Size and shape variability in the skull of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from two geographic areas in Brazil

Brazilian Journal of Biology

R. Bornholdt²  Lr. Oliveira¹  Me. Fabián² 

[1] ,Universidade Federal do Rio Grande do Sul Instituto de Biociências Departamento de ZoologiaPorto Alegre RS ,Brazil

关键词: Chiroptera;    Myotis nigricans;    skull morphology;    geometric morphometrics;    Chiroptera;    Myotis nigricans;    morfologia craniana;    morfometria geométrica;   

DOI  :  10.1590/S1519-69842008000300021

来源: SciELO

【 摘 要 】

We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz, 1821) assessed by geometric morphometrics. Differences in size and shape of skulls were investigated using 30 landmarks plotted on two-dimensional images of lateral and ventral views. Results of geometric morphometrics revealed sexual dimorphism in the centroid size of the skull in both views. Females were larger than males. Nevertheless, there was no sexual dimorphism in skull shape of M. nigricans. Geographic variation was detected in size and shape of the skull. South Brazilian specimens were significantly larger than Ceará specimens only in the lateral view. Differences in skull shape were statistically significant in both views: specimens from South Brazil were brevirostri and presented a more expanded skull in the posterior region while Ceará specimens were longirostri and do not present any expansion in the brain case. Ecological factors for these phenomena are discussed in the text.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License