Giant Rat Less Giant Than Originally Thought

If one Canadian researcher is right, the largest rodent ever found just lost about 1,300 pounds. A biological brouhaha started this week over the fossils of the Josephoartigasia monesi, a giant rat that made its home a couple million years ago in what is now Uruguay. Unfortunately, only the fossilized skull survived -- scientists never unearthed any of the remainder of the skeleton, so they had had to do a little guessing as to the rest of the creature's proportions. Using the ratio of the size of a modern rat's head to its body, the Uruguayan scientists who dug up the bones in January said the creature would have weighed a full ton -- about 2,200 pounds, or 15 times heavier than the largest rodent roaming the earth today. But their calculations may have been inaccurate, says Virginie Millien of McGill University in Montreal. By taking a wider sample of ...