Indoor Blip: Sparrow Skull

More moving parts in large
Extra: Shadowy skull

Imogen found this sparrow skull in the garden last year (apparently), but I only spotted it in the garden room last week...
This shows most of the skeletal parts involved in prokinesis (a form of cranial kinesis, resulting in both the lower and upper parts of the beak moving as one coupled "mechanism" since both articulate with the quadrate bone at the base of the skull):
The upper part of the beak (maxilla) is part of the cranium, but joined via a flexion zone (nasal-frontal hinge). Rotation of the quadrate bone transmits force to the long, thin jugal bones (visible here, attached to the upper beak), causing the maxilla to flex ("prokinesis"), and the quadrate also mediates rotation of the lower part of the beak (mandible/dentaries). So the maxilla and mandible are moved up and down by muscles acting mostly on the quadrate.
My description ignores several small bones, as well as all the control and lateral movement muscle groups! This is probably the primitive form of cranial kinesis in birds, with ducks and others having elaborations such as rhynchokinesis.

I'm feeling rather better today, but still recuperating, so I just pointed the macro lens and flash at the skull (on one of Imogen's pebbles of interest).

Other angles here (or right from Sparrow skull)