Rotation of Embryo in Eggs of Petaluridae, Gomphidae, and Corduliidae, in Connection with Types of Oviposition, Egg Shape and Germ Band (Odonata, Anisoptera) :
In gomphid Sieboldius albardae, Davidius nanus and corduliid Somatochlora viridiaenea atrovirens, the eggs are ellipsoidal like those of Libellulidae, and the embryos exclusively show a gravity-dependent rotation to take a venter-up position just after revolution quite similarly to libellulid embryos. The same is true for petalurid Tanypteryx pryeri, and their shape is ellipsoidal. Thus in the ellipsoidal eggs the gravity-dependent rotation takes place without reference to systematic positions. Aeshnid Aeshna juncea and Gynacantha japonica embryos never rotate during development like A. nigroflava embryo.
昆蟲 58(3), 447-463, 1990