The New Zealand cricket captain has compared South Africa's pace bowling arsenal to the all-conquering Australian attack of a decade ago.
In the wake of his team's innings and 27 runs defeat in the first test in three days in Cape Town, McCullum says Proteas pace bowlers Dale Steyn, Vernon Philander and Morne Morkel provide a challenge like no other in the modern game.
He says they contantly put pressure on batting sides and their seam attack is relentless.
Man of the match Philander took 5 for 7 as the Black Caps were skittled for 45 in the first innings while Steyn led the way in New Zealand's second innings of 275, finishing with 3 for 67.
