Sure Longisquama had giant plumes
that likely entranced the lay-dees… and/or the gents…
But as the proximal outgroup to the Pterosauria,
and provided with a similar pectoral girdle (sternal complex, strap-like scapulae, quadrant-shaped coracoids, it was a likely flapper, as we talked about earlier here with similar traits in Cosesaurus (Fig. 1)
With these traits and behaviors basal fenestrasaurs converged with theropods ancestral to birds. In these ways flapping preceded powered flight, in both cases co-opted from secondary sexual behaviors in these highly visual reptiles.