What are the effects of introducing 2600 sharks of the primitive Edestus Gigantus specie* in modern waters in different places on earth? Will they survive, how ? for how long? can they destroy the environment as being ''new'' predators to animals that didn't adapt to them?
The information on the net about this shark is not very detailed, but a recent census puts the population of its' nearest modern counterpart, the Great White Shark, at about 2400.
So what you are basically doing is doubling the number of potentially enormous sharks into a world where other shark populations are declining rapidly.
Would it unbalance the entire eco-system? Probably not. Certainly no more than the depopulation that human fisheries are already doing.
As for whether they would survive in our modern oceans... again probably not. A couple dozen would end up living in artificial habitates at seaquriums and ocean-themed amusement parts, and the rest would end up stuffed and hanging on some human's wall.
We are the apex predators of this world and no ugly fish, even a giant one, stands a chance against our numbers or our savagery!
First off, the only parts recovered from that fish are its teeth, so the ecology of that shark is...incomplete....to say the least. Also, the paper sited from wikipedia straight up says they have no idea what its odd tooth structure was for.
However, one thing that might be relevant is the Mesozoic Marine Revolution. Basically, before the Mesozoic (i.e. the age of the Dinosaurs), which is the age that Edestus lived in, durophagous (shell-crushing/eating) predation hadn't really evolved. There were several forms of life, like crinoids and brachiopods that used to be common/dominant were pushed out because their soft shells were no protection against new fish and reptile predators with more powerful jaws. Modern corals and bivalves replaced the crinoids and brachiopids, respectively; both of these modern groups have much stronger and tougher shells.
In any case, since Edestus lived in before the Mesozoic, there is a solid chance that those jaws are specialized for eating somethign that doesn't exist any more. Therefore, to answer your question, the 2600 Edestus will immediately starve and die.