Easter Island, together with its closest neighbor, the tiny island of Isla Sala y Gómez 415 kilometers (258 mi) further east, is recognized by ecologists as a distinct ecoregion, the Rapa Nui subtropical broadleaf forests. The original subtropical moist broadleaf forests are now gone, but paleobotanical studies of fossil pollen and tree moulds left by lava flows indicate that the island was formerly forested, with a range of trees, shrubs, ferns, and grasses. A large extinct palm, Paschalococos disperta, related to the Chilean wine palm (Jubaea chilensis), was one of the dominant trees as attested by fossil evidence. Like its Chilean counterpart it probably took close to 100 years to reach adult height. The Polynesian rat, which the original settlers brought with them, played a very important role in the disappearance of the Rapanui palm. Rat teeth marks can be observed in 99% of the nuts found preserved in caves or excavated in different sites, indicating that the Polynesian rat impeded the palm's reproduction. That, and the clearance of the palms to make the settlements, led to their extinction almost 350 years ago.