Novel insight into the origin of the growth dynamics of sauropod dinosaurs
(A) General view of the cortex, which is composed almost entirely of well vascularized primary bone tissue. Normal light. (B) General view of the cortical bone showing the predominance of parallel fibered bone in the compacta. Polarized light. (C) Enlarged view of the primary bone. Note the flattened appearance of the osteocyte lacunae and its circumferential arrangement. Normal transmitted light. (D) Primary bone tissue in which circumferential vascular canals predominate, and are often anastomosed by large radial canals. Normal transmitted light. (E) Primary bone tissue in which longitudinally oriented vascular canals predominate, with some anastomosing oblique canals. Normal transmitted light. (F, G) General view of the cortex showing a stratified pattern in the primary bone tissue caused by the presence of poorly vascularized annuli (arrowheads). Normal transmitted light. (H) Detailed view of a LAG in mid cortex. Polarized light. Abbreviations: an: annulus; cv: circumferentially oriented vascular canal; lv: longitudinally oriented vascular canal; rv: radially oriented vascular canal.