The femur of "Protoavis" is astonishingly similar to non-tetanurans, namely coelophysoids. The proximal femur displays a trochanteric shelf caudal to the lesser and greater trochanters, a feature distinguishing non-tetanurans theropods from Tetanurae. Further similarities between the proximal humerus of "Protoavis" and that of non-tetanuran theropods are found in the shared presence of an enlarged obturator ridge, whose morphology in "Protoavis" is again, uncannily like that observed in robust basal theropods, e.g., ""Syntarus" kayentakatae". The resemblance between the femur of "Protoavis" and that of a non-tetanuran theropod becomes ever more pronounced at the distal end of the bone. Both share a crista tibiofibularis groove, a feature of a non-tetanuran theropod separating the medial and lateral condyles.