The APC is a feature located on the epitheca of many marine, armoured (thecated) dinokont species. It includes an apical pore plate (Po), which bears an apical pore (ap), and often times, small periferal pores. The apical pore can be elevated on a horn. The pore is not always a round or oval hole, it can be long and narrow and/or curved, or even fishhook shaped. If the pore is a hole, then it may have a closing/cover plate (cp) or canopy. In addition, there can be a ventral apical plate or canal plate (X plate). The X plate is always posterior and ventral to the pore plate (Steidinger and Tangen, 1996).

Alternative form for apical pore complex : APC.