Osteohistology of the mid-diaphyseal ulna of <i>Tenontosaurus</i> in two adults.

<p><b>A.</b> Cross-section of FMNH PR 2261. <b>B.</b> Detail of A, showing primary and secondary tissues of the mid- and outer cortex. The midcortex experiences dense secondary remodeling, and the outer cortex shows longitudinal primary osteons in parallel-fibered bone tissues grading into longitudinal simple canals in lamellar bone. Seven LAGs (arrows) are shown. <b>C.</b> Detail of OMNH 62990 (no cross-section shown), illustrating the radial arrangement of longitudinal primary osteons in an unremodeled area of the midcortex. One LAG (arrow) is shown. Periosteal surface to the top of this image. Scale bars: A = 4 mm; B,C = 1 mm.