FIG. 7 in Cranial Morphology And Phylogenetic Relationships Of Trigonostylops Wortmani, An Eocene South American Native Ungulate

FIG. 7. Homalodotherium sp. MPM PV 17490, reconstructions of brain endocast and endocranial vasculature in A, dorsal; B, right lateral; C, ventral; and D, caudal views (on this and facing page). For neural features see text. Where possible, interpretations were checked against Patterson's (1937) latex endocast of Homalodotherium segoviae FMNH P13092. Morphological divisions of inferred dural sinuses and their connectors are color-coded to aid interpretation of similarly positioned (but uncolored) structures in figures 8-10. Key: yellow, dorsal sagittal sinus and transverse sinuses, including accessory lacunae of latter; brown, vasa diploetica magna (whether both arteria and vena diploetica magna were present is not determinable); green, temporal sinus and connectors (retroarticular vein, cranioorbital sinus, parietosquamosal veins); blue, sigmoid sinus and connectors (petrosal sinuses and condylar, vertebral, and internal jugular veins). In C, red indicates apparent trackways for putative rostral cerebral and vertebral arteries. Inset, segment at level of hypoglossal canals illustrating large sulci for inferred vertebral arteries (white asterisks). In this and following vascular reconstructions, CT resolution inadequate to detect separate trackways of arteries that typically accompany veins (e.g., arteria diploetica magna in posttemporal canal; meningeal arterial branches in parietosquamosal canals; cranioorbital artery accompanying cranioorbital sinus). Left side of specimen's basicranium is damaged, which accounts for incomplete reconstruction of some vessels (e.g., sigmoid sinus). Most vessels reconstructed from shallow sulci or other indicators and sizes cannot be considered dimensionally accurate. Supposed accessory vascular tissues (yellow) in extraneural space dorsal to cerebellum require further study (see text).