Cranial integration in the sciuridae

SYNOPSIS. High correlations among measurements of the cranium in the fox squirrel suggested to Olson and Miller (1958) that the skull in this species is highly integrated: that is, it tends to vary as a unit, and without clear subdivision into discrete independently-varying subunits. The evolutionary conservatism of the sciurid cranium, and the morphological convergence among pygmy squirrels of several distinct lineages, suggest that in the squirrel family high integration is also a feature of variation among species. A review of preliminary results of two- and three-dimensional morphometrics of the cranium, bivariate allometry of the mandible, and the anatomy of the masticatory musculature supports this suggestion, and highlights the importance of further clarifying phylogenetic relationships. Examination of embryos suggests that pygmy squirrels can not be considered strictly paedomorphic.

Duke Scholars

Author V. Louise Roth Biology