Virtual Cranial Reconstruction of the Endemic Gigantic Dormouse Leithia melitensis (Rodentia, Gliridae) from Poggio Schinaldo, Sicily

Abstract

The endemic dormouse Leithia melitensis from the Pleistocene of Sicily is considered an insular giant, whose body size is exceptionally large in comparison to that of any extant dormouse species. However, knowledge of the skull morphology of this giant glirid species is limited as cranial material is rare and mostly fragmentary. A fossil conglomerate representing a cave floor segment from Poggio Schinaldo, Sicily, presented an exceptional opportunity to reconstruct the cranium of Leithia melitensis. Following microCT scanning, five partial crania were digitally extracted from the conglomerate. A composite skull of the partial crania was then reconstructed with the use of merging and warping techniques, resulting in the best approximation to the complete skull morphology of this species thus far. All major structures except for the nasal bone are present in the composite model, indicating very robust morphology, especially in the zygomatic area and the pterygoid flange. This model could potentially be very important for our understanding of the morphology and ecology of this gigantic dormouse, as well as for providing valuable data for understanding the phenomenon of insular gigantism more generally.