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Zebra
extinct animals
Image by Digo_Souza
As zebras são mamíferos, membros da mesma família dos cavalos, os equídeos, nativos da África central e do sul. A pelagem deste animal consiste num conjunto de listras contrastantes de cor, alternadamente, pretas e branca, dispostas na vertical, exceptuando nas patas, onde se encontram na horizontal.

É nas savanas africanas onde as zebras habitam. Encontram-se distribuídas por famílias: macho, fêmeas e filhotes. Estes animais, por serem atacados habitualmente por leões, podem se tornar animais extremamente velozes, pois para fugirem dos predadores, utilizam a fuga e seus fortes coices, podendo quebrar até a mandíbula de um felino. As listras das zebras vão escurecendo com a idade, e estes animais, embora se pareçam, não são todos iguais.

Apesar de parecerem todas iguais, as espécies de zebra existentes não são estreitamente relacionadas umas com as outras. As zebras-de-grevy têm origem de animais diferentes (de outro subgênero) daqueles que originaram as zebras-das-planícies e as zebras-das-montanhas.

Não se encontram à beira da extinção, embora a zebra-das-montanhas esteja ameaçada. A subespécie de zebra-das-planícies conhecida como cuaga (do inglês quagga, que designa o som que o animal produzia cuahaa), Equus quagga quagga, estava extinta, mas projetos de cruzamento entre zebras com coloração semelhante já recuperaram a espécie antes extinta, e o projeto liberou com sucesso vários exemplares na natureza.
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Zebras are African equids best known for their distinctive white and black stripes. Their stripes come in different patterns unique to each individual. They are generally social animals and can be seen in small harems to large herds. In addition to their stripes, zebras have erect, mohawk-like manes. Unlike their closest relatives, horses and asses, zebras have never been truly domesticated.

There are three species of zebra: the Plains Zebra, Grévy's Zebra and the Mountain Zebra. The Plains zebra and the Mountain zebra belong to the subgenus Hippotigris, but Grevy's zebra is the sole species of subgenus Dolichohippus. The latter resembles an ass while the former two are more horse-like. Nevertheless, DNA and molecular data show that zebras do indeed have monophyletic origins. All three belong to the genus Equus along with other living equids. In certain regions of Kenya, Plains zebras and Grevy's zebras coexist.

The unique stripes and behaviors of zebras make these among the animals most familiar to people. They can be found in a variety of habitats, such as grasslands, savannas, woodlands, thorny scrublands, mountains and coastal hills. However, various anthropogenic factors have had a severe impact on zebra populations, in particular hunting for skins and habitat destruction. Grevy's zebra and the Mountain zebra are endangered. While Plains zebras are much more plentiful, one subspecies, the quagga, went extinct in the late nineteenth century.

The name "zebra" comes from the Old Portuguese word zevra which means "wild ass". The pronunciation is /ˈzɛbrə/ ZEB-rə or /ˈziːbrə/ ZEE-brə.


Homo floresiensis adult female - model of head - Smithsonian Museum of Natural History - 2012-05-17
extinct animals
Image by dctim1
Mock-up of the head and shoulders of Homo floresiensis on display in the Hall of Human Origins in the Smithsonian Museum of Natural History in Washington, D.C. This is set at the average height of this species. It is nicknamed "the Hobbit," because these proto-humans were just three feet tall!

It's not clear at all if Homo floresiensis is an ancestor of Homo sapiens, or if it was an off-shoot that resulted in an evolutionary dead-end. Some scientists think it is a form of Homo erectus (which lived about the time that Homo floresiensis appeared). The discoverers first suggested the name Sundanthropus floresianus, but later examinations of the cranium led to the placement of the species in the same lineage as modern human beings.

Homo floresiensis was discovered by a joint Australian-Indonesian team or acheologists in 2003 on the island of Flores in Indonesia. Partial skeletons and a complete skull have been found. They were not fossilized; the bones were found buried in anaerobic mud (which preserved them from decay).

Homo floresiensis lived about 38,000 to 13,000 years ago, although it is possible that it may have appeared as far back as 74,000 years ago.

The brain is very small, just 380 cubic centimeters. That's half the size of Homo erectus, and about that of the modern chimpanzee. But examination of the impressions left on the inside of the skull by the brains of Homo floresiensis show highly developed cognitive features that one just does not see in small-brained animals. Furthermore, very complex stone and wood tools were discovered alongside Homo floresiensis -- giving great weight to the idea that these were a form of dwarf human rather than microcephalics or people suffering from disease.

There is evidence suggesting that Homo floresiensis hunted the dwarf elephants of Flores, and possibly had language. But since many scientists say that Homo floresiensis was pathological (e.g., suffered from disease or genetic faults that left it essentially mentally deficient), these conclusions remain highly disputed.


Elds Deer 2
extinct animals
Image by daryl_mitchell
These deer are nearly extinct in the wild in much of their original range.

 
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