Mammalia     Ecuador boasts of 369 species which puts it by far in first place by species per square area and in 9th place in species found by country. Most mammals live in tropical regions and decrease in number the higher one moves up the Andes mountain range. The Galapagos islands have only twelve native mammal species but nine of them are endemic, only place in the world, where they can be found. As a whole, Ecuador boasts of 30 endemic species, most of them of the rodent family.    There exists some 100 known rodents but the number is probably higher as not enough research is yet done. The largest living rodent in the world is the Capybara and lives in the tropical rainforest of the nation's Amazon. The same goes for bats, where 132 species are accounted for in the country but more are believed to exist. 23 species belong to the marsupial sub-class with the opossum, the most visible representative. The largest terrestrial mammal found is the Tapir, which can weigh up to 300 kg and belongs to the odd-toed ungulates (hoofed animals). Three species of those inoffensive animals are counted however with one specie on the brink of extinction. 11 even-toed  animals are also part of the landscape with the Llamas the most interesting one. The carnivores have 31 species present in the country with two beautiful members of the cat family, the mighty Jaguar and the smaller Ocelot found in the tropical rainforests. But the most versatile of all cats is the Puma, which adapted to all habitats and can be found in all regions of the country although it is now under siege by human encroachment. In the higher Andean region of the paramo you find two more carnivores, the Andean Fox, a member of the dog family and the Spectacled Bear, the only bear specie in the whole national territory. Other carnivores, which adapted to life in water are the otters with the Giant Otter being the most fascinating one and the marine Sea Lions. Many, of course, are interested in the New World Monkeys and 19 members of those primates inhabit the lower tropical regions. Introduced here are the Woolly, Spider, Squirrel and Howler Monkeys. Other mammals found are a lone member of the rabbit family, a manatee or sea cow in the Amazon rivers, 3 species of insectivores and 12 members of the armadillo, anteater and Sloth family of Edentata (or Xenarthra). In the oceans surrounding Galapagos and Ecuador are furthermore found some 33 species of Whales and Dolphins, with two dolphins inhabiting the freshwater rivers and lakes of the Amazon.    The natural history of mammals in South America is an interesting case study of evolutionary biology. Mammals need a large island, a continent, to properly disperse and speciate. Historically there were only 3 cases of that happening in Eurasia, Australia and South America ( for a long time the continent was an isolated island ). After the decline of the dinosaurs beginning at 65 million years ago the first primitive mammals radiated and took over the abandoned ecological niches in the next 40 million years. At that time also the huge continent of Gondwana (conglomeration of Antarctica, South America, Africa, Madagascar, India and Australia) started to break up. On the new continent known today as South America marsupial and placental animals got stranded. The interesting part is that the herbivores were mostly placental hunted by marsupial carnivores. All marsupial carnivores are extinct now and from the earliest placental animals only the edentates (xenarthrans), the armadillos, anteaters and sloth are still around. After the breakup South America stayed closest connected to the African continent, moving away slowly from it by continental drift. A new wave of mammals invaded the continent from there by island hopping 30 million years ago and that is how the first primates arrived here. They gave later rise to the New World Monkeys as known today. Other island hoppers included rodent ancestors of capybaras, guinea pigs and porcupines. From that time on South America was separated from other continents by broad and unbridgeable seaways. Unique grazing animals like horse-like litopterns and giant ground sloth (weighing up to 4 tones and reaching heights of 6m) and many others graced the landscape. They were preyed upon by marsupial saber-toothed tigers and a giant carnivorous bird among others. All, prey and predators, are now gone.  With time South America drifted closer to the North American continent, which itself broke away from the Eurasian continent and then some 3 million years ago the Panama isthmus appeared creating a natural land bridge. This opened up a new route of migrations and animals from the south migrated to the north and vice versa enriching both continent's fauna, the Great American Interchange. Over time however most SA animals had to give in to the northern animals occupying the same ecological niche and became extinct in the process. It seems that placental mammals of North America  were exposed to competition for a much longer time than the South American ones and therefore out competed them. Presently half of the mammal species (cats, llamas, bear, peccaries, otters, foxes,...) on the continent are of that recent foreign invasion.     Another important region of evolutionary biology (but completely unconnected with the above story) are the Galapagos archipelago. Terrestrial mammals are scarce as they have major difficulties reaching those remote Pacific islands which arose out of the sea and never were connected with any continent. They cannot survive long trips on vegetation rafts as reptiles do. Only a few mice and bats arrived thus but always played a secondary role to birds and reptiles. The most influential mammals therefore are aquatic species like whales and sea lions, which play an important role in the marine environment. Nowadays however, mammal species introduced by humans play an important role on land, alas seen from the ecological view a very negative one as they play havoc in the lives of native animals. Feral goats, pigs, dogs and other formerly domestic animals compete for scarce food resources or predate on the animals themselves or their eggs. Also the opening up of pastures for cattles and horses destroyed many ecological habitats for native animals.

Natural History Mammals are descendants of mammal-like reptiles  which lived in the earlier period of of Mesozoic era some 210 million years ago. For a long time they co-existed with other reptiles but stayed for a long time in the shadow of reptiles, especially dinosaurs which occupied many ecological niches. Mammals at that time were smaller creatures, probably burrowing in the soil or living in the trees and active mostly at night. But the mass extinction of 65 million years ago changed all that with the dinosaurs and other reptiles becoming extinct. The mammals had then the opportunity to fill the abandoned niches left by the former rivals. They did that very successfully and split into multiple species by adaptive radiation. Some became grazers, others carnivores preying on them, one group turned to the skies to evolve into bats, some even returned to the seas. One specie transformed itself into the huge whales, the largest animal ever to have lived.      Mammalian Classification Monotremata Monotremes are egg-laying mammals with only a few species left (e.g. spiny anteater, platypus) in Australia and surrounding islands. They represent the most primitive lineage going back to the Mesozoic. Marsupialia Marsupials is another sub-class with 282 species, most of them in Australia and a few (e.g. opossums) on the American continent. Eutheria are the placental animals which comprise the majority of the over 4600 species of mammals worldwide. They are found on all continents but with only a few species living in Australia.      Orders of placental mammals   Insectivora shrew, mole, hedgehog, tenrec Primata monkeys, apes, humans, lemurs Chiroptera bats Dermoptera colugos or flying lemurs Scandentia tree shrews Pholidota pangolins Rodentia mice, rats, squirrels, beavers, guinea pigs, capibaras Lagomorpha rabbits, hares, pikas Cetacea whales, dolphins Carnivora cats (jaguar, puma, ocelot) dogs (Andean fox), bears (spectacled bear), otters, sea lions Hyracoidea hyraxes Artiodactyla pigs, camels, llamas, deer, cattle, goats, sheep, giraffes Perissodactyla horses, tapir, rhinoceros Tubulidentata aardvarks Proboscidea elephants Edentata armadillos, sloth, anteaters Sirenia manatees, dugong Macroscelidea elephant shrews      Biologically Speaking Mammals inhabit all parts of the earth and range in sizes from a few centimeters and weighing a few grams (mice)  to 30 meters and up to a hundred tons (whales) but all are warm-blooded vertebrates (having a spinal column) with a relatively well-developed brain. Some or all parts of their body are covered by hair and all have (or had once) four limbs, which evolved into walking, handling, flying and swimming appendages. Another distinguishing trait is the sexual breeding through copulation by male and females and  the parental care they give to their young, nourishing them with milk, produced in the female mammary glands, which gave that class its name.      Recommended Books (used in research) SPLENDID ISOLATION   by George Gaylord Simpson NEOTROPICAL RAINFOREST MAMMALS    by Louise H. Emmons MAMIFEROS DEL ECUADOR  by Diego Tirira S.