WAS it Tyrannosaurus rex or Tyrannosaurus regina? Until now, telling the tyrant-lizard kings from their queens has been pure guesswork. But the discovery of an unusual type of bone in a T. rex femur has given palaeontologists a reliable way of identifying the females.
Discerning the gender of fossilised animals is notoriously difficult, as the obvious differences are all in soft tissues that are not preserved. Some sex-specific traits do remain in bones, such as differences in size or skull adornment, but without any living animals for comparison, it is hard to be sure which sex is which. What’s more,…
