Q.20 Did aquatic life forms get fossilised? If, yes where do we come across such fossils?

Yes, aquatic forms of life do get fossilised, infact, there are more aquatic than terrestrial fossil organisms. Such fossils of sea creatures are found in mountains as opposed to deep sea beds. 

This is because the rocks in which the fossils are found used to be at bottom of oceans. Due to the changes in the crustal plates over time, the ocean sediments were pushed up to form mountains.