Fig. 1

Distribution of bone mineral, lipid and muscle tissue in the coelacanth. a Volume rendering of a three-dimensional bone mineral density (BMD) map of the coelacanth and three extant species of lungfishes. b,c Distribution of bone mineral content (BMC) fraction of total BMC along the total length (TL) in the coelacanth and lungfishes. The dashed gray square in b is magnified in c. d Putative time calibrated phylogeny of extant non-tetrapod sarcopterygians. e Volume rendering of a three-dimensional lipid fraction map of the coelacanth. Same color scale as in a is used for lipid fraction ranging from 0 to 100%. f,g Sagittal (f) and transversal (g) sections of lipid fraction (f and leftmost sections in g) and water fraction (rightmost sections in g). Yellow isosceles triangles point to the lipid-filled fatty organ, yellow equilateral triangle points to the lipid-filled pericerebral space, yellow arrows point to the lipid-filled post ocular space, yellow arrow head points to the lipid-filled perivertebral space, purple isosceles triangle points to the water-rich muscle, purple arrow points to the water-rich notochord. h Distribution of mass of different tissue types along the total length in the coelacanth. Here, all water-rich lean tissues are included in “muscle”