FIG. 27. Astrapotherium magnum, selected basicranial features. A in Cranial Morphology And Phylogenetic Relationships Of Trigonostylops Wortmani, An Eocene South American Native Ungulate

FIG. 27. Astrapotherium magnum, selected basicranial features. A, AMNH VP-9278, right basicranium in ventral aspect. Prominent impression labelled "?vasc sulc" may have conducted extracranial venous structures similar to basicranial plexuses seen in extant Equus (fig. 6; see also similarly positioned sulcus in Tapirus, fig. 38: feature 5). Basicapsular fenestra is hidden in this perspective, except for extreme rostral and caudal ends. B, Digitally reconstructed left petrosal of A . magnum MACN A 3208, reversed and rotated to permit com-Published 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 92, DOI: 10.1206/0003-0090.449.1.1, http://zenodo.org/record/541502