Ulughbegsaurus
Temporal range: Turonian, 92–90 Ma
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Holotype specimen, showing initial interpretation as a carcharodontosaurian maxilla
Holotype specimen, showing initial interpretation as a carcharodontosaurian maxilla
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Clade: Avetheropoda
Genus: †Ulughbegsaurus
Tanaka et al., 2021
Type species
†Ulughbegsaurus uzbekistanensis
Tanaka et al., 2021

Ulughbegsaurus (meaning "Ulugh Beg's lizard") is a dubious genus of theropod dinosaur from the Late Cretaceous aged Bissekty Formation, Uzbekistan.[1] The type species is Ulughbegsaurus uzbekistanensis.[2]

Discovery and naming

Ulughbegsaurus was initially discovered within the Bissekty Formation, Uzbekistan in the 1980s based on the holotype UzSGM 11-01-02, consisting of a partial left maxilla. The holotype, despite its significance, would remain in the collection of the State Geological Museum of the State Committee of the Republic of Uzbekistan on Geology and Mineral Resources, Tashkent, Uzbekistan, until 2019, when it was rediscovered. Two additional referred specimens have been attributed to the genus, including CCMGE 600/12457, an jugal ramus of a left maxilla that was previously referred to the dromaeosaurid Itemirus and ZIN PH 357/16, the posterior end of a right maxilla.[2]

Isolated teeth from the Bissekty Formation show similarities with carcharodontosaurian morphology, suggesting they may belong to Ulughbegsaurus or possibly another genus of carcharodontosaurian.[2]

The genus and species was later named in 2021 by Tanaka et al., honouring the 15th century Timurid sultan and scientist Ulugh Beg and the country of its discovery.[1][2]

Description

The body length of Ulughbegsaurus is estimated at 7.5–8 metres (25–26 ft) and its body mass at over 1,000 kilograms (2,200 lb).[2]

Classification

Tanaka et al. ran two phylogenetic analyses using two different datasets to determine the relationships of Ulughbegsaurus. The first placed it in a polytomy including Neovenator and other megaraptorans, while the second placed it in a polytomy including other basal carcharodontosaurians; megaraptorans were instead recovered as members of the Tyrannosauroidea.

Both analyses are shown below:[2]

However, a later 2022 study suggested that the taxon was a nomen dubium due to lacking diagnostic features, and that it was plausible that the maxilla fragment originated from a dromaeosaurid instead.[3]

Paleoecology

Ulughbegsaurus coexisted in the Bissekty Formation environment alongside other carnivorous theropods, including the tyrannosauroid Timurlengia and the dromaeosaurid Itemirus.[2][4]

References

  1. ^ a b Rieger, Sarah (7 September 2021). "Newly discovered dinosaur predated tyrannosaurs — and at the time was a bigger apex predator". CBC News. Retrieved 8 September 2021.
  2. ^ a b c d e f g Tanaka K, Anvarov OU, Zelenitsky DK, Ahmedshaev AS, Kobayashi Y (2021). "A new carcharodontosaurian theropod dinosaur occupies apex predator niche in the early Late Cretaceous of Uzbekistan". Royal Society Open Science. 8 (9): Article ID 210923. Bibcode:2021RSOS....810923T. doi:10.1098/rsos.210923. PMC 8424376. PMID 34527277.
  3. ^ Sues, Hans-Dieter; Averianov, Alexander; Britt, Brooks B. (2022-12-22). "A giant dromaeosaurid theropod from the Upper Cretaceous (Turonian) Bissekty Formation of Uzbekistan and the status of Ulughbegsaurus uzbekistanensis". Geological Magazine. 160 (2): 355–360. doi:10.1017/S0016756822000954. ISSN 0016-7568.
  4. ^ Black, Riley. "New, Giant Carnivorous Dinosaur Was a Terror to Smaller Tyrannosaurs". Smithsonian Magazine. Retrieved 2021-09-08.


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