Halszkaraptor (/ˈhɑːlʃkəræptər/; meaning "Halszka's seizer") is a genus of waterfowl-like dromaeosaurid dinosaurs from Mongolia that lived during the Late Cretaceous period.

The holotype specimen of Halszkaraptor likely came from the Djadochta Formation at Ukhaa Tolgod in southern Mongolia, and was illegally removed by fossil poachers in or before 2011.

He identified it as a new species, and in 2015 took it to the Royal Belgian Institute of Natural Sciences in Brussels, showing it to paleontologists Pascal Godefroit and Andrea Cau for further verification.

[1][4] The holotype, MPC D-102/109, was found in a layer of orange sandstone of the Bayn Dzak Member of the Djadochta Formation, dating from the late Campanian, about seventy-five million years old.

[1] The type species Halszkaraptor escuilliei was in 2017 named and described by Andrea Cau, Vincent Beyrand, Dennis F. A. E. Voeten, Vincent Fernandez, Paul Tafforeau, Koen Stein, Rinchen Barsbold, Khishigjav Tsogtbaatar, Philip John Currie, and Pascal Godefroit.

The jugal bone is rod-shaped and its ascending branch occupies only a tenth of the bar behind the eye socket, not reaching the orbit.

The external bony nostril is situated behind the main body of the premaxilla, the point where it connects to the front branch of the maxilla.

From a larger chamber in the rear, neurovascular channels permeate the entire bone, not just the sides as in Neovenator, but the top also.

The teeth in the maxilla, estimated in number at twenty to twenty-five, are more robust, curve only at their tips, and are spaced at a larger distance.

Despite the length of the snout, the main opening in the side of the front skull, the antorbital fenestra, is short; shorter than high.

[1] On the front neck, the neural spines, normally rectangular plates, have been reduced to a low ridge; more to behind they have disappeared.

The neural spines of the front tail are already strongly reduced: only the first three vertebrae possess them and they are formed like low bumps.

The cladogram below is based on the phylogenetic analysis conducted in 2017 by Cau et al. using updated data from the Theropod Working Group.

Halszkaraptor occupied a basal position within Halszkaraptorinae, as the sister group of a clade formed by Hulsanpes and Mahakala.

[1] Halszkaraptor Mahakala Hulsanpes Unenlagiinae Shanag Zhenyuanlong Microraptoria Bambiraptor Tianyuraptor Dromaeosaurinae Velociraptorinae Andrea Cau argues that Halszkaraptor had characteristics that allowed it to spend time both in water and on land, including strong hindlimbs for running and smaller flipper-like forelimbs for swimming.

It had many sharp, backward-curving teeth in its mouth, a long neck and sensory neurons in its snout that may have allowed it to detect vibrations in water, leading scientists to believe that it hunted aquatic prey.

He stated that these birds are probably the closest ecological analogs to Halszkaraptor as they share similar traits with this dromaeosaurid taxon, such as the long neck and a serrated snout edge used to catch small prey.

While they are less active moving on land, assuming a hip-extended body posture, on water, they use a distinct swimming model including forelimb-propelled locomotion.

[3] In response, Cau has pointed out on his blog that swans similarly have low bone density yet have adaptations for semi-aquatic feeding.

[6] A 2024 study by Tse, Miller, and Pittman, focusing on the skull morphology and bite forces of various dromaeosaurids discovered that Halszkaraptor had a rapid bite unsuited to piscivorous feeding as previously hypothesized based on its skull morphology, and instead suggest it was an insectivore that hunted small invertebrates possibly in low-light conditions (at night or in murky water), since it likely had exceptional low-light vision among dromaeosaurids based on its relatively large orbit size.