Figure 1 in Air sac attachments or tendon scars: the distinction between soft tissue traces in archosaur bone

Figure 1. Lamellar bone fibres in an anhanguerid pterosaur ulna (DGEO-CTG-UFPE 7516; A-F) and in a spinosaurine theropod tibia (LPP-PV-0042; G-L). Note that these fibres are only visible at high magnifications (100×; arrowheads). Silhouettes in A and G indicate sampled elements (not to scale; art by Felipe A. Elias). All polarized light. Crossed nicols in A-E and G-L. Parallel nicols in F. Compensator in A-D, G-I and L. The relative angle to the cortical surface is approximately 80° in A, B; 340° in C; 290° in D-F; 120° in G-L. Scale bar in A, H = 250 µm; in B, I = 50 µm; G = 500 µm; in C-F, J-L = 10 µm.