The bones were then stored at the Royal Tyrrell Museum in Alberta. In 2005 Nick Longrich, a paleontologist at the University of Calgary in Canada, happened upon the small fossils while comparing "Albertosaurus" claws to other dinosaur species. Longrich then analyzed the remains, concluding that they represented a previously unknown species. Although fragments of "Albertonykus" had been discovered before, they had never been identified as a separate species. "Albertonykus" is the smallest known alvarezsaurid ever discovered in North America, measuring only 70 centimeters (2.5 ft) in length. Other estimates are 1.1 meters and 5 kg. Alvarezsaurs typically had slender hind legs, long rigid tails, and unusually short arms that were powerfully built to support a large claw. Although no skull bones of "Albertonykus" have been found, related animals from Mongolia show that they likely had long, slender snouts filled with tiny teeth similar to those of armadillos and anteaters. It is likely that "Albertonykus" ate insects, using its large thumb claw to tear open rotten logs to find its prey. As in other alvarezsaurs, the forelimbs of "Albertonykus" were specialized for digging, but were too short to permit burrowing. Unfortunately at this time the skeleton of "Albertonykus" is not complete, but its Mongolian relatives give us a distinct idea of what the rest of the skeleton would have looked like. Possible prey items were evaluated and compared with the fossil record of social insects. Ants were not an important part of the ecosystem during the Cretaceous, and mound-building termites do not appear until the Eocene. This leaves the possibility that "Albertonykus" preyed on wood-nesting termites. This hypothesis was tested by examining petrified wood from the Horseshoe Canyon Formation, where "Albertonykus" was found. The wood found there frequently contains borings, which resemble those of termites. "Albertonykus" is a member of an unusual theropod group known as the Alvarezsauridae and is one of only a few alvarezsaurid fossils that has been found outside of South America and Asia. After a phylogenetic analysis, it was shown that "Albertonykus" is the sister taxon of the Asian clade Mononykinae, which supported the hypothesis that the alvarezsaurs originated in South America, and then dispersed to Asia through North America.