Everybody knows that Tyrannosaurus had small arms tipped in only two fingers. ... Several specimens discovered by fossil hunter Barnum Brown between 1900 and 1907 filled in the general picture, but even the famous specimen that was reconstructed in the American Museum of Natural History lacked fingers.

Does T. rex have 3 fingers?

T. rex also had only two fingers on its hands, rather than the three seen in most other carnivorous dinosaurs, so its arms and hands really do appear to have been less important than they were in its relatives.

What fingers did T. rex have?

Here's the problem: The most primitive dinosaurs in the famous theropod group (that later included Tyrannosaurus rex) had five "fingers." Later theropods had three, just like the birds that evolved from them.