It's a battle of shark versus shark dating back over a century:
Which species set the stage for modern great white sharks, the
biggest carnivorous fish to roam the seas today? In one corner
are "megatooth" sharks, which include the largest sharks ever to
have lived. In the other is the smaller-but-plenty-toothy mako
shark. Now, researchers say they have new evidence pointing to
the mako shark as the great white's ancestor. Great white sharks
(Carcharodon carcharias) are the biggest meat-eating shark in
the world, with some reaching more than 20 feet (6 meters) long
and weighing more than 5,000 pounds (2,250 kilograms). They hunt
in more of the world's seas than any other sharks, ranging
across the Atlantic, Pacific and Indian oceans, from the cold
waters near the Antarctic to the tropical waters near the
equator, cruising up to 43 miles per hour (70 kilometers per
hour) in pursuit of prey. Science news from NBCNews.com Their
numbers are rapidly declining worldwide, however, mostly because
of accidental entang