The bug that may have killed a dinosaur

Sue is a famous Tyrannosaurus Rex whose skeleton lives in the Field Museum in Chicago. Small, smooth holes in Sue’s jawbones have been a scientific mystery for years. Scientists may have solved the mystery in Sue’s jaws. A new study suggests that the holes were caused by something much smaller than another dinosaur. Researchers say the holes may have come from infection by a tiny parasite... and that infection may have killed the mighty dinosaur. A parasite is an organism that cannot live on its own. Instead, it feeds and lives on another organism, but this parasite is called Trichomonas. Unlike the dinosaurs, which became extinct about 65 million years ago, different kinds Trichomonas still live on the Earth. A Trichomonas infection can cause tissues to swell and block the throat. It can also cause the jaw to rot and leave holes in the bones.Today, this parasite often infects such birds as pigeons, turkeys and chickens. The scientists caught a break with the skull of an osprey, a fish-eating hawk easily recognized by its dark back and white chest. The osprey had holes in its jaws similar to Sue’s, and the scientists knew that when the bird was alive it was infected with Trichomonas. They started looking at other T. Rex skulls and found nine, including Sue’s, with the telltales holes of a Trichomonas infection.

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