Digital Atlas of Scientific Life
- Class Gastropoda (digitalatlasofancientlife.org)
Gastropods are the second largest class of animals (after the Insecta)—with 40,000–90,000 living species and at least 13,000 extant and fossil genera (Ponder and Lindberg, 2020)—and are also one of the most evolutionarily successful groups in the variety of ecosystems and habitats that they occupy.
- Antarctica - The World Factbook (cia.gov)
Speculation over the existence of a “southern land” was confirmed in the early 1820s when British and American commercial operators and British and Russian national expeditions began exploring the Antarctic Peninsula region and other areas south of the Antarctic Circle. In 1840, it was finally established that Antarctica was indeed a continent and not merely a group of islands or an area of ocean.