FIG. 29 in Cranial Morphology And Phylogenetic Relationships Of Trigonostylops Wortmani, An Eocene South American Native Ungulate

FIG. 29. Toxodon sp., selected basicranial features. A, MCL 5192 (adult), caudal cranium in ventral aspect, with undivided rostral (piriform) portion of basicapsular fenestra; B, MACN Pv 16615 (juvenile), right auditory region in ventral aspect, with divided fenestra (C, closeup of area in box in B). Key: 1, vascular sulcus crossing tympanic tympanic floor externally; 2, medial portion of rostral basicapsular fenestra, transmitting internal carotid; 3, vascular sulcus crossing entoglenoid region, presumably conducting tributaries of basicranial venous plexuses; 4, auditory bulla; 5, vascular sulcus between jugular area and hypoglossal canal,?for anastomosis between ventral petrosal sinus and condylar emissary vein; 6, squamoectotympanic suture. Van Kampen (1905: 615) reasonably assumed that feature 1, seen crossing external surface of bulla in A, was aPublished as part of MacPhee, R.D.E., Del Pino, Santiago Hernández, Kramarz, Alejandro, Forasiepi, Analía M., Bond, Mariano & Sulser, R. Benjamin, 2021, Cranial Morphology And Phylogenetic Relationships Of Trigonostylops Wortmani, An Eocene South American Native Ungulate, pp. 1-185 in Bulletin of the American Museum of Natural History 2021 (449) on page 96, DOI: 10.1206/0003-0090.449.1.1, http://zenodo.org/record/541502