(1) The basis for the confusion arises from the visible suture between somites 4 and 5, which suggests that the fusion is not complete.(2) If male abdomina are preserved, the fusion of the somites is also diagnostic; pseudoziids exhibit no fusion of somites while carpiliids have somites 3-5 fused.(3) The neural tube of the body tends to segment in an orderly way along the boundaries between somites .(4) The trunk section, the perion, consists of the remainder of the typical thoracic somites .(5) This takes the vertebrate embryo up to the stage at which it has become recognizably vertebrate, with somites , notochord, and neural tube.
