Toilet claw
A toilet claw (or grooming claw) is the specialized claw or nail on the foot of certain primates, used for personal grooming. All prosimians have a toilet claw, but the digit that is specialized in this manner varies.[1] Tarsiers have a toilet claw on toe two and toe three. With one possible exception, in the suborder Strepsirrhini, which includes lemurs, galagos and lorises, the toilet claw is on the second toe. The possible exception is the aye-aye, which has claws instead of nails on toes 2 through 5. There is some debate concerning whether any of these claws (and if so which ones) are toilet claws.[citation needed] Less commonly known, a toilet-claw is also found on the second pedal digit of owl monkeys (Aotus), titis (Callicebus), and possibly other New World monkeys.[2]
The first toe is the large one, the equivalent of a human big toe. However, in all these prosimians the foot is more or less hand-like. The first toe is opposable, like a human thumb, and the second and third toes correspond approximately to the index and middle fingers.
Like a claw or a nail, the toilet-claw is also made of keratin. It resembles a claw in both its lateral compression and longitudinal curvature. However, the tip is not as pointed, and it always stands at a steeper angle, a characteristic that also distinguishes it from a nail.[1]
[edit] Function
The toilet-claw is used in personal grooming to rake through the fur or scratch, particularly around the head and neck.[2]
[edit] References
- ^ a b Soligo, C.; Müller, A. E. (1999). "Nails and claws in primate evolution". Journal of Human Evolution 36 (1): 97–114. doi:10.1006/jhev.1998.0263. PMID 9924135.
- ^ a b Maiolino, S.; Boyer, D. M.; Rosenberger, A. (2011). "Morphological Correlates of the Grooming Claw in Distal Phalanges of Platyrrhines and Other Primates: A Preliminary Study" (PDF). The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology 294 (12): 1975. doi:10.1002/ar.21498. http://onlinelibrary.wiley.com/doi/10.1002/ar.21498/pdf.
| Wikimedia Commons has media related to: Toilet claws |
| This primate-related article is a stub. You can help Wikipedia by expanding it. |