Fig. 5

Bone histology of partially fused caudal centra of Elemgasem nubilus MCF-PVPH-380. The letters in the inset boxes indicate the position of the detailed pictures in the figure. A, B Complete longitudinal (A) and sagittal (B) sections of partially fused centra. The sedimentary matrix has been digitally eroded to for better contrast. The black arrowhead signals the junction area between the centra. C Detail of the cancellous bone. D Unfused portion of the intervertebral joint showing a preserved layer of calcified cartilage in the articular surface of the centrum. Chondrocyte lacunae are detailed in the enlarged view. E Detail of the unfused portion of the intervertebral joint in the sagittal section. F Vertebral cortex formed by secondary bone tissue. G, H. General view (G) and detail (H) of the intercentral protuberance core. Note the prevalence of secondarily formed cancellous bone. I-K General views (I, J) and detail (K) of the compact bone tissue formed in the intervertebral joint area of the fused vertebral centra. Note the presence of a distinct resorption line dividing two different portions of the compact bone. L, M. Remains of subperiosteal bone showing abundant Sharpey’s fibers. Abbreviations: cl, chondrocyte lacunae; Hc, Haversian canal; icp, intercentral protuberance; its, intertrabecular space; ivs, intervertebral space; rl, resorption line; Shf, Sharpey’s fibers