Monday, 22 March 2010

Seal legs

Following on from the last post (cue for a tune) and in particular the photos of the limbs of the grey seal...
There is a good picture of how the skeleton sits within the seal's body here and you can see that most of the bones lie buried in the blubber with really just the 'hands' and 'feet' visible. In this group of seals all the thrust to move through the water is derived from the rear limbs which have evolved into large webbed flippers.  Meanwhile the stumpy front limbs are handy for a scratch or the occasional wave and help the seal to drag itself across land when it does come ashore. 

The rear limbs might well be wonderfully adapted for powerful swimming but once out of water they are no help since they can no longer be rotated into a position under the body.

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