"I'm a virgin by choice," protests testosterone-challenged tribesman Oh! (Cera).

"Not your choice," is the crushing reply from Jack Black's incompetent ancient warrior Zed in director Harold Ramis' sure-fire caveman comedy.

Oh! And Zed find themselves banished from the tribe when it becomes apparent that neither of them is a hunter-gather and "hunter-gatherer is about the only job around here."

Traipsing through the jungle they eventually cross a mountain ridge - the "end of the world" of superstitious legend -  and walk into biblical baddie Cain (Cross) just as he is murdering his brother Abel (an all-too-short cameo from Paul Rudd).

Launching into a non-PC orgy of Christian Fundamentalist baiting, they also manage to call a halt to Abraham slaying his son Isaac as well as just happening to be around when the ancient custom of circumcision is getting its first run-through.

Niceties such as a coherent chronology also go out of the window when they are sold into slavery along with their prehistoric totty Maya (June Raphael) and Eema (Juno Temple)  only to be captured by Vinnie Jones and his Roman Legion.

There's a lot of fun to be had with a script as sharp as a flint axe-head and terrific performances from Black - improvising wildly - and Cera, who reworks his innocent abroad schtick and times travels it backs a couple of thousand years.

Highlights include a climax - don't titter missus - in Sodom, where Zed gets the chance to live out his wildest fantasies (and narrowly escapes a rear assault from Vin) while Oh! finds himself painted gold and oiling up Oliver Platt's lascivious high priest.

Short and sweet, it's mammoth fun that knows when to stop. About 2054 BC.

Tim Evans