<Tr> <Td_colspan="2"> Anatomical terms of bone (edit on Wikidata) </Td> </Tr> <P> In human anatomy of the arm, the lateral portion of the distal articular surface of the humerus consists of a smooth, rounded eminence, named the capitulum of the humerus . In non-human tetrapods, the name capitellum is generally used, with "capitulum" limited to the anteroventral articular facet of the rib (in archosauromorphs). </P> <P> It articulates with the cupshaped depression on the head of the radius, and is limited to the front and lower part of the bone . </P> <P> Lepidosaurs show a distinct capitellum and trochlea on the centre of the ventral (anterior in upright taxa) surface of the humerus at the distal end . </P>

What portion of the radius articulates with the capitulum of the humerus