1. A robotic joint, comprising: a pitch-output roll assembly including: a housing, a differential mechanism, supported by the housing, including a left input gear, a right input gear, an output gear, a cross element interconnecting the gears, and a clevis supporting the gears and the cross element within the housing, a left four-bar linkage coupled to the left input gear, a right four-bar linkage coupled to the right input gear, and first and second linear actuators connected to the left and right four-bar linkages, respectively, selectively driving the left and right input gears to rotate the output gear about an output roll axis and to rotate the cross element about a pitch axis passing through the cross element and the input gears.