Any of the projections on each side of the vertebra from the point where the neural arch lamina joins the pedicel for the articulation with the head of a single-headed rib or the upper head of a double-headed rib. Also called diapophyses. They provide surfaces for the attachment of muscles. In anurans, the term transverse process is used in reference to the processes associated with the presacral and postsacral vertebrae. [ AAO:0000698 ]