Morphology of the external nose in Hipposideros diadema and Lavia frons with comments on its diversity and evolution among leaf-nosed Microchiroptera.
In some bats, a noseleaf is thought to help focus echolocation calls emitted through the nostrils. I studied the ontogenetic mode of the rhinarial cartilages and the associated facial muscles to assess how these rhinarial infrastructures interact with the noseleaf, and the inferred function of such a rhinarial complex. This study focuses on developmental stages of Hipposideros diadema and Lavia frons. Based on new data on these two rhinolophoids and a review of former studies concerning rhinopomatids, rhinolophoids and phyllostomids, the functional and phylogenetic implications of the rhinarial complex among leaf-nosed Microchiroptera are evaluated by the current study. Nasal emitting forms evolved several times independently in the Microchiroptera and share various features, irrespective of their phylogenetic position: the nostrils lie dorsally; the noseleaf has a well-developed horseshoe-shaped plate; the cartilago cupularis bears a large processus cupularis; M(iv) is extended on the lateral plate of the processus alaris superior. The unique similarities of the ontogenetic process of the nasal 'resonators' support the assumption that the rhinolophids + megadermatids and rhinopomatids may represent a natural group. In some features, the rhinolophids + megadermatids differ significantly from the phyllostomids. The noseleaf has a median flap and anterior-facing pockets. The processus alaris superior is half-tube-shaped or included in the lateral wall of the cupula nasi anterior. The cartilago accessoria and the attendant musculature perform an important function for supporting and moving the noseleaf. Similar emission of the echolocation pulses but alternative constructional designs of the external nose structures suggest that a separate history of rhinolophoids and phyllostomids might account for these differences.
Göbbel
L
L
Department of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany. luminita.goebbel@medizin.uni-halle.de
D000818:Animals; D005075:Biological Evolution; D002685:Chiroptera / Q000033:anatomy & histology* / Q000145:classification / Q000196:embryology; D004455:Echolocation; D006651:Histocytochemistry; D009666:Nose / Q000033:anatomy & histology* / Q000196:embryology; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology