92 



AUometrical sex comparison 



As already mentioned tliis comparison can only be performed by random samples of those 

 genera comprising many specimens available. In tab. 11 "upper tooth row" (as a regression 

 to the volume measure SIZE) shows for the three genera Anoiira, Glossophciga and 

 Lonchophylla that no sex difference could be secured at all. 

 Instead, there were differerences calculated in position and/or gradient m 



- Anoiira: Molar width of the palate (p<0.05/p<0.05); width of brain case (p<0.05/n.s.); 

 mandible length (p<0.05/n.s.) 



- Choeronisciis: Molar width of the palate (p<0.05/p<0.05); width over canini 

 (p<0.05/p<0.05) 



- Glossophaga: Coronoid height (p<0.05/n.s.) 



- Lonchophylla: Mandible length (p<0.05/n.s.) 



These arithmetical differences refer to random samples of genera comprising many 

 individuals - unfortunately, samples of some species are represented by one sex only, for 

 example mAnoura brevirostrum (females only). Tlius, by means of the material available, 

 no statements can be made on sex-related differences iii the studied allometrics. 



Allometric conclusions 



All this considered, my data give evidence of the following: 



In the nectarivorous bats studied here, the proportions of the visceral skull compared to 

 the braincase do not all follow the same allometrics. Five rostrum-related skull measures 

 of the viscerocranium compared to the proportions of the calculated neurocranium 

 volimies, give evidence of different construction principles. 



In relative temiinal rostal width - measured at the distance of the upper canine teeth - all 

 nectarivorous genera show narrower rostra compared to the genera of the outgroups. The 

 palate surfaces of the Glossophaginae are more {Choeronisciis, Hylonycteris) or less 

 {Glossophaga, Monophylhis) rectangular; in Lionycteris, Lonchophylla but also in 

 Platalina the geometry of palate surface tends to be trapezoid. Referring to their allome- 

 tric gradient only the Lonchophyllmae differ from the outgroup genera. 

 Tliree measures (length of the palate, upper tootli row, mandible length) represent rostrum 

 length to a considerable extent. Allometric analysis of all tliree parameters in proportion 

 to the volume quantity SIZE does not reveal any difference of the Brachyphyllinae 

 {Brae hyphy IIa) and Phyllonycteriiiae {Erophylla, Phyllonycteris) - classified as basic 

 groups compared to the outgroup {Carollia, Phyllostomus). Comparing the upper tooth 

 row to SIZE and of the mandible length to SIZE, the genera of the Lonchophyllinae 

 {Lionycteris, Lonchophylla, Platalina) and Glossophaginae {Anoura, Choeroniscus, 

 Choeronycteris, Glossophaga, Hylonycteris, Leptonycteris, Lichonycteris, Monophyllus, 

 Musonycteris) do differ significantly from the outgroup, but they do not differ among each 

 other. There is a remarkably precise correspondence of the measures taken m Platalina 

 with the allometrics calculated for Lonchophylla. 



A clear difference between the genera Choeronisciis, Choeronycteris and Hylonycteris 

 towards the remaining Glossophaginae was revealed by allometric comparison of palate 

 length to the SIZE measure. Tlie allometric regression line (reduced elliptic major axis) 

 shows a transposition (towards a relativly longer palate at equal size), revealing principle 

 differences m skull morphology. 



