Data from: Bony labyrinth morphometry indicates locomotor adaptations in the squirrel-related clade (Rodentia, Mammalia)

The semicircular canals (SCs) of the inner ear detect angular acceleration
and are located in the bony labyrinth of the petrosal bone. Based on
high-resolution computed tomography, we created a size-independent
database of the bony labyrinth of 50 mammalian species especially rodents
of the squirrel-related clade comprising taxa with fossorial, arboreal and
gliding adaptations. Our sampling also includes gliding marsupials,
actively flying bats, the arboreal tree shrew and subterranean species.
The morphometric anatomy of the SCs was correlated to the locomotion mode.
Even if the phylogenetic signal cannot entirely be excluded, the main
significance for functional morphological studies has been found in the
diameter of the SCs, whereas the radius of curvature is of minor interest.
Additionally, we found clear differences in the bias angle of the canals
between subterranean and gliding taxa, but also between sciurids and
glirids. The sensitivity of the inner ear correlates with the locomotion
mode, with a higher sensitivity of the SCs in fossorial species than in
flying taxa. We conclude that the inner ear of flying and gliding mammals
is less sensitive due to the large information flow into this sense organ
during locomotion.