Morphology of the otic ganglion in some Arvicolidae

Abstract

The variability in the mandible dimensions has been investigated in bats of the genus Plecotus Geoffroy, 1818 from Central Europe. The material consisted of 100 individuals of P. auritus and 100 individuals of P. austriacus. The variability in the mandible length appeared to be relatively low in both species (Cv = 3.41-3.99), whereas that in the height of the ramus mandibulae was slightly higher (Cu = 4.93-8.62). For both species the common values of the measurements of the mandible length are found in 10.8-11.0 mm classes, which contain 4 per cent of P. auritus and 18 per cent of P. austriacus. As to the height of the ramus mandibulae, the common range for both species falls to the 3.2 mm class (3 per cent of P. auritus and 4 per cent of P. austriacus). A complete separation of both species can be done by simultaneous comparison of two dimensions using the diagram of their correlation considering morphological characteristics of the mandible. This method may find practical application in indentifying fossil materials or those in owl pellets.