75 



a 



Glossophaga Monophyllus Lichonycteris Scleronycteris Hylonycteris Musonycieris 

 commissarisi redmani obscura ega underwoodi harrisoni 



Lionycteris Lonchophylla Platalina 



spurelli handleyi genovensium 



Fig. 55: Incisivi within Glossophaginae (a) and Lonchophyllinae (b) 



Dentition 



Incisivi (fig. 55) 



The incisors are rudimentary or in some genera the lower ones are lacking completely 

 ("tongue guiding chamiel"). Comparatively primitive genera with a short rostrum 

 {Glossophaga, Lionycteris) still have two pairs of incisors in the upper and lower jaw. 

 In the Lonchophyllinae, the inner upper incisivi are clearly larger than the outer ones. This 

 corresponds to the configuration which apperars to be primitive for the entire group. Both, 

 the Phyllostominae and the CaroUiinae as outgroups, show this pattern of incisivi in the 

 upper jaw. 



Within the Glossophaginae, however, this condition remained merely in two Glossophaga 

 species, as all other species and genera developed quite considerable modifications: 

 starting from a very uniform iiicisor pattern (e.g. Glossophaga commissarisi) the tex')th 

 pairs move apart. In Leptonycteris there is just a little median gap between the big but flat 

 inner incisors; Lichonycteris developed several gaps distributed evenly between the 

 differently formed upper incisors (the inner ones are flat, the outer ones pointed). Tliis 

 situation with the inner upper incisivi becoming distinctly smaller {Aiwiira) and addi- 

 tionally flattened (Choeroniscus, Hylonycteris, Scleronycteris, Choeronycteris) is found in 

 other genera, too. In this evolutionary trend the space for the tongue between the canine 

 teeth also in the upper jaw increases. 



Lonchophyllinae, Brachyphylhnae and Phyllonycterinae have two pairs of incisors equal 

 in size in their lower jaw. Though this plesiomorph condition is preserved in Glossophaga, 

 in Monophyllus, a closely related genus, the lower incisors have become very small and 

 moved apart, both pairs separated by a wide median gap. In Leptonycteris there is also a 

 gap between the iimer lower incisors, but the inner ones are clearly larger than the outer 

 ones. In Lichonycteris, Anoiira, Scleronycteris, Hylonycteris, Choeroniscus and Choero- 

 nycteris, the lower incisivi are completely absent, and the lower canine teeth are separated 

 from each other by a deep V-shaped groove above the mandibular symphysis (tongue 

 guiding channel). 



Canini 



Canines are distinctly developed in all genera, though they remain slim and dehcate in the 

 highly specialized nectar feeders. Thus, although the canine teeth seem quite useless for 

 nectar intake, they must have some biological value. Their fimction, however, is not 

 necessarily corresponding to foraging rather for other biological purposes like grooming 



