Kileskus digital by christopher252-d5h2i0r

Kileskus (meaning lizard in the Khakas language) is a genus of tyrannosauroid dinosaur known frompartial remains found in Middle Jurassic (Bathonian stage) rocks of Krasnoyarsk Krai, Russia. Fossils recovered include the holotype maxilla, a premaxilla, a surangular, and a few bones from the hand and foot. The skull bones are similar to those of Proceratosaurus. The type species is K. aristotocus. Kileskus was named in 2010 by Averianov and colleagues. They performed a phylogenetic analysis and found it to be a basal proceratosaurid.


Kileskus is a case study in the subtleties of theropod paleontology: technically, this middle Jurassic dinosaur is classified as a "tyrannosauroid" rather than a "tyrannosaurid," which means it almost, but didn't quite, belong to the exact same evolutionary line that evolved into animals like Tyrannosaurus. (In fact, Kileskus' closest relative seems to have been Proceratosaurus, which isn't recognized by most amateurs as a true tyrannosaur, though paleontologists might disagree.) However you choose to describe it, the (possibly feathered) Kileskus was clearly near the top of the food chain in its central Asian habitat, even if it was decidedly shrimpy compared to later tyrannosaurs.


Kileskus has been included in two phylogenetic analyses and found to be a basal proceratosaurid both times.

Although it is unknown whether Kileskus sported a nasal crest, it can be assigned to Proceratosauridae due to a number of other features. These include elongated external nares, a short ventral margin of the premaxilla, and the area of the antorbital fossa directly below the antorbital fenestra being deeper than the maxilla directly below it. Kileskus also shares with Proceratosaurus nares inclined posterodorsally at a 40 degree angle to the skull. Kileskus is distinguished from other proceratosaurids by the anterior rim of its maxilla being confluent with the ascending process of the maxilla and gently sloping posterodorsally.