S. Fig. 7.

Euperipatoides kanangrensis. Schematic illustrations of early developmental stages. (A) A single layer of cells, the blastoderm, covers the yolk. (B) The germinal disc (gd) has formed as an area with more densely packed cells. (C) The blastopore (bp) forms as an elevation of cells with a central pit (cp) within the germinal disc. (D) The elongation of the blastopore pit forms a furrow in the anterior part of the blastopore (ab) that is continuous with the posterior part of the blastopore (bp). (E) The early gastrula has started to form unsegmented mesoderm (u) lateral to the central pit. (F) A magnification of the box in (E) showing the areas of mesoderm formation (red line) and the area of endoderm formation (yellow line).