EVOLUTION OF HYPSODONTY IN A CRICETID (RODENTIA) LINEAGE: PRELIMINARY RESULTS USING PATCH ANALYSIS

The development of hypsodonty in the Cricetulodon hartenbergeri – Cricetulodon sabadellensis- Rotundomys montisro-tundi – Rotundomys bressanus lineage is studied using patch analysis. The lower second molar of a sample of each species is scanned using a 3D laser scanner. Then, the scans are processed with GIS software which provides orientation maps of the slopes of the occlusal surface. Contiguous points with the same orientation are grouped into a ‘patch ’ that represents a functional structure of the molar crown, so the number of patches relates to dental complexity. This parameter is found to decrease in the lineage coupled with increased crown height. This is interpreted as a result of the evolution of crown planation and loss of cusp interlocking in Rotundomys