This article is about the tyrannosaur. For the Dinopedia user, see user:Lythronax.
Temporal range: Late Cretaceous
An artist's restoration of Lythronax
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Suborder: Theropoda
Genus: Lythronax
Loewen et al., 2013
Species: L. argestes
Binomial name
Lythronax argestes
Loewen et al., 2013
Lythronax-016 863d

Lythronax is an extinct genus of tyrannosaurid theropod dinosaur which lived around 80 to 78 million years ago in what is now southern Utah. The generic name is derived from the Greek words lythron meaning "gore" and anax meaning "king". Lythronax was a large sized, moderately-built, ground-dwelling, bipedal carnivore, that could grow up to an estimated 9 m (30 ft) in length and weighed 2.5 tonnes (5,500 lb).

L. argestes is the oldest known tyrannosaurid, based on its stratigraphic position. It is known from a specimen thought to be from a single adult that consists of a mostly complete skull, both pubic bones, a tibia, fibula, and metatarsal II and IV from the left hindlimb, as well as an assortment of other bones. Its skull anatomy indicates that, like Tyrannosaurus, Lythronax had both eyes facing the front, giving it depth perception and like Tyrannosaurus, it possibly had binocular vision and extremely good senses of smell, hearing and night vision.

Lythronax acristavus by paleoguy-d6z59bv


Its genus name comes from the Greek words ''lythron'' meaning "gore" and ''anax'' meaning "king". The species name is the Greek ἀργεστής, "clearing", used by the ancient poet Homer.


Lythronax was a fairly medium to large tyrannosaur, growing up to 9 metres (30 feet) long from nose to tail and standing over 2 metres tall. It was about the weight of a large crocodile which is around 1-2 tons. It had typical tyrannosauroid features such as the large head, large teeth, small, almost useless arms, the classic ''s'' feature commonly found in theropods, forward facing eyes and long heavy tail to balance it while it was running and walking. It probably had a very strong bite which is common with tyrannosaurs so its bite might have been similar in force to the American alligator. It was definitely a carnivore from the shape of its teeth. This particular species would not have been a bone crusher like T. rex but a species that was adept at taking huge chunks out of its prey and waiting for it to die of blood loss like modern day wolves.

In Popular Culture

  • Lythronax made a debut in Fossil Fighters Frontier.
  • Lythronax will appear in the game Jurassic World: Alive. While it is accurately portrayed with a coat of feathers, it is shown inaccurately to be able to pronate it's hands.