皮翼目目

名称来历

鼯猴名称描述其外观像鼯鼠又像狐猴，其面部像狐猴，又可以像鼯鼠一样滑行，但与两者无关。

习性

滑翔能力极强。

分类

本目是灵长总目的成员，当中的灵长目是本目的现存姐妹群，两者共同组成灵长形上目。

内部分类

史前曾经有许多个科，鼯猴科的成员也比现在多。与史前比较，本目多样性是处在衰败状态下，现仅存1科2属2种。已知现存与化石成员如下：

• 鼯猴科 Cynocephalidae
• 鼯猴属 Cynocephalus
• 菲律宾鼯猴 Cynocephalus volans
• 斑鼯猴属 Galeopterus
• 巽他鼯猴 Galeopterus varigatus
• †皮翼兽属 Dermotherium
• †大皮翼兽 Dermotherium major
• †怪皮翼兽 Dermotherium chimaera
• †混咬兽科 Mixodectidae
• †混咬兽属 Mixodectes
• †Dracontolestes
• †Dracontolestes aphantus
• †Eudaemonema
• †Eudaemonema cuspidata
• †侧膜兽科 Plagiomenidae
• †侧膜兽属 Plagiomene
• †游翔兽属 Planetetherium

Colugos , flying lemurs, or cobegos , are arboreal gliding primatomorphs that are native to Southeast Asia. Their evolutionary closest relatives are primates. There are just two living species of colugos: the Sunda flying lemur (Galeopterus variegatus) and the Philippine flying lemur (Cynocephalus volans). These two species make up the entire family Cynocephalidae and order Dermoptera, from Ancient Greek δέρμα (dérma), meaning "skin", and πτερόν (pterón), meaning "wing".

Characteristics

Colugos are nocturnal, tree-dwelling, gliding mammals.

Appearance and anatomy

They reach lengths of 35 to 40 cm (14 to 16 in) and weigh 1 to 2 kg (2.2 to 4.4 lb). They have long, slender front and rear limbs, a medium-length tail, and a relatively light build. The head is small, with large, front-focused eyes for excellent binocular vision, and small rounded ears.

The incisor teeth of colugos are highly distinctive; they are comb-like in shape with up to 20 tines on each tooth. The incisors are analogous in appearance and function to the incisor suite in strepsirrhines, which is used for grooming. The second upper incisors have two roots, another unique feature among mammals. The dental formula of colugos is: 2.1.2.33.1.2.3

Movement

Colugos are proficient gliders, and thought to be better adapted for flight than any other gliding mammal. They can travel as far as 70 m (230 ft) from one tree to another without losing much altitude, with a Malayan colugo (Galeopterus variegatus) individual having been observed traveling about 150 m (490 ft) in one glide.

Their ability to glide is possible because of a large membrane of skin that extends between their paired limbs. This gliding membrane, or patagium, runs from the shoulder blades to the fore paws, from the tip of the rear-most fingers to the tip of the toes, and from the hind legs to the tip of the tail. Colugos' gliding ability is aided by specialized muscles that control the tension and movement of the gliding membrane. The platysma myoides and platysma cervicale help adjust the patagium’s shape for better control during flight. The sternomastoideus and cleidomastoideus stabilize the head and neck, improving balance and maneuverability mid-air.

Status

Both species are threatened by habitat destruction, and the Philippine flying lemur was once classified by the IUCN as vulnerable. In 1996, the IUCN declared the species vulnerable owing to destruction of lowland forests and hunting. It was downlisted to least-concern status in 2008 but still faces the same threats. In addition to the ongoing clearing of its rainforest habitat, it is hunted for its meat and fur. It is also a favorite prey item for the critically endangered Philippine eagle; some studies suggest colugos account for 90% of the eagle's diet.

Etymology

Their family name Cynocephalidae comes from the Ancient Greek κύων (kúon), meaning "dog", and κεφαλή (kephalḗ), meaning "head", because their heads are broad with short snouts like dogs.

Classification and evolution

The ancestors of the colugos are estimated to split from other mammals about 80 million years ago, leading to the present-day forms, which may include up to 14 extant species. Mixodectidae and Plagiomenidae are two extinct families of North American mammals which may represent fossil dermopterans or at least close relatives. However, some studies doubt a close relationship between these families and modern dermopterans (Cynocephalidae). A complete skeleton of Mixodectes shows that, though it was well-adapted for an arboreal lifestyle, it had no adaptations for gliding. Although other Paleogene mammals have been interpreted as related to dermopterans, the evidence for this association is uncertain and many of the fossils are no longer interpreted as being gliding mammals. At present, the fossil record of definitive dermopterans is limited to two species of the Eocene and Oligocene cynocephalid genus Dermotherium.

Molecular phylogenetic studies have demonstrated that colugos emerged as a basal Primatomorpha clade – which, in turn, is a basal Euarchontoglires clade. Scandentia are widely considered to be the closest relatives of Primatomorpha, within Euarchonta. Some studies, however, place Scandentia as sister of Glires (lagomorphs and rodents), in an unnamed sister clade of the Primatomorpha.

Order Dermoptera

†Family Plagiomenidae?

†Family Mixodectidae?

• Family Cynocephalidae
• Cynocephalus
• Philippine flying lemur, Cynocephalus volans
• Galeopterus
• Sunda flying lemur, Galeopterus variegatus
• †Dermotherium
• †Dermotherium major
• †Dermotherium chimaera