If Pets Had Thumbs Day is celebrated on March 3rd of each year. The staff at National Whatever Day was not able to locate the origin of If Pets Had Thumbs Day.
The thumb is the first digit of the hand. When a person is standing in the medical anatomical position (where the palm is stretched forward), the thumb is the lateral-most digit. The Medical Latin English adjective for thumb is pollical.
The opposable thumb has helped the human species develop more accurate fine motor skills. It is also thought to have directly led to the development of tools, not just in humans or their evolutionary ancestors, but other primates as well. The opposable thumb ensured that important human functions such as writing were possible. The thumb, in conjunction with the other fingers, makes human hands and those of other species with similar hands some of the most dexterous in the world.
Opposable thumbs are shared by many primates, including most simians, and some prosimians. The climbing and suspensory behaviour in orthograde apes, such as chimpanzees, has resulted in elongated hands while the thumb has remained short. As a result, these primates are unable to perform the pad-to-pad grip associated with opposability. However, in pronograde monkeys such as baboons, an adaptation to a terrestrial lifestyle has led to reduced digit length and thus hand proportions similar to those of humans. Consequently, these primates have dexterous hands and are able to grasp object using a pad-to-pad grip. It can thus be difficult to identify hand adaptations to manipulation-related tasks based solely on thumb proportions.