The skeleton and the mineralized tissues of the living coelacanths

Abstract

The present overview of the histological studies on Latimeria mineralized tissues, since the discovery of the first living coelacanth in 1938, allows some anatomical and evolutionary considerations. It enlightens: i) a drastic reduction of cartilage to bone transformation processes during evolution; ii) the persistence of large volume of cartilage in the endoskeleton at adult stage; iii) the bony nature of the plates that surround the lung diverticle; iv) the presence of a developed process of spheritic mineralization in various skeletal organs: in teeth, in odontodes of the tegumentary skeleton (scales, fin rays), in scales at the interface between the external layer and the basal plate, as well as in lung bony plates.