erspamer and Roseghini, 1967). The point was stressed that biochemical taxonomy, in its broadest sense, is possibly more discriminating than traditional taxonomy, based on somatic or osteological structures, size or coloration. In the first paper of this series sets of biochemical and pharmacological data concerning the skins of lep- todactylid frogs were reported and discussed. The present paper deals similarly with representatives of another very important family of Procoela, the Bufonidae.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Taxonomic and evolutionary significance of biogenic amines and polypeptides occurring in amphibian skin. I. Neotropical Leptodactylid frogs

Qualitative identification and quantitative estimation both of aromatic biogenic amines and pharmacologically active polypeptides in the skin of amphibians appear to offer a valuable contribution to studies in taxonomy and evolution of this vertebrate class. Several examples of the accordance of the biochemical data herein reported with the data of traditional taxonomy are described for the neotropical family of frogs Leptodactylidae, but particular emphasis is laid on the striking correspondence between the systemic distribution of the spectra of biogenic amines and morphological taxonomy which is demonstrated by the species of the genus Leptodactylus.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Taxonomic and Evolutionary Significance of Biogenic Amines and Polypeptides in Amphibian Skin. II. Toads of the Genera Bufo and Melanophryniscus

The value of the study of biogenic amines and active polypeptides of the amphibian skin in providing taxonomic evidence has been pointed in an earlier paper (Cei, Erspamer and Roseghini, 1967). The point was stressed that biochemical taxonomy, in its broadest sense, is possibly more discriminating than traditional taxonomy, based on somatic or osteological structures, size or coloration. In the first paper of this series sets of biochemical and pharmacological data concerning the skins of lep- todactylid frogs were reported and discussed. The present paper deals similarly with representatives of another very important family of Procoela, the Bufonidae.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse