FIG. 17 in Cranial Morphology And Phylogenetic Relationships Of Trigonostylops Wortmani, An Eocene South American Native Ungulate

FIG. 17. Cochilius volvens AMNH VP-29651, transverse segments through caudal cranium in rostrocaudal sequence (on this and opposite page). Note different scales. In A, external acoustic canal bordered by epitympanic sinus, retroarticular canal. In B, closely spaced segments depict trajectory of channel (prootic canal) for lateral head vein/prootic sinus, which typically opens into tympanic cavity on margin of secondary facial foramen (asterisks). In C, asterisk marks distal part of intratympanic sulcus for