Gigantic Fish that outlived the Dinosaurs exist today, they are called sturgeon, and we really need to appreciate how gigantic they truly are.
We really have to have a discussion about how absolutely massive sturgeon are.
Sturgeons are fascinating creatures and we forget that such ancient beings swim in rivers and lakes throughout the world. These things are even found in the Hudson river which is just a couple blocks away from where I am currently writing.
Sturgeon are ancient creatures, they haven't changed in millions of years. They exist in the fossil record for 120 million years. They outlived the dinosaurs and live up to 60 years. The largest was 24 ft long and 3,436 lbs.
Absolute monsters just swimming in waterways we all frequent.