Halszkaraptorinae
Halszkaraptorinae is a clade of small, early-diverging predatory dinosaurs known from the Late Cretaceous of Mongolia, and includes the enigmatic genera Halszkaraptor, Natovenator, Mahakala, and Hulsanpes. Its members were roughly the size of modern ducks and are distinguished by their unusually long necks, along with a suite of features in the tail vertebrae, forelimbs, hips, and hindlimbs. On the basis of their forelimb and body proportions, some researchers have interpreted these animals as semiaquatic swimmers that used their long necks to forage in water while remaining bipedal on land, though this lifestyle has been questioned. The clade is usually recovered at or near the base of Dromaeosauridae, but its exact placement is contested, with some analyses instead allying it with Unenlagiidae or drawing it toward the bird lineage.
Under dispute
The position of Halszkaraptorinae is contested. It is most often recovered at the base of Dromaeosauridae (Cau and colleagues, 2017; Lee and colleagues, 2022), but Hartman and colleagues (2019) pair it with Unenlagiinae as Unenlagiidae, the sister of dromaeosaurids plus troodontids, and Wang and colleagues (2026) recover that pair closer to birds than to dromaeosaurids and troodontids. The proposed semiaquatic ecology of its members has also been questioned (Fabbri and colleagues, 2022).
Diagnosis
- Elongate cervical vertebrae producing a long neck
- Numerous small, closely packed teeth
- Premaxilla with a battery of small teeth and neurovascular foramina
- Dorsoventrally flattened, elongate forelimb elements
Genera placed directly in Halszkaraptorinae
- Halszkaraptor Campanian (83.6–72.2 Ma)Mongolia
- Hulsanpes Campanian (83.6–72.2 Ma)Mongolia
- Mahakala Campanian (83.6–72.2 Ma)Mongoliaunder dispute
- Natovenator Santonian–Maastrichtian (85.7–66.0 Ma)Mongolia
References
- Cau, A.; Beyrand, V.; Voeten, D. F. A. E.; Fernandez, V.; Tafforeau, P.; Stein, K.; Barsbold, R.; Tsogtbaatar, K.; Currie, P. J.; Godefroit, P. (2017). Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs. Nature 552(7685): 395-399. Springer Science and Business Media LLC. doi:10.1038/nature24679 cau2017a
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Lee, S.; Lee, Y. N.; Currie, P. J.; Sissons, R.; Park, J. Y.; Kim, S. H.; Barsbold, R.; Tsogtbaatar, K. (2022). A non-avian dinosaur with a streamlined body exhibits potential adaptations for swimming. Communications Biology 5(1). Springer Science and Business Media LLC. doi:10.1038/s42003-022-04119-9
Recovered the Halszkaraptorinae arrangement the clade follows, in describing a streamlined non-avian dinosaur.
lee2022a -
Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247. PeerJ. doi:10.7717/peerj.7247
Large paravian phylogenetic analysis bearing on Halszkaraptorinae placement, contra adopted arrangement.
hartman2019a -
Fabbri, M.; Navalón, G.; Benson, R. B. J.; Pol, D.; O'Connor, J.; Bhullar, B. A. S.; Erickson, G. M.; Norell, M. A.; Orkney, A.; Lamanna, M. C.; Zouhri, S.; Becker, J.; Emke, A.; Dal Sasso, C.; Bindellini, G.; Maganuco, S.; Auditore, M.; Ibrahim, N. (2022). Subaqueous foraging among carnivorous dinosaurs. Nature 603(7903): 852-857. Springer Science and Business Media LLC. doi:10.1038/s41586-022-04528-0
Questioned the proposed semiaquatic ecology of halszkaraptorines.
fabbri2022a -
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.
Treats Halszkaraptorinae with Unenlagiinae as Unenlagiidae.
jones2026c -
Wang, X.; Ji, Y.; Cau, A.; Kundrát, M.; Liu, Y.; Wang, Y.; Ji, Q. (2026). Independent assembly of the flight apparatus in a non-avian dinosaur clade. Nature Communications 17(1): 10074. Springer Science and Business Media LLC. doi:10.1038/s41467-026-77804-6
Recovered Halszkaraptorinae with Unenlagiinae closer to birds than to dromaeosaurids and troodontids.
wang2026b