The Derivative Delta is a marshy piece of land in the Fiddler's Green region of the island. It is best known for containing a gigantic amount of fossils, oddly enough overwhelmingly primate in nature. Researchers found that all of these primates somehow are derivative of one another when it comes to their official species classification. With there only being very minor differences in these primates making it hard to truly correctly classify them it has been determined that this area will be a archeological site for years to come. A recent survey trying to date the different remains has led to proving without a shadow of a doubt that most of these different primate species lived within a single year of one another.
It is almost impossible to correctly classify all of the fossils in the marsh, given the very subtle differences between species. The sheer amount of fossils stacked on top of one another also doesn't make it easier for archeologists to separate the fossils correctly. This contributes to the fact that archeologists become intensely bored while classifying primates. The burnout rate on the archeological site ensures that we haven't seen the last of these primates get dug up from the swampy area.