A new specimen of one of the most controversial species of dinosaur has the potential to overturn decades of research on the T rex. Nanotyrannus, the “miniature T rex”, has been the centre of one of the fiercest debates in palaeontology.

In a paper in the journal Nature, paleontologists Lindsay Zanno and James Napoli conclude that some of the bones from that specimen belong not to a teenage T. rex, but to a fully grown individual of ...