Lythronax

Lythronax is an extinct genus of tyrannosaurid theropod dinosaur. It lived about 80 million years ago (mya) in what is now southern Utah. L. argestes is the oldest known tyrannosaurid based on its stratigraphic position.^[1]

Lythronax Temporal range: Late Cretaceous, 80.6–79.9 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Reconstructed skeleton alongside those of other tyrannosaurs, Science Center of Iowa
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Family:	†Tyrannosauridae
Subfamily:	†Tyrannosaurinae
Genus:	†Lythronax Loewen et al., 2013
Type species
†Lythronax argestes Loewen et al., 2013

Comparisons to its close relatives suggest that Lythronax would have been about 8 m (26.2 ft) long, with a weight of around 2.5 tonnes (5,500 lb) and had a large skull filled with sharp teeth.^[2]

The rostrum^[3] is comparatively short: it makes up less than two thirds of the total skull length. The whole skull is very broad, 0.4 times as wide as long. Overall, the skull is similar to that of Tyrannosaurus and Tarbosaurus. Its robust jaws have two sizes of teeth: its first five teeth are much larger than the other six. Behind the skull, the rest of the skeleton is similar to that of other tyrannosaurids.^[1]