As much as I would love to think a relic population could survive I’m afraid it is so unlikely as to be impossible. A creature of that size would have a pretty high caloric intake, especially if they needed to search far and wide for food sources. Perhaps an altered version might exist but if it does I have to guess it would be around the size of a lowland gorilla. 5 million years is a lot of time for evolution to have its way with you, not to mention the possibility of cross breedings and bottle necked populations. But then again, considering the tree lobster story posted recently, maybe there is a slim chance.