Placental mammals are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less developed young which are then nurtured for a period inside the mother's pouch. Placentalia represents the only living group within Eutheria, which contains all mammals more closely related to placentals than to marsupials.
Colugos are arboreal gliding mammals that are native to Southeast Asia. Their closest evolutionary relatives are primates. There are just two living species of colugos: the Sunda flying lemur and the Philippine flying lemur. These two species make up the entire family Cynocephalidae and order Dermoptera.
The patagium is a membranous body part that assists an animal in obtaining lift when gliding or flying. The structure is found in extant and extinct groups of flying and gliding animals including bats, birds, some dromaeosaurs, pterosaurs, gliding mammals, some flying lizards, and flying frogs. The patagium that stretches between an animal's hind limbs is called the uropatagium or the interfemoral membrane.
Stenomylus is an extinct genus of miniature camelid native to North America that is known from the Oligocene and Miocene epochs. Its name is derived from the Greek στενός and μύλος.
A number of animals are capable of aerial locomotion, either by powered flight or by gliding. This trait has appeared by evolution many times, without any single common ancestor. Flight has evolved at least four times in separate animals: insects, pterosaurs, birds, and bats. Gliding has evolved on many more occasions. Usually the development is to aid canopy animals in getting from tree to tree, although there are other possibilities. Gliding, in particular, has evolved among rainforest animals, especially in the rainforests in Asia where the trees are tall and widely spaced. Several species of aquatic animals, and a few amphibians and reptiles have also evolved this gliding flight ability, typically as a means of evading predators.
Acrophoca longirostris, sometimes called the swan-necked seal, is an extinct genus of Late Miocene pinniped. It was thought to have been the ancestor of the modern leopard seal; however, it is now thought to be a species of monk seal.
Eurhinodelphis is an extinct genus of Miocene cetacean. Its fossils have been found in Belgium, France, and Maryland.
Pachyrukhos is an extinct genus of hegetotheriid notoungulate from the Early to Middle Miocene of Argentina and Chile. Fossils of this genus have been found in the Collón Curá, Sarmiento and Santa Cruz Formations of Argentina and the Río Frías Formation of Chile.
Diacodexis is an extinct genus of small herbivorous mammals belonging to the family Diacodexeidae that lived in North America, Europe and Pakistan from 55.4 mya to 46.2 mya and existing for approximately 9.2 million years.
Birbalomys is an extinct genus of rodent from Asia.
Tremacebus is an extinct genus of New World monkeys from the Early Miocene. The type species is T. harringtoni.
Mesopithecus is an extinct genus of Old World monkey that lived in Europe and Asia 7 to 5 million years ago. Mesopithecus resembled a modern macaque, with a body length of about 40 centimetres (16 in). It was adapted to both walking and climbing, possessing a slender body with long, muscular limbs and flexible fingers. Its teeth suggest that it primarily ate soft leaves and fruit. It was once thought that these extinct monkeys might be an ancestor of the grey langur, but a study in 2004 suggested that they are more closely related to the snub-nosed monkeys and doucs.
The Sunda flying lemur, Sunda colugo, Malayan flying lemur or Malayan colugo is the sole colugo species of the genus Galeopterus native to Southeast Asia ranging from southern Myanmar, Thailand, southern Vietnam, Malaysia to Singapore and Indonesia.
The Philippine flying lemur or Philippine colugo, known locally as kagwang, is one of two species of colugo or "flying lemurs". It is monotypic of its genus. Although it is called "flying lemur", the Philippine flying lemur is neither a lemur nor does it fly. Instead, it glides as it leaps among trees.
A toothcomb is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates, treeshrews, colugos, hyraxes, and some African antelopes. The structures evolved independently in different types of mammals through convergent evolution and varies both in dental composition and structure. In most mammals the comb is formed by a group of teeth with fine spaces between them. The toothcombs in most mammals include incisors only, while in lemuriform primates they include incisors and canine teeth that tilt forward at the front of the lower jaw, followed by a canine-shaped first premolar. The toothcombs of colugos and hyraxes take a different form with the individual incisors being serrated, providing multiple tines per tooth.
Dendropithecus is an extinct genus of apes native to East Africa between 20 and 15 million years ago. Dendropithecus was originally suggested to be related to modern gibbons, based primarily on similarities in size, dentition, and skeletal adaptations. However, further studies have shown that Dendropithecus lacks derived hominoid traits. Instead, the traits shared between this taxon and modern primates are primitive for all catarrhines. Dendropithecus is now considered to be a stem catarrhine, too primitive to be closely related to any modern primates.
Mixodectidae is an extinct family of insectivorous placental mammals in the order Dermoptera. The mixodectids originated in the late Cretaceous and survived into the Paleocene in Europe and North America.
Astrapotherium is an extinct genus of large astrapotherian ungulate native to South America during the early-middle Miocene. It is the best known member of the group. The type species. A. magnus have been found in the Santa Cruz Formation in Argentina. Other fossils have been found in the Deseado, Sarmiento, and Aisol Formations of Argentina and Chile.
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 were probably forested environments and the fossil species were probably forest dwellers like living colugos, but whether they had the gliding adaptations of the living species is unknown.
The Ghosts in Our Machine is a 2013 Canadian documentary film by Liz Marshall. The film follows the photojournalist and animal rights activist Jo-Anne McArthur as she photographs animals on fur farms and at Farm Sanctuary, among other places, and seeks to publish her work. The film as a whole is a plea for animal rights.
