NOTORYCTEMORPHIA, Kirsch in Hunsaker, 1977

MacPhee, Ross D. E., Gaillard, Charlène, Forasiepi, Analía M. & Sulser, R. Benjamin, 2023, Transverse Canal Foramen And Pericarotid Venous Network In Metatheria And Other Mammals, Bulletin of the American Museum of Natural History 2023 (462), pp. 1-125 : 55-57

NOTORYCTEMORPHIA

NOTORYCTES ( NOTORYCTIDAE ) (figs. 34, 35). The dry skull of a single adult specimen, Notoryctes typhlops AMNH M –202103, was available for study and scanning. Compared with other taxa in the comparative set, the skull of Notoryctes is rostrocaudally telescoped, with the result

OS, orbitosphenoid; ov, ophthalmic vein; PAS, parasphenoid; pbs, presphenoid-basisphenoid synchondrosis; pglv, postglenoid vein; ptcn, nerve of pterygoid canal; rbv, rostral branch vein; SQ, squamosal; tcl, transverse canal (for rostral branches); tg, trigeminal ganglion; tmc, tympanic cavity.

that the caudal end of the nasal cavity extends over part of the rostral TBS when seen in coronal section (fig. 35A–C). Archer (1976: 270) states that in Notoryctes the “transverse canal involves large mesial external foramen ovale. Transverse canal, as in many dasyurids, connects with entocarotid canals within body of basisphenoid.” In our specimen the foramen ovale and TCF are quite distinct, with no indication of internal merger (fig. 34B). Archer’s (1976) mention of a pathway connected with the carotid canal is, in other contexts, a reference to the CBTC of this paper. The carotid groove is, unusually, partly subdivided by a septum (fig. 34A, 35G: asterisk), interpreted here as a plate between separate pathways for the internal carotid neurovascular bundle and the CBTC. The short conduit leading away from the carotid groove is assumed to have carried the CBV (fig. 35F). Unfortunately, this channel cannot be traced further rostrally.

There is unquestionably a RBTC pathway in Notoryctes as well, which Archer (1976) did not separately mention. Its canal runs rostral to the hypophyseal fossa and a junction exists in the expected place, confirming its identity (fig. 35A, B). Possession of both branches constitutes a nonexclusive resemblance to Dasyurus (fig. 27). The RBTCs are fully integrated into the large rostral TBS (compound pattern, fig. 35A–E), another nonexclusive resemblance to Dasyurus . Apart from one aperture in a relatively rostral position (fig. 35D: double asterisks), there is little osteological evidence of communication between the TBS and the endocranium. The basijugular sulcus is inconspicuous and the two condylohypoglossal foramina are recessed within a joint aperture on the ventral surface of the exoccipital.