About Extinct Animals
In biology and ecology, extinction is the end of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "re-appears" (typically in the fossil record) after a period of apparent absence.
A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils, survive virtually unchanged for hundreds of millions of years. Most extinctions have occurred naturally, prior to Homo sapiens walking on Earth: it is estimated that 99.9% of all species that have ever existed are now extinct.
Mass extinctions are relatively rare events; however, isolated extinctions are quite common. Only recently have extinctions been recorded and scientists have become alarmed at the high rates of recent extinctions. Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing species may become extinct by 2100. It is difficult to estimate the trajectory that biodiversity might have taken without human impact but scientists at the University of Bristol estimate that biodiversity might increase exponentially without human influence.
I have a great passion and interest in the conservation of species, and it saddens me greatly when animals go extinct through no fault of their own. Hunting (for bounties or food) and land clearance have been the biggest contributors to the decline of other animals and it continues to be so. Some of the most well-known extinct animals include the dodo, mammoth, Tasmanian tiger, passenger pigeon, quagga, golden toad and the Javan tiger. Of course, the biggest mass extinction in Earth's history was the elimination of the dinosaurs, however this was not caused by anthropogenic events.
The layout features my favourite extinct animal, the paradise parrot (Psephotus pulcherrimus), which range occurred in south-eastern Queensland, Australia. McNaughton (2004) noted that even if the population of the parrot had been plentiful before European settlement, it would most likely still be endangered (if not extinct) because the “greatest changes by humans to its traditional environment have occurred since the last sighting in 1927”. The critically endangered orange-bellied parrot of southern Australia may follow a similar fate; before Europeans arrived, it had a small (but stable) population size within its restricted range; but due to clearance of its food plants among many other factors, it has declined steadily over the past twenty years and is likely to be extinct in the wild within five years. This is a terrible tragedy, as is the other countless animals that fall under the IUCN RedList, and the list grows more and more every year.
If man doesn't learn to treat the oceans and the rain forest with respect, man will become extinct. ~ Peter Benchley
+ List of Extinct Animals (Wikipedia)