1. Department of Comparative Biomedicine and Food Science; University of Padova; Legnaro (PD) 35020 Italy
2. Museum of Natural History of Milan; Milan 20121 Italy
3. Department of Animal Medicine, Production and Health; University of Padova; Legnaro (PD) 35020 Italy
4. Civic Museum of Natural History “G; Doria,”; Genova 16121 Italy
5. Department II of Anatomy; University of Cologne; Cologne 50924 Germany