Island of Resurgence: A Haven for Ancient Creatures and Human Colonists

In your alternate scenario, let's christen this biologically lush island as "Nueva Pangea." Discovered in the early Holocene period, between 4,000 and 2,000 years ago by seafaring settlers from both North and South America, it features an incredibly diverse ecosystem derived primarily from animals of the North American mainland during the Eocene, Oligocene, Miocene, Pliocene, and Pleistocene eras. This island is located in the Pacific Ocean, twice the size of Madagascar, and lies just over 50 miles off the Pacific coast of Mexico. One of the most iconic creatures on Nueva Pangea are the evolved descendants of adapiform primates, also known as "American lemurs." These arboreal creatures are comparable to the true lemurs of Madagascar and monkeys of South America, Asia and mainland Africa and have diverse species filling different ecological niches across the island's forests. Another notable animal is the Nueva Pangean Brontothere, reminiscent of prehistoric rhinoceros-like creatures, which has evolved into a formidable beast of burden revered by the locals despite its size. The local Entelodonts have also developed unique characteristics in line with the island's predator-prey dynamic. Reminiscent of predatory pigs, they have grown large and robust. Chalicotheres browsing on tree canopies, mastodons and Columbian mammoths grazing in herds, sloths hanging from trees, persisting descendants of Tapirus californicus hiding in shrubbery, herds of peccaries trotting through grasslands, placid opossums foraging at night, peculiar platypus-like monotremes in the rivers, a fascinating array of bats fluttering about, a plethora of avian species that have adapted perfectly to the island; all these create an even more intriguing biodiversity. Imposing caimans, alligators and gharial-like crocodiles dominate Nueva Pangea's waters alongside large populations of tortoises, both terrestrial (gopher tortoises) and marine (giant sea tortoises). A sight that goes beyond a reader's wildest imaginations being the persistence of dinosaurs in the form of troodontids and thescelosaurs. These late surviving Mesozoic remnants add another layer of wonder to this fascinating location. Nueva Pangea was first colonized by human settlers during the early Holocene and its population has now grown to around 1 million native people with a rich cultural tapestry, interspersed by the introduction of European settlers in the late 19th century. Despite the influx of settlers, the island’s local fauna and people have been symbiotic, leading to a developed yet ecologically harmonious society.