Australia - the original land of alligators

According to Australian researchers, the ancestors of alligators (American alligator and caïman) probably appeared on the supercontinent Gondwana, located in the southern hemisphere.

American alligator alligator (Photo: eveandersson)

Steven Salisbury and his team discovered in Queensland, Australia a fossil bone form about 95 million years ago that has a lot in common with modern crocodiles. Isisfordia duncani is a small crocodile, about 1 meter long, weighs 3-4 kilos. This size is much smaller than the modern crocodile with 7m in length.

This crocodile plays a very important role in the evolutionary history of crocodiles. The first reptiles shaped like crocodiles have appeared 200 million years ago.

Modern crocodiles began to grow in diversity from 80 million years ago. Isisfordia duncani appears just before this branching occurs and has the same ancestor with alligator alligator.

Until now, most fossil bones of modern crocodile species have been found in the northern hemisphere. That led the researchers to hypothesize that crocodiles began to grow in diversity in the north before appearing abundantly in the south.

Australia's discovery has a crucial role to learn more about the evolutionary history of crocodiles.