''Dzharacursor'' (meaning "Dzharakuduk runner") is a genus of

ornithomimid Ornithomimidae (meaning "bird-mimics") is an extinct family of theropod dinosaurs which bore a superficial resemblance to modern ostriches. Ornithomimids were fast, omnivorous or herbivorous dinosaurs known mainly from the Late Cretaceous Period ...

theropod dinosaurs from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

age)

Bissekty Formation The Bissekty Formation (sometimes referred to as Bissekt) is a formation (geology), geologic formation and Lagerstätte which outcrop, crops out in the Kyzyl Kum desert of Uzbekistan, and dates to the Late Cretaceous Period (geology), Period. Laid ...

of Uzbekistan. The type and only species is ''Dzharacursor bissektensis'', originally assigned to the genus ''

Archaeornithomimus ''Archaeornithomimus'' (meaning "ancient bird mimic") is a genus of ornithomimosaurian theropod dinosaur that lived in Asia during the Late Cretaceous period, around 96 million years ago in the Iren Dabasu Formation. Discovery and naming In 1 ...

''.

Discovery and naming

In 1995, Nesov named a new species of ornithomimosaur from the

as ''Archaeornithomimus bissektensis'', based on the holotype CCMGE 479/12457 (formerly N 479/12457), a

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

of a juvenile individual, along with other referred specimens including the

metatarsals The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges (toes). Lacking individual names, the metatarsal bones are nu ...

. However, in subsequent studies, the affinity of ''A. bissektensis'' was generally doubted or not mentioned. In 2025, Averianov & Sues assigned this taxon to the new genus ''Dzharacursor''. The new generic name combines Dzharakuduk, the name of the locality where its fossils were found, with the Latin word ''cursor'', meaning "runner". They also referred various partial cranial and postcranial materials of several individuals discovered from the same locality for a sufficient diagnosis. These include cranial bones (a premaxilla, frontal, and quadrate), several cervical, dorsal, and caudal vertebrae, sacra, pectoral and pelvic girdles, forelimb bones (humeri, ulnae, metacarpals, phalanges, and unguals), and hindlimb bones (femora, tibiae, fibulae, metatarsals, phalanges, and unguals), most of which were described by Sues & Averianov in 2016.

Classification

In their

phylogenetic analyses In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...

, Averianov & Sues (2025) recovered ''Dzharacursor'' as a basal member of the Ornithomimidae, more derived than ''Archaeornithomimus''. Their results are displayed in the

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below:

Paleobiology

A femur (ZIN PH 1400/16) referred to ''Dzharacursor'' may preserve

medullary bone The medullary cavity (''medulla'', innermost part) is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored; hence, the medullary cavity is also known as the marrow cavity. Located in the ma ...

, a type of endosteal bone tissue found in the bones of female birds when preparing to lay eggs. Similar tissues are found in other non-avian dinosaurs and pterosaurs. Based on the size of the individual whose femur was sampled, the presence of this tissue type may indicate that ''Dzharacursor'' females reached sexual maturity before somatic maturity.

Paleoecology

''Dzharacursor'' coexisted in the Bissekty Formation environment with other theropods, including the carcharodontosaurian '' Ulughbegsaurus'', the tyrannosauroid ''

Timurlengia ''Timurlengia'' is an extinct genus of tyrannosauroid theropod dinosaur found in Uzbekistan, in the Bissekty Formation in the Kyzylkum Desert, hailing from the Turonian age of the early Late Cretaceous. The type species is ''Timurlengia euotica ...

'', and the dromaeosaurid '' Itemirus''.

References

{{Taxonbar, from=Q48785254 Ornithomimidae Dinosaur genera Turonian dinosaurs Bissekty Formation Fossil taxa described in 2025 Taxa named by Hans-Dieter Sues Taxa named by Alexander O. Averianov Dinosaurs of Uzbekistan