there is no scientific evidence or consensus on the existence of time travel, and no known functioning time machine has been created. The possibility of traveling into the past using any kind of machine remains purely speculative and falls within the realm of science fiction.
If time travel were possible, the question of who may have traveled to the past before us is speculative and would depend on the specific theory or model of time travel being considered. Some theories propose the idea of closed timelike curves, where time loops back on itself, allowing events in the past to have already been influenced by future actions. In such a scenario, it would be conceivable that individuals from the future have already traveled to the past and influenced events.
However, it is important to note that these concepts are highly theoretical and not supported by scientific evidence at present. Time travel to the past raises a range of complex paradoxes and logical inconsistencies, such as the famous grandfather paradox (the notion of going back in time and preventing your own existence).
As for the question of who may have traveled to the past before us, without concrete evidence of time travel, it is impossible to know for certain. In the absence of empirical data, any claims of past time travelers would be purely speculative and fall within the realm of imagination, science fiction, or urban legends.