Advanced search
Start date
Betweenand


Geographical variation in morphology of the genus Micrablepharus and Vanzosaura (Squamata, Gymnophthalmidae, Gymnophthalmini) and test of biogeographic hypotheses with the use of species distribution modeling

Full text
Author(s):
Renato Sousa Recoder
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
Defense date:
Examining board members:
Miguel Trefaut Urbano Rodrigues; Taran Grant; Cristiano de Campos Nogueira
Advisor: Miguel Trefaut Urbano Rodrigues
Abstract

Vanzosaura rubricauda and Micrablepharus maximilian are two species of microteiid lizards (Gymnophthalmidae) widespread in the \"great diagonal\" of open formations in South America. Throughout their distribution, the species are subject to highly variable environmental conditions, in a region with complex geomorphological history. Therefore, represent good models for a study of geographic variation. With the use of biometry techniques and spatial analysis I studied the patterns of morphological variation in V. rubricauda and M. maximiliani. Both species showed sexual dimorphism and significant geographical variation in morphometry and scale counting. Geographic variation in V. rubricauda is consistent between the sexes and can be defined by a contrast between body elongation and length of limbs. Populations of \"Eastern Cerrado\" are distinguished by having smaller body size, shorter trunks, longer limbs and low number of smooth subcaudal scales. The color patterns are highly variable at the local level, with polymorphism in populations of the Caatinga and Chaco. In M. maximiliani geographical variation observed is less clear however, populations of the \"Western Cerrado\" are larger and possess higher scale counts, while the group \"Northeast\" present shorter trunks and proportionately larger feet. Regarding geographic patterns, the morphological heterogeneity among populations of both species in the Cerrado region is highlighted, and its differentiation from the populations of the \"Northeast\" group. The ecogeographical model that best explains the variation in V. rubricauda is aridity, due a contrast in morphology between populations of the Cerrado in relation to other regions. For M. maximiliani, temperature, seasonality and geography had greater model selection; however, the geographical pattern is affected by spatial autocorrelation. Paleodistributional models suggest that climatic fluctuations may have caused isolation of population during past climates with drier conditions than current. The degree of intraspecific differentiation in V. rubricauda suggests the need of a taxonomic reassessment for the genus. (AU)

FAPESP's process: 08/07598-0 - Morphological geographic variation in the lizards genus Vanzosaura and Micrablepharus(Squamata, Gymnophthalmidae, Gymnophthalmini) and hypothesis testing with use of potential distribution modeling.
Grantee:Renato Sousa Recoder
Support Opportunities: Scholarships in Brazil - Master