The Flores giant rat (Papagomys armandvillei) is an extinct species of rodent belonging to the Muridae family. It was endemic to the island of Flores in Indonesia and is known exclusively from subfossil remains discovered in archaeological and paleontological sites. Its name reflects its considerable size, being significantly larger than most extant rat species.
Description and Size The Flores giant rat was a remarkably large rodent. Based on skeletal remains, it is estimated to have weighed around 1.5 kilograms (3.3 pounds), possibly reaching up to 2 kilograms (4.4 pounds), making it one of the largest murid rodents ever known. Its teeth suggest an adaptation for a diet of tough plant material, possibly including leaves, fruits, and stems, indicative of a largely herbivorous or omnivorous diet. Its large size is a common feature of island gigantism, a phenomenon where species on islands evolve to become larger than their mainland relatives due to reduced predation pressure and resource availability.
Habitat and Discovery Remains of Papagomys armandvillei have been found in various cave deposits on Flores, notably Liang Bua, the same site where the remains of Homo floresiensis (the "hobbit") were discovered. These archaeological contexts suggest that the Flores giant rat coexisted with early human populations on the island for a significant period. Its habitat would have encompassed the diverse forest ecosystems of Flores.
Extinction The exact timing and cause of the Flores giant rat's extinction are not precisely determined, but it is believed to have disappeared relatively recently, likely within the last 1,000 to 2,000 years. While the exact factors are debated, the extinction of this species, like much of Flores's unique megafauna, is generally attributed to the arrival and expansion of modern human populations on the island. Contributing factors may include overhunting, habitat destruction due to agricultural expansion, and the introduction of invasive species (such as domesticated rats, cats, or dogs) that competed for resources or preyed upon the giant rats.
Related Species The genus Papagomys includes another extinct giant rat from Flores, Papagomys theodorverhoeveni (Verhoeven's giant tree rat), which was somewhat smaller than P. armandvillei. The existence of these two large species highlights the unique evolutionary history of Flores, an island known for its distinctive fauna, including dwarf elephants (Stegodon florensis insularis) and the enigmatic Homo floresiensis.