Figure 1. Locations of traditional morphometric measurements on beaded and smooth vibrissae.

A ringed seal (top) and California sea lion (bottom) vibrissa are shown with locations of three traditional morphometric measurements (peak-to-peak distance, crest width and trough width) indicated by the black arrows. The measurements are labeled by the text between the two vibrissae. Peak-to-peak distance is not in reference to any physical structures on smooth vibrissae; it is simply the distance between successive measurements of vibrissal width.