In all frogs analyzed ,the gastrocoel roof plate (grp) had a triangular shape and was detected in the dorsal lining of the primitive gut of the late gastrula and neurula ,as detected in H.Aeischmanni and E. callistomma embryos (fig.12A-F;table1.).AsinX.callistomma embryos consisted of the ventral surface of the posterior notochord and paraxial mesoderm ,and it was bordered by the lateral endodermal crests(lec), illustrated for E. callistomma(figs.12D-E). However, in a more rostral region, only the notochord was exposed to tha cavity of the primitive gut because the paraxial mesoderm was already covered by the dosing lec (Fig.12F). The major difference detected among frogs was the presence of the grp already in the late gastrula of the centrolenid frogs , as shown for E. callistomma (Fig.12D), whereas the grp developed in the neurula of X. laevis (Blum et al.2014b). The precocious onset of grp formation may relate to the overlap of neurulation and gastof the rulation in centrolenid frogs, another example of the modular nature frog gastrulation .