platypus wake and sleep

http://www.npr.org/templates/story/story.php?storyId=90228565&ps=bb3

jerry siegel, UCLA
1 minute clip on platypus swimming and almost eating a shrimp/crustacean thing.
and 30 seconds into it - slow wave sleep vs. REM sleep.
b/c they have REM sleep, and they're more ancient than other mammals - REM sleep likely preserved much more earlier in evolution than previously speculated.