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
Ring-tailed lemur Molecular analysis suggests that either the bamboo lemurs diverged from the ring-tailed lemur, making the group monophyletic and supporting the current 3-genera taxonomy, or that the ring-tailed lemur is nested in with the bamboo lemurs. The karyotype of the ring-tailed lemur has 56 chromosomes, of which four are metacentric (arms of nearly equal length), four are submetacentric (arms of unequal length), and 46 are acrocentric (the short arm is hardly observable). The X chromosome is metacentric and the Y chromosome is acrocentric. Linnaeus first used the genus name "Lemur" to describe ""Lemur tardigradus"" (the red slender loris, now known as