Jaculinykus Temporal range: Late Cretaceous, | |
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Holotype specimen and skeletal reconstruction | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Alvarezsauridae |
Subfamily: | † Parvicursorinae |
Genus: | † Jaculinykus |
Species: | †J. yaruui |
Binomial name | |
†Jaculinykus yaruui Kubo et al., 2023 |
Jaculinykus (meaning "Jaculus claw") is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous Baruungoyot Formation of Mongolia. The genus contains a single species, J. yaruui, known from a nearly complete articulated skeleton including bones of the skull. Jaculinykus is notable for its unique hand, which has a hypertrophied first digit and greatly reduced second digit, which is intermediate between the tridactyl hand of Shuvuuia and monodactyl hand of Linhenykus . [1]
The Jaculinykus holotype specimen, MPC-D 100/209, was discovered in sediments of the Baruungoyot Formation (Nemegt locality), of Ömnögovi Province, Mongolia. The specimen consists of a nearly complete skeleton with most of the skull. [1]
In 2023, Kubo et al. described Jaculinykus yaruui as a new genus and species of parvicursorine alvarezsaurid based on these fossil remains. The generic name, "Jaculinykus", combines a reference to the Jaculus, a small dragon in Greek mythology with the Greek word "onykus," meaning "claw". The specific name "yaruui" is derived from "yaruu" ("яаруу"), the Mongolian word for "speedy" or "hasty". [1]
Jaculinykus was added to a phylogenetic analysis and found to be in the clade Parvicursorinae, in a clade consisting of all alvarezsaurs from the Nemegt Basin. The cladogram from Kubo et al. (2023) is shown below: [1]
Fossils of Ondogurvel , another parvicursorine alvarezsaurid, as well as fossils of Nemegtomaia , an oviraptorosaur, are also known from the Nemegt locality of the Mongolian Barun Goyot Formation. [2] Other localities from the formation have yielded dinosaurs including additional alvarezsaurids ( Ceratonykus, Khulsanurus , and Parvicursor ), [1] as well as dromaeosaurs ( Hulsanpes , [3] Kuru , and Shri devi [4] ), oviraptorosaurs ( Conchoraptor and Heyuannia ), [5] a sauropod ( Quaesitosaurus ), [6] ceratopsians ( Bagaceratops and Breviceratops ), [7] a pachycephalosaur ( Tylocephale ), [8] and ankylosaurs ( Saichania , [9] Tarchia , [10] and Zaraapelta [11] ).