Figure 4: MGUH VP 6139, skull, shoulder girdle, thoracic and presacral region of Ichthyostega. If we are correct and the axial morphology did not permit lateral trunk flexion in Ichthyostega ...

Additionally, all three taxa resemble modern snakes in lacking a sacral region and in having a pelvis that is not suspended from the axial skeleton but rather lies within the ribcage 10.