The Insertion of Septa in the Later Growth Stages of Palaeosmilia murchisoni (Edwards and Haime)

AbstractIn the later growth stages of Palaeosmilia, minor septa are inserted simultaneously on both sides of each newly added major septum and they originate high up near the growing crest of this major septum. Thus, a minor septum occupies the interseptal space in which the next major septum will be inserted. The next major septum develops directly upon the axial edge of this minor septum and it originates deep down in the calyx. The similarity is pointed out between the septal insertion in Palaeosmilia and in the more typical aulophyllid (clisiophyllid) corals.