Gaylord Simpson in 1945 on the basis of anatomical evidence, such as testicondy and similar fetal development. The Paenungulata, along with the Afrotheria, are one of the most well-supported mammalian clades in molecular phylogeny. Sirenia, Proboscidae, and Desmotylia are grouped together in the clade Tethytheria. On the basis of morphological similarities, Tethytheria, Perissodactyla, and Hyracoidea were previously thought to be grouped together as the Altungulata, but this has been invalidated by molecular data. Sirenia families † = Extinct Family Dugongidae: Genus Dugong D. dugon Genus †Anisosiren †A. pannonica Genus †Indosiren †I. javanense Genus †Bharatisiren †B. indica Genus †Callistosiren †C. boriquensis Genus †Crenatosiren †C. olseni Genus †Corystosiren †C. varguezi Genus †Dioplotherium †D. allisoni †D. manigualti Genus †Domningia †D. sodhae Genus †Kutchisiren †K. cylindrica Genus †Nanosiren †N. garciae †N. sanchezi Genus †Rytiodus †R. capgrandi †R. heali Genus †Xenosiren †X. yucateca Genus †Caribosiren †C. turneri Genus †Halitherium †H. alleni †H. schinzii Genus †Paralitherium †P. tarkanyense Genus †Priscosiren †P. atlantica Genus †Sirenavus †S. hungaricus Genus †Metaxytherium †M. albifontanum †M. arctodites †M. crataegense †M. floridanum †M. krahuletzi †M. medium †M. serresii †M. subapenninum Genus †Dusisiren †D. dewana †D. jordani †D. reinharti †D. takasatensis Genus †Hydrodamalis †H. cuestae †H. gigas Family Trichechidae: Genus Trichechus T. manatus T. senegalensis T. inunguis Genus †Anomotherium †A. langewieschei Genus †Miosiren †M. canhami †M. kocki Genus †Potamosiren †P. magdalenensis Genus †Ribodon †R. limbatus †Family Protosirenidae: Genus †Ashokia †A. antiqua Genus †Libysiren †L. sickenbergi Genus †Protosiren †P. eothene †P. fraasi †P. minima †P. sattaensis †P. smithae †Family Prorastomidae: Genus †Pezosiren †P. portelli Genus †Prorastomus †P. sirenoides Distribution The warm shallow waters of the equator have been the center of Sirenian habitation. The northernmost living population, the Florida subspecies of the West Indian manatee (T. manatus latirostris), inhabits the coast and frequents freshwater springs, power plants, and canals in Florida to stay warm during the winter. Individuals may migrate north in the warm summer months, some up to 1,000 kilometers (about 621.37 mi) from their winter range. The Antillean subspecies (T. manatus manatus) occurs in the Caribbean, South America, and Central America and frequent drowned cays, mangroves, lagoons, and sea grass beds. The Amazonian manatee (T. inunguis) has been documented in all parts of the Amazon River Basin in South America. River channels that connect allow easy travel to other waterways where food may be plentiful. The Amazonian manatee lives only in freshwater. The West African manatee (T. senegalensis) lives in murky isolated