Diuqin

Diuqin; Temporal range: Late Cretaceous, Santonian PreꞒ Ꞓ O S D C P T J K Pg N ↓
	3D scans of the holotype specimen
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Family:	†Dromaeosauridae
Subfamily:	†Unenlagiinae
Genus:	†Diuqin; Porfiri et al., 2024
Species:	†D. lechiguanae
Binomial name
	†Diuqin lechiguanae; Porfiri et al., 2024

Diuqin (meaning "bird of prey") is an extinct genus of unenlagiine theropod dinosaurs from the Late Cretaceous (Santonian) Bajo de la Carpa Formation of Argentina. The genus contains a single species, Diuqin lechiguanae, known from a humerus and fragmentary vertebrae.

Discovery and naming

The Diuqin holotype specimen, MUCPv 1401, was discovered in sediments of the Bajo de la Carpa Formation in Neuquén Province of Argentinian Patagonia. The specimen consists of most of the left humerus and pieces of a sacral and caudal vertebra, and other possibly vertebral fragments.^[1]

It was described as a new genus and species of unenlagiine theropod in 2024. The generic name, Diuqin, is Mapudungun for "bird of prey". The specific name, lechiguanae, refers to Lechiguana, the witch in the 1975 Argentine film Nazareno Cruz y Lobo.^[1]

Diuqin represents the first unenlagiine described from the Bajo de la Carpa Formation. Its discovery helps to fill in a gap of at least 15 million years in the fossil record of this clade between Austroraptor (Allen Formation) and taxa like Unenlagia (Portezuelo Formation).^[1]

Classification

Diquin was scored in a phylogenetic analysis and found in a large polytomy of maniraptoriforms. It had to be pruned from the analysis to recover better resolution in the tree. Doing this suggested possible close relationships to any of the tested unenlagiines.^[1]

Paleoenvironment

Diuqin is known from the Bajo de la Carpa Formation, which dates to the Santonian age of the late Cretaceous period. Its depositional environment was likely warm and semiarid. Many other dinosaurs are known from the formation, including several other non-avian theropods (the alvarezsauroids Alvarezsaurus and Achillesaurus, the abelisaurs Velocisaurus, Viavenator, and Llukalkan, and the megaraptoran Tratayenia), many titanosaurian sauropods (Bonitasaura, Inawentu, Overosaurus, Rinconsaurus, and Traukutitan), birds (Neuquenornis, Patagopteryx, and some eggs and nests), the ornithopod Mahuidacursor, and an indeterminate ankylosaur.^[2]^[3] Other animals include snakes (Dinilysia), lizards (Paleochelco), turtles (Lomalatachelys), crocodyliforms (Comahuesuchus brachybuccalis, Cynodontosuchus, Gasparinisuchus, Kinesuchus, Microsuchus, Neuquensuchus, Notosuchus, and Wargosuchus), and indeterminate pterosaurs.^[1]

References

^ ^a ^b ^c ^d ^e Porfiri, Juan D.; Baiano, Mattia A.; dos Santos, Domenica D.; Gianechini, Federico A.; Pittman, Michael; Lamanna, Matthew C. (2024-06-14). "Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina". BMC Ecology and Evolution. 24 (1): 77. Bibcode:2024BMCEE..24...77P. doi:10.1186/s12862-024-02247-w. ISSN 2730-7182. PMC 11177497. PMID 38872101.
^ Filippi, Leonardo S.; Juárez Valieri, Rubén D.; Gallina, Pablo A.; Méndez, Ariel H.; Gianechini, Federico A.; Garrido, Alberto C. (2023). "A rebbachisaurid-mimicking titanosaur and evidence of a Late Cretaceous faunal disturbance event in South-West Gondwana". Cretaceous Research. 154. doi:10.1016/j.cretres.2023.105754. ISSN 0195-6671.
^ Rozadilla, Sebastián; Agnolín, Federico; Manabe, Makoto; Tsuihiji, Takanobu; Novas, Fernando E. (September 2021). "Ornithischian remains from the Chorrillo Formation (Upper Cretaceous), southern Patagonia, Argentina, and their implications on ornithischian paleobiogeography in the Southern Hemisphere". Cretaceous Research. 125: 104881. Bibcode:2021CrRes.12504881R. doi:10.1016/j.cretres.2021.104881. ISSN 0195-6671.