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The fossil record shows sirenians appearing in the Eocene, where they most likely lived in the Tethys Ocean. Dugongs and elephants share a monophyletic group with hyraxes and the aardvark, one of the earliest offshoots of eutherians. ĭugongs and other sirenians are not closely related to other marine mammals, being more related to elephants. It was later assigned as the type species of Dugong by Lacépède and further classified within its own family by Gray and subfamily by Simpson. It was first classified by Müller in 1776 as Trichechus dugon, a member of the manatee genus previously defined by Linnaeus. ĭugong dugon is the only extant species of the family Dugongidae, and one of only four extant species of the Sirenia order, the others forming the manatee family.

It is known as the balguja by the Wunambal people of the Mitchell Plateau area in the Kimberley, Western Australia. Other common local names include "sea cow", "sea pig" and "sea camel". Despite common misconception, the term does not come from Malay duyung and it does not mean "lady of the sea" ( Mermaid). The name ultimately derives from Proto-Malayo-Polynesian *duyuŋ. The name was first adopted and popularized by the French naturalist Georges-Louis Leclerc, Comte de Buffon, as " dugon" in Histoire Naturelle (1765), after descriptions of the animal from the island of Leyte in the Philippines. The word "dugong" derives from the Visayan (probably Cebuano) dugung. With its long lifespan of 70 years or more, and slow rate of reproduction, the dugong is especially vulnerable to extinction.ĭugong skeleton displayed at Philippine National Museum Despite being legally protected in many countries, the main causes of population decline remain anthropogenic and include fishing-related fatalities, habitat degradation and hunting. The IUCN lists the dugong as a species vulnerable to extinction, while the Convention on International Trade in Endangered Species limits or bans the trade of derived products. The dugong's current distribution is fragmented, and many populations are believed to be close to extinction. Traditional hunting still has great cultural significance in several countries in its modern range, particularly northern Australia and the Pacific Islands. The dugong has been hunted for thousands of years for its meat and oil. The molar teeth are simple and peg-like, unlike the more elaborate molar dentition of manatees. Its snout is sharply downturned, an adaptation for feeding in benthic seagrass communities.

The dugong is easily distinguished from the manatees by its fluked, dolphin-like tail, but also possesses a unique skull and teeth. The forelimbs or flippers are paddle-like. Like all modern sirenians, the dugong has a fusiform body with no dorsal fin or hind limbs. The northern waters of Australia between Shark Bay and Moreton Bay are believed to be the dugong's contemporary stronghold. The dugong is largely dependent on seagrass communities for subsistence and is thus restricted to the coastal habitats which support seagrass meadows, with the largest dugong concentrations typically occurring in wide, shallow, protected areas such as bays, mangrove channels, the waters of large inshore islands and inter-reefal waters. The dugong is the only sirenian in its range, which spans the waters of some 40 countries and territories throughout the Indo-West Pacific. It is the only living representative of the once-diverse family Dugongidae its closest modern relative, Steller's sea cow ( Hydrodamalis gigas), was hunted to extinction in the 18th century. It is one of four living species of the order Sirenia, which also includes three species of manatees. The dugong ( / ˈ d( j) uː ɡ ɒ ŋ/ Dugong dugon) is a marine mammal.