A biaxially extensible and retractable wheel-leg mechanism for a vehicle includes a pantograph coupling limb assembly with a plurality of coupling limbs which are coupled together in an articulated manner. A wheel hub motor and a steering actuator operatively connected thereto are arranged on a first coupling limb, and the wheel hub motor is designed to rotate a vehicle wheel drivingly connected to the wheel hub motor. The steering actuator is designed to set a steering angle of the wheel of the vehicle. The wheel-leg mechanism additionally comprises a rotary drive for positioning the coupling limb, said rotary drive being drivingly arranged on a first joint between a second coupling limb and a third coupling limb. The rotary drive is designed to set a relative angular position between the coupling limbs coupled together in an articulated manner such that the position of the wheel hub motor relative to the rotary drive can be adjusted in the longitudinal direction and/or in the vertical direction of the vehicle.