You may have recently heard news about “Ardi” (Ardipithecus ramidus), which is the oldest and most complete hominid skeleton that has been found to date. Not surprisingly, controversy abounds regarding what this skeleton means for the ancestral trees of apes and humans. See the following video for a quick peek into the ongoing discussion about where to place Ardi on the primate family tree.

FOR MORE ABOUT ARDI, check out Discovery Channel’s interactive website “DISCOVERING ARDI.”

You can also read more about “Lucy” and other primate fossils of Africa near the end of the page in our “Primates of Africa” section.

J.H. Matternes / Science via AFP – Getty Images

Check out this popular YouTube Video of a chimpanzee showing a little excitement at the zoo.

So…what’s going on here? Is the chimp happy, angry, annoyed? Although we can’t know for sure since it is impossible to get into this little guy’s head, scientists can use what we know about wild chimpanzee behavior to proffer a guess as to why he seems to be “going crazy.” Below is a video excerpt from Discovery.com which offers one scientist’s point of view on the display.