Setifer setosus (Schreber, 1778)

ASHER, ROBERT J., 2001, Cranial Anatomy in Tenrecid Insectivorans: Character Evolution Across Competing Phylogenies, American Museum Novitates 3352, pp. 1-55 : 36-37

Setifer setosus (ZIUT, celloidin­embedded individual)

The vomeronasal organ of this adult Setifer specimen extends approximately 5 mm posteriorly beyond the premaxilla, to the level of the first premolars (slice 75.2.1). Unfortunately, length estimates for the nasal fossa and head of this specimen are unavailable. One particularly large blood vessel lies lateral to the vomeronasal organ along most of its length; numerous other vessels of moderate caliber are also evident scattered throughout the organ (e.g., slice 64.1.1).

The paraseptal cartilage borders the vomeronasal organ ventrally and medially throughout its length. In some sections it extends lateral to the vomeronasal organ (e.g., slice 57.2.1), but the paraseptal cartilage does not give off an outer bar that passes dorsal to the vomeronasal organ or the vomeronasal duct.

At its anterior margin the vomeronasal organ grades into the vomeronasal duct, which enters the nasopalatine duct ventral to and separate from the nasal fossa (slice 48.1.1). The nasopalatine canal of Setifer leaves the nasal fossa paired; farther ventrally, however, Setifer resembles Echinops in that the canals on each side join with each other to form a single canal that opens into the oral cavity (slice 38.1.1; see also Hofer, 1982a). A very small nasopalatine duct cartilage is evident connected with the paraseptal cartilage (e.g., 48.3.1).

Anterior to the vomeronasal organ, the paraseptal cartilage ends, showing no continuity with the anterior transverse lamina. The posterior margin of the anterior transverse lamina supports the inferior septal ridge, extending out from the nasal septum, just dorsal and anterior to the nasal openings of the nasopalatine ducts (slice 47.2.1).

Anterior to the premaxilla, the nasal floor descends relative to the roof, greatly increas­ ing the volume within the nasal cupula (compare slices 35.2.1 and 25.2.1). In this region, Setifer shows a broad continuity, or zona annularis, between the nasal septum, floor, and sidewall.

The superior alar processes are relatively narrow, showing only a short connection with the anterior nasal floor and no connection with the anterior nasal cupula. However, the alar processes do provide attachments for small muscles of the rhinarium (e.g., slice 13.2.1).