FIGURE 7 in Bone histology reveals the first record of titanosaur (Dinosauria: Sauropoda) from the Late Cretaceous of Bulgaria

FIGURE 7. Osteohistology of specimen NMNHS FR-16, a putative titanosaurian long bone fragment, in transmitted cross-polarized light. Arrow in the lower right corner of each image indicates the direction of the periosteum. 1, Heavily remodeled outer cortex with anisotropic primary bone tissues preserved as interstices between secondary osteons; 2, Same area with preserved primary cortex as 1, but at higher magnification. Primary osteons appear to be longitudinal; 3, Dense Haversian bone with 4 generations of secondary osteons in the outer third of the cortex. Abbreviations: po–primary osteon; so–secondary osteon; wpc–woven-parallel complex. Scale bar equals 1–200 µm; 2-3 –100 µm.