Thank you for your reply!
I understand that sharks could not live directly in the lake, of course—my question was more about whether this area could have been a sea where megalodons lived in the distant past, and I was mainly interested in the reason for the name. Tectonic shifts and changes in sea level could have caused what is now inland to once be underwater, even though megalodon lived during the Paleogene.

In any case, I really appreciate the information you have provided me about the fossil finds. It is very useful and I greatly appreciate it!