Morphological and ultrastructural analysis of the teeth of guaiquica (Gracilinanus microtarsus, Wagner, 1842)

Abstract

Introduction: The guaiquica (Gracilinanus microtarsus) is an omnivorous-frugivorous marsupial, which belongs to family Didelphidae and subfamily Didelphinae. By feeding on small fruits, it is a species of considerable ecological importance in seed dispersal of some plants. The teeth are calcified and have adapted anatomical structures, which exhibit morphological variation among vertebrates. They are important for the systematic and sometimes represent the only traces of extinct species, and may also assist the phylogenetic reconstruction of these species. Objective: In order to establish morphological patterns of the teeth of G. microtarsus, the establishment of dental formula of the species was performed. Materials and methods: We used macroscopic analysis, microstructural analysis by light microscopy and ultrastructural analysis by scanning electron microscopy in five G. microtarsus adults (n= 3 males and n= 2 females) were performed. Results and conclusion: We conclude that the dental formula of G. microtarsus (2× I 5/4 C1/1 P 3/3 M 4/4), totaling 50 teeth is similar to that described in opossum (Didelphis sp.). The teeth are classified as thecodont and bunodont and microscopic morphology of teeth is also similar to Didelphis sp. and other species that have braquidonts teeth.