Nanotyrannus is a highly debated dinosaur genus, potentially a distinct species of small tyrannosaurid or merely a juvenile Tyrannosaurus rex. Paleontologists...
Nanotyrannus is a proposed genus of tyrannosaurid dinosaur, smaller than Tyrannosaurus rex, whose classification is a subject of intense scientific debate among paleontologists.
The controversy stems from whether fossil specimens attributed to Nanotyrannus represent a distinct, smaller tyrannosaur species or are simply juvenile forms of the well-known Tyrannosaurus rex.
The 'Jane' fossil (BMRP 2002.4.1) is a remarkably well-preserved, sub-adult tyrannosaur skeleton. It is central to the debate, with some paleontologists identifying it as Nanotyrannus and others as a juvenile Tyrannosaurus rex.
Proponents point to distinct anatomical features like a more elongated snout, different tooth counts, and fused bones suggesting maturity at a smaller size, arguing these traits differentiate it from juvenile T. rex.
Opponents argue that the unique features fall within the expected developmental changes of a growing T. rex. They cite growth rings in bones and comparisons with other juvenile tyrannosaur specimens as evidence.