I have not checked because I am on a Tablet..
I suspect that you have a 40-pin display. The ILI9341 version will say 9341 on pcb and probably on antistatic envelope.
Buy a 40-pin adapter shield for Mega2560. Plug display into adapter shield on your MEGA2560 board.
Install UTFT and URTouch libraries.
Use ILI9341_16 model for ILI9341 or SSD1289 model for SSD1289 in the constructor() statement.
David.