The joy of T-Rex: Scientists show how dinosaurs had sex (tricky, when you weigh 30 tonnes and one crucial part is 12ft long). By Rob Waugh.
The pre-teens heralded sexual maturity. Combat for mates and nesting sites would turn T. rex against T. rex. Females would also likely.
Historically, scientists have sidestepped the issue of dinosaur sex, both T. rex was one of the largest carnivorous dinosaurs, measuring 5.