The Wolves of Cretaceous Antarctica.

Imperobator is an extinct genus of paravian theropod, a group of large, three-toed carnivorous dinosaurs, that lived during the very latest stages of the Cretaceous Period in what is now the continent of Antarctica. 

The genus' only representative species, Imperobator antarcticus, is one of only two non-avian theropods known from Antarctica. The first fossilized remains of the species were discovered in 2003 by an expedition launched by the University of California Museum of Paleontology and initially described as a dromaeosaur in 2007. Subsequent expeditions uncovered additional fossils including teeth and skull bones, with the fossils being formally described as a new genus of giant paravian in 2019.

Imperobator antarcticus is one of the largest known paravians, with an estimated height of approximately two meters, making it comparable to the largest of the dromaeosaurs such as the North American Utahraptor. As a result of the lack of the characteristic "sickle claw" of dromaeosaurs on the second digit, I. antarcticus is classified as a basal paravian of uncertain affinities, of undetermined lineage. I. antarcticus exhibited gigantism, a physical trait somewhat rare among paravians, best documented in the genera Utahraptor, Austroraptor, Deinonychus and Dakotaraptor. Despite its prior assignment to Dromaeosauridae, Imperobator has since been assigned to the clade Paraves due to several physical characteristics that differ from those of dromaeosaurids; the lack of a sickle claw, the smooth surface of the distal metatarsal, and the lack of an ungual on the second pedal digit. 

Fossilized remains of Imperobator antarcticus are known solely from James Ross Island, an island on the northeastern edge of the Antarctic Peninsula. The island's Snow Hill Island Formation is one of only two major dinosaur-bearing rock formations found in Antarctica, formations that hold a wide variety of other fossils, many of them unique and endemic as animals evolved in the geographical isolation of Antarctica after the breakup of Gondwana in the Early Cretaceous. I. antarcticus coexisted with the ornithopod dinosaur Morrosaurus and Antarcticavis, an avian dinosaur, in addition to a menagerie of mosasaurs, plesiosaurs, and a small pterosaur. During the time in which I. antarcticus was in existence, the climate of the planet was much warmer and far more humid than it is today, and as a result, Antarctica was free of the permanent ice sheets that currently cover the continent. The environment was mainly dominated by large dense conifer forests, cycads, and ginkgos. The animals inhabiting Antarctica during the Cretaceous would still have had to endure long periods of darkness during the bitterly cold winters, much like in modern-day Antarctica.

Imperobator antarcticus was a pack-hunting predator, with a complex social structure similar to modern-day wolves. Due to the environmental stresses placed on the species, I. antarcticus was highly active, warm-blooded, and fully adapted to successfully survive in polar climates and conditions. As with today's wolves, a high level of intelligence in the species is a strong possibility. In my humble opinion, the species was likely a highly intelligent animal, a magnificent reptile. 

The species most likely went extinct during the Cretaceous/Paleogene extinction event, although some paleontologists are considering the possibility that some polar dinosaurs may have managed to live beyond the boundary due to their evolutionary adaptations to such cold, difficult environmental conditions. A fascinating possibility to consider. 

Thank you for your time and consideration.