part of overlaps develops from start stage end stage metapterygoid TAO:0000240 zebrafish_anatomy ZFA:0000240 The metapterygoid is a posterior bone that ossifies in the cartilaginous palatoquadrate arch. It first appears as a rod of bone with an anterodorsally projecting process from the middle of the dorsal surface (6.4 mm). The adult metapterygoid is roughly rectangular in shape with rounded corners and an anterodorsally projecting spine that meets the entopterygoid medially in a synostosis at its posteromedial edge. The posterior end curves dorsally to form the posteroventral surface of the orbit. metapterygoids palatoquadrate arch endochondral bone hyomandibula-metapterygoid joint quadrate-metapterygoid joint palate pterygoid process larval:days 14-20 adult