Re: Theropod pre-avian aerial behavior

On 10/27/24 1:37 AM, Pandora wrote:

Theropod trackways as indirect evidence of pre-avian aerial behavior
 Open access:
https://www.pnas.org/doi/10.1073/pnas.2413810121
 Abstract
 Body fossils set limits on feasible reconstructions of functional capacity and behavior in theropod dinosaurs, but do not document in-life behaviors. In contrast, trace fossils such as footprints preserve in-life behaviors that can potentially test and enhance existing reconstructions. Here, we demonstrate how theropod trackways can be used as indirect evidence of pre-avian aerial behavior, expanding the approaches available to study vertebrate flight origins. This involved exploring the behavioral implications of a two-toed Cretaceous-aged theropod trackway produced by a small, bird-like microraptorine moving at high speed. Applying first principle running biomechanics, we were able to conclude that the trackway is atypical, indirectly evidencing pre-avian aerial behavior. This trackway documents the evidence of wing-assisted aerodynamic force production during locomotion, supporting a broader distribution of this behavior than currently known. These findings support previously proposed aerial behavior in early bird-like theropods, showing how trackways will help to deepen our understanding of theropod flight origins.

Is this really telling us about the origin of flight? Does a running takeoff from the ground support a ground-up origin of flight? And are the tracks really diagnostic at the subfamily level?