Boxplot of distal phalanx distal shaft width scaled to total phalanx length.

Raw values of shaft width taken at ¾ of the length of the shaft (SW-3/4) are divided by total phalanx length (TPL). SW-3/4 and TPL are demonstrated using illustrations of specimens scaled to the same length. The median specimen from each extant group is illustrated: Tupaia glis represents the falculae group; Callithrix sp., tegulae; Galago senegalensis, grooming claws; and Saimiri sp., ungulae. See Materials and Methods for measurement descriptions.