Back and abdominal musculature of Xenopus laevis; both sides of M. longissimus dorsi and M. coccygeoiliacus are shown, otherwise only right side structures are depicted. Specimen shown in oblique view (A); dorsal view with ligamentous plate, M. longissimus dorsi and M. latissimus dorsi removed (B); ventral view (C); and transverse cross‐sections (D,E) shown in (A). Muscles are identified using uppercase abbreviations; non‐muscle structures are identified using lowercase abbreviations. CGI, M. coccygeoiliacus; ICI, M. intertransversarius capitis inferior; ICS, M. intertransversarius capitis superior; IL, M. iliolumbaris; ITR, M. intertransversarii; LGD, M. longissimus dorsi; lp, ligamentous plate; LTD, M. latissimus dorsi; OBE, M. obliquus externus; PEC, M. pectoralis pars abdominalis; RAP, M. rectus abdominus profundus; RAS, M. abdominus superficialis; TRA, M. transversus abdominus.