Fig. 4 in Osteohistology of the Early Triassic ichthyopterygian reptile Utatsusaurus hataii: Implications for early ichthyosaur biology

Fig. 4. Details of dorsal rib microstructure of the ichthyopterygian Utatsusaurus hataii Shikama, Kamei, and Murata, 1978 (Osawa Formation, Spathian; Miyagi Prefecture, Japan). A, B. NSM-VP-21865, proximal section (see Fig. 2A). C. NSM-VP-20028, mid-diaphyseal section (see Fig. 2B). D, E. NSM- VP-21865, close-up views of cell lacunae in the inner (D) and outer (E) cortices of proximal dorsal rib (see Fig. 2D). F. NSM-VP-20028, distal section (Fig. 2C). Photographed under natural light (A, C–F) and polarized light without lambda compensator (B).