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San Miguel de Tucumán, Argentina

Vera Candioti M.F.,Institute Herpetologia | Altig R.,Mississippi State University
Biological Journal of the Linnean Society

Labial teeth of anuran tadpoles are keratinized structures derived from the activity of a single epidermal cell of the oral labia; they are not homologous with adult anuran teeth, nor with teeth of other vertebrates. The present study comprises a first approach for studying labial tooth shape variation that will be useful for future studies of comparative development and the functional mechanics of feeding structures. We examined interspecific shape variations in the labial teeth of anuran tadpoles and searched for correlations of these variations with ecomorphological guilds and phylogeny. Species ordination shows that important variations at various taxonomic levels are related mainly to the general curvature of the tooth axis, the angle between the labial tooth base and tip, head length and curvature, and sheath width. The teeth of most basal taxa are broad-based and curved, although some broad-based teeth also characterize some phthanobatrachian species. Teeth of hyloids and ranoids differ in the oral angle, overall curvature, and sheath width. A phylogenetically independent ecomorphological effect is significant only for lotic suctorial and gastromyzophorous guilds; teeth in these forms have short, thick and curved heads, wide sheaths, and generally acute oral angles. The lack of a significant correlation between labial tooth shape and trophic guilds suggests that labial tooth harvesting ability has a wide latitude that could be particularly functional only under specific circumstances. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society. Source

Visual displays in lizards are used to convey information related to species, sex, reproductive state, context and even individuality. Two displays that have been reported are headbobs, up and down movements of the head, and forelimb waves, circular movements of the forelegs, the former display generally being more conspicuous and frequent than the latter. Here I investigated these two displays in an iguanian neotropical species, Liolaemus quilmes, from northwestern Argentina. One-hundredand- fifteen males and females were filmed over six years, in their habitat, during their daily activities. Headbob and forelimb display rates were compared between males and females and between the reproductive and postreproductive seasons. In addition, the relation between headbob display rates and home range size was explored. As reported for many iguanian lizards, males made significantly more headbob displays than females in both the reproductive and post-reproductive seasons. They also performed more forelimb waves than females in both seasons. Finally, no correlation was found between headbob display rates and home range sizes in any of the two seasons, suggesting that although headbob displays have been associated with territorial defence it does not seem to be associated with the size of the defended area. Source

Scrocchi G.J.,Institute Herpetologia | Giraudo A.R.,CONICET
Check List

Phalotris sansebastiani is recorded for the first time in Argentina based on five specimens from Jujuy and Salta provinces, and its characters are compared with Argentinean specimens of P. tricolor. © 2012 Check List and Authors. Source

Barrionuevo J.S.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Barrionuevo J.S.,Institute Herpetologia
Journal of Morphology

The osteological diversity among species of Telmatobius has been considered conservative. Nonetheless, the degree of ossification of several features varies both intraspecifically and interspecifically. Herein, intraspecific osteological variation and postmetamorphic ontogenetic changes in osteological features are described in Telmatobius oxycephalus. These data are compared with published descriptions of congeners. There is a considerable intraspecific osteological variation in T. oxycephalus, with cranial characters varying polymorphically, and the hyoid and postcranial characters being sexually dimorphic. This intraspecific variation is expressed by subtle differences in the degree of ossification or mineralization. Interspecific variation also can be described in terms of differential development of osteological features; these differences are more obvious than intraspecifically variable characters. The adult skeletons of several species of Telmatobius resemble the morphology observed in early stages of postmetamorphic development of T. oxycephalus. This is especially evident in the neopalatines, parasphenoid, sphenethmoid, exoccipitals, prootics, vomers, nasals, and plectra. These results suggest that within the conservative osteological architecture of Telmatobius, the variation observed is the result of heterochronic changes during the ossification process. © 2012 Wiley Periodicals, Inc. Source

Klaczko J.,University of Campinas | De Andrade Machado F.,University of Sao Paulo | Scrocchi G.,Institute Herpetologia | Zaher H.,University of Sao Paulo

Recently four subspecies of Chironius multiventris were recognized as valid distinct species: C. m. foveatus, C. m. multiventris, C. m. cochranae, and C. m. septentrionalis. Although C. foveatus and C. septentrionalis clearly deserve specific status, a re-evaluation of the characters pointed in the literature as diagnostic of C. multiventris and C. cochranae does not support their recognition as valid distinct taxa. Additionally, our analysis of the scutellation pattern, continuous characters, and hemipenial morphology of 34 specimens, and of the available data in literature, shows that there are no significant differences between them. We therefore suggest that C. cochranae should be synonymized with C. multiventris. © 2010 by the Herpetologists' League, Inc. Source

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