Sealandia

Sealandia is a hypothetical continent proposed by geologists and paleontologists to explain the distribution of certain fossil finds, particularly those from the Mesozoic Era. The concept suggests that during certain geological periods, a large landmass existed in the southern hemisphere, encompassing parts of what are now South America, Africa, Antarctica, Australia, and India. This supercontinent is theorized to have broken apart, with its constituent pieces drifting to their current locations.

The primary evidence supporting Sealandia's existence comes from the discovery of identical fossil species on widely separated continents. For instance, fossils of the reptile Mesosaurus have been found in both South America and Africa, and the Glossopteris plant fossil is present across Australia, India, South America, and Antarctica. The existence of Sealandia provides a plausible mechanism for how these organisms could have spread across such vast distances before the continents separated.

While the term "Sealandia" is sometimes used colloquially, the scientifically accepted term for this ancient supercontinent is Gondwana. Gondwana was a major component of the larger supercontinent Pangea, which existed during the Paleozoic and Mesozoic eras. The breakup of Gondwana, a process that began in the Jurassic period, led to the formation of the southern continents as we know them today. The study of continental drift and plate tectonics has provided robust evidence for the existence and breakup of these ancient landmasses.