Shifts in stability and control effectiveness during evolution of the Paraves support aerial maneuvering hypotheses for flight origin

The capacity for aerial maneuvering shaped the evolution of flying animals. Here we evaluate consequences of paravian morphology for aerial performance [1, 2] by quantifying static stability and control effectiveness of physical models [3] for numerous taxa sampled from within the lineage leading to birds (Paraves, [4, 5]). Results of aerodynamic testing are mapped phylogenetically [6, 7, 8, 9, 10] to examine how maneuvering characteristics correlate with tail shortening, foreand hindwing elaboration, and other morphological features. In the evolution of the Paraves we observe shifts from static stability to inherently unstable aerial planforms; control effectiveness also migrated from tails to the forewings. These shifts suggest that some degree of aerodynamic control and and capacity for maneuvering preceded the evolution of strong power stroke. The timing of shifts suggests features normally considered in light of development of a power stroke also play important roles in control.