The ecology of Archaeopteryx

As the oldest known dinosaur to use aerodynamic surfaces comprised of asymmetrical feathers for flight, Archaeopteryx undoubtedly occupied a unique ecological niche unlike that utilized by closely related fully terrestrial non-avian theropods, more derived Mesozoic birds, and extant taxa. New specimens together with computed tomography data elucidate how the ecology of Archaeopteryx is shaped both by its position as a basal avian close to the terrestrial-volant transition and its environment. The size of the feathered wings, primary vane asymmetry, and the large tertial tract all indicate Archaeopteryx was capable of volant locomotion. The reversed hallux, absent in closely related non-avian terrestrial dinosaurs, indicates incipient perching abilities, whereas the proportions of the footpads and morphology of the scales indicate the soft tissue of the foot was predominantly adapted for terrestrial locomotion. Curved manual claws, well developed articular surfaces on the minor digit phalanges, separate major and minor digits, and manual proportions all indicate ancestral grasping abilities were retained and possibly exapted for climbing. All known specimens fit a growth curve suggesting somatic maturity was achieved over a protracted period although even the smallest known individuals preserve wing feathers indicating aerial capabilities. Diet is unknown but avian features of the rostrum indicate increased rostral sensitivity and oral dexterity, which suggests a diet targeting small, energy rich foods. Together these morphologies reveal a generalist bird that foraged on the ground and utilized a diverse set of locomotor behaviors including incipient powered flight.