South Georgia & south sandwich islands

The South Georgia Pipit (eBird) breeds farther south than any other songbird. The South Georgia Pintail Anas georgica (CalPhotos) is sometimes considered distinct from the more widespread Yellow-tailed Pintail Anas spinicauda. The South Georgia Shag (eBird) is also sometimes restricted to populations from South Georgia. The South Georgia Gentoo Penguin (Species New to Science) (iNaturalist) has recently been recognized as a full species.

Marine fish known exclusively from South Georgia include the Antarctic Sculpin Bathylutichthys taranetzi (FishBase), the Antarctic dragonfishes Parachaenichthys georgianus (FishBase) and Psilodraco breviceps (BHL), a snailfish Careproctus georgianus (BHL), the South Georgian Plunderfish Artedidraco mirus (FishBase), the Permitin Spiny Plunderfish Harpagifer permitini (Semantic Scholar WM), the Narrowhead Rockcod Gobionotothen angustifrons (BHL), and the Orange Notothen Pseudotrematomus vicarius (BHL).

Arthropods unique to South Georgia include the perimylopid beetles Hydromedion sparsutum (p. 20 of MTU pdf) (iNaturalist) and Perimylops antarcticus (flickr) (iNaturalist), a water beetle Lancetes claussi (flickr), a midge Eretmoptera murphyi (flickr), a chalcidoid wasp Notomymar aptenosoma (Bishop Museum WM pdf), a springtail Friesea grisea (Semantic Scholar WM), and the spiders Notiomaso grytvikensis (South Georgia Newsletter WM) and Notiomaso spei (BioOne). Entrychid worms known only from South Georgia include Marionina fusca (GBIF) and Marionina collpites (GBIF).

Endemic marine molluscs include Margarella achilles (Eddie Hardy), Gigantopelta chessoia (Wikipedia), Provanna cooki (ResearchGate), Bruceiella indurata (Species New to Science), Spinaxinus caldarium (ResearchGate), Amauropsis powelli (Eddie Hardy), Lissotesta (or Submargarita) notalis (fig. 10 at BHL), Chlanidota paucispiralis (Eddie Hardy), Proneptunea duplicarinata (fig. 13 at BHL), Skenella wareni (fig. C at BHL), Trophon distantelamellatus (WMSDB), and Neolepton georgianum (BHL). Other endemic marine invertebrates include a sponge Iophon husvikensis (fig. 4 at ResearchGate) and the isopod crustaceans Vanhoeffenura eltaniae (GBIF) and Rectisura sepigia (GBIF). A family of copepod crustaceans, the Codobidae (BHL) (Oxford Academic), is a parasite of brittle stars and known only from South Georgia.

There are no endemic vascular plant species (the sedge previously known as Uncinia smithii is a synonym of Uncinia macrolepis). Endemic non-vascular plants include the liverworts Austrolembidium crassum (GBIF) and Acrolophozia sulcata (GBIF) (Taylor & Francis) and a moss Bucklandiella longtonii (Schweizerbart). There are four endemic algae species (Internet Archive).

South Georgia is an overseas territory of the United Kingdom and part of the Scotia Sea Islands Tundra terrestrial ecoregion (EoE). Information on levels of endemism for marine species can be found at (PLOS). A list of endemic marine gastropods can be found at (BHL).