Schematic drawing of musculotendinous system (MTS) of different body regions in Polymetme sp. (MNHN 1997 830, 160 mm SL). (a) Myoseptum of V15 at 0,43L. DAC/VAC present. ECT, ENTB and EPTB present. (b) Myoseptum of V23 at 0,59L. LTs extending from anterior into posterior cones. ECT, ENTB and EPTB present. (c) Myoseptum of V30 at 0,73L. LTs extending from the anterior into posterior cones. ENT and EPT present. (d) Tendons that insert on caudal‐fin rays and represent LTs of V38–V41. (e) Overview of different body regions and their MTS. Abbreviations: DAC, dorsal anterior cone; DPC, dorsal posterior cone; ECT, epicentral tendon; ENT, epineural tendon; ENTB, epineural tendon bone; EPT, epipleural tendon; EPTB, epipleural tendon bone; F.NL, foramen for the nervus lateralis; HM, horizontal midline; LT, lateral tendon; MT, myorhabdoid tendon; RMTs, tendons within red muscle bundles; VAC, ventral anterior cone; VPC, ventral posterior cone