File:Arthrodire ventral shields.jpg

English: Ventral shields of arthrodires in external view. A–C, ventral shields of non-eubrachythoracid (A–B) and coccosteid (C) arthrodires, showing the absence of a posteriorly-projecting triangular process of the anterior ventrolateral plate. D–F, ventral shields of incisoscutoid (D) and aspinothoracidan (E–F), showing the prominent, posteriorly-projecting process of the anterior ventrolateral plate. G–I, ventral shield of Dunkleosteus terrelli, showing the very large process. A, Phlyctaenius acadicus (modified from Heintz, 1933); B, Bryantolepis brachycephala (modified from Denison, 1962); C, Coccosteus cuspidatus (redrawn from Miles and Westoll, 1968); D, Compagopiscis croucheri (redrawn from Gardiner and Miles, 1994); E, Heintzichthys gouldii (following Carr, 1991); F, Gymnotrachelus hydei (redrawn from Carr, 1994); G, composite juvenile, after Hussakof and Kepler (1905) and CMNH 7424 and CMNH 8982; H, CMNH 6090; I, CMNH 5768. Dashed lines represent overlap areas between plates, with grey shaded area representing the overlap between anterior and posterior ventrolateral plates. In D, G, and I, precise internal shapes were not available, so overlap is approximated.