There are always two tensions in scientific exploration. One is the effort to consolidate the known facts into a stable theory. The other is to discover new facts. Last week a dinosaur bone upset everyone’s expectations in ways that may ripple outward for a long time. Workers at a field site in Montana had broken the 70-million-year-old fossilised thighbone of a Tyrannosaurus rex in half for purely logistical reasons — huge bone, small helicopter. When scientists examined the bone fragments in the lab, they discovered unfossilised soft tissue.

Just how these tissues were preserved is a very good question, one that may lead scientists to re-examine their theories of fossilisation. One of the central questions will be whether scientists are able to extract from these samples any fragments of T rex’s genetic code. We’re not likely to wake up one morning and read that some embryonic T rex is waiting to be hatched. What these soft tissues may do is help to lay give us a clearer picture of the relation between life on Earth now and life as it was 65 million years ago. It seems appropriate that this discovery came from the bone of a T rex, the most familiar, and fearsome, of those ancient species, a creature that perfectly embodies the pleasure of science. We wake up thinking we know what we know, only to find that we have to think all over again. — The New York Times