Fossil evidence for continental drift
Topic: Continental Drift, Sea-floor Spreading and Plate Tectonics · NCERT: Class 11, Ch 4 "Distribution of Oceans and Continents"
Meaning
Fossil evidence for continental drift means finding the same land or freshwater species on continents that are now separated by wide oceans. Such animals and plants could not have crossed open sea. The best explanation is that these continents were once joined and later drifted apart. Wegener used this as one of his main kinds of evidence.
Example
Lemurs live in India, Madagascar and Africa. This once led some people to imagine a lost land bridge called "Lemuria". In another case, Mesosaurus, a small reptile of shallow brackish (slightly salty) water, is found only in South Africa and Brazil, which are now 4,800 km apart. Other standard examples are the Glossopteris fern flora and the land reptiles Lystrosaurus and Cynognathus. These are found across the old Gondwana lands, including India.
Don't confuse with
- Evidence for sea-floor spreading: This evidence comes from the ocean floor, such as rock ages, magnetism and earthquake depth. "Fossil distribution was used as evidence for sea-floor spreading" is false, because fossils support continental drift.