girdle

In fish, the pelvic fins and bones of the pelvic girdle are relatively small and float freely in the body.

Fossils were meticulously prepared to remove the surrounding matrix of rock and expose the skull, shoulder girdle and pectoral fins.

If allowed to grow up the trunk of a tree, it can eventually girdle or smother and kill it.

Now, by reanalysing an ancient fossil fish skull from soon after the shoulder girdle emerged, alongside other lines of evidence, the team suggest the truth may lie in a modified version of the gill-arch hypothesis that reconciles it with the fin-fold hypothesis.

The shoulder girdle -- the configuration of bones and muscles that in humans support the movement of the arms -- is a classic example of an evolutionary 'novelty'.