International Journal of Morphology
versión On-line ISSN 0717-9502
VALENZUELA, Carlos, Y; BERRIOS-LOYOLA, R y CANALS, M. The First Metacarpal is the Thumb First Phalange: EvoDevo Implications. Int. J. Morphol. [online]. 2009, vol.27, n.4, pp.985-988. ISSN 0717-9502. http://dx.doi.org/10.4067/S0717-95022009000400004.
We examined the status of the first metacarpal bone whose shape, fetal and post-natal development correspond to those of the thumb proximal phalanx. Galen already described this, circa 170 CE. Our radiographic data confirm that the pre-axial (radial or anterior) side of the hand matures, later than the post-axial (ulnar or posterior) side, both, pre- and post-natally. A new perspective on thumb primate and human ontogeny is discussed and comparative observations on the Evolutionary Development (EvoDevo) of the thumb and the first toe are proposed along with a nomenclature honoring Galen's original proposition.
Palabras clave : Bone maturity; Thumb EvoDevo; First metacarpal; Thumb's first phalanx.