What was the biggest crocodile that ever lived? (It can be extinct)

Sarcosuchus imperator

Explanation:

The biggest freshwater croc ever, Sarcosuchus imperator, lived 110 million years ago, grew as long as 40 feet (12 meters), and weighed up to eight metric tons (17,500 pounds).

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.