File:Evolution-of-a-Novel-Muscle-Design-in-Sea-Urchins-(Echinodermata-Echinoidea)-pone.0037520.g003.jpg

English: (A, I) Volume-rendered models of the lantern based on μCT datasets with 27 µm isotropic voxel resolution. The boxes indicate the areas shown in C, D and K, L. (B, J) Virtual horizontal section through MRI datasets with 78×78×500 µm resolution showing the flat and frilled protractor muscles prior to their insertion on the epiphysis. (C, D, K, L) SEM micrographs of the muscle scars created by flat and frilled protractor muscles on the epiphysis and upper pyramid. The dotted lines indicate the outline of the protractor muscle. (K, L, E, M) Volume-rendered models of lantern and perignathic girdle based on μCT datasets with 27 µm isotropic voxel resolution. The boxes indicate the location of the interambulacral insertion site of the protractor muscle on the perignathic girdle. (F, N) Virtual horizontal section through MRI datasets with 78×78×500 µm resolution showing the protractor muscles prior to their insertion on the perignathic girdle. (G, H, O, P) SEM micrograph of the muscle scars created by flat and frilled protractor muscles on the perignathic girdle. The dotted lines indicate the outline of the protractor muscle. au = auricle, bn = buccal notch, ep = epiphysis, lo = lobe, pg = perignathic girdle, pr = protractor muscle, py = pyramid, to = tooth, ts = tooth support.