The Malagasy rats and mice are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble gerbils, rats, mice, voles, and even rabbits. There are arboreal, terrestrial, and semi-fossorial varieties.
Ambondro mahabo is a mammal from the middle Jurassic of Madagascar. The only species of the genus Ambondro, it is known from a fragmentary lower jaw with three teeth, interpreted as the last premolar and the first two molars. The premolar consists of a central cusp with one or two smaller cusps and a cingulum (shelf) on the inner, or lingual, side of the tooth. The molars also have such a lingual cingulum. They consist of two groups of cusps: a trigonid of three cusps at the front and a talonid with a main cusp, a smaller cusp, and a crest at the back. Features of the talonid suggest that Ambondro had tribosphenic molars, the basic arrangement of molar features also present in marsupial and placental mammals. It is the oldest known mammal with putatively tribosphenic teeth; at the time of its discovery it antedated the second oldest example by about 25 million years.
Megalomys audreyae, known as the Barbudan (?) muskrat or the Barbuda giant rice-rat, is an extinct oryzomyine rodent from Barbuda in the Lesser Antilles. Described on the basis of a single mandible with the first molar missing and an isolated upper incisor, both of uncertain but Quaternary age, it is one of the smaller members of the genus Megalomys. Little is known about the animal, and its provenance and distinction from "Ekbletomys hypenemus", an even larger extinct oryzomyine that also occurred on Barbuda, have been called into question. The toothrow in the lower jaw has a length of 8.7 mm at the alveoli. The third molar is relatively narrow and both the second and third molars have a wide valley between their outer cusps.
Juliomys anoblepas is a rodent in the genus Juliomys of the subfamily Sigmodontinae known from a single broken skull. The specimen was collected by Peter Wilhelm Lund in the caves of Lagoa Santa, Minas Gerais, Brazil, in the first half of the 19th century and described by Herluf Winge in 1888 as Calomys anoblepas. The species remained unstudied and its affinities unclear until 2011, when it was recognized as a member of the genus Juliomys, which includes three other species from southern Brazil and nearby Argentina and Paraguay. J. anoblepas is probably a separate extinct species of the genus, which is no longer found at Lagoa Santa.
Hipposideros besaoka is an extinct bat from Madagascar in the genus Hipposideros. It is known from numerous jaws and teeth, which were collected in a cave at Anjohibe in 1996 and described as a new species in 2007. The site where H. besaoka was found is at most 10,000 years old; other parts of the cave have yielded H. commersoni, a living species of Hipposideros from Madagascar, and some material that is distinct from both species. H. besaoka was larger than H. commersoni, making it the largest insectivorous bat of Madagascar, and had broader molars and a more robust lower jaw. As usual in Hipposideros, the second upper premolar is small and displaced from the toothrow, and the second lower premolar is large.
Triaenops goodmani is an extinct bat from Madagascar in the genus Triaenops. It is known from three lower jaws collected in a cave at Anjohibe in 1996, and described as a new species in 2007. The material is at most 10,000 years old. A bat humerus from the same site could not be identified as either T. goodmani or the living T. menamena. T. goodmani is identifiable as a member of Triaenops or the related genus Paratriaenops by a number of features of the teeth, such as the single-cusped, canine-like fourth premolar and the presence of a gap between the entoconid and hypoconulid cusps on the first two molars. T. goodmani is larger than the living species of Triaenops and Paratriaenops on Madagascar, and on the first molar the protoconid cusp is only slightly higher than the hypoconid, not much higher as in the other species.
Wabulacinus ridei lived during the early Miocene in Riversleigh. It is named after David Ride, who made the first revision of thylacinid fossils. The material was found in system C of the Camel Spurtum assembledge.
Lagrivea is a fossil genus of squirrel from the Middle Miocene of France. The single species, L. vireti, is known from three mandibles and two isolated teeth. All come from the fissure filling of La Grive L5, part of the La Grive-Saint-Alban complex in Saint-Alban-de-Roche, southeastern France. Lagrivea was a large tree squirrel with flat lower incisors and a large, triangular fourth lower premolar (p4). Each of the four cheekteeth bears a deep basin in the middle of the crown. The m3 is about rectangular in shape, but rounded at the back. Although m1 and m2 have two roots, m3 has three.
Agathaeromys is an extinct genus of oryzomyine rodents from the Pleistocene of Bonaire, Netherlands Antilles. Two species are known, which differ in size and some details of tooth morphology. The larger A. donovani, the type species, is known from hundreds of teeth, found in four localities that are probably 900,000 to 540,000 years old. A. praeuniversitatis, the smaller species, is known from 35 teeth found in a single fossil site, which is probably 540,000 to 230,000 years old.
Pennatomys nivalis is an extinct oryzomyine rodent from the islands of Sint Eustatius, Saint Kitts, and Nevis in the Lesser Antilles. The only species in the genus Pennatomys, it is known from skeletal remains found in Amerindian archeological sites on all three islands, with dates ranging from 790–520 BCE to 900–1200 CE. No live specimens are known, but there are several historical records of rodents from Saint Kitts and Nevis that could conceivably refer to Pennatomys. The animal apparently belongs to a group within the tribe Oryzomyini that includes many other island-dwelling species.
The Malagasy mountain mouse or Koopman's montane voalavo(Monticolomys koopmani) is a rodent within the subfamily Nesomyinae of the family Nesomyidae. It is monotypic within the genus Monticolomys, and is closely related to the big-footed mouse (Macrotarsomys). It is found in the highlands of eastern Madagascar. A small mouse-like rodent, it is dark brown on the upperparts and dark gray below. It has small, rounded, densely haired ears and broad feet with well-developed pads. The long tail lacks a tuft at the tip. The skull is delicate and lacks crests and ridges on its roof.
? Nycticebus linglom is a fossil strepsirrhine primate from the Miocene of Thailand. Known only from a single tooth, an upper third molar, it is thought to be related to the living slow lorises, but the material is not sufficient to assign the species to Nycticebus with certainty, and the species name therefore uses open nomenclature. With a width of 1.82 mm, this tooth is very small for a primate. It is triangular in shape, supported by a single root, and shows three main cusps, in addition to various crests. The absence of a fourth cusp, the hypocone, distinguishes it from various other prosimian primates.
Tupaia miocenica is a fossil treeshrew from the Miocene of Thailand. Known only from a single tooth, an upper first or second molar, it is among the few known fossil treeshrews. With a length of 3.57 mm, the tooth is large for a treeshrew. At the back lingual corner, the tooth shows a small cusp, the hypocone, that is separated from the protocone in front of it by a narrow valley. The condition of the hypocone distinguishes this species from various other treeshrews. In addition, the presence of a well-developed but simple mesostyle is distinctive.
Dermotherium is a genus of fossil mammals closely related to the living colugos, a small group of gliding mammals from Southeast Asia. Two species are recognized: D. major from the Late Eocene of Thailand, based on a single fragment of the lower jaw, and D. chimaera from the Late Oligocene of Thailand, known from three fragments of the lower jaw and two isolated upper molars. In addition, a single isolated upper molar from the Early Oligocene of Pakistan has been tentatively assigned to D. chimaera. All sites where fossils of Dermotherium have been found probably developed in forested environments and the fossil species probably were forest dwellers like living colugos, but whether they already had the gliding adaptations of the living species is unknown.
Afrasia djijidae is a fossil primate that lived in Myanmar approximately 37 million years ago, during the late middle Eocene. The only species in the genus Afrasia, it was a small primate, estimated to weigh around 100 grams (3.5 oz). Despite the significant geographic distance between them, Afrasia is thought to be closely related to Afrotarsius, an enigmatic fossil found in Libya and Egypt that dates to 38–39 million years ago. If this relationship is correct, it suggests that early simians dispersed from Asia to Africa during the middle Eocene and would add further support to the hypothesis that the first simians evolved in Asia, not Africa. Neither Afrasia nor Afrotarsius, which together form the family Afrotarsiidae, is considered ancestral to living simians, but they are part of a side branch or stem group known as eosimiiforms. Because they did not give rise to the stem simians that are known from the same deposits in Africa, early Asian simians are thought to have dispersed from Asia to Africa more than once prior to the late middle Eocene. Such dispersals from Asia to Africa also were seen around the same time in other mammalian groups, including hystricognathous rodents and anthracotheres.
Indraloris is a fossil primate from the Miocene of India and Pakistan in the family Sivaladapidae. Two species are now recognized: I. himalayensis from Haritalyangar, India and I. kamlialensis from the Pothohar Plateau, Pakistan. Other material from the Potwar Plateau may represent an additional, unnamed species. Body mass estimates range from about 2 kg (4.4 lb) for the smaller I. kamlialensis to over 4 kg (8.8 lb) for the larger I. himalayensis.
Apeomyoides savagei is a fossil rodent from the Miocene of the United States, the only species in the genus Apeomyoides. It is known from fragmentary jaws and isolated teeth from a site in the early Barstovian, around 15–16 million years ago, of Nevada. Together with other species from scattered localities in the United States, Japan, and Europe, Apeomyoides is classified in the subfamily Apeomyinae of the extinct rodent family Eomyidae. Apeomyines are a rare but widespread group that may have been adapted to a relatively dry habitat.
