"Few birds are as likely to start as many arguments among paleontologists as 'vegavis,'" said professor Christopher Torres.

Located 3,000 miles below the Earth's surface, the inner core is anchored by gravity within the molten liquid outer core. Until now the inner core was widely thought of as a solid sphere.

A land of spectacular scenery and unique wildlife, many cruises of the southern hemisphere enable you to see Antarctica, but only dedicated itineraries with smaller ships actually take you ashore.