Imperial diptych offerings to the emperor. However, the fact that the Barberini ivory was almost certainly not a diptych, but some kind of imperial icon without a second panel is a serious argument against the existence of the imperial diptych type. The two panels representing the empress Ariadne, in the Bargello in Florence and the Kunsthistorisches Museum in Vienna, also belong to the hypothesied imperial diptych type. They are the only central panels of such a diptych (other than the Barberini ivory) to survive, since all other fragments of such diptychs are from side panels. Imperial diptych In Late Antiquity, an imperial
Green imperial pigeon Indonesia. It has several subspecies, including the distinctive Celebes form, chestnut-naped imperial pigeon ("Ducula aenea paulina"). This is an arboreal dove, feeding on plant material in the tree canopy. Its flight is fast and direct, with the regular beats and an occasional sharp flick of the wings which are characteristic of pigeons in general. It builds a stick nest in a tree and lays a single white egg. The birds are not very gregarious, but will form small flocks. Green imperial pigeon The green imperial pigeon ("Ducula aenea") is a large forest pigeon. The green imperial pigeon is a large,