parent_taxon embrithopoda
A Mangrove swamp is a distinct saline woodland or shrubland habitat formed by mangrove trees . They are characterized by depositional coastal environments , where fine sediments ( often with high organic content ) collect in ___MASK62___ protected from high - energy wave action . The saline conditions tolerated by various mangrove species range from brackish water , through pure seawater ( 3 to 4 %), to water concentrated by evaporation to over twice the salinity of ocean seawater ( up to 9 %). ___MASK91___ , commonly referred to as sea cows , is an order of fully aquatic , herbivorous mammals that inhabit swamps , rivers , estuaries , marine wetlands , and coastal marine waters . ___MASK91___ comprises the families ___MASK79___ ( the dugong ), ___MASK82___ ( manatees ),  ___MASK88___ ( Eocene sirenians ), and  ___MASK85___ ( terrestrial sirenians ). There are currently four extant species of sirenians . Sirenians are classified in the clade ___MASK6___ , alongside the elephants and the hyraxes , and evolved in the Eocene 50 million years ago . The ___MASK79___ diverged from the ___MASK82___ in the late Eocene or early Oligocene . A ___MASK28___ ( meaning " nose horn "), often abbreviated to rhino , is one of any five extant species of odd - toed ungulates in the family Rhinocerotidae , as well as any of the numerous extinct species . Two of these extant species are native to Africa and three to Southern Asia . ___MASK95___ ( from Greek  " desma ", " bundle ", and  " stylos ", " pillar ") is an extinct order of aquatic mammals that existed from the late Oligocene ( Arikareean ) to the late Miocene ( Tortonian ). Tropical rainforests occur in ___MASK62___ of tropical rainforest climate in which there is no dry season  all months have an average precipitation of at least 60 mm  and may also be referred to as " lowland equatorial evergreen rainforest ". They rarely extend more than 10 degrees north or south of the equator and are a sub - set of the tropical forest biome type that occurs roughly within the 28 degree latitudes ( in the equatorial zone between the Tropic of Cancer and Tropic of Capricorn ). Within the World Wildlife Fund ' s biome classification , tropical rainforests are a type of tropical moist broadleaf forest ( or tropical wet forest ) that also includes tropical seasonal forests . Arsinoitherium is an extinct genus of paenungulate ___MASK56___ belonging to the extinct order Embrithopoda . It is related to elephants , sirenians , hyraxes and the extinct desmostylians . Arsinoitheres were superficially rhinoceros - like herbivores that lived during the late Eocene and the early Oligocene of northern Africa from 36 to 30 million years ago , in ___MASK62___ of tropical rainforest and at the margin of mangrove swamps . A species described in 2004 , " A . giganteum ", lived in Ethiopia about 27 million years ago . A herbivore is an ___MASK99___ anatomically and physiologically adapted to eating ___MASK20___ material , for example foliage , for the main component of its diet . As a result of their ___MASK20___ diet , herbivorous animals typically have mouthparts adapted to rasping or grinding . Horses and other herbivores have wide flat teeth that are adapted to grinding grass , tree bark , and other tough ___MASK20___ material . ___MASK70___ ( `` heavy - footed '' ) is an order of extinct mammals known from Asia , Africa and eastern Europe . Most of the embrithopod genera are known exclusively from jaws and teeth dated from the late Paleocene to the late Eocene , but the order is best known from its terminal member , the elephantine Arsinoitherium . Elephants are large mammals of the family ___MASK17___ and the order ___MASK22___ . Two species are traditionally recognised , the African elephant (" ___MASK87___ africana ") and the ___MASK53___ (" Elephas maximus "), although some evidence suggests that African bush elephants and African forest elephants are separate species (" L . africana " and " L . cyclotis " respectively ). Elephants are scattered throughout sub - Saharan Africa , South Asia , and Southeast Asia . ___MASK17___ is the only surviving family of the order ___MASK22___ ; other , now extinct , members of the order include deinotheres , gomphotheres , mammoths , and mastodons . Male African elephants are the largest extant terrestrial animals and can reach a height of and weigh . All elephants have several distinctive features , the most notable of which is a long trunk or proboscis , used for many purposes , particularly breathing , lifting water , and grasping objects . Their incisors grow into tusks , which can serve as weapons and as tools for moving objects and digging . Elephants ' large ear flaps help to control their body temperature . Their pillar - like legs can carry their great weight . African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs . Ethiopia ('), officially known as the Federal Democratic Republic of Ethiopia "' (     , " yetiyoya Fdralaw Dmokirasyaw Rpebilk " ), is a country located in the Horn of Africa . It shares borders with Eritrea to the north and northeast , Djibouti and Somalia to the east , Sudan and South Sudan to the west , and Kenya to the south . With nearly 100 million inhabitants , Ethiopia is the most populous landlocked country in the world , as well as the second - most populous nation on the African continent after Nigeria . It occupies a total ___MASK14___ of , and its capital and largest city is Addis Ababa . The transition between the end of the Eocene and the beginning of the Oligocene is marked by large - scale extinction and floral and faunal turnover ( although minor in comparison to the largest mass extinctions ). Most of the affected organisms were marine or aquatic in nature . They included the last of the ancient cetaceans , the ___MASK50___ . The Eocene Epoch , lasting from , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era . The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch . The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope C in the atmosphere was exceptionally low in comparison with the more common isotope C . The end is set at a major extinction event called the " Grande Coupure " ( the " Great Break " in continuity ) or the Eocene  Oligocene extinction event , which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay . As with other geologic periods , the strata that define the start and end of the epoch are well identified , though their exact dates are slightly uncertain . The Paleogene ( or ; also spelled Palaeogene or Palæogene ; informally Lower Tertiary ) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago ( ___MASK77___ ) to the beginning of the Neogene Period ___MASK77___ . It is the beginning of the Cenozoic Era of the present Phanerozoic Eon . The Paleogene is most notable for being the time during which mammals diversified from relatively small , simple forms into a large group of diverse animals in the wake of the Cretaceous  Paleogene extinction event that ended the preceding Cretaceous Period .