Seeing the skeleton in action can give viewers a very different perspective on adaptation and evolution, and most museums endeavour to pose their exhibits in real life position. This can be tricky, reassembling the bones and trying to give a realistic impression of total body shape and size beyond the skeleton itself. These images, from artist Arie van’t Riet, take this idea one step further and include whole animal subjects imaged by X-ray. Van’t Riet poses intact animal subjects into realistic positions and even allows a glimpse at the soft tissue within his models. Here, we can see the unique foot anatomy of the chameleon – in life, chameleons appear to have two large toes on each foot, which they use to grip thin or rough branches. However, the X-ray shows that there are in fact five fully-formed digits grouped into a two and a three, with the skin completely fused over the top. This isn’t seen anywhere else in the animal kingdom, and there isn’t currently an agreed name for this configuration which is neither didactyl (‘two-toed’, when there are clearly five overall) nor truly zygodactyl (~’paired toes’, traditionally used to describe birds where two toes point forwards and two backwards).

Image courtesy of Arie van’t Riet. To see more of van’t Riet’s work, see here and here.