FIGURE 5. Occlusal view of upper second molars (M2) representing the different morphotypes observed in the Fiene Arvicolini sample. Left M2 (VP-13799) exhibiting 'Normal' condition (1). Right M2 (VP-16948) exhibiting incipient posterolingual dentine field (pdf; 2). Right M2 (VP-16953) exhibiting intermediate pdf (3). Left M2 (VP-13794) exhibiting well-developed pdf (4). Left M2 (VP-16911) exhibiting closed pdf (5). Right M2 (VP-16958) exhibiting an intermediate pdf and an anomalous dentine field on T2 (6).