Solenodon paradoxus (ZIUT)

ASHER, ROBERT J., 2001, Cranial Anatomy in Tenrecid Insectivorans: Character Evolution Across Competing Phylogenies, American Museum Novitates 3352, pp. 1-55 : 39

Solenodon paradoxus (ZIUT)

Despite the enormous length of the Solenodon anterior nose, the vomeronasal organ is not elaborate. The vomeronasal organ is in fact quite small, failing to extend farther posteriorly than the row of upper incisors. Unfortunately, the available Solenodon specimen is only partially sectioned through the midrostrum, leaving no means of precisely inferring the nasal capsule or head length in this specimen. However, it is likely that the vomeronasal organ of Solenodon comprises a very small percentage of nasal capsule and head length, given the great size of the latter two structures in this genus. No major blood vessels are evident coursing adjacent to the vomeronasal organ.

The paraseptal cartilages are relatively small J­shaped structures that, as in most oth­ er mammals described here, course medially along most of the length of the vomeronasal organ (e.g., slice 110.3.1). At its anterior end, Solenodon shows a small outer bar which does not enclose the vomeronasal organ laterally, but ends in a free process. At the anterior margin of the vomeronasal organ, the vomeronasal duct opens ventrally, medial to the inferior septal ridge, and empties directly into the nasal fossa (slice 100.3.1; fig. 34) anterior to the superior margin of the nasopalatine duct (slice 106.3.2). Unlike other animals described here, and like some ‘‘archaeorhinate’’ taxa described by Broom (1897), the nasopalatine and vomeronasal ducts do not directly communicate (see also Menzel, 1979; Hofer, 1982b). However, Solenodon differs from Broom’s ‘‘archaeorhinates’’ in possessing cartilaginous support for the nasopalatine duct. A connection is evident between the inferior arm of the paraseptal cartilage and the cartilage supporting the nasopalatine duct (slice 101.2.1; fig. 25). The latter cartilage is present at the superior margin of the nasopalatine duct, and extends lateral to the duct to the lateral rim of the bony incisive foramina. The nasopalatine ducts run posteroinferiorly to empty into the oral cavity adjacent to the palatine papilla (slice 108.2.2).

The relatively tiny medial arm of the paraseptal cartilage has no connection with the anterior transverse lamina, which lies far anterior to the vomeronasal organ and its cartilages. Although the nasal septum and floor are continuous throughout most of the elongate external nose of Solenodon , the connection between the nasal floor and sidewall is never complete, as Solenodon shows an anteroposteriorly running suture between nasal floor and roof adjacent to the nasolacrimal duct.

The superior alar processes of Solenodon are relatively small, consisting of an extend­ ed nasal sidewall that ends freely, with no connection to the anterior nasal cupula (e.g., slice 11.1.3).