Kileskus

Kileskus Temporal range: Bathonian, 166 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Diagram showing fossil remains described in initial description
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Family:	†Proceratosauridae
Genus:	†Kileskus Averianov et al., 2010
Species:	†K. aristotocus
Binomial name
†Kileskus aristotocus Averianov et al., 2010

Life restoration

Estimated size of Kileskus compared to a human

Skull diagram of Kileskus aristotocus. Known material in white

Kileskus (meaning lizard in the Khakas language) is a genus of tyrannosauroid dinosaur known from partial remains found in Middle Jurassic (Bathonian stage) Itat Formation of Sharypovsky District, Krasnoyarsk Krai (Russia). Fossils recovered include the holotype maxilla, a premaxilla, a surangular, and a few bones from the hand and foot.^[1] Additional remains referred to the species include cervical and caudal vertebrae, as well as a fibula.^[2] The skull bones are similar to those of Proceratosaurus. The type species is K. aristotocus. Kileskus was named in 2010 by Averianov and colleagues. Its size has been estimated at 5.2 meters (17 ft) in length and 700 kg (1,540 lbs) in weight.^[3]

Classification

Kileskus has been included in two phylogenetic analyses and found to be a basal proceratosaurid both times.^[1][4]

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.^[1]

Below is a cladogram published in 2013 by Loewen et al..^[4]

Tyrannosauroidea	Proceratosauridae Proceratosaurus bradleyi Kileskus aristotocus Guanlong wucaii Sinotyrannus kazuoensis Juratyrant langhami Stokesosaurus clevelandi Dilong paradoxus Eotyrannus lengi Bagaraatan ostromi Raptorex kriegsteini Dryptosaurus aquilunguis Alectrosaurus olseni Xiongguanlong baimoensis Appalachiosaurus montgomeriensis Alioramus altai Alioramus remotus Tyrannosauridae

Cladogram published in 2018.^[5]

Tyrannosauroidea

Proceratosauridae Guanlong wucaii Proceratosaurus bradleyi Kileskus aristotocus Sinotyrannus kazuoensis Yutyrannus huali Pantyrannosauria Aviatyrannis jurassica Dilong paradoxus Santanaraptor placidus Timimus hermani Stokesosaurus clevelandi Juratyrant langhami Eotyrannus lengi Xiongguanlong baimoensis NMV P186046 ("Australian tyrannosaur") Alectrosaurus olseni Timurlengia euotica Eutyrannosauria Dryptosaurus aquilunguis Appalachiosaurus montgomeriensis Bistahieversor sealeyi Tyrannosauridae Albertosaurinae Gorgosaurus libratus Albertosaurus sarcophagus Tyrannosaurinae Alioramini Qianzhousaurus sinensis Alioramus remotus Alioramus altai Nanuqsaurus hoglundi Teratophoneus curriei Lythronax argestes Daspletosaurus torosus Daspletosaurus horneri Zhuchengtyrannus magnus Tarbosaurus bataar Tyrannosaurus rex

See also

• 2010 in paleontology
• List of dinosaurs
• Timeline of tyrannosaur research

References

1. Averianov, A. O.; Krasnolutskii, S. A.; Ivantsov, S. V. (2010). "A new basal coelurosaur (Dinosauria: Theropoda) from the Middle Jurassic of Siberia". Proceedings of the Zoological Institute. 314 (1): 42–57. doi:10.31610/trudyzin/2010.314.1.42.
2. O. Averianov, Alexander; Osochnikova, Anastasia; Skutschas, Pavel; Krasnolutskii, Sergei; Schellhorn, Rico; A. Schultz, Julia; Martin, Thomas (2019-09-16). "New data on the tyrannosauroid dinosaur Kileskus from the Middle Jurassic of Siberia, Russia". Historical Biology. 33 (7): 897–903. doi:10.1080/08912963.2019.1666839. ISSN 0891-2963. S2CID 203890300.
3. Molina-Pérez & Larramendi (2016). Récords y curiosidades de los dinosaurios Terópodos y otros dinosauromorfos. Spain: Larousse. p. 264.
4. Loewen, M.A.; Irmis, R.B.; Sertich, J.J.W.; Currie, P. J.; Sampson, S. D. (2013). Evans, David C (ed.). "Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans". PLoS ONE. 8 (11): e79420. Bibcode:2013PLoSO...879420L. doi:10.1371/journal.pone.0079420. PMC 3819173. PMID 24223179.
5. Delcourt, R.; Grillo, O. N. (2018). "Tyrannosauroids from the Southern Hemisphere: Implications for biogeography, evolution, and taxonomy". Palaeogeography, Palaeoclimatology, Palaeoecology. 511: 379–387