One of the differences between cambrian animals and precambrian animals was the appearance such as antenne as cambrian animals evolved.

The difference that you are searching for is the addition of Appendages. They appeared in Cambrian animals and were used to increase their physical capabilities like when sensing and processing the information found in the environment. Common appenadges found in animals are things like antennae found in insects that are used to help them communicate or notice things or similar things.

Wetlands form where water and land meet. a lake with a wetland fringe can fill in with decayed plant and animal material to become a wet meadow. a pond can fill in to become a bog or fen. sediment can fill in a river marsh to become a swamp.flooding of coastal lowlands from rising sea levels has created broad coastal marshes that are protected from wave action by barrier islands or reefs. coastal wetlands also form when rivers deposit sediment as they reach the ocean. plants then take root and hold the soil firm against the forces of tides and waves.