The inside of the <i>S</i>. <i>stellaris</i> egg case at stage 7.

A: Position of placoid denticles and banded patterns on the body (dorsal view). B: Fully developed eye and greater pigmentation on skin (lateral view). C: The magnified head and fully consumed yolk (ventral view). The key feature for stage 7 embryo was a fully consumed external yolk. See S7 File for original photographs of Fig 7 illustrations.