Fig. 1 in Function and evolution of ankylosaur dermal armor

Fig. 1. An osteoderm from the polacanthid Gastonia (DMNH 49754−1) from the Lower Cretaceous Cedar Mountain Formation of Utah. A. Photograph of the external surface of the specimen. B. Thin−section, cut along plane indicated by dashed line in A. The thin−section was cut parallel to the ridge of the osteoderm; photograph (B1) and interpretive drawing (B2). The cortex completely surrounds the inner cancellous bone: dark gray, cortical bone consisting of woven or structural fiber bone; white, cancellous bone built up of bone trabeculae which show primary bone tissue in most parts. C, D. Cortical bone tissue of the osteoderm. Detail of the cortex and inner trabecular bone in normal (C) and polarized light (D); external surface is to the top. Many structural fiber bundles occur within the cortex.