And it's often very hard to determine whether deformations in a dinosaur's bone structure were caused by disease or the crush of sediment over time. What's more, with soft tissue largely missing from fossils, scientists rely on bones for information. Until relatively recently, however, diagnosing multi-million-year-old diseases from fossilized bones was decidedly hit-and-miss.įirst off, the fossil record only reveals a small fraction of the creatures that lived in the past, and those that reach us have withstood multiple obstacles over millions of years.
