posted on Apr, 3 2004 @ 06:07 AM
A tiny fossil found by a road cutting in Pennsylvania, US, could be the earliest example of an arm bone.
The 360-370-million-year-old humerus, or upper arm bone, indicates that limbs may have evolved for use in water and not to get around on land.
It suggests the earliest limbed animals were fish navigating shallow rivers, but its place in the evolutionary tree is the subject of some
US biologists have published details of the discovery in the journal Science.