Extinct Animals

the short faced bear or arctodus simus is an extinct species of bear, it was the largest land predator of it's time, the largest bear known to science and lived in the americas. estimates on it's size range from 1300 pounds to as much as a ton, on all fours it was six feet high at the shoulders and may have been 12 feet high when standing upright. though larger than it's contemporay the grizzly bear, the short faced bear had a more graceful build with longer limbs in proportion to it's body, it's feet pointed forward as opposed to the pigeon toed gait and stance of the brown bear and it may have been adapted to a more active predatorial existence. it is thought to have been a purely carnivorous animal as opposed to it's omnivorous brown bear cousin. the short faced bear also called the bulldog faced bear had a much shorter face than other bears, structured more like a feline's. it's jaw muscles were exceptionally powerful and it may have regularly crushed the bones of it's prey to get at the nutrient and fat rich marrow. predator versus scavenger is a popular debate among experts, with some saying that it was adapted to run down it's prey and was therefore an active hunter, others say that the shear size of the beast would have limited it to bullying other predators off their kills. it probably did both. the mass extinction of megafauna at the end of the last ice-age resulting in loss of food resourse, competition with it's more adaptable brown bear cousins, and contention with humans probably lead to the short faced bear's extinction. it's closest living relative is the spectacled bears.

The kind and numbers of fossils found in different kinds of rocks give clues about past ecosystems. Fossils give evidence that, in any ecosystem, some plants and animals survive well, and some do not.

1. There is an unusually high concentration of Iridium found at the K-T boundary. Iridium loves to stick to Iron, so the Iridium that would have been on Earth originally is in the Iron core, not in the crust. Therefore, the Iridium must have been introduced by an external source; a meteorite.

2. Shocked Quartz is found at the K-T Boundary all around North America. Shocked Quartz is only produced naturally by bolide impact. Since the K-T meteorite impacted in the Mexican peninsula, it makes sense that the shocked quartz would be found only in relatively close proximity to the impact site.

3. Microtektites, which are normally found at meteorite impact sites, are found at all K-T boundary impact sites.

4. There is a massive impact crater in the Mexican peninsula.

5. In many of the K-T Boundary sections there is a fine layer of ash (disseminated Carbon) from the global wildfires that were caused.

6. There was a fern spike because other flowering plants stopped producing pollen for awhile.

7. Microdiamonds have been detected at K-T Boundary sites, but not above or below.

Here are some reasons that some species become extinct:

Thyllacine, the "marsupial wolf" was hunted into extinction, as was the passenger pigeon and probably the moa.

Competition for resources can drive species into extinction.

Disease and predators also take their toll.

Insecticides like DDT weaken bird egg shells so that fewer of them hatch.

Loss of habitat is yet another factor.

No one is certain why the mammoth became extinct. They died. They may have succumb to climate change at the end of the last Ice Age. Other theories are related to the arrival of modern humans, which may have spread diseases that were fatal to mammoths, or over-hunted them.

A background extinction is the continuous extinction of individual species caused by climate change, disease, loss of habitat, and competitive disadvantages against other species. Background extinctions occur at a slow rate over time, affecting only a few species at one time.

Saber toothed cats died out 10,000 years ago. That was at the end of the Pleistocene, the first series of the Quaternary. The Quaternary is the current period, and it is part of the Cenozoic era.

They were razor sharp that in one bite your dead

Most North American ice age megafauna such as columbian mammoths, jefferson ground sloths, short-face bears, and dire wolves (actually marsupials) died out 12,700 years ago, and some survived until 9,000 years ago, while Eurasian ice age megafauna died out around 11,000 years ago

Species endangerment is when the population is reduced below a point where it is sustainable. When the species is below this point, it can be reduced to the point to extinction.

Once the most abundant bird in North America, with flocks numbering in the billions. This bird was hunted to extinction in the early 1900's.

around the same time as the ice age (20,000 years ago)

no, it is the top predator of its time, so it has no enemies or competators

The Prasinohaema Skinks e.g. The Green green-blooded skink (Prasinohaema virens) and apparently some Marine worms have green blood.

Fossil evidence suggests that the Megalodon would have fed upon many other animals, including the early whales and other sharks, as well as other large aquatic creatures. It would have had a very large appetite due to its incredibly large size and would have needed to eat in large quantities in order to sustain itself.

The effects of animal extinction are felt by the environment for years. All plants and animals of a particular ecosystem work together to keep things leveled out. When an animal becomes extinct, it affect the food web and how the remaining plants and animals depend on each other.

The "terror birds" (Phorusrhacidae) were large carnivorous flightless birds that lived in South America during the Cenozoic era (from about 2 to 60 million years ago).

Standing 1 to 3 meters (3-10 feet) in height, they were one of the dominant predators of their time. Their closest modern relatives may be the seriema birds of Brazil, Argentina, and Paraguay.

it looked like a leopard but with big fangs.

a satyr ( say-ter )

The study of how living and extinct organisms are related to one another is simple. This study is called evolution.

The last white footed rabbit rat was recorded at about 1845, but some were reported in 1856â??57 and maybe in the 1930s. Rats may have spread diseases or competed for food with the white footed rabbit rat.

The correct answer is that no one knows.

A popular theory at the moment is that a large meteor struck the earth 65 million years ago. There is evidence of large meteor strike at a site called Chicxulub, near Mexico.

There are alternative theories such a volcanism. There are immense lava flows that date back to the time of the dinosaurs, indicating that volcanic activity was at a peak contributing to a climate change which dinosaurs could not survive.

Increased competition for resources from the growing mammal kingdom provides yet another theory.

There is evidence for all these theories, so it could just be the combined effect of all these factors that led to the dinosaurs demise.

It is a sort of cat-like mammal that lived a long time ago, and it was the very first carnivor. Sort of weasel-like. It's fur was mostly dark---wolfish colors. It hunted bugs and looked for plants---Until, that is, some of the Miacisi grew carnassials(cheek teeth) And that led to hunting small rodents and birds,etc.

No, Metalworking is fake. There are no such things as mega sharks!

The biggest reason was over hunting, but deforestation also contributed. The Passenger Pigeon was the largest species of birds, during the 1800's. It contained more individuals than all other North American birds combined. But sadly, by 1900s that powerful population had been reduced to one bird named," Martha" who died on September 1, 1914 in captivity at the Cincinnati Zoo. At one time a single flock of passenger pigeons might have more than 2 billion birds. That is just one flock, there were many flocks in the US at the time of this bird's peak of abundance. But, unregulated commercial hunting, specifically for their meat, on a wholesale scale, used those large billion bird flocks to man's advantage and it devastated the birds populations. The species migration and nesting habits also made them easy targets for large number kills, either by netting, torching, or special firearms, even one, the forerunner of the machine gun. By 1855 one year in Michigan a billion birds were, so called "harvested". The passenger pigeon's population, of course suffered a collapse under the strain, and could not recover. There were no protection measures, no conservation lands. The pigeons left were scattered across the US and that made breeding difficult and the numbers continued to decline. By 1900 all wild passenger pigeons were extinct. Now, with today's knowledge, some believe that the species should have been able to recover from the uncontrolled commercial hunting, but the scattering of the birds may have been the final straw. The large flocks may have been part of their rituals for breeding and once scattered these rituals were not triggered, therefore the breeding declined and the species suffered extinction. For more details, please see sites listed below.
The passenger pigeon went extinct because of hunters over hunting the animal and habitat loss.