Figure 4 in Air sac attachments or tendon scars: the distinction between soft tissue traces in archosaur bone

Figure 4. Side-by-side comparison between lamellar bone fibres A, pneumosteum B and Sharpey's fibres C, all indicated by arrowheads. A, an anhanguerid pterosaur ulna (DGEO-CTG-UFPE 7516). B, a megaraptoran theropod caudal vertebra (MPMA 08-003-94). C, a dorsal vertebra of Arrudatitan (MPMA 12-0001-97-1024). Magnifier indicates microscope magnification. All polarized light and crossed nicols. Compensator in B. The relative angle to the bone surface is approximately 290° in A; 320° in B; 150° in C. Scale bar in A = 10 µm; in B = 50 µm; in C = 300 µm.