Tyrannosaurus rex could have been laid low not by a planetwide dinosaur holocaust or vicious infighting, but by a parasite that still affects modern birds. Researchers have taken a close look at lesions on T. rex fossils once presumed to be battle scars and concluded that they are the work of trichomonosis, a parasite that ravages a bird’s mouth and throat, making eating tricky. A similar infection could have starved the ancient carnivore to death.
Paleontologists had thought the holes in the T. rex’s jaws were injuries from battles between the dinosaurs, but the new research suggests they resemble trichomonosis lesions much more than puncture wounds. Evidence of the disease is found only in T. rex fossils, notes LiveScience. (Read more Tyrannosaurus rex stories.)