Figure 2 : Symphysis specimen 2007.111.1(20) in transverse section showing the most extensive amount of medullary bone-like tissue among all investigated symphyses.

From: Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance

Figure 2

(a) Overview of a thin section under cross polarized light (inset aided by lambda wave plate) and (b) its posterior counterpart obtained from the same cut under single plane polarizers. The larger extent and merging of the recesses of the medullary cavity system is already evident in this slightly more posteriorly positioned symphyseal region. (c) Line drawing of (a) revealing the recesses of the medullary cavity system, the distribution of primary and secondary tissues, and the microanatomy, relative amount, and position of medullary bone-like tissue growing into the medullary cavity recesses (see also legend within the figure). (d) Close-up of the area marked by blue square in (c) under plane polarized light and (e) line drawing of the same area highlighting the microanatomy of the medullary bone-like tissue and the distribution of primary and secondary tissues as indicated by the legend. Abbreviations: Ds, dorsal symphysis surface; LAG, line of arrested growth; Ls, lateral symphysis surface; Mb, medullary bone-like tissue; Mcr, medullary cavity recess; Nf, nutritive foramen; Pb, primary bone; Vk, ventral keel.