How did the neanderthals differ physically from modern humans?

There are a number of differences between Neanderthal and modern human anatomy:

Neanderthal:

• long, low cranium (braincase) and double-arched browridge
• wide, funnel-shaped chest
• wide pelvis
• thick fingers and toes

Modern human:

• tall, rounded cranium and small, divided browridge
• cylindrical, barrel-shaped chest
• narrow pelvis
• narrow fingers and toes

These differences are probably related to the ice-age conditions in which the Neanderthals lived.

See:

http://amnh.org/exhibitions/permanent/humanorigins/history/neanderthals.php

http://www.sciam.com/article.cfm?articleID=00011272-3CDE-1C75-9B81809EC588EF21

http://www.bbc.co.uk/sn/tvradio/programmes/horizon/neanderthal_prog_summary.shtml