Fig. 7 in The osteoderm microstructure in doswelliids and proterochampsids and its implications for palaeobiology of stem archosaurs

Fig. 7. Histology of proterochampsid Chanaresuchus bonapartei Romer, 1971, PULR 07 osteoderm from La Rioja province, Ladinian–Carnian. A. Complete longitudinal section view. Note the poorly vascularization. Red line indicates separation between the complete osteoderm and the rest of another. B, C. Detail of basal cortex. It is constituted in the outermost cortex by parallel-fibered bone and toward the interior of osteoderm, it acquires the features of woven-fibered bone. Multiple growth marks and some Sharpey fibers are observed. D, E. View of the upper portion of osteoderm. The abundance of Sharpey fibers prevents clear observance of the bone matrix, which appears to be parallel-fibered bone. Some LAGs can be tracked also. F. Detail of the marginal region. It is formed in its outer region by lamellar bone and in the perimedular portion by woven-fibered bone. Large and dense bundles of Sharpey fibers are observed. Some LAGs are also present. Arrowheads point to growth marks (LAGs). A, B, D, F, normal light; C, E, cross-polarized light with lambda compensator. Abbreviations: PFB, parallel-fibered bone; Shf, Sharpey fibers; svc, simple vascular canal; WFB, woven-fibered bone.