Figure 6 in The lungs of extinct and extant coelacanths: a morphological and histological review

Figure 6. – †Axelrodichthys araripensis from the Cretaceous of Brazil ("Josa collection"; specimen deposited at the MNHN, Paris). Sections of bony plates of the lung. A: Section of a bony plate showing the central artefactual fracture (black arrowheads), as on Latimeria plates (see Fig. 4A). B: Detail of a section of a bony plate showing the artefactual fracture (black arrowheads) and the Liesegang lines (black arrows) indi- cating a spheritic mineralization process. C: Section of a bony plate showing the histological organization with regu- lar collagenous layers and osteocytes with canalicles crossing the extracellular matrix. D: Horizontal ground section of a bony plate showing numerous star-shape osteocytes with cytoplasmic processes. Inset: detail of an osteocyte with its ramified canalicles. E: Ground section showing some large vascular cavities (white asterisks). F: Cross- ground section of a bony plate showing Liesegang lines (black arrowheads) and some mineralized spherules (black arrows). G: Horizontal ground section of a bony plate showing an osteocyte with its cytoplasmic processes (on the left, black arrow) and some mineralized spherules (on the right). Scale bars: A = 100 μm; B, C = 25 μm; D, F = 20 μm; inset D, E, G = 10 μm. Deposited at the Laboratoire de Paléontologie, MNHN, Paris.