Mesosaurus
Topic: Continental Drift, Sea-floor Spreading and Plate Tectonics · NCERT: Class 11, Ch 4 "Distribution of Oceans and Continents"
Meaning
Mesosaurus was a small reptile that lived in shallow brackish water, meaning slightly salty water. Its fossils are found only in two places: the southern Cape province of South Africa and the Irati formations of Brazil. These are now 4,800 km apart across the Atlantic. Such a small shallow-water animal could not have swum across a wide, deep ocean. So the two continents must once have been joined. This makes Mesosaurus a key fossil proof of continental drift.
Example
Mesosaurus skeletons from the Irati formations of Brazil (eastern South America) match those from the southern Cape province of South Africa. This links two coasts that now face each other across the South Atlantic.
Don't confuse with
- Lemurs: Lemurs are living animals found today in India, Madagascar and Africa. Mesosaurus is an extinct reptile known only from fossils in South Africa and Brazil.
Related concepts
- Jigsaw fit of continents
- Rocks of the same age across oceans
- Radiometric dating
- Tillite
- Fossil evidence for continental drift