In 1892 Edward Drinker Cope described more tyrannosaur material in the form of isolated vertebrae, and gave this animal the name Manospondylus gigas.

This discovery was mostly overlooked for over a century, and caused controversy in the early 2000s when it was discovered that this material actually belonged to, and had name priority over, Tyrannosaurus rex.

[5] Later in 1905 Henry Fairfield Osborn described two tyrannosaur specimens that had been collected in Montana and Wyoming during a 1902 expedition of the American Museum of Natural History, led by Barnum Brown.

It was discovered in 1921 near Steveville, Alberta, by Charles Mortram Sternberg, who thought it was a new species of Gorgosaurus, but was found to be a new genus by Dale Russell using the aforementioned CMN 8506.

Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous period.

[23] In the same year Zhuchengtyrannus was named by David W. E. Hone and colleagues based on the holotype ZCDM V0031, a nearly complete right maxilla and associated left dentary (lower jaw, both with teeth) housed at Zhucheng Dinosaur Museum.

[27] Lythronax, the oldest known member of Tyrannosauridae, was described in 2013 by Mark A. Loewen and colleagues from a nearly complete specimen that was uncovered in 2009 in the Wahweap Formation of the Grand Staircase–Escalante National Monument.

[27] Like albertosaurines, tyrannosaurines also had heterodont dentition, large heads design to catch and kill their prey, and short didactyl arms.

Based on the growth stages of Tyrannosaurus (and possibly Tarbosaurus[20]), tyrannosaurines undergone ontogenetic changes from gracile or slender, semi-longirostrine immatures to robust, heavy-headed adults.

[31] The study used skin impressions which are small, found widely dispersed across the post-cranium at different regions of the body with a pattern similar to crocodiles.

There was an alternative hypothesis from Phil Currie and colleagues (2003) who suggested Daspletosaurus to be more closely related to Tarbosaurus and Alioramus than to Tyrannosaurus based on cranial features.

[37] In the second edition of The Princeton Field Guide to Dinosaurs published in 2016, Paul would continue this thought as well as including Bistahieversor, Teratophoneus, Lythronax, and Nanuqsaurus into the genus as well.

[2] The cladogram below displays the results of the strict consensus phylogenetic analysis performed by Scherer & Voiculescu-Holvad (2023), indicating the distinct lineages of tyrannosaurines.