Fig. 38 in Morphology of the Braincase in the Cretaceous Hybodont Shark Tribodus limae (Chondrichthyes: Elasmobranchii), Based on CT Scanning

Fig. 38. Reconstructions of the basicranial circulation in Tribodus limae. A, ventral (external) view of the braincase showing the basicranial arterial circuit; solid lines represent vessels visible on the surface or external to the cartilage, and dashed lines represent those internal to the cartilage or endocranial space; B, dorsal cutaway (interior) view of the floor of the cranial cavity, showing the same vessels as seen from above; note the internal carotid arteries emerging from the basicranial cartilage through paired foramina in the floor of the braincase anterior to the dorsum sellae, and then diverging to form the optic artery anteriorly and the efferent pseudobranchial/ophthalmic artery posteriorly (the latter divides after exiting the braincase). Solid lines represent vessels visible on the surface of the cutaway (on the floor of the cranial cavity), and dashed lines represent vessels internal to the cartilage or ventral to the basicranium (compare with A). No scale.