Stunning new proof that the Planet of the Apes is a true story.

Chimpanzees living in the West African savannah have been observed fashioning deadly spears from sticks and using the tools to hunt small mammals — the first routine production of deadly weapons ever observed in animals other than humans.

The multistep spearmaking practice, documented by researchers in Senegal who spent years gaining the chimpanzees’ trust, adds credence to the idea that human forebears fashioned similar tools millions of years ago.

The landmark observation also supports the long-debated proposition that females — the main makers and users of spears among the Senegalese chimps — tend to be the innovators and creative problem solvers in primate culture.

Using their hands and teeth, the chimpanzees were repeatedly seen tearing the side branches off long, straight sticks, peeling back the bark and sharpening one end. Then, grasping the weapons in a “power grip,” they jabbed them into tree-branch hollows where bush babies — small, monkeylike mammals — sleep during the day.

In one case, after repeated stabs, a chimpanzee removed the injured or dead animal and ate it, the researchers reported in yesterday’s online issue of the journal Current Biology.

“It was really alarming how forceful it was,” said lead researcher Jill D. Pruetz of Iowa State University, adding that it reminded her of the murderous shower scene in the Alfred Hitchcock movie “Psycho.” “It was kind of scary.”

The new observations are “stunning,” said Craig Stanford, a primatologist and professor of anthropology at the University of Southern California. “Really fashioning a weapon to get food — I’d say that’s a first for any nonhuman animal.”

Scientists have documented tool use among chimpanzees for decades, but the tools have been simple and used to extract food rather than to kill it.

Oh, and does this lend credence to that whole Adam and Eve story?

…females — the main makers and users of spears among the Senegalese chimps — tend to be the innovators and creative problem solvers in primate culture.

It wasn’t a pear or apple from the tree of knowledge, but a spear?

Just kidding ladies. Seems like some good weekend reading…