Ivory gull narrower os pubis, and potentially more flexibility in skull kinetic structure. Structurally, it is most similar to the kittiwakes; however, recent genetic analysis based on mtDNA sequences shows that Sabine's gull is the ivory gull's closest relative, followed by the kittiwakes, with Ross's gull and swallow-tailed gull sharing a clade with these species. "Pagophila" is maintained as a unique genus because of the bird’s morphological, behavioral and ecological differences from these species. Colloquial names from Newfoundland include slob gull (from "slob", a local name for drift ice) and ice partridge, from a vague resemblance to a ptarmigan. This species is
Ivory gull Ivory gull The ivory gull ("Pagophila eburnea") is a small gull, the only species in the genus Pagophila. It breeds in the high Arctic and has a circumpolar distribution through Greenland, northernmost North America, and Eurasia. The ivory gull was initially described by Constantine Phipps, 2nd Baron Mulgrave in 1774 as "Larus eburneus" from a specimen collected on Spitsbergen. Johann Jakob Kaup later recognized the unique traits of the ivory gull and gave it a monotypic genus, "Pagophila", in 1829. Johan Ernst Gunnerus later gave the species a new specific name, "Pagophila alba". The genus name "Pagophila" is from Ancient