FIG. 5. Didelphis virginiana TMM M-2517 in Transverse Canal Foramen And Pericarotid Venous Network In Metatheria And Other Mammals

FIG. 5. Didelphis virginiana TMM M-2517 (Didelphidae, Didelphimorphia), adult caudal cranium, selected coronal (A–H) and parasagittal (I–K) segments (data source, table 2). In A and B, note junction of rostral branches of transverse canals, communicating with but not enveloped by transverse basicranial sinus. Boundary between transverse basisphenoid sinus and regular diploe is gradational. In B–D, craniopharyngeal canal, of uncertain function, connects transverse canal junction with hypophyseal infundibular sulcus (see also I). In E, true caudal branches of transverse canals are absent; only short interstitial canaliculi represented. In J and K, pneumatized areas (possible additional sites of hematopoiesis) also seen in basioccipital and presphenoid). Key: AS, alisphenoid; BO, basioccipital; BS, basisphenoid; cc, carotid canal; cpc, craniopharyngeal canal; cpf, craniopharyngeal foramen; crp, cribriform plate; ctbs, caudal portion of transverse basisphenoid sinus; el, ethmoid labyrinth; encf, endocranial carotid foramen; encg, endocranial carotid groove; excf, exocranial carotid foramen; fm, foramen magnum; FR, frontal; his, hypophyseal infundibular sulcus; hpf, hypophyseal fossa; isc, interstitial canaliculus; junc, junction of transverse canals; junc + rtbs, combined junction and rostral transverse basisphenoid sinus; le, lateral extension of transverse basisphenoid