Fig. 9
From: Panarthropod tiptop/teashirt and spalt orthologs and their potential role as “trunk”-selector genes
Correlation of tio/tsh expression, appendage-types, and tagmosis in panarthropods and the predicted last common ancestor (LCA) of arthropods and lobopodians. The vertical black lines represent the border between the “head” carrying highly modified appendages (orange), and the “trunk” carrying walking-limb type appendages (blue and yellow). Shown is the situation as predicted for the last common ancestor (LCA), the onychophoran Euperipatoides (Ony), the chelicerate Parasteatoda (Che), the myriapod Glomeris (Myr), and the insect Drosophila (Ins). Abbreviations as in Fig. 2, and fap/an, the onychophoran frontal appendage (a functional antenna), ic intercalary limb-less segment of insects, lb labium, lr labrum, pmd premandibular limb-less segment of myriapods