Fig. 6
From: Cranial and mandibular anatomy of Plastomenus thomasii and a new time-tree of trionychid evolution
Computed tomographs through the cranium of Plastomenus thomasii (AMNH FR 6015) and frontal morphology. A–C, cropped µCT slices through the frontal (A–B) and parietal (C) region of the skull roof. D Partial cranium in dorsal view, with prefrontals removed to illustrate the anterior frontal process. Note that bones are labelled in bold. White arrows show examples of traceable suture lines, red arrow indicates region in which an interfrontal suture would have been expected if the bones were not fused. Straight lines in D indicate slice positions for (A–C). apf anterior frontal process, f fused frontals, prff prefrontal facet on frontal