Extinction of species can be traced back to times wherein 'man' was not even in the picture, with several species giving in to drastic changes brought about by the end of the ice age, while others falling prey to catastrophic events such as a meteor collision. Things did change after Homo sapiens came into picture though, and changed for the worse. A look at the list of recently extinct animals, and you will notice that most of the species in this list have had to bear the brunt of human activities - such as hunting for food, poaching for their body parts which have a huge demand in the international market, deforestation which results in loss of habitat, etc. Irrespective of whether it was human onslaught or nature's fury, the fact is that we have lost some of the most amazing animals over the course of time. 10 Most Amazing Extinct Animals Right from various species of dinosaurs - which became extinct somewhere around 65 million years ago, to species like the Passenger pigeon, Golden toad, Baiji river dolphin, etc. - which became extinct more recently, several animals have disappeared from the planet since it came into existence. Even though we don't understand the severity of the issue as we are not dependent on them directly, a loss of single species can come heavy on various species which are directly dependent on it. Discussed below are the details about the 10 most popular animal species which became extinct over the course of time - with emphasis on the factors which contributed to their extinction. If the name Tyrannosaurus rex - often abbreviated as T. rex, doesn't sound familiar, the hint that it's the same dinosaur species which featured in the 1993 American film Jurassic Park will help you picture it. There is no questioning the popularity of this dinosaur species when it comes to popular culture, but as far as Tyrannosaurus rex facts are concerned - they continue to evade layman's mind. Most of the scientific information about this species known to man is based on the fossil remains of this species. These T.rex fossils suggest that its range spanned across the present-day continent of America. One of the largest known land predators to have ever existed on the planet, T. rex boasted of a towering height of 42 ft and weighed somewhere between 6 - 7 metric tons. It was one of the last species of dinosaurs to have existed on the planet before the Cretaceous-Tertiary extinction event which occurred 65 million years ago. As with the extinction of various other species of dinosaurs, even the extinction of Tyrannosaurus rex is a mystery with some theories suggesting it was a meteor which triggered the same, while others pointing the needle of suspicion towards climate change. The woolly mammoth (Mammuthus primigenius) was a species of mammoths - closely related to modern elephants, which inhabited the planet during the Pleistocene epoch. Also known as the Tundra mammoth, it is considered to be one of the most studied species of mammoth on the planet. This can be attributed to the fact that their fossils are preserved in an organic state, unlike the fossils of the other prehistoric animals which are found in stone state, in the cold regions which they inhabited. These Woolly mammoth fossils reveal several things about this species including the facts like a full-grown individual of this species attained a height of around 13 ft and weighed somewhere around 8 tons. This mammoth species began disappearing from its natural habitat on the continent of North America towards the end of the last ice age allegedly due to climate change, loss of habitat as a result of glacial retreat and excessive hunting by prehistoric man. The extinction of woolly mammoth is believed to be a part of the mass extinction of megafauna which spelled doom for species like the woolly rhino, Smilodons and Giant beavers, etc. While records suggest that this species became extinct somewhere between 10,000 BC and 8,000 BC, a dwarfed race of woolly mammoths did survive on the Wrangel Island until somewhere around 1,700 BC. The dodo (Raphus cucullatus) was a species of flightless bird which was found in abundance on the island of Mauritius at one point of time. The evolution of this species into a flightless bird can be attributed to the fact that its diet consisted of fruits and seeds - which were available in plenty on ground, and the absence of land predators in its natural habitat. The extinction of this bird was triggered when European sailors who took a stopover on this island hunted them on a large-scale for meat. Being flightless bird, the dodo was an easy prey. As human settlements on the island increased, dodo hunting became even more rampant. At the same time, domesticated animals and rats which made it to the island along with humans also feasted on dodo eggs, and all these factors together drove the species to extinction. The sightings of dodo became relatively rare towards the beginning of the 17th century, and the condition just worsened further and resulted in extinction of dodo by 1681. Also known as the Sabre-toothed cat, Smilodon was a large cat which inhabited the continent of North America and South America during the Pleistocene epoch. The species derived its name sabre-toothed cat or saber-toothed cat from their relatively long canines that resembled sabers - stout swords with a curved blade, to a great extent. Smilodon fossils suggest that the extinction of this species was a part of the mass extinction of megafauna towards the end of Pleistocene epoch. Other than human encroachment - with the prehistoric man reaching North America after the ice age, severe food shortage also contributed to the extinction of Sabre-toothed cats which occurred somewhere around 10,000 BC. (Of the three sub-species of smilodon, only Smilodon gracilis and Smilodon fatalis were left to face human wrath, while Smilodon populator had become extinct long before humans encroached upon their natural habitat.) It may come as a surprise for many but the thylacine (Thylacinus cynocephalus) - which was also known as the Tasmanian tiger or the Tasmanian wolf, was neither a tiger nor a wolf. It was in fact a carnivorous marsupial - one of the largest to have ever existed on the Earth, native to the continent of Australia. The use of the term 'Tasmanian' in its name (Tasmanian tiger with reference to the stripes on its body and Tasmanian wolf as it resembled a wolf species) can be attributed to the fact that it was only found on the island of Tasmania 2,000 years ago where it continued to exist until 1930s. Excessive hunting by farmers and bounty hunters, loss of habitat and human interference in their natural habitat, introduction of dogs by European settlers and extinction of prey species brought it to the verge of extinction. While the last thylacine in the wild was killed by a farmer in Tasmania in 1930, the last individual in captivity died on 7th September, 1936, in the Hobart Zoo, Tasmania. The quagga (Equus quagga quagga) was a species of plains' zebra which inhabited the vast plains of the Cape Province of South Africa. This species was typically characterized by the fact that it only had stripes on the front portion of its body, which faded as they reached the midsection and then disappeared. The farmers of this region considered quagga a pest and hunted it extensively as it used to feed on the vast stretches of grass which served as the grazing ground for their cattle. At the same time, it was also hunted for its meat - which was considered to be a delicacy back then, and for its skin - which was used in leather industry. Quagga population further declined as a result of excessive hunting of this species in Africa by Europeans and North Americans for whom it was a game animal. After struggling for its survival, the species eventually became extinct with the last one dying in the Amsterdam Zoo in 1883. The Woolly rhino (Coelodonta antiquitatis) was a species of rhino which was found in the Eurasian steppes during the Pleistocene epoch. As its name suggests, this animal was typically characterized by a thick coat which had two types of hair. Several theories about the extinction of Woolly rhino have been put forth, with hunting by the Neanderthal man being cited as one of the most prominent reasons for the same. There do exist some sources which suggest that this species - along with other Pleistocene megafauna, became extinct as it was not able to cope up with the climate change which followed the ice age. The carbon dating studies of Woolly rhinoceros fossils suggest that this species existed on the planet until 8000 BC. The Caspian tiger (Panthera tigris virgata) was a species of tiger which was found in Western and Central Asia until 1950s. One of the most recently extinct animals, the Caspian tiger features in the list of animals which became extinct in the last 100 years. The extinction of Caspian tiger is a textbook example of destruction in the name of development. Several hundreds of tigers were exterminated by the Russian authorities in the course of a land reclamation project in the beginning of the 20th century. Habitat loss as a result of deforestation also added to the woes of this species and fragmentation of habitat made it difficult for them to move around freely for the purpose of reproduction. It is believed that the last Caspian tiger was shot dead in Iran in 1959, and that put this species in the International Union for Conservation of Nature (IUCN) Red List. The Irish Elk (Megaloceros giganteus) was a species of deer which inhabited the vast plains of Eurasia during the Late Pleistocene epoch. Even though it was named 'Irish elk', its habitat actually ranged across Eurasia - right from Ireland in the west to Russia in the east. The name Irish elk can be attributed to the fact that most of the skeletal remains of this species were retrieved from the bogs in Ireland. While the claim that it was the largest species of deer to have ever existed on the planet is debatable, there is absolutely no doubt about the fact that it had the largest antlers of them all. The Irish elk allegedly became extinct as it was not able to survive the changes in climatic condition on the planet which followed the last glacial period. The Steller's sea cow (Hydrodamalis gigas) was a marine herbivorous mammal that was found in the North Pacific Ocean in abundance at one point of time. The name 'Steller's sea cow' can be attributed to the fact that it was first described by the German zoologist Georg Wilhelm Steller. With an average length of 30 ft, this species was a lot larger than its closest relatives the manatee and dugong. However, this large size in itself came as a curse for this species as it was mercilessly hunted to extinction for food, as well as for their skin and subcutaneous fat. Shockingly, it was wiped off from the planet within three decades from when it was first described. While the last confirmed sighting of this species came in 1768, unverified reports of this species being spotted do surface once in a while. Extinction of species is not a rare phenomenon as such, with the Earth witnessing as many as five mass extinctions till date. (Even more fascinating is the fact that the number of animals which are found on the planet today constitute for a mere 1 percent of the species to have ever existed on the planet, while the remaining 99 percent have become extinct over the course of time.) What is astonishing is the rate at which extinctions are occurring of late, with more than 40 species being added to the list of extinct animals over the period of last 100 years alone. If this continues, it won't take much time for humans to become endangered first, and extinct in course of time. While our casual attitude can be attributed to the fact that this seems quite impossible, this very casual attitude will catch us off-guard eventually.