Figure 1

Lung plates of fossil and extant coelacanths. (a) Mirrored image of Axelrodichthys araripensis (KMNH VP 100,328), Lower Cretaceous of the Santana Formation, Araripe Basin, Brazil (Photo: Y. Yabumoto). (b) Transverse ground cross-thin section of an uncrushed lung of Axelrodichthys araripensis (‘Josa collection’); arrows indicating ossified plates and asterisk pointing to lung lumen. (c) Swenzia latimerae (Holotype, MNHN.F.JRE 47), Upper Oxfordian of Burgundy, France. Specimen in left lateral view. (d) Close-up of boxed area in (c), focusing on lung covered by ossified plates. (e) Interpretive drawing of ossified lung plates of Swenzia latimerae lung in (c) and (d). (f) 3D reconstruction of Latimeria chalumnae, left lateral view of adult specimen CCC 22 (130 cm TL). (g) Three-dimensional reconstruction of vestigial lung and bony plates of adult specimen CCC 28. (h) Isolated hard plate of Latimeria chalumnae, adult specimen CCC 24. (i) Isolated half of a hard plate of Latimeria chalumnae, adult specimen CCC 79 stained with alizarin red; asterisk 1, mineralised portion of plate stained dense pink; asterisk 2, extremity of plate, corresponding to non-mineralised region. Green, fatty organ; pink, ossified plates; red dashed line, outline of calcified lung; red, lung; yellow, oesophagus and stomach. Scale bars, 5 cm (a,c) 1 cm (b,d,e,g) 10 cm (f) 0.25 cm (h) 0.05 cm (i).