Kippenhahn diagrams displaying the structural evolution in lagrangian coordinates. Pop III models are presented with 60 M_⊙, and with an initial rotation of 40% (by Murphy et al. 2021, top panel) and 70% (by Tsiatsiou et al. 2024, bottom panel) of the critical rotation velocity. The last evolutionary stage for both models is the end of the core He-burning phase. The blue regions are convective zones, while the white ones are radiative. The black lines are iso-radius lines (in units of solar radius, R_⊙). The blue and green lines show the mass coordinates where hydrogen and helium are burning, respectively. The solid lines indicate the peak of the energy generation rate, and the dashed ones delimit 10% of the peak energy generation rate for each burning phase.