Fig. 6 in Shell bone histology of solemydid turtles (stem Testudines): palaeoecological implications

Fig. 6 Thin-sections of Plastremys lata. Images in a and d are in normal transmitted, b and c in cross-polarised light. a Costal fragment (NHMUK R 2251). b Close-up of the central part of the section. Note well preserved interior bone tissue. c Close-up of the external cortex showing a clear front of bone tissue alteration (upper part of image). d Close-up of the internal cortex, consisting of parallel-fibred bone. Abbreviations: CB cancellous bone; ECO external cortex; ICO internal cortex; ISF interwoven structural fibres; LB lamellar bone; PFB parallel-fibred bone; trFB transversally sectioned fibre bundles