Head musculature of Sphaeromimus kalambatritra. A, B, D–G micro-CT images C 3D segmentation. A Arrangement of mandible, tentorium and head capsule, frontal section B Incisura lateralis in detail, frontal section C 3D segmentation of the isolated tentorium and its muscles, medial view D, E Muscles of the epipharyngeal bar, fronto-medial view F Muscles of the posterior process, frontal section G Muscles of the nebententorium, frontal section. Top is frontal, left is lateral. Scale bars: A, D 1000 µm B, E–G 500 µm C not to scale. Abbreviations: a1 = lateral antennal muscle (m.); a2 = anterior antennal m.; at1 = first antennomere; co = condyle of mandibular gnathal lobe; eb = epipharyngeal bar; et = external tooth of mandible, g1 = lamella lingualis m.; g2 = lamello-mentum m.; aut = mandibular gnathal lobe sclerite (außententorium); hb = hypophayrangeal bar; hc = head capsule; il = incisura lateralis; ilp = projection arising from incisura lateralis; it = internal tooth of mandible; lab = labrum; ll = lamella lingualis of gnathochilarium; lm = lamello-mentum; mdb = mandibular base; mdg = mandibular gnathal lobe; mp = molar plate; nt = nebententorium; p1 = pharyngeal dilator m.; ph = pharynx; pl = pectinate lamellae of mandible; pp = posterior process; st = stipes of gnathochilarium; t1 = anterior tentorial m.; t2 = dorsal tentorial m.; t3 = posterior tentorial m.