YOUTHFUL years were the golden years for big predatory dinosaurs. Most juveniles survived to reach sexual maturity, but then their death rate rose sharply.
Palaeontologists have long wondered why fossils of juvenile dinosaurs are so rare. The answer is they just didn’t die young, says Gregory Erickson of Florida State University in Tallahassee. “Not until they reached mid-life did they start getting knocked off.” The pattern is similar to that in large modern herbivores like elephants and buffalos, he says.
Erickson started with a bone bed in Alberta that contained the bones of at least 22 Albertosaurus individuals between…
