Forktail manatees
| Forktail manatees | ||||||||||||
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| Dugongidae | ||||||||||||
| Gray , 1821 |
The fork-tailed manatees - also called dugongs (Dugongidae) - represent a family within the manatees (Sirenia). Today there is only one species left , the dugong ( dugong dugon ). Another species, Steller's manatee ( Hydrodamalis gigas ), was exterminated by humans about 250 years ago.
From the second family of manatees , the manatees or manatees (Trichechidae), the fork- tailed manatees differ in a number of characteristics. The name-giving feature is the deeply grooved, crescent-shaped caudal fin. The skull is elongated and slightly curved downwards. Further differences to the manatees are in the flippers , which have no nails, in the number of teeth and the cervical vertebrae (fork-tailed manatees have seven, round-tailed manatees only six).
While the dugong reached a length of 2.5 to 3.5 meters, Steller's manatee was significantly larger with a length of up to 8 meters.
Forktail manatees are common along the coasts of the Indian Ocean and Red Sea, as well as the western Pacific .
Fossils of the fork-tailed manatees' ancestors are numerous and date back to the Eocene (about 50 million years ago). In the past, numerous genera of fork tailed sea cows were distributed almost worldwide.
literature
- Ronald M. Nowak: Walker's Mammals of the World. 6th edition, Johns Hopkins University Press, Baltimore 1999, ISBN 0-8018-5789-9 .
