Fig. 4 in Growth and life habits of the Triassic cynodont Trirachodon, inferred from bone histology

Fig. 4. Transverse sections showing the bone histology of the Trirachodon scapula and rib. A. Scapula (SAM−PK−K5881g) where a LAG (arrowhead) is observed at the sub−periosteal surface. Moderately vascularized fibrolamellar bone becomes less vascularized towards the periphery. B. Rib (SAM−PK−K5881d) with abundant longitudinally oriented primary and secondary osteons scattered throughout the cortex (arrows). Arrowhead indicates the double LAG near the periphery. MC refers to medullary cavity. Scale bars 125 µm.