Lepidoptera: Papilionidae
Ornithoptera richmondia
A Richmond Birdwing pupa (or chrysalis as butterfly pupae are called).
The pupa is the third stage of the butterfly's life (egg -> larva -> pupa -> adult).
My very grateful thanks to Jo of Mount Mellum who found me wandering along the roadside looking for Richmond Birdwing butterflies, and whilst there were no butterflies presenting themselves, was able to show me this pupa.