Archaeoindris
Though similar to "Palaeopropithecus", "Archaeoindris" was significantly larger and more robust. "Archaeoindris" was one of the largest primates to ever evolve, and was the largest-known strepsirrhine primate, weighing an estimated . It was roughly the size of an adult male gorilla, which was first noted by Lamberton.
Phong Nha-Kẻ Bàng National Park
The park is home to significant populations of primates in Vietnam, with ten species and sub-species. These include the globally vulnerable pig-tailed macaque, Assam macaque, stump-tailed macaque and white-cheeked crested gibbon ("Nomascus leucogenys" and "Nomascus leucogenys siki"). The park is probably home to the largest population of François' langur in Vietnam, including two different forms of the species. The area is highly significant for its population of Hatinh langur and black langur. It is undoubtedly the largest population of these species in the world, and probably the only population represented in a protected area. Other endangered large mammals include the mainland serow ("Capricornis sumatraensis"), giant muntjac ("Megamuntiacus vuquangensis") and possibly the saola ("Pseudoryx nghetinhensis"). The Asian black bear ("Selenarctos thibetanus") and sun bear ("Helarctos malayanus") are confirmed. Other smaller mammals include Sunda pangolins ("Manis javanica") and the recently discovered striped hare, called locally "tho van" ("Nesolagus timminsii"). Ten bat species listed in the IUCN List of Threatened Species have been recorded in this park.